Charah Solutions, Inc. 8.50% Se (CHRB) 10-K 31 May 23 2022 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2022	May 15, 2023	Jun. 30, 2022
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2022
Document Transition Report	false
Entity File Number	001-38523
Entity Registrant Name	CHARAH SOLUTIONS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-4228671
Entity Address, Address Line One	12601 Plantside Drive
Entity Address, City or Town	Louisville
Entity Address, State or Province	KY
Entity Address, Postal Zip Code	40299
City Area Code	502
Local Phone Number	245-1353
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	No
Entity Interactive Data Current	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 65,662,181
Entity Common Stock, Shares Outstanding		3,402,624
Documents Incorporated by Reference	None.
Entity Central Index Key	0001730346
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
Common Stock, par value $0.01 per share
Document Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	CHRA
8.50% Senior Notes due 2026
Document Information [Line Items]
Title of 12(b) Security	8.50% Senior Notes due 2026
Trading Symbol	CHRB

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2022
Audit Information [Abstract]
Auditor Name	Deloitte & Touche LLP
Auditor Location	Louisville, Kentucky
Auditor Firm ID	34

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash	$ 21,559,000	$ 24,266,000
Restricted cash	40,100,000	34,908,000
Trade accounts receivable, net	45,696,000	49,303,000
Contract assets	20,981,000	26,844,000
Inventory	5,204,000	6,289,000
Prepaid expenses and other current assets	4,709,000	6,113,000
Total current assets	138,249,000	147,723,000
Property and equipment, net	93,940,000	70,473,000
Operating lease assets	32,748,000	0
Goodwill	62,193,000	62,193,000
Intangible assets, net	0	53,531,000
Equity method investments	0	7,000
Other assets	11,413,000	10,180,000
Total assets	338,543,000	344,107,000
Current liabilities:
Accounts payable	36,475,000	30,641,000
Contract liabilities	8,418,000	6,199,000
Finance lease obligations, current portion	10,592,000	6,979,000
Operating lease obligations, current portion	12,483,000	0
Notes payable, current maturities	9,649,000	7,567,000
Asset retirement obligation	37,982,000	27,534,000
Accrued liabilities	26,296,000	36,874,000
Other liabilities	1,027,000	460,000
Total current liabilities	142,922,000	116,254,000
Deferred tax liabilities	819,000	949,000
Contingent payments for acquisitions	1,950,000	1,950,000
Asset retirement obligation	30,579,000	14,879,000
Finance lease obligations, less current portion	24,585,000	19,444,000
Operating lease obligations, less current portion	23,621,000	0
Notes payable, less current maturities	149,584,000	133,661,000
Other liabilities	4,192,000	641,000
Total liabilities	378,252,000	287,778,000
Commitments and contingencies (see Note 17)
Mezzanine equity
Preferred Stock, Series A — $0.01 par value; 50,000,000 shares authorized, 26,000 shares issued and outstanding as of December 31, 2022; aggregate liquidation preference of $37,176 and $28,783 as of December 31, 2022 and 2021, respectively		35,532,000
Stockholders’ equity
Retained losses	(222,522,000)	(94,679,000)
Common Stock — $0.01 par value; 20,000,000 shares authorized, 3,379,605 and 3,340,782 shares issued and outstanding as of December 31, 2022 and 2021, respectively	339,000	334,000
Additional paid-in capital	110,931,000	114,880,000
Total stockholders’ equity	(111,252,000)	20,535,000
Non-controlling interest	0	262,000
Total equity	(111,252,000)	20,797,000
Total liabilities and equity	338,543,000	344,107,000
Series A Preferred Stock
Mezzanine equity
Preferred Stock, Series A — $0.01 par value; 50,000,000 shares authorized, 26,000 shares issued and outstanding as of December 31, 2022; aggregate liquidation preference of $37,176 and $28,783 as of December 31, 2022 and 2021, respectively	42,743,000	35,532,000
Series B Preferred Stock
Mezzanine equity
Preferred Stock, Series A — $0.01 par value; 50,000,000 shares authorized, 26,000 shares issued and outstanding as of December 31, 2022; aggregate liquidation preference of $37,176 and $28,783 as of December 31, 2022 and 2021, respectively	$ 28,800,000	$ 0

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Series A & B Preferred Stock, shares outstanding (in shares)		26,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares issued (in shares)	3,379,605	3,340,782
Common stock, shares outstanding (in shares)	3,379,605	3,340,782
Series A Preferred Stock
Series A & B Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Series A & B Preferred Stock, shares authorized (in shares)	50,000,000	50,000,000
Series A & B Preferred Stock, shares issued (in shares)	26,000
Series A & B Preferred Stock, shares outstanding (in shares)	26,000	26,000
Series A & B Preferred Stock, aggregate liquidation preference	$ 37,176	$ 28,783
Series B Preferred Stock
Series A & B Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Series A & B Preferred Stock, shares authorized (in shares)	50,000,000	50,000,000
Series A & B Preferred Stock, shares issued (in shares)	30,000	30,000
Series A & B Preferred Stock, shares outstanding (in shares)	30,000	30,000
Series A & B Preferred Stock, aggregate liquidation preference	$ 30,000	$ 30,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 293,167	$ 293,219	$ 232,377
Total cost of sales	(302,781)	(267,321)	(209,570)
Gross (loss) profit	(9,614)	25,898	22,807
General and administrative expenses	(39,365)	(42,189)	(34,064)
Gain on sales-type lease	0	5,568	0
Gains on sales of real estate, property and equipment, net	12,245	23,543	0
Gain on ARO settlement, net	4,789	3,623	0
Other operating expenses from ERT services	(15,372)	(5,078)	0
Gain on change in contingent payment liability	0	0	9,702
Impairment expense	(62,271)	(827)	(38,014)
Operating income (loss)	(109,588)	10,538	(39,569)
Interest expense, net	(18,567)	(15,227)	(13,774)
Loss on extinguishment of debt	0	(638)	(8,603)
(Loss) income from equity method investment	(7)	191	(2,516)
Loss from continuing operations before income taxes	(128,162)	(5,136)	(64,462)
Income tax (expense) benefit	57	(661)	914
Loss from continuing operations, net of tax	(128,105)	(5,797)	(63,548)
Income from discontinued operations, net of tax	0	0	8,883
Net loss	(128,105)	(5,797)	(54,665)
Less (loss) income attributable to non-controlling interest	(262)	17	1,198
Net loss attributable to Charah Solutions, Inc.	(127,843)	(5,814)	(55,863)
Amounts attributable to Charah Solutions, Inc.
Loss from continuing operations, net of tax and non-controlling interest	(127,843)	(5,814)	(64,746)
Deemed and imputed dividends on Series A Preferred Stock	(599)	(592)	(461)
Series A Preferred Stock dividends	(5,307)	(8,156)	(4,064)
Net loss from continuing operations attributable to common stockholders	(133,749)	(14,562)	(69,271)
Net loss from continuing operations attributable to common stockholders	(133,749)	(14,562)	(69,271)
Net income from discontinued operations	0	0	8,883
Net loss attributable to common stockholders	(133,749)	(14,562)	(60,388)
Net loss attributable to common stockholders	$ (133,749)	$ (14,562)	$ (60,388)
Net loss from continuing operations per common share
Basic (in dollars per share)	$ (39.77)	$ (4.61)	$ (23.17)
Diluted (in dollars per share)	(39.77)	(4.61)	(23.17)
Net income from discontinued operations per common share
Basic (in dollars per share)	0	0	2.97
Diluted (in dollars per share)	0	0	2.97
Net loss attributable to common stockholders per common share
Basic (in dollars per share)	(39.77)	(4.61)	(20.20)
Diluted (in dollars per share)	$ (39.77)	$ (4.61)	$ (20.20)
Weighted-average shares outstanding used in loss per common share:
Basic (in shares)	3,363	3,157	2,990
Diluted (in shares)	3,363	3,157	2,990
Construction and service revenue
Disaggregation of Revenue [Line Items]
Total revenues	$ 246,779	$ 261,987	$ 187,509
Total cost of sales	(259,845)	(239,847)	(168,605)
Raw material sales
Disaggregation of Revenue [Line Items]
Total revenues	46,388	31,232	44,868
Total cost of sales	$ (42,936)	$ (27,474)	$ (40,965)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Series A Preferred Stock	Series B Preferred Stock	Total	Common Stock	Additional Paid-In Capital	Retained Losses	Non-Controlling Interest
Beginning balance (in shares) at Dec. 31, 2019	0
Beginning balance at Dec. 31, 2019	$ 0
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of Series A & B Preferred Stock, net of issuance costs (in shares)	26,000
Issuance of Series A & B Preferred Stock, net of issuance costs	$ 24,253
Deemed and imputed dividends on Series A Preferred Stock	$ 3,169
Series A Preferred Stock Dividends		$ 3,169
Ending balance (in shares) at Dec. 31, 2020	26,000
Ending balance at Dec. 31, 2020	$ 27,423
Balance beginning of period (in shares) at Dec. 31, 2019					2,962,284
Balance beginning of period at Dec. 31, 2019	53,273			$ 52,481	$ 296	$ 85,187	$ (33,002)	$ 792
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(54,665)			(55,863)			(55,863)	1,198
Share based compensation expense	2,539			2,539		2,539
Distributions	(1,580)							(1,580)
Shares issued under share-based compensation plan (in shares)					54,971
Shares issued under share-based compensation plans	0			0	$ 5	(5)
Taxes paid related to net settlement of shares (in shares)					(9,552)
Taxes paid related to the net settlement of shares	(232)			(232)	$ (1)	(231)
Contribution from sale of subsidiary to entity under common control	25,506			25,506		25,506
Deemed and imputed dividends on Series A Preferred Stock	(461)			(461)		(461)
Series A Preferred Stock Dividends	(4,064)			(4,064)		(4,064)
Balance end of period (in shares) at Dec. 31, 2020					3,007,703
Balance end of period at Dec. 31, 2020	20,316			19,906	$ 300	108,471	(88,865)	410
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of Series A & B Preferred Stock, net of issuance costs (in shares)			0
Issuance of Series A & B Preferred Stock, net of issuance costs			$ 0
Deemed and imputed dividends on Series A Preferred Stock	$ 8,109
Series A Preferred Stock Dividends		$ 8,156
Ending balance (in shares) at Dec. 31, 2021	26,000	26,000	30,000
Ending balance at Dec. 31, 2021	$ 35,532	$ 35,532	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(5,797)			(5,814)			(5,814)	17
Share based compensation expense	2,702			2,702		2,702
Issuance of common stock (in shares)					288,889
Issuance of common stock	13,000			13,000	$ 29	12,971
Distributions	(165)							(165)
Shares issued under share-based compensation plan (in shares)					53,542
Shares issued under share-based compensation plans	1			1	$ 6	(5)
Taxes paid related to net settlement of shares (in shares)					(9,352)
Taxes paid related to the net settlement of shares	(512)			(512)	$ (1)	(511)
Deemed and imputed dividends on Series A Preferred Stock	(592)			(592)		(592)
Series A Preferred Stock Dividends	$ (8,156)			(8,156)		(8,156)
Balance end of period (in shares) at Dec. 31, 2021	3,340,782				3,340,782
Balance end of period at Dec. 31, 2021	$ 20,797			20,535	$ 334	114,880	(94,679)	262
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of Series A & B Preferred Stock, net of issuance costs (in shares)			30,000
Issuance of Series A & B Preferred Stock, net of issuance costs			$ 28,800
Deemed and imputed dividends on Series A Preferred Stock		7,211
Series A Preferred Stock Dividends		$ 0
Ending balance (in shares) at Dec. 31, 2022		26,000	30,000
Ending balance at Dec. 31, 2022		$ 42,743	$ 28,800
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(128,105)			(127,843)			(127,843)	(262)
Share based compensation expense	2,660			2,660		2,660
Shares issued under share-based compensation plan (in shares)					64,721
Shares issued under share-based compensation plans	0			0	$ 6	(6)
Taxes paid related to net settlement of shares (in shares)					(25,898)
Taxes paid related to the net settlement of shares	(698)			(698)	$ (1)	(697)
Deemed and imputed dividends on Series A Preferred Stock	(599)			(599)		(599)
Series A Preferred Stock Dividends	$ (5,307)			(5,307)		(5,307)
Balance end of period (in shares) at Dec. 31, 2022	3,379,605				3,379,605
Balance end of period at Dec. 31, 2022	$ (111,252)			$ (111,252)	$ 339	$ 110,931	$ (222,522)	$ 0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (128,105)	$ (5,797)	$ (54,665)
Adjustments to reconcile net loss to net cash and restricted cash (used in) provided by operating activities:
Depreciation and amortization	25,283	24,612	19,886
Non-cash lease expense	11,734	0	0
Loss on extinguishment of debt	0	638	8,603
Paid-in-kind interest on long-term debt	0	2,844	4,448
Impairment expense	62,271	827	40,772
Amortization of debt issuance costs	2,451	1,086	599
Deferred income tax expense (benefit)	(129)	581	(834)
Gain on sales-type lease	0	(5,568)	0
(Gain) loss on sales of real estate, property and equipment	(11,873)	(23,436)	708
(Income) loss from equity method investment	7	(191)	2,516
Distributions received from equity investment	0	0	1,731
Non-cash share-based compensation	2,660	2,702	2,539
Loss (gain) on interest rate swap	0	270	(181)
Interest rate swap settlement	0	(745)	0
Gain on ARO settlement, net	(4,789)	(3,623)	0
Realization of deferred gain on ERT project performance	(284)	0	0
Gain on change in contingent payment liability	0	0	(9,702)
Interest accreted on contingent payments for acquisition	0	0	171
Increase (decrease) in cash and restricted cash due to changes in:
Trade accounts receivable	3,607	105	(21,791)
Contract assets and liabilities	8,083	(8,612)	8,025
Inventory	1,085	(803)	6,037
Accounts payable	7,071	13,636	(457)
Lease liabilities	(11,972)	0	0
Asset retirement obligation	(32,636)	(9,712)	(9,694)
Accrued expenses and other liabilities	(11,598)	1,020	13,811
Net cash and restricted cash (used in) provided by operating activities	(77,134)	(10,166)	12,522
Cash flows from investing activities:
Proceeds from the sales of real estate, property and equipment	16,265	36,383	1,517
Purchases of property and equipment, including costs of demolition	(5,152)	(8,499)	(4,304)
Proceeds from sale-leaseback transaction	0	0	7,000
Cash and restricted cash received from ERT transaction	38,240	34,900	0
Payments of working capital adjustment and other items for the sale of subsidiary		(7,367)	0
Proceeds from the sale of subsidiary, net of subsidiary cash	0	0	37,860
Distributions received from equity method investment	0	1,015	0
Net cash and restricted cash provided by investing activities	49,353	56,432	42,073
Cash flows from financing activities:
Proceeds from senior unsecured notes	0	135,000	0
Proceeds from term loan	0	0	15,000
Proceeds on related party term loan	20,000	0	0
Proceeds from promissory note	0	17,852	0
Proceeds from equipment and other debt	3,023	3,449	3,897
Principal payments on term loan	0	(128,083)	(46,397)
Principal payments on promissory note	0	(17,852)	0
Principal payments on equipment and other debt	(10,615)	(8,841)	(17,599)
Payments of debt issuance costs	(861)	(13,380)	(1,623)
Principal payments on finance lease obligations	(9,381)	(4,768)	(316)
Taxes paid related to net settlement of shares	(700)	(512)	(150)
Proceeds from issuance of common stock	0	13,000	0
Distributions to non-controlling interest	0	(165)	(1,580)
Net cash and restricted cash provided by (used in) financing activities	30,266	(16,303)	(31,512)
Net increase (decrease) in cash and restricted cash	2,485	29,963	23,083
Cash and restricted cash, beginning of period	59,174	29,211	6,128
Cash and restricted cash, end of period	61,659	59,174	29,211
Supplemental disclosures of cash flow information:
Cash paid during the year for interest	15,461	12,579	13,331
Cash paid (refunded) during the year for taxes	46	884	(942)
Supplemental disclosures and non-cash investing and financing transactions:
Gross proceeds from revolving loan included in line of credit	0	85,820	118,895
Gross payments on revolving loan included in line of credit	0	73,817	125,892
ASC 842 lease adoption	32,480	0	0
Right-of-use asset added in exchange for lease liabilities	15,866	0	0
Equipment acquired through finance leases	18,134	24,508	0
Sale of structural fill asset through a sales-type lease	0	6,000	0
Non-cash Series A Preferred Stock dividends included in accrued expenses	689	1,994	1,356
Proceeds from the sale of equipment in accounts receivable, net	0	1,313	0
Changes in property and equipment included in accounts payables and accrued expenses	1,237	1,187	205
Debt issuance costs included in accounts payable and accrued expenses	0	102	0
Property and equipment reduction due to sale-leaseback	0	0	7,000
Working capital owed related to sale of subsidiary included in accrued expenses	0	0	6,954
Sale of equipment through the issuance of a note receivable	0	0	1,450
Asset retirement obligation reduction through property and equipment	0	0	279
Taxes paid related to the net settlement of shares included in current liabilities of discontinued operations held for sale	0	0	79
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash from continuing operations	21,559	24,266	24,787
Restricted cash from continuing operations	40,100	34,908	4,424
Total cash and restricted cash	61,659	59,174	29,211
Series A Preferred Stock
Cash flows from financing activities:
Net proceeds from issuance of convertible Series A & B Preferred Stock	0	0	24,253
Supplemental disclosures and non-cash investing and financing transactions:
Series A Preferred Stock Dividends	0	8,156	3,169
Series B Preferred Stock
Cash flows from financing activities:
Net proceeds from issuance of convertible Series A & B Preferred Stock	28,800	0	0
Credit Agreement
Cash flows from financing activities:
Net payments on line of credit	(13,000)	0	0
Proceeds on asset-based lending credit agreement	13,000	0	0
Payments on asset-based lending credit agreement	(13,000)	0	0
Line of Credit
Cash flows from financing activities:
Net payments on line of credit	0	(12,003)	(6,997)
Payments on asset-based lending credit agreement	$ 0	$ (12,003)	$ (6,997)

Nature of Business and Basis of

Nature of Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	Nature of Business and Basis of Presentation Organization Charah Solutions, Inc. (together with its wholly-owned subsidiaries, “Charah Solutions,” the “Company,” “we,” “us,” or “our”), is a holding company formed in Delaware in January 2018. The Company's majority shareholder is Bernhard Capital Partners Management, LP and its affiliates (“BCP”). BCP owns 73% of the total voting power of our outstanding shares of common stock and all of the outstanding Series A and Series B Preferred Stock (collectively, the “Preferred Stock”), which is convertible at BCP's option at any time following the three-month anniversary of the issuance date into shares of common stock. Description of Business Operations The Company is a leading national service provider of mission-critical environmental services and byproduct recycling to the power generation industry, enabling our customers to address challenges related to the remediation of coal ash ponds and landfills at open and closed power plant sites while continuously operating and providing necessary electric power to communities nationwide. Services offered include a suite of remediation and compliance services, byproduct services, raw material sales and Environmental Risk Transfer (“ERT”) services. The Company has corporate offices in Kentucky and North Carolina and principally operates in the eastern and mid-central United States. The accompanying consolidated financial statements include the assets, liabilities, stockholders’ equity, members’ equity, and results of operations of the Company and its consolidated subsidiaries. Intercompany transactions and balances have been eliminated in consolidation. Under the Jumpstart Our Business Startups Act (the “JOBS Act”), the Company meets the definition of an “emerging growth company,” which allows the Company to have an extended transition period for complying with new or revised accounting standards pursuant to Section 107(b) of the JOBS Act. The Company intends to take advantage of all of the reduced reporting requirements and exemptions, including the longer phase-in periods for the adoption of new or revised financial accounting standards under Section 107 of the JOBS Act until the Company is no longer an emerging growth company. Among other things, we are not required to provide an auditor attestation report on the assessment of the internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act of 2002 and our disclosure obligations regarding executive compensation may be reduced. We may take advantage of these provisions until the last day of our fiscal year following the fifth anniversary of the IPO, or December 31, 2023. However, if certain events occur before the end of such five-year period, including if we become a “large accelerated filer,” our annual gross revenue exceeds $1.07 billion, or we issue more than $1.0 billion of non-convertible debt in any three-year period, we will cease to be an emerging growth company before the end of such five-year period. Going Concern The accompanying consolidated financial statements are prepared in accordance with generally accepted accounting principles applicable to a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. As discussed in Note 10, Long-Term Debt, the Company entered into an amendment to its Credit Agreement (as defined elsewhere herein) to change the maturity date from November 9, 2025 to January 31, 2024, amongst other changes. The Company does not have sufficient cash on hand or available liquidity to repay the maturing credit agreement debt, including the outstanding letters of credit, as it becomes due within one year after the date that these consolidated financial statements are issued. Combined with the Company’s recurring losses, recurring and continuing negative operating cash flows, and lack of available liquidity or cash on hand to sustain operations, these conditions, raise substantial doubt about the Company’s ability to continue as a going concern. In response, the Company has entered into a definitive agreement to be acquired by SER Capital Partners, which management anticipates will bring necessary funding to support the ongoing operations of the Company, and has implemented certain cost saving strategies to preserve liquidity. Additionally, the Company is currently pursuing a plan to refinance its Credit Agreement before the maturity date and other strategies to secure additional liquidity. However, these factors are subject to external conditions that are not within the Company’s control, and therefore, implementation of management’s plans cannot be deemed probable. As a result, management has concluded these plans do not alleviate substantial doubt about the Company’s ability to continue as a going concern. The accompanying consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. Discontinued Operations On November 19, 2020, the Company sold its Allied subsidiary engaged in maintenance, modification and repair services to the nuclear and fossil power generation industry to an affiliate of BCP (the “Purchaser”), the Company’s majority shareholder, in an all-cash deal for $40,000 (the “Allied Transaction”), subject to adjustments for working capital and certain other adjustments as set forth in the purchase agreement (the "Purchase Agreement"). Discontinued operations comprise those activities that have been disposed of during the period and represent a separate major line of business that can be clearly distinguished for operational and financial reporting purposes. Accordingly, the Consolidated Balance Sheets, Statements of Operations, and the Notes to Consolidated Financial Statements reflect the Allied results as discontinued operations for all periods presented. Unless otherwise specified, disclosures in these consolidated financial statements reflect continuing operations only. The Consolidated Statements of Cash Flows include both continuing and discontinued operations. Refer to Note 3, Discontinued Operations, for further information on the discontinued operations relating to the Allied Transaction. Segment Information After the Allied Transaction, the Company operates as one reportable segment, reflecting the suite of end-to-end services we offer our utility partners and how our Chief Operating Decision Maker (“CODM”) reviews consolidated financial information to evaluate results of operations, assess performance and allocate resources. Due to the nature of the Company’s business, the Company's Chief Executive Officer, who is also the CODM, evaluates the performance of the Company and allocates resources of the Company based on consolidated gross profit, general and administrative expenses, balance sheet, liquidity, capital spending, safety statistics and business development reports for the Company as a whole. Since the Company has a single operating segment, all required financial segment information can be found in the consolidated financial statements. We provide the following services through our one segment: remediation and compliance services, byproduct services, raw material sales and ERT transfer services. Remediation and compliance services are associated with our customers’ need for multi-year environmental improvement and sustainability initiatives, whether driven by regulatory requirements, power generation customer initiatives or consumer expectations and standards. Byproduct services consist of recurring and mission-critical coal ash management and operations for coal-fired power generation facilities while also supporting both our power generation customers’ desire to recycle their recurring and legacy volumes of coal combustion residuals (“CCRs”), commonly known as coal ash, and our ultimate end customers’ need for high-quality, cost-effective supplemental cementitious materials (SCMs) that provide a sustainable, environmentally-friendly substitute for Portland cement in concrete. Our raw materials sales provide customers with the materials essential to their business while also providing the sourcing, logistics, and management needed to facilitate these raw materials transactions around the globe. ERT services represent an innovative solution designed to meet the evolving and increasingly complex needs of utility customers' evolving and increasingly complex plant closure and environmental remediation needs. These customers need to retire and decommission older or underutilized assets while maximizing the asset's value and improving the environment. Our ERT services manage the sites' environmental remediation requirements, benefiting the communities and lowering the utility customers' costs

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Management’s Use of Estimates The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions, in particular estimates of legal reserves, remediation costs for asset retirement obligations (“ARO”), costs to complete contracts in process, contract modifications and unapproved change orders, that affect the reported amounts in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Balance Sheet Classification The Company includes in current assets and liabilities contract assets, contract liabilities and retainage amounts payable, which may extend beyond one year. One year is used as the basis for classifying all other assets and liabilities. Reclassification Resulting from the increase in significance of the Company's raw material sales, revenue and cost of sales amounts reported in prior years have been reclassified to conform to the current year’s presentation. Cash The Company maintains cash in bank deposit accounts which, at times, may exceed federally insured limits. The Company has not experienced any losses in such accounts. The Company believes it is not exposed to any significant credit risk on cash. Restricted Cash We maintain restricted cash in non-interest bearing escrow accounts for specific remediation and compliance projects, cash collateral for letters of credit, and insurance-related items. This cash becomes unrestricted as project milestones are completed in accordance with each project's defined project schedule, or when credit agreements requiring cash collateral are terminated. As of December 31, 2022 and 2021, restricted cash in these accounts held $40,100 and $34,908, respectively. Trade Accounts Receivable, Net Trade accounts receivable, net consist of amounts due from customers. An allowance for doubtful accounts is recorded to the extent it is probable that a portion of a particular account will not be collected. Management determines the allowance for doubtful accounts by evaluating individual customer receivables and considering a customer’s financial condition, credit history, and current economic conditions. An allowance for doubtful accounts of $1,130 and $146 was included in trade accounts receivable, net as of December 31, 2022 and 2021, respectively. Trade accounts receivable balances are considered past due based upon contract or invoice terms and are charged off when deemed uncollectible. The Company does not charge interest on customer accounts and generally does not require collateral on sales and services during the normal course of business. The Company has the right to file liens on the owner’s property with regard to certain construction contracts. Inventory Inventories, mainly comprising ash for resale, are valued using the first-in, first-out (“FIFO”) method. Inventories are stated at the lower of cost or net realizable value. Property and Equipment Property and equipment are stated at cost. Construction-in-progress represents costs incurred on the construction of assets that have not been completed or placed in service as of the end of the year. We evaluate the long-lived assets each reporting period to determine whether events and circumstances continue to support the asset's carrying value. Depreciation is provided principally by the straight-line method over the estimated useful lives of the assets as follows: Plant, machinery and equipment 2 - 15 years Vehicles 2 - 10 years Office equipment 2 - 10 years Buildings and leasehold improvements 5 - 40 years Finance lease assets 3 - 7 years Repair and maintenance costs are expensed as incurred and expenditures for improvements are capitalized. Asset Retirement Obligations AROs associated with retiring long-lived assets are recognized as a liability in the period in which a legal obligation is incurred and becomes determinable. The ARO liability reflects the estimated present value of the closure and post-closure activities associated with the Company’s land and structural fill assets. The Company utilizes current retirement costs to estimate the expected cash outflows for retirement obligations. Inherent in the present value calculation are numerous assumptions and judgments, including the ultimate settlement amounts, inflation factors, credit-adjusted discount rates, timing of settlement, and changes in the legal, regulatory, environmental and political environments. To the extent future revisions to these assumptions impact the present value of the existing ARO liability, a corresponding adjustment is made to the land and/or structural fill balance. Accretion expense is recognized over time as the discounted liability is accreted to its expected settlement value. Gains and losses on ARO settlement are recognized as specific remediation tasks are performed. These gains and losses are determined based on the differences between the estimated costs used in the measurement of the fair value of the Company's AROs and the actual costs incurred for specific remediation tasks recognized on a proportionate basis. Goodwill and Indefinite Lived Intangible Assets Goodwill represents the excess purchase price over the estimated fair value of net assets acquired in a business combination. Our intangible assets in the Consolidated Balance Sheets as of December 31, 2021 included a trade name that was considered to have an indefinite life. All intangible assets were impaired to zero during the year ended December 31, 2022. Goodwill and indefinite-lived intangible assets are not amortized but instead are tested for impairment at least annually or more often if events or changes in circumstances indicate that the fair value of the asset may have decreased below its carrying value. Goodwill is tested at the reporting unit level, which has been determined to be the Company. When performing its goodwill impairment test, the Company considers a qualitative assessment, when appropriate, and a quantitative assessment using the market approach and its market capitalization when determining the fair value of the reporting unit. We evaluate the indefinite-lived trade name each reporting period to determine whether events and circumstances continue to support an indefinite useful life. When performing its indefinite-lived intangible asset impairment test, the Company considers a qualitative assessment, when appropriate, and a quantitative assessment using the relief-from-royalty method, an income approach, that estimates the present value of royalty income that could be hypothetically earned by licensing the brand name to a third party over the remaining useful life. The assets will be written down to their implied fair value if the carrying value exceeds its fair value. Definite-Lived Intangible Assets Definite-lived intangible assets are comprised of our customer relationships. We evaluate our definite-lived intangible asset each reporting period to determine whether events and circumstances indicate that a triggering event has occurred that suggests that the fair value of the asset is below its carrying value. These assets are amortized on a straight-line basis over their estimated useful lives, as shown in the table below. Definite Lived Intangible Useful Life Customer relationships 10 years Fair Value Disclosure The Company follows Accounting Standards Codification (“ASC”) 820, Fair Value Measurements , which provides a framework for measuring and disclosing fair value under generally accepted accounting principles. ASC 820 requires disclosures about the fair value of assets and liabilities recognized in the balance sheet in periods subsequent to initial recognition, whether the measurements are made on a recurring basis or on a nonrecurring basis. ASC 820 defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. ASC 820 also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard describes three levels of inputs that may be used to measure fair value. Fair Value Hierarchy Level 1 - Valuation is based on quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 1 assets and liabilities generally include debt and equity securities that are traded in an active exchange market. Valuations are obtained from readily available pricing sources for market transactions involving identical assets and liabilities. Level 2 - Valuation is based on inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. The valuation may be based on quoted prices for similar assets and liabilities; quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability. Level 3 - Valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which determination of fair value requires significant management judgment or estimation. In determining the appropriate levels, the Company performs a detailed analysis of assets and liabilities that are subject to ASC 820. The Company's contingent payments for acquisitions and interest rate swap are the only assets or liabilities subject to fair value measurements on a recurring basis. The Company may also be required, from time to time, to measure certain other financial and non-financial assets and liabilities at fair value on a non-recurring basis in accordance with GAAP. There have been no transfers between levels of the fair value hierarchy during the years ended December 31, 2022 and 2021 . The fair value of the Company's 8.50% Senior Notes due 2026 (the "Notes") were valued using quoted prices in active markets for the Notes, which is considered to be a Level 1 measurement. The Notes had a fair value of $54,594 and $131,760 as of December 31, 2022 and 2021, respectively, and a carrying value of $135,000 as of December 31, 2022 and 2021. The book value of our outstanding equipment and other notes of $14,209 approximated fair value as December 31, 2022 based on consideration of recently executed transactions for similar debt, which are considered to be Level 2 measurements. Our outstanding debt as of December 31, 2020 primarily bore interest at variable rates and book value approximated fair value, which were considered to be Level 2 measurements. The carrying amounts and fair values of the Company’s recurring fair value measurements as of December 31, 2022 and 2021 are presented in the following table: December 31, 2022 Level 1 Level 2 Level 3 Total Fair Value Total Carrying Value Recurring: Contingent payments for acquisitions (1) $ — $ — $ 1,950 $ 1,950 $ 1,950 December 31, 2021 Level 1 Level 2 Level 3 Total Fair Value Total Carrying Value Recurring: Contingent payments for acquisitions (1) — — 1,950 1,950 1,950 1. As of December 31, 2022 and 2021, t he fair value of the contingent payments for acquisitions was estimated at the acquisition date using the present value of future payments. This analysis is updated at each reporting date to determine if any changes to the fair value are required and is considered to be a Level 3 measurement. The Company's non-recurring level 3 fair value measurements consist of the measurement of AROs as described in Notes 5 and 7, the valuation of goodwill, intangible assets, and real estate, property and equipment, net as described in Notes 6 and 9 and the measurement of the preferred stock paid-in-kind dividends as described in Note 13. Debt Issuance Costs Debt issuance costs associated with our various credit agreements are amortized as interest expense over the term of the applicable agreement. Debt issuance costs related to the Notes are presented as a direct deduction from the carrying amount of the related liability in the Consolidated Balance Sheet. Debt issuance costs related to the Asset-Based Lending Credit Agreement (the “Credit Agreement”) are included in other assets in the Consolidated Balance Sheet. Freight Costs Freight costs charged to customers are included in construction and service revenue and raw material sales. Costs incurred by the Company for freight are included in construction and service cost of sales and raw material cost of sales. Leases We lease equipment, vehicles, and real estate under various arrangements which are classified as either operating or finance leases. We recognize operating lease right-of-use assets and operating lease liabilities for operating leases and finance lease assets and liabilities for finance leases based on the present value of the lease payments over the lease term. The present value is based on our incremental borrowing rate, which represents the rate of interest that we would pay to borrow on a collateralized basis, over a similar term, an amount equal to the lease payments. See note 20 for further discussion of leases. Income Taxes Income taxes are accounted for in accordance with ASC 740. Income tax expense, or benefit, is calculated using the asset and liability method under which deferred tax assets and liabilities are recorded based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The Company assesses its deferred tax assets each quarter to determine whether the assets are more likely than not (probability of more than 50%) realizable under ASC 740. The Company is required to record a valuation allowance for any portion of the tax assets that, based on the assessment, are not more likely than not realizable. The assessment considers, among other things, earnings in prior periods, forecasts of future taxable income, statutory carryforward periods, and tax planning strategies, to the extent feasible. The realization of deferred tax assets largely depends part on the generation of future taxable income during the periods in which the differences become deductible. The value of the deferred tax assets will also depend on applicable income tax rates. Judgment is required in determining the future tax consequences of events that have been recognized in the financial statements. Differences between anticipated and actual outcomes of these future tax consequences could have a material impact on the financial statements. Changes in existing tax laws and tax rates also affect actual tax results and the valuation of deferred tax assets over time. Stock-Based Compensation Plans The Company accounts for its stock-based compensation plans as equity-classified plans, in accordance with the fair value recognition provisions of ASC 718, Compensation-Stock Compensation . The Company utilizes the Black-Scholes model, which requires the input of subjective assumptions. These assumptions include estimating (i) the volatility of the common stock price over the expected term, (ii) the expected term, and (iii) expected dividends. Where the vesting of the stock is also based upon performance measures, management determines the likelihood of meeting such measures. Changes in the subjective assumptions can materially affect the estimate of the fair value of stock-based compensation and, consequently, the related amounts recognized on the Consolidated Statements of Operations. Stock-based compensation expense is recognized in general and administrative expenses. Revenue from Contracts with Customers Revenue is measured based on the amount of consideration specified in a contract with a customer. Revenue is recognized when our performance obligations under the terms of the contract are satisfied, which generally occurs with the transfer of control of the goods or services to the customer. Contract Combination To determine revenue recognition for contracts, we evaluate whether two or more contracts should be combined and accounted for as one single contract and whether the combined or single contract should be accounted for as more than one performance obligation. This evaluation requires significant judgment, and the decision to combine a group of contracts or separate a combined or single contract into multiple performance obligations could change the amount of revenue and profit recorded in a given period. Contracts are considered to have a single performance obligation if the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts primarily because we provide a service that involves multiple inter-related and integrated tasks to achieve the completion of a specific, single project. We allocate the transaction price to each performance obligation for contracts with multiple performance obligations using our best estimate of the stand-alone selling price of each distinct good or service in the contract. Sales and Services Contracts For sales and service contracts where we have the right to consideration from the customer in an amount that corresponds directly with the unit price for the product and the value received by the customer based on our performance to date, revenue is recognized at a point in time when product is delivered to the customer and services are performed and contractually billable. Certain service contracts contain provisions dictating fluctuating rates per unit for the certain services in which the rates are not directly related to changes in the Company’s effort to perform under the contract. We recognize revenue based on the stand-alone selling price per unit for such contracts, calculated as the average rate per unit over the term of those contractual rates. This creates a contract asset or liability for the difference between the revenue recognized and the amount billed to the customer. Under the typical payment terms of our services contracts, amounts are billed as work progresses in accordance with agreed-upon contractual terms, at periodic intervals ( e.g. , weekly, biweekly or monthly). Construction Contracts We recognize revenue over time, as performance obligations are satisfied, for substantially all of our construction contracts due to the continuous transfer of control to the customer. For most of our construction contracts, the customer contracts with us to provide a service that involves multiple inter-related and integrated tasks to complete a specific, single project and is therefore accounted for as a single performance obligation. We recognize revenue using the cost-to-cost input method, based primarily on contract costs incurred to date compared to total estimated contract costs. This method is the most accurate measure of our contract performance because it depicts the company’s performance in transferring control of goods or services promised to customers according to a reasonable measure of progress toward complete satisfaction of the performance obligation. Contract costs include all direct material, labor and subcontractor costs and indirect costs related to contract performance. The costs incurred that do not relate directly to transferring a service to the customer are excluded from the input method used to recognize revenue. Project mobilization costs are generally charged to the project as incurred when they are an integrated part of the performance obligation being transferred to the client. Pre-contract costs are expensed as incurred unless they are expected to be recovered from the client. The payment terms of our construction contracts from time to time require the customer to make advance payments as well as interim payments as work progresses. The advance payment generally is not considered a significant financing component as we expect to recognize those amounts in revenue within a year of receipt as work progresses on the related performance obligation. Variable Consideration It is common for our contracts to contain contract provisions that give rise to variable consideration such as unpriced change orders or volume discounts that may either increase or decrease the transaction price. We estimate the amount of variable consideration at the expected value or most likely amount, depending on which is determined to be more predictive of the amount to which the Company will be entitled. Variable consideration is included in the transaction price when it is probable that a significant reversal of cumulative revenue recognized will not occur or when the uncertainty associated with the variable consideration is resolved. Our estimates of variable consideration and determination of whether to include such amounts in the transaction price are based largely on our assessment of legal enforceability, anticipated performance, industry business practices, and any other information (historical, current or forecasted) that is reasonably available to us. Variable consideration associated with unapproved change orders is included in the transaction price only to the extent of costs incurred. We provide limited warranties to customers for work performed under our contracts. Such warranties are not sold separately, assure that the services comply with the agreed-upon specifications and legal requirements and do not provide customers with a service in addition to assurance of compliance with agreed-upon specifications. Accordingly, these types of warranties are not considered to be separate performance obligations. Historically, warranty claims have not resulted in material costs incurred. Contract Estimates and Modifications Due to the nature of the work required to be performed on many of our performance obligations, the estimation of total revenue and cost at completion is complex, subject to many variables and requires significant judgment. As a significant change in one or more of these estimates could affect the profitability of our contracts, we routinely review and update our contract-related estimates through a disciplined project review process in which management reviews the progress and execution of our performance obligations and the estimated costs at completion. As part of this process, management reviews information including, but not limited to, outstanding contract matters, progress towards completion, program schedule and the associated changes in estimates of revenue and costs. Management must make assumptions and estimates regarding the availability and productivity of labor, the complexity of the work to be performed, the availability and cost of materials, the performance of subcontractors, and the availability and timing of funding from the customer, along with other risks inherent in performing services under all contracts where we recognize revenue over-time using the cost-to-cost method. We recognize changes in contract estimates on a cumulative catch-up basis in the period in which the changes are identified. Such changes in contract estimates can result in the recognition of revenue in a current period for performance obligations that were satisfied or partially satisfied in prior periods. Changes in contract estimates may also result in the reversal of previously recognized revenue if the current estimate differs from the previous estimate. If at any time the estimate of contract profitability indicates an anticipated loss on the contract, we recognize the total loss in the period it is identified. Contracts are often modified to account for changes in contract specifications and requirements. Most of our contract modifications are for goods or services that are not distinct from existing contracts due to the significant integration provided in the context of the contract and are accounted for as if they were part of the original contract. The effect of a contract modification on the transaction price and our measure of progress for the performance obligation to which it relates is recognized as an adjustment to revenue (either as an increase in or a reduction of revenue) on a cumulative catch-up basis. We account for contract modifications when the modification results in the promise to deliver additional goods or services that are distinct and the increase in the price of the contract is for the same amount as the stand-alone selling price of the additional goods or services included in the modification. We evaluate our contracts whether we are acting as the principal or as the agent when providing services, which we consider in determining if revenue should be reported on a gross or net basis. We determine the Company to be a principal if we control the specified service before that service is transferred to a customer. Contract Assets and Liabilities Billing practices are governed by each project's contract terms based upon costs incurred, achievement of the milestones or predetermined schedules. Billings do not necessarily correlate with revenue recognized over time using the cost-to-cost input method. Contract assets include unbilled amounts typically resulting from revenue under long-term contracts when the revenue recognized exceeds the amount billed to the customer. Contract liabilities consist of billings in excess of revenue recognized as well as deferred revenue. Contract assets also include retainage, which represents amounts withheld by our clients from billings according to provisions in the contracts and may not be paid to us until the completion of specific tasks or the completion of the project and, in some instances, for even longer periods. Our contract assets and liabilities are reported in a gross position on a contract-by-contract basis at the end of each reporting period. We include in current assets and liabilities contract assets and liabilities, which may extend beyond one year. Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) , requiring all leases to be recognized on the balance sheet as a right-of-use asset and a lease liability unless the lease is a short-term lease (generally a lease with a term of 12 months or less). On January 1, 2022, we adopted ASC 842. As further described in Note 20, we lease equipment and vehicles primarily used at our project sites. We adopted ASC 842 using a modified retrospective approach (Comparatives Under 840 Option). The Comparatives Under 840 Option requires recognition under the new standard in ASC 842, Leases (“Leases (Topic 842)”) to be applied as of the date of adoption (January 1, 2022) with all prior periods being presented under Accounting Standards Codification (ASC) 840, Leases (“Leases (Topic 840)”). As a result, the comparative financial information has not been updated and the required disclosures prior to the date of adoption have not been updated and continue to be reported under the accounting standards in effect for those periods. ASC 842 also permitted the election of certain practical expedients upon adoption. We elected the transition package of practical expedients which allowed us to carryforward the historical lease classification. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) - Measurement of Credit Losses on Financial Instruments , which introduces a new model for recognizing credit losses on financial instruments based on an estimate of current expected credit losses. The new model will apply to: (1) loans, accounts receivable, trade receivables, and other financial assets measured at amortized cost, (2) loan commitments and certain other off-balance sheet credit exposures, (3) debt securities and other financial assets measured at fair value through other comprehensive income, and (4) beneficial interests in securitized financial assets. The amendments contained in this ASU will be applied through a modified retrospective approach through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. In November 2018, the FASB issued ASU No. 2018-19, which amended the effective date of ASU No. 2016-13 and clarified that receivables arising from operating leases are not within the scope of Subtopic 326-20. In October 2019, the FASB delayed the effective date of this ASU, extending the effective date for non-public business entities and making the ASU effective for the Company for the fiscal year ending December 31, 2023, and interim periods therein, with early adoption permitted. The adoption of this ASU is not expected to have a material impact on the Company's consolidated financial statements. In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848) Facilitation of the Effects of Reference Rate Reform on Financial Reporting . The ASU provides optional expedients and exceptions for applying GAAP to contract modifications and hedging relationships, subject to meeting certain criteria, that reference LIBOR or another rate that is expected to be discontinued. In January 2021, the FASB issued ASU No. 2021-01, Reference Rate Reform (Topic 848) . This ASU provides supplemental guidance and clarification to ASU No. 2020-04, and these updates must be adopted concurrently, cumulatively referred to as “Topic 848.” The amendments in Topic 848 are currently effective for all entities and upon adoption may be applied prospectively to contract modifications made on or before December 31, 2022. The adoption of this ASU is not expected to have a material impact on the Company's consolidated financial statements. In August 2020, the FASB issued ASU No. 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815 – 40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity . This ASU eliminates the current models that require separation of beneficial conversion and cash conversion features from convertible instruments and simplifies the derivative scope exception guidance pertaining to equity classification of contracts in an entity’s own equity. The new standard also introduces additional disclosures for convertible debt and freestanding instruments that are indexed to and settled in an entity’s own equity. ASU No. 2020-06 amends the diluted earnings per share guidance, including the requirement to use the if-converted method for all convertible instruments. The Company adopted ASU No. 2020-06 effective as of January 1, 2022. The adoption of ASU No. 2020-06 did not have an impact on the Company’s consolidated financial statements.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2022
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations On November 19, 2020, the Company completed the Allied Transaction through an all-cash deal for $40,000, subject to adjustments for working capital and certain other adjustments as set forth in the Purchase Agreement. The Allied Transaction was approved by a special committee of the Company’s board of directors consisting solely of independent directors, which obtained a fairness opinion in connection with the Allied Transaction. This Allied Transaction has been treated as a sale to an entity under common control, with $25,506 recognized as a contribution to equity. The parties made customary representations and warranties and have agreed to customary covenants in the Purchase Agreement. The Company entered into a non-competition and non-solicitation arrangement under the Purchase Agreement with the Purchaser, subject to customary exceptions. In addition, the parties also entered into a Transition Services Agreement pursuant to which the Company provided Allied and the Purchaser with certain transition assistance services from the date of the Allied Transaction until April 30, 2021 in exchange for payment. The Transition Services Agreement was subsequently amended and extended with certain transition assistance services provided until August 30, 2021. In total, the Company received $0 and $60 for its performance under the Transition Services Agreement during the year ended December 31, 2022 and 2021, respectively. The Company had receivables outstanding from Allied of $0 at December 31, 2022 and 2021, respectively. In accordance with applicable accounting guidance for the disposal of long-lived assets, the results of the Allied Transaction are presented as discontinued operations and, as such, have been excluded from continuing operations for all periods presented. The Company derecognized the following assets and liabilities through this Allied Transaction: Restricted cash $ 240 Trade accounts receivable, net 25,752 Prepaid expenses and other current assets 1,453 Property and equipment, net 1,112 Goodwill (a) 12,020 Accounts payable (8,681) Accrued liabilities (26,367) Carrying value of Allied $ 5,529 (a) Goodwill was allocated to discontinued operations on a relative fair value basis. The following amounts related to discontinued operation were derived from historical financial information and have been segregated from continuing operations and reported as discontinued operations in our Consolidated Statements of Operations: Year Ended December 31, 2020 Revenue $ 314,251 Cost of sales 295,423 Gross profit 18,828 General and administrative expenses 7,106 Operating income 11,722 Interest expense, net (b) (2,745) Income from discontinued operations before income taxes 8,977 Income tax expense 94 Income from discontinued operations $ 8,883 (b) Interest expense was allocated to discontinued operations due to a requirement in our amended Credit Agreement that cash generated from the Allied Transaction was to be used to reduce our borrowings. The following table provides supplemental cash and restricted cash information related to discontinued operations: Year Ended December 31, 2020 Cash and restricted cash: Cash and restricted cash - continuing operations $ 29,211 Cash and restricted cash - discontinued operations — Total cash and restricted cash $ 29,211 The depreciation and amortization, capital expenditures and significant operating noncash items of Allied were as follows: Year Ended December 31, 2020 Cash flows from discontinued operating activities: Depreciation and amortization $ 755 Loss on disposal of fixed assets 22 Non-cash shared-based compensation 145 Cash flows from discontinued investing activities: Purchase of property and equipment $ 93

Revenue

Revenue	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Revenue	Revenue We disaggregate our revenue from customers by customer arrangement and geographic region as we believe it best depicts how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors. See details in the tables below. Year Ended December 31, 2022 2021 2020 Construction contracts 140,798 160,632 80,805 Byproduct services 105,981 101,355 106,704 Raw material sales 46,388 31,232 44,868 Total revenue $ 293,167 $ 293,219 $ 232,377 Year Ended December 31, 2022 2021 2020 United States $ 293,167 $ 293,219 $ 231,032 Foreign — — 1,345 Total revenue $ 293,167 $ 293,219 $ 232,377 On December 31, 2022, we had $517,914 in transaction price for existing contracts allocated to remaining performance obligations. We expect to recognize approximately 19% of our remaining performance obligations as revenue during 2023, 13% in 2024, 11% in 2025 and 56% thereafter. Revenue associated with our remaining performance obligations relates to our construction contracts. The balance of remaining performance obligations does not include variable consideration that was determined to be constrained as of December 31, 2022. As of December 31, 2022, there were $2,923 in unapproved change orders associated with project scope changes included in estimated costs at completion on certain construction contracts, of which $2,330 were approved after year end. The timing of revenue recognition, billings and cash collections results in accounts receivable, contract assets, and contract liabilities on the Consolidated Balance Sheets. Our contract assets are as follows: December 31, 2022 2021 Costs and estimated earnings in excess of billings $ 11,700 $ 17,163 Retainage 9,281 9,681 Total contract assets $ 20,981 $ 26,844 The increase in contract assets in 2022 was primarily attributable to the timing of the billings for construction contracts. Our contract liabilities are as follows: December 31, 2022 2021 Deferred revenue $ 258 $ 483 Billings in excess of costs and estimated earnings 8,160 5,716 Total contract liabilities $ 8,418 $ 6,199 We recognized revenue of $5,941 for the year ended December 31, 2022, which was previously included in the contract liability balance at December 31, 2021. The following table sets forth the costs and estimated earnings on uncompleted contracts as of: December 31, 2022 2021 Costs incurred on uncompleted contracts $ 344,692 $ 227,195 Estimated earnings 20,267 22,331 Total costs and earnings 364,959 249,526 Less billings to date (361,419) (238,079) Costs and estimated earnings in excess of billings $ 3,540 $ 11,447 The following table sets forth the net balance in process as of: December 31, 2022 2021 Costs and estimated earnings in excess of billings $ 11,700 $ 17,163 Billings in excess of costs and estimated earnings (8,160) (5,716) Net balance in process $ 3,540 $ 11,447

Asset Acquisition

Asset Acquisition	12 Months Ended
	Dec. 31, 2022
Business Combination and Asset Acquisition [Abstract]
Asset Acquisition	Asset Acquisitions The Company closed on two acquisitions during the year ended December 31, 2022, and one acquisition during the year ended December 31, 2021, as part of our ERT service offerings. As each asset group lacked the necessary elements of a business, these transactions were accounted for as asset acquisitions in accordance with ASC 805, Business Combinations. The purchase price comprised the assumed liabilities plus expenses and cash paid by or owed to the seller. Since the fair value of the net assets acquired was different than the purchase price of the assets, the Company allocated the difference pro rata on the basis of relative fair values to reduce the basis of land, land improvements and structural fill sites, property and equipment and other assets acquired. For Cheswick Generating Station asset acquisition as discussed further herein, the Company recognized a deferred gain representing the excess of fair value of the financial assets acquired over the consideration given (including transaction costs incurred). The Company has identified asset retirement obligations within the assumed liabilities to be initially measured and valued in accordance with ASC 410, Asset Retirement and Environmental Obligations . We developed our estimates of these obligations using input from our operations personnel. Our estimates are based on our interpretation of current requirements and proposed regulatory changes and are intended to approximate fair value. In the absence of quoted market prices, we determine the estimate of fair value based on the best available information, including the results of present value techniques. We use professional engineering judgment and estimated prices based on quotes rates from third parties and amounts paid for similar work to determine the fair value of these obligations. We are required to recognize these obligations at market prices, whether we plan to contract with third parties or perform the work ourselves. Once we determined the estimated closure and post-closure costs for each asset retirement obligation, we inflation-adjusted those costs to the expected time of payment using an estimated inflation rate. We then discounted those expected future costs back to present value using the credit-adjusted, risk-free rate effective at the time the obligation was incurred, consistent with the expected cash flow approach. Any changes in expectations that result in an upward revision to the estimated cash flows are treated as a new liability and discounted at the current rate, while downward revisions are discounted at the historical weighted average rate of the recorded obligation. The credit-adjusted, risk-free discount rate used to calculate the present value of an obligation is specific to each specific asset retirement obligation. Gains on ARO settlements result from the requirement to record costs plus an estimate of third-party profit in determining the ARO. When we perform the work using internal resources and reduce the ARO for work performed, we recognize a gain if actual costs are less than the estimated costs plus the third-party profit. Because these obligations are measured at estimated fair value using present value techniques, changes in the estimated cost or timing of future closure, demolition, and post-closure activities could result in a material change in these liabilities, related assets, and results of operations. We assess the appropriateness of the estimates used to develop our recorded balances annually or more often if conditions warrant. Changes in the timing or extent of future final closure and post-closure activities typically result in a current adjustment to the recorded liability and land, land improvements and structural fill sites assets. Avon Lake Asset Acquisition On April 4, 2022, the Company, through its wholly-owned special purpose vehicle subsidiary Avon Lake Environmental Redevelopment Group, LLC (“ALERG”), completed the full acquisition of the Avon Lake Generating Station and adjacent property (the "Avon Lake Property") from GenOn Power Midwest, LP, (“GenOn”) and has begun environmental remediation and sustainable redevelopment of the property. As part of this agreement, the Company acquired the Avon Lake Property, which is a 40-acre area located on Lake Erie that consists of multiple parcels of land adjacent to the retired generating plant, including the generating station, which ceased electric generation in March 2022, submerged lands lease in Lake Erie, substation/switch gear and transformers, administrative offices and structures, coal rail and storage yard parcels. ALERG assumed all liabilities related to the Avon Lake Property and will be responsible for the shutdown and decommissioning of the coal power plant and performing all environmental remediation and redevelopment work at the site. The decommissioning of the coal power plant and redevelopment of the property are expected to be completed within 36 months from the date of acquisition. The assets acquired and liabilities assumed as recognized within the Company's consolidated balance sheet upon closing on the APA consisted of the following: Consideration and direct transaction costs: Asset retirement obligations $ (34,300) Direct transaction costs (1,345) Total consideration and transaction costs incurred $ (35,645) Assets Acquired: Restricted Cash $ 2,900 Land, land improvements and structural fill sites 32,109 Plant, machinery and equipment 623 Vehicles 13 Total allocated value of assets acquired $ 35,645 A summary of the other assumptions included in the fair value measurement of the asset retirement obligations to be recognized upon closing of the APA consisted of the following: Other Assumptions: Inflation rate 2.50 % Weighted average rate applicable to our long-term asset retirement obligations 7.35 % As part of the acquisition, the Company acquired certain plant, machinery and equipment and vehicles for which management committed to a plan to sell. Property and equipment of $505 that was initially classified as held for sale were sold to third parties as of December 31, 2022. The Company received proceeds of $1,565 and recorded a gain of $1,060 within gains on sales of real estate, property and equipment, net, in the Company's consolidated statements of operations. The proceeds were recorded in cash flows from investing activities in the Company's consolidated statements of cash flows. The amount of land, land improvements and structural fill sites acquired includes fair value estimates for real estate and scrap to be sold from the demolition of the coal power plant. Restricted cash is exclusively used to fund initial costs related to the acquisition and the remaining balance will be used to fund a portion of the asset retirement obligations. Restricted cash is held and will be disbursed by an escrow agent. Funds will be released to the Company as asset retirement obligation costs are incurred and performance of remediation activities are certified by an authorized representative of GenOn. Cheswick Generating Station Asset Acquisition On April 6, 2022, the Company, through its wholly-owned special purpose vehicle subsidiaries, Cheswick Plant Environmental Redevelopment Group, LLC, Cheswick Lefever, LLC and Harwick Operating Company, LLC (collectively, “CPERG”), completed the full acquisition of the Cheswick Generating Station, the Lefever Ash Landfill and the Monarch Wastewater Treatment Facility (the "Cheswick Property") from GenOn and will begin environmental remediation and sustainable redevelopment of the Pennsylvania properties immediately. The Cheswick Generating Station ceased electrical generation operations on March 31, 2022. As part of this agreement, the Company, through CPERG, has acquired properties consisting of: ▪ The retired Cheswick Generating Station, a 565 MW coal-fired plant previously operated by GenOn, located in Springdale, PA. The 56-acre primary generating station site, along with an adjacent 27-acre parcel, consists of an operating rail line, a coal yard, bottom ash emergency and recycle ponds, waste ponds and a coal pile runoff pond, coal delivery equipment, and an ash handling parcel. CPERG will be responsible for the shutdown and decommissioning of the coal power plant, the remediation of the two ash ponds and performing all environmental remediation and redevelopment work at the site. ▪ The Lefever Ash Landfill in Cheswick, PA. The 182-acre site, including the 50-acre landfill facility, provided disposal of coal combustion residuals (CCR) and residual waste from the Cheswick Generating Station. CPERG will be responsible for the closure design, remediation closure work and post-closure monitoring of the landfill. ▪ The Monarch Wastewater Treatment Facility in Allegheny County, PA. CPERG will be responsible for management and compliance with all applicable environmental regulations. In the process of accounting for this transaction, the basis of the land, property and equipment acquired was reduced to zero, resulting in an excess of financial assets over and above the purchase price. The Company recorded a deferred gain of $4,476, representing the difference between the fair value of the assets acquired and the consideration given (including transaction costs incurred). This deferred gain will be recognized ratably over the entire project as remediation costs are incurred in proportion to total estimated remediation costs. During the year ended December 31, 2022, the Company recognized $284 of the deferred gain within gains on sales of real estate, property and equipment, net, in the Company's consolidated statements of operations. The decommissioning of the coal power plant and redevelopment of these properties are expected to be completed within 42 months from the date of acquisition, and the post-closure monitoring associated with the Lefever Ash Landfill and Monarch Wastewater Treatment Facility will occur for 30 years after the closure of the sites. The assets acquired and liabilities assumed as recognized within the Company's consolidated balance sheet upon closing on the APA consisted of the following: Consideration and direct transaction costs: Asset retirement obligations $ (30,179) Direct transaction costs and accrued expenses (684) Total consideration and transaction costs incurred $ (30,863) Assets Acquired: Cash $ 5,577 Restricted cash 29,762 Total allocated value of assets acquired $ 35,339 Excess of fair value of assets acquired over total consideration – deferred gain $ (4,476) A summary of the other assumptions included in the fair value measurement of the asset retirement obligations to be recognized upon closing of the APA consisted of the following: Other Assumptions: Inflation rate 2.50 % Weighted average rate applicable to our long-term asset retirement obligations 7.45 % As part of the acquisition, the Company acquired certain plant, machinery and equipment and vehicles for which management committed to a plan to sell. The Company received proceeds and recorded a gain of $526 within gains on sales of real estate, property and equipment, net, in the Company's consolidated statements of operations. The proceeds were recorded in cash flows from investing activities in the Company's consolidated statements of cash flows. Restricted cash is exclusively used to fund initial costs related to the acquisition and the remaining balance will be used to fund a portion of the asset retirement obligations. Restricted cash is held and will be disbursed by an escrow agent. Funds will be released to the Company as certain project milestones are met and performance of remediation activities are certified by an authorized representative of GenOn. Gibbons Creek Asset Acquisition In February 2021, the Company, through its wholly-owned special purpose vehicle subsidiary Gibbons Creek Environmental Redevelopment Group (“GCERG”), closed on an Asset Purchase Agreement (the “APA” or the “Agreement”) with Texas Municipal Power Agency (“TMPA”) to acquire, remediate and redevelop the Gibbons Creek Steam Electric Station and Reservoir (the “Gibbons Creek Transaction”). As part of this Agreement, GCERG took ownership of the 6,166-acre area (collectively, the “Purchased Assets”), which includes the closed power station and adjacent property, the 3,500-acre reservoir, dam and floodway. GCERG assumed all environmental obligations and became responsible for the decommissioning of the coal power plant as well as performing all environmental remediation work for the site landfills and ash ponds. At the closing of the APA, GCERG became liable for and expressly fully assumed any and all environmental liabilities and environmental compliance, as well as, without limitation, any remediation, investigation, management, mitigation, closure, maintenance, reporting, removal, disposal of and any other actions with respect to any hazardous substances at, on, in, under, or emanating from the Purchased Assets. GCERG, at its discretion, plans to redevelop the property in an environmentally conscious manner that will expand economic activity and benefit the surrounding communities, as well as restore the property to a state that will enable it to be put to its best potential use. The existing power plant is being demolished, and GCERG is working with the Texas Commission on Environmental Quality to complete all environmental remediation required for the property and then plans to redevelop the remediated property within all zoning restrictions. The redevelopment of the property is expected to be completed within 34 months from the date of acquisition. The assets acquired and liabilities assumed as recognized within the Company's Consolidated Balance Sheet upon closing on the APA consisted of the following: Consideration and direct transaction costs: Asset retirement obligations $ (50,590) Bond and insurance accrued expenses, net (2,229) Direct transaction costs (2,336) Total consideration and transaction costs incurred $ (55,155) Asset Received: Cash $ 6,354 Restricted cash 28,546 Water rights 5,196 Land 14,385 Plant, machinery and equipment 610 Vehicles 64 Total allocated value of assets acquired $ 55,155 A summary of the other assumptions included in the fair value measurement of the asset retirement obligations to be recognized upon closing of the APA consisted of the following: Other Assumptions: Inflation rate 3.00 % Weighted average rate applicable to our long-term asset retirement obligations 4.50 % Demolition costs will be capitalized as part of the land as incurred as part of preparing the site for sale since, at the acquisition date, (i) we planned to demolish the existing structure as part of the redevelopment plan for the acquired property, (ii) demolition is expected to occur within a reasonable period of time after the acquisition, and (iii) such expected costs will be incurred to make the land saleable to a third party. As part of the acquisition, the Company acquired certain plant, machinery and equipment and vehicles for which management committed to a plan to sell. Property and equipment of $193 that was initially classified as held for sale was subsequently sold to third parties.

Balance Sheet Items

Balance Sheet Items	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Items	Balance Sheet Items Property and equipment, net The following table shows the components of property and equipment, net: December 31, 2022 2021 Plant, machinery and equipment $ 60,377 $ 63,937 Structural fill site improvements 55,760 55,760 Vehicles 11,619 11,718 Office equipment 600 600 Buildings and leasehold improvements 267 267 Land, land improvements and structural fill sites 44,790 12,231 Finance lease assets 49,306 31,172 Construction in progress — 1,522 Total property and equipment $ 222,719 $ 177,207 Less: accumulated depreciation (128,779) (106,734) Property and equipment, net $ 93,940 $ 70,473 Land, land improvements and structural fill sites include $19,107 of real property acquired in the asset acquisitions discussed in Note 5 that the Company is actively demolishing and for which depreciation expense is not being recorded. During the year ended December 31, 2022, the Company capitalized $3,129 of demolition costs and sold scrap with a cost basis of $2,679. Depreciation expense for the years ended December 31, 2022, 2021, and 2020 was $19,363, $16,718, and $17,659, respectively. Impairment of Long-Lived Assets Other than Goodwill and Intangible Assets Long-lived assets other than goodwill and indefinite-lived intangible assets, held and used by the Company, including inventory and property and equipment, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. The Company evaluates the recoverability of assets to be held and used by comparing the carrying amount of an asset to the future net undiscounted cash flows expected to be generated by the asset to determine if the carrying value is not recoverable. If the carrying value is not recoverable, the Company fair values the asset and compares that fair value to the carrying value. If the asset is considered to be impaired, the impairment loss is measured as the amount by which the carrying amount of the asset exceeds its fair value. During the year ended December 31, 2022, the Company determined that a triggering event occurred that indicated that the carrying value of certain long-lived assets may not be recoverable. The Company determined that the discounted future cash flows were less that the carrying value of the asset group, indicating impairment. The fair value of the assets was determined through a market approach using the net realizable value of the assets, which indicated that certain assets were impaired that resulted in an impairment charge of $10,484. The long-lived assets impaired had a remaining fair value of $20,003 as of December 31, 2022. During the year ended December 31, 2021, the Company determined that a triggering event occurred that indicated that the carrying value of certain remaining grinding technology-related equipment may not be recoverable. The fair value of the assets was determined through a market approach using the net realizable value of the assets, which indicated that the assets were impaired and resulted in an impairment charge of $673. The long-lived assets impaired had no remaining fair value as of December 31, 2021. During the year ended December 31, 2020, as a result of the expiration of the option as discussed below, the Company determined that a triggering event had occurred that indicated that the asset group may not be recoverable as the option expiration led to a significant adverse change in the manner in which the long-lived asset was being used. The Company evaluated the recoverability of the structural fill site assets to be held and used by comparing the carrying amount of the asset group to the future net undiscounted cash flows expected to be generated to determine if the carrying value is not recoverable. The recoverability test indicated that these assets were not recoverable. The fair value of the assets was determined using an income approach of the discounted cash flows expected from the assets and compared to the assets' carrying value, which indicated that the assets were impaired and resulted in an impairment charge. The Company recognized an impairment During the year ended December 31, 2020, as a result of a significant adverse change in the manner in which the long-lived assets were being used, the Company determined that certain grinding technology-related equipment and construction in progress assets were no longer viable as certain performance sales levels would not be achieved. We concluded that a triggering event had occurred that indicated that the asset group may not be recoverable. The fair value of the assets was determined through a market approach using the net realizable value of the assets, which indicated that the assets were impaired and resulted in an impairment charge. The Company recognized an impairment charge of $9,150. During the year ended December 31, 2020, in connection with the impairment of certain grinding technology equipment and construction in progress assets, the Company determined that certain slow-moving inventory stored at two locations would no longer be used to create finished goods through the use of the previously mentioned technology-related equipment and would be sold to external parties. We concluded that a triggering event had occurred that the inventory value may not be recoverable. The fair value was determined through a market approach using the net realizable value of the inventory, which indicated that the assets were impaired and resulted in an impairment charge. The Company recognized an impairment charge of $2,757, which was recorded in cost of sales in the Consolidated Statement of Operations. As of December 31, 2022 and 2020, the inventory impaired during the year ended December 31, 2020 had a remaining fair value of $8 and $1,090, respectively. Sales-type lease In March 2021, the Company amended an existing ground lease with a third party concerning one of the Company's structural fill assets with a 30-year term expiring on December 31, 2050. The lease includes multiple options that may be exercised at any time during the lease term for the lessee to purchase all or a portion of the premises, as well as a put option (the “Put Option”) that provides the Company the option to require the lessee to purchase all of the premises at the end of the lease term. In accordance with ASC 840 and ASC 842, Leases , the Company considered whether this lease, as amended, met any of the following four criteria as part of classifying the lease at the amendment date: (a) the lease transfers ownership of the property to the lessee by the end of the lease term; (b) the lease contains a bargain purchase option; (c) the lease term is equal to 75 percent or more of the estimated economic life of the lease property; and (d) the present value of the minimum lease payments, excluding executory costs, equals or exceeds 90 percent of the excess of the fair value of the lease property to the lessor at lease inception. This lease was recorded as a sales-type finance lease due to the Put Option provision contained within the lease agreement that represents a transfer of ownership of the property by the end of the lease term. Additionally, the Company determined that collectability of the lease payments was reasonably assured and that there were not any significant uncertainties related to costs that it has yet to incur with respect to the lease. At the amendment date of the lease, a discount rate of 3.9% implicit in the sales-type lease was used to calculate the present value of the minimum lease payments, which the Company recorded as a lease receivable. The Company recognized a gain of $5,568 within operating income in the Consolidated Statements of Operations. The following table reflects the classification of the lease receivable within our Consolidated Balance Sheet: December 31, 2022 Lease receivable $ 5,872 Less: current portion in prepaid expenses and other current assets (68) Non-current portion in other assets $ 5,804 Asset sale agreement In June 2021, the Company consummated an asset sale with an unrelated third party in which the Company assigned a lease agreement to the purchaser and sold certain grinding-related inventory and fixed assets for an aggregate sale price of $2,852. The Company received $1,250 in cash at closing, with the remaining portion to be paid over time on specified dates, with the final payment to be received 36 months from the closing date. The following table reflects the classification of the note receivable within our Consolidated Balance Sheet: December 31, 2022 Note receivable $ 852 Less: current portion in prepaid expenses and other current assets (500) Non-current portion in other assets $ 352 Accrued liabilities The following table shows the components of accrued liabilities: December 31, 2022 2021 Accrued expenses $ 17,022 $ 25,074 Accrued payroll and bonuses 5,732 7,798 Accrued preferred stock dividends 689 1,994 Accrued interest 2,853 2,008 Accrued liabilities $ 26,296 $ 36,874 Contingent payments for acquisitions The following table presents the changes in the contingent payments for acquisitions: December 31, 2022 2021 Balance, beginning of period $ 1,950 $ 1,950 Add: interest accreted on contingent payments for acquisition — — Less: gain on change in contingent payment liability — — Balance, end of period $ 1,950 $ 1,950 On March 30, 2018, Charah Management completed a transaction with SCB Materials International, Inc. and affiliated entities (“SCB”), a previously unrelated third party, pursuant to which Charah Solutions acquired certain assets and liabilities of SCB for a purchase price of $35,000, with $20,000 paid at closing and $15,000 to be paid over time in conjunction with certain performance metrics. The contract also contained various mechanisms for a working capital true-up. The acquisition was accounted for under the acquisition method of accounting in accordance with ASC 805, Business Combinations , (“ASC 805”) with the allocation of the purchase price for the acquisition finalized as of March 31, 2019 with the recognized goodwill allocated to the Consolidated Balance Sheets. In November 2018, the $15,000 to be paid over time was reduced by $3,300. As previously discussed and as further discussed in Note 9, during the year ended December 31, 2020, the Company evaluated the recoverability of certain grinding technology assets. As part of that review, we assessed the likelihood of paying the contingent liability based on achieving certain performance sales levels using these technology assets. The Company concluded that certain sales levels would not be achieved, and we reduced the corresponding liability by $9,702 and this reduction was recognized as a component of operating (loss) income in the Consolidated Statement of Operations. As of December 31, 2022, the remaining liability balance of $1,950 is expected to be paid after 2022.

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2022
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligation	Asset Retirement Obligations The Company owns two structural fill sites with continuing maintenance and monitoring requirements after their closure, one wastewater treatment facility with continuing maintenance and monitoring requirements, and eight tracts of real property with decommissioning, remediation and monitoring requirements. As of December 31, 2022 and 2021, the Company has accrued $68,561 and $42,413, respectively, for the asset retirement obligations ( “ ARO ” ). Structural Fill Site ARO Asset retirement activities and our related accounting for this ARO are as follows: • Final capping and closure involve the installation of drainage and compacted soil layers and topsoil over areas where total airspace capacity has been consumed. Asset retirement obligations are recorded on a units-of-consumption basis as airspace is consumed. The liability is based on estimates of the discounted cash flows. • Post closure involves the maintenance and monitoring of the structural fill sites. Generally, we are required to maintain and monitor the structural fill sites for a 30-year period. These maintenance and monitoring costs are recorded as an asset retirement obligation as airspace is consumed over the life of the structural fill sites. Post-closure obligations are recorded over the life of the structural fill sites on a units-of-consumption basis as airspace is consumed, based on estimates of the discounted cash flows associated with performing post-closure activities. We develop our estimates of these obligations using input from our operations personnel. Our estimates are based on our interpretation of current requirements and proposed regulatory changes and are intended to approximate fair value. Absent quoted market prices, the estimate of fair value is based on the best available information, including the results of present value techniques. We use professional engineering judgment and estimated prices paid for similar work to determine the fair value of these obligations. We are required to recognize these obligations at market prices whether we plan to contract with third parties or perform the work ourselves. In those instances where we perform the work with internal resources, the incremental profit margin realized will be recognized as a component of operating income when the work is completed. Once we determined the final capping, closure, and post-closure costs, we inflated those costs to the expected time of payment and discount those expected future costs back to present value using an inflation rate of 3.0%. We discounted these costs to present value using the credit-adjusted, risk-free rate effective of 5.25% at the time an obligation was incurred, consistent with the expected cash flow approach. We record the estimated fair value of final capping, closure, and post-closure liabilities for our structural fill sites based on the capacity consumed through the current period. Because these obligations are measured at estimated fair value using present value techniques, changes in the estimated cost or timing of future final capping, closure, and post-closure activities could result in a material change in these liabilities, related assets, and results of operations. We assess the appropriateness of the estimates used to develop our recorded balances annually, or more often if conditions warrant. Real Estate AROs The Company acquired certain real property through three separate asset acquisitions with decommissioning, remediation and monitoring requirements. Refer to Note 5, Asset Acquisitions, for asset retirement activities and our related accounting for these AROs. The following table reflects the activity for our asset retirement obligations: December 31, 2022 2021 Balance, beginning of period $ 42,413 $ 5,159 Liabilities incurred 64,479 50,590 Liabilities settled (37,901) (11,725) Accretion 4,359 2,012 Gain on ARO settlement, net (4,789) (3,623) Balance, end of period 68,561 42,413 Less: current portion (37,982) (27,534) Non-current portion $ 30,579 $ 14,879 During the years ended December 31, 2022 and 2021, the Company recognized a gain on ARO settlement, net of $4,789 and $3,623, respectively, representing differences between the estimated costs used in the measurement of the fair value of the Company's AROs and the actual expenditures incurred for specific remediation tasks performed during the year. During the year ended December 31, 2020, after the expiration of the option and the impairment of the structural fill site assets in August 2020 as discussed above, the Company performed a review of the asset retirement obligation to determine if there had been changes in the estimated amount or timing of cash flows. The Company identified a downward adjustment of

Distributions to Stockholders,

Distributions to Stockholders, Receivable from Affiliates, and Related Party Transactions	12 Months Ended
	Dec. 31, 2022
Related Party Transactions [Abstract]
Distributions to Stockholders, Receivable from Affiliates, and Related Party Transactions	Distributions to Stockholders, Receivable from Affiliates, and Related Party Transactions ATC Group Services LLC (“ATC”), an entity owned by BCP, our majority stockholder, provided environmental consulting and engineering services at certain service sites. Expenses to ATC were $55, $100, and $288, during the years ended December 31, 2022, 2021, and 2020, respectively. The Company had no receivables outstanding from ATC at December 31, 2022 and 2021. The Company had payables and accrued expenses, net of credit memos, due to ATC of $14 and $4 at December 31, 2022 and 2021, respectively. As further discussed in Note 10, Long-term Debt, in August 2021, the Company completed an offering of $135,000, in the aggregate, of the Notes, which amount included the exercise by the underwriters of their option to purchase an additional $5,000 aggregate principal amount of Notes. B. Riley Securities, Inc. (“B. Riley”), a shareholder of the Company with board representation, served as the lead book-running manager and underwriter for this offering, purchasing a principal amount of $80,325 of the Notes. Fees paid to B. Riley related to this offering were $7,914 for the year ended December 31, 2021. These fees were capitalized as debt issuance costs within notes payable, less current maturities in the Consolidated Balance Sheets and will be amortized prospectively through interest expense, net in the Consolidated Statements of Operations using the effective interest method through the maturity date of the Notes. In addition, Charah, LLC, a Kentucky limited liability company and indirect subsidiary of the Company, issued a promissory note in exchange for cash in favor of B. Riley Commercial Capital, LLC, an affiliate of B. Riley, evidencing a loan in aggregate principal amount of $17,852. The promissory note was repaid in full as of December 31, 2021. As further discussed in Note 3, in November 2020, the Company sold its Allied subsidiary to an affiliate of BCP. As further discussed in Note 13, in March 2020, the Company entered into an agreement with an investment fund affiliated with BCP to sell 26 (twenty-six thousand) shares of Series A Preferred Stock and, in November 2022, the Company entered into an investment agreement with BCP to sell 30 (thirty thousand) shares of Series B Preferred Stock.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill and indefinite-lived intangible assets are not amortized but instead are tested for impairment annually or more often if events or changes in circumstances indicate that the fair value of the asset may have decreased below its carrying value. We perform our impairment test effective October 1st of each year and evaluate for impairment indicators between annual impairment tests. Goodwill As of December 31, 2022 and 2021, goodwill was $62,193. We performed a quantitative assessment of the Company, which we concluded was a single reporting unit, as of October 1, 2022 and 2021 using a market approach, whereby the market capitalization of the Company was compared to its carrying value. The market capitalization was derived from the Company's publicly traded stock price. The fair value of the reporting unit exceeded its carrying value, and therefore, no impairment was recognized. Indefinite-Lived Intangible Asset Our intangible assets, net include a trade name that is considered to have an indefinite life. The Charah trade name fair value is based upon the income approach, primarily utilizing the relief-from-royalty methodology. This methodology assumes that, in lieu of ownership, a third party would be willing to pay a royalty in order to obtain the rights to use the comparable asset. An impairment loss is recognized when the estimated fair value of the intangible asset is less than the carrying value. The fair value calculation requires significant judgments in determining both the assets’ estimated cash flows as well as the appropriate discount and royalty rates applied to those cash flows to determine fair value. Variations in economic conditions or a change in general consumer demands, operating results estimates or the application of alternative assumptions could produce significantly different results. During the year ended December 31, 2022, we recorded an impairment $13,316 , primarily as a result of decreases in projected revenue, operating results and the royalty rate used in the valuation that was primarily attributable to the recent performance of the Company. During the year ended December 31, 2020, we recorded an impairment Definite-Lived Intangible Assets Definite-lived intangible assets were comprised of our customer relationships. Amortization expense of def inite-lived intangible assets was $5,921, $7,894, and $8,582 for the years ended December 31, 2022, 2021, and 2020, respectively. Long-lived assets, including definite-lived intangible assets are reviewed for impairment whenever certain triggering events may indicate impairment. In 2022, due to current-period operating losses and decline in market capitalization, we determined that a triggering event had occurred indicating it was more likely than not the fair value of the customer relationships definite-lived intangible assets were less than the associated carrying value. As a result of the Company’s continued poor financial performance, lack of profitability and negative projected cash flows, we determined that the customer relationships definite-lived intangible assets had no value. The Company recognized an impairment charge During the year ended December 31, 2020, as discussed in Note 6, the Company determined that certain technology- related equipment and construction in progress assets were no longer viable and recognized an impairment charge associated with those assets. As a result of this impairment, we concluded that a triggering event had occurred that indicated that the technology intangible asset group may not be recoverable. We determined that the technology intangible asset had no value since we will no longer be attempting to use the technology in construction equipment. The Company recognized an impairment The Company’s intangible assets consist of the following as of: December 31, 2022 December 31, 2021 Gross Carrying Amount Accumulated Amortization and Impairment Net Carrying Amount Gross Carrying Amount Accumulated Amortization and Impairment Net Carrying Amount Definite-lived intangibles Customer relationships $ 78,942 $ (78,942) $ — $ 78,942 $ (38,727) $ 40,215 Indefinite-lived intangibles Charah trade name 13,316 (13,316) — 13,316 — 13,316 Total $ — $ 53,531

Long-term Debt

Long-term Debt	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Long-term Debt	Long-term Debt Senior Notes On August 25, 2021, the Company completed an offering of $135,000, in the aggregate, of the Company’s Notes, which amount includes the exercise by the underwriters of their option to purchase an additional $5,000 aggregate principal amount of Notes. The Notes were issued pursuant to the First Supplemental Indenture (the “First Supplemental Indenture”), dated as of August 25, 2021, between the Company and Wilmington Savings Fund Society, FSB, as trustee (the “Trustee”). The First Supplemental Indenture supplements the Indenture entered into by and between the Company and the Trustee, dated as of August 25, 2021 (the “Base Indenture” and, together with the First Supplemental Indenture, the “Indenture”). The public offering price of the Notes was 100.0% of the principal amount. The Company received proceeds before payment of expenses and other fees of $135,000. The Company used the proceeds, along with cash from the issuance of $13,000 of common stock, to fully repay and terminate the Company’s Credit Facility, as defined below. The Notes bear interest at the rate of 8.50% per annum. Interest on the Notes is payable quarterly in arrears on January 31, April 30, July 31 and October 31 of each year, commencing October 31, 2021. The Notes will mature on August 31, 2026. The Company may redeem the Notes for cash in whole or in part at any time (i) on or after August 31, 2023 and prior to August 31, 2024, at a price equal to 103% of their principal amount, plus accrued and unpaid interest to, but excluding, the date of redemption, (ii) on or after August 31, 2024 and prior to August 31, 2025, at a price equal to 102% of their principal amount, plus accrued and unpaid interest to, but excluding, the date of redemption, and (iii) on or after August 31, 2025 and prior to maturity, at a price equal to 100% of their principal amount, plus accrued and unpaid interest to, but excluding, the date of redemption. On and after any redemption date, interest will cease to accrue on the redeemed Notes. The Indenture also contains customary event of default and cure provisions. If an uncured default occurs and is continuing, the Trustee or the holders of not less than 25% in aggregate principal amount of the Notes may declare the Notes to be immediately due and payable. The Notes are senior unsecured obligations of the Company and rank equal in right of payment with the Company’s existing and future senior unsecured indebtedness. As a result of the issuance of the Notes, $12,116 of third-party fees were capitalized as debt issuance costs that will be amortized through interest expense, net in the Consolidated Statements of Operations using the effective interest method through the maturity date of the Notes. Asset-Based Lending Credit Agreement On November 9, 2021, the Company entered into a new Credit Agreement with JPMorgan Chase Bank, N.A. (“JPMorgan”), as administrative agent, the lenders party thereto and certain subsidiary guarantors named therein. The Credit Agreement provides for a four-year senior secured revolving credit facility with initial aggregate commitments from the lenders of $30,000, which includes $5,000 available for swingline loans, plus an additional $5,000 of capacity available for the issuance of letters of credit if supported by cash collateral provided by the Company (with a right to increase such amount by up to an additional $5,000) (“Aggregate Revolving Commitments”). Availability under the Credit Agreement is subject to a borrowing base calculated based on the value of certain eligible accounts receivable, inventory, and equipment of the Company and subject to redeterminations made in good faith and in the exercise of permitted discretion of JPMorgan. Proceeds of the Credit Agreements may be used for working capital and general corporate purposes. The Credit Agreement provides for borrowings of either base rate loans or Eurodollar loans. Principal amounts borrowed are payable on the maturity date with such borrowings bearing interest that is payable (i) with respect to base rate loans, monthly and (ii) with respect to Eurodollar loans, the last day of each Interest Period (as defined below); provided that if any Interest Period for a Eurodollar loan exceeds three months, interest will be payable on the respective dates that fall every three months after the beginning of such Interest Period. Eurodollar Loans bear interest at a rate per annum equal to the Adjusted LIBOR for one, three or six months (the “Interest Period”), plus an applicable margin of 2.25%. Base rate loans bear interest at a rate per annum equal to the greatest of (i) the agent bank’s reference rate, (ii) the federal funds effective rate plus 50 basis points and (iii) the rate for one month Adjusted LIBOR loans plus 100 basis points, plus an applicable rate of 125 basis points. The Credit Agreement contains a provision for sustainability adjustments annually that will impact the applicable margin by between positive 0.05% and negative 0.05% based on the achievement, or lack thereof, of certain metrics agreed upon between JPMorgan and the Company and publicly reported through the Company’s annual non-financial sustainability report. The Credit Agreement is guaranteed by certain of the Company’s subsidiaries and is secured by substantially all of the Company’s and such subsidiaries’ assets. The Credit Agreement contains customary restrictive covenants for asset-based loans that may limit the Company’s ability to, among other things: incur additional indebtedness, sell assets, make loans to others, make investments, enter into mergers, make certain restricted payments, incur liens, and engage in certain other transactions without the prior consent of the lenders. A covenant testing period (“Covenant Testing Period”) is a period in which excess availability (which is defined in the Credit Agreement as the sum of availability and an amount up to $1,000), is less than the greater of (a) 12.5% of the lesser of the aggregate revolving commitments and the borrowing base, (b) the lesser of $7,500 and the PP&E Component as defined in the Credit Agreement, and (c) $3,500, for three consecutive business days. During a Covenant Testing Period, the Credit Agreement requires the Company to maintain a fixed charge coverage ratio as defined in the Credit Agreement, determined for any period of twelve (12) consecutive months ending on the last day of each fiscal quarter, of at least 1.00 to 1.00. As of December 31, 2022, the Company had no borrowings outstanding on the Credit Agreement. Outstanding letters of credit were $10,687 as of December 31, 2022. As a result of entering into the Credit Agreement, $1,366 of third-party fees were capitalized as debt issuance costs that will be amortized through interest expense, net in the Consolidated Statements of Operations using the effective interest method through the maturity date of the Credit Agreement. On April 28, 2023, the Company entered into Consent and Amendment No. 3 to Credit Amendment ("Amendment No. 3") that, among other things, (i) provides consent to the Merger Agreement (as defined elsewhere herein), subject to certain conditions, provided that it occurs before October 16, 2023, is materially consistent with the terms of the Merger Agreement and related documents, and no event of default, as defined within the Credit Agreement, has occurred or will result from the acquisition; (ii) amends the definition of Progress Billings Cap Amount to be used in certain borrowing base certificates; (iii) amends the definition of the Applicable Rate; (iv) changes the maturity date from November 9, 2025 to January 31, 2024; and (v) consents to an extension of the deadline for certain financial deliverables for the fiscal year ended December 31, 2022. Term Loan Agreement On August 15, 2022, the Company, through its GCERG subsidiary (the “Term Loan Borrower”), entered into a term loan agreement (the “Term Loan Agreement”) with Charah Preferred Stock Aggregator, LP, an affiliate of Bernhard Capital Partners Management, LP (“BCP”). As a result of unexpected operating losses, an increase in contract assets and accelerated cash outflows for remediation activities on an ERT project that led to a decrease in cash during the six months ended June 30, 2022, the Company sought additional financing options to fund ongoing operations and project level investment. The Term Loan Agreement was executed to provide additional liquidity for the Company and accelerate the timing of the Company's cash flows for anticipated sales of the GCERG real estate parcels. The Term Loan Agreement provides for a delayed-draw term loan in an aggregate principal amount of $20,000. The Term Loan Agreement is scheduled to mature on the earlier of the sale of the remaining GCERG real estate parcels or April 15, 2024. The Company elected to draw down the full borrowing capacity available under the Term Loan Agreement by November 8, 2022 through separate funding requests in order to fund operating activities. Borrowings under the Term Loan Agreement accrue interest at a percentage per annum equal to 12.0%, with interest payments due on the first business day of each calendar quarter following the effective date of the Term Loan Agreement and on the maturity date. The Term Loan Borrower agreed to pay a commitment fee equal to $1,000 that is payable on the earliest of (i) April 15, 2024, (ii) the date on which the loans are redeemed in full and all commitments are terminated and (iii) the date on which all commitments are terminated in full. The Term Loan Agreement is secured by a lien on, and security interest in, substantially all of the Term Loan Borrower’s assets, including real property, and is guaranteed on an unsecured basis by the Company and Charah, LLC. Voluntary prepayments are permitted at any time, without premium or penalty. The Term Loan Agreement contains certain customary representations and warranties and affirmative and negative covenants. The negative covenants include, subject to customary exceptions, limitations on indebtedness, investments and acquisitions, mergers and consolidations, restricted payments, transactions with affiliates, liens and dispositions. The Term Loan Agreement allows the Term Loan Borrower to make distributions to its equity holders with the proceeds of the loans made thereunder. The Term Loan Agreement contains customary events of default. If an event of default occurs and is continuing, the lenders may declare all loans to be immediately due and payable. As a result of entering into the Term Loan Agreement, $598 of third-party fees were capitalized as debt issuance costs that will be amortized through interest expense, net in the consolidated statements of operations using the effective interest method through the maturity date of the Term Loan Agreement. On April 16, 2023, the Company entered into Amendment No. 2 to the Term Loan Amendment that, among other things, (i) waives the mandatory prepayment provisions with respect to certain asset sale proceeds, (ii) joins certain subsidiaries of the Company as guarantors under Term Loan Agreement, and (iii) consents to an extension of the deadline for certain financial deliverables for the fiscal year ended December 31, 2022. In connection with the Term Loan Amendment, ALERG, Cheswick Lefever LLC and Cheswick Plant Environmental Redevelopment Group LLC (collectively, the “Grantors”) entered in to a security agreement, dated as of April 16, 2023, with Charah Preferred Stock Aggregator, LP, an affiliate of BCP, as the secured party (the “Secured Party”), pursuant to which the Grantors granted liens over substantially all of their assets in favor of the Secured Party. Previous Credit Facility On September 21, 2018, we entered into a credit agreement (the “Credit Facility”) by and among us, the lenders party thereto from time to time and Bank of America, N.A., as administrative agent (the “Administrative Agent”). The Credit Facility included: • A revolving loan not to exceed $50,000 (the “Revolving Loan”); • A term loan of $205,000 (the “Closing Date Term Loan”); and • A commitment to loan up to a further $25,000 in term loans, which expired in March 2020 (the “Delayed Draw Commitment” and the term loans funded under such Delayed Draw Commitment, the “Delayed Draw Term Loan,” together with the Closing Date Term Loan, the “Term Loan”). Pursuant to the terms of the Credit Facility and its related amendments, all amounts associated with the Revolving Loan and the Term Loan under the Credit Facility were set to mature in July 2022. The interest rates per annum applicable to the loans under the Credit Facility were based on a fluctuating rate of interest measured by reference to, at our election, either (i) the Eurodollar rate, currently LIBOR, or (ii) an alternative base rate. Various margins were added to the interest rate based upon our consolidated net leverage ratio (as defined in the Credit Facility). Customary fees were payable regarding the Credit Facility and included (i) commitment fees for the unused portions of the Credit Facility and (ii) fees on outstanding letters of credit. Amounts borrowed under the Credit Facility were secured by substantially all of the assets of the Company. The Credit Facility contained various customary representations, warranties, restrictive covenants, certain affirmative covenants, including reporting requirements, and customary events of default. Outstanding letters of credit under the previous Credit Facility were $11,079 as of December 31, 2020. During the year ended December 31, 2021, using the proceeds from the Notes, along with cash from the issuance of $13,000 of common stock, to fully repay and terminate the Credit Facility, the Company paid $114,123 of outstanding principal on the Closing Date Loan and $12,340 of outstanding loans on the Revolver. Further, the Company paid $2,000 of previously accrued fees required as consideration for Amendment No. 3 to Credit Agreement that was otherwise due and payable on the maturity date. During the year ended December 31, 2021, the Company wrote off unamortized debt issuance costs of $638 as a result of extinguishment of debt , which is included in loss on extinguishment of debt in the Consolidated Statements of Operations. The following table summarizes the significant components of debt at each balance sheet date and provides maturities and interest rate ranges for each major category as of December 31, 2022 and 2021: December 31, 2022 2021 Various equipment notes entered into in November 2017, payable in monthly installments ranging from $6 to $24, including interest at 5.2%, maturing in December 2022 through December 2023. The notes are secured by equipment with a net book value of $0 as of December 31, 2022. $ 565 $ 1,748 Various equipment notes entered into in 2018, payable in monthly installments ranging from $1 to $39, including interest ranging from 5.6% to 6.8%, maturing in March 2023 through May 2025. The notes are secured by equipment with a net book value of $3,469 as of December 31, 2022. 3,818 5,952 Various equipment notes entered into in 2019, payable in monthly installments ranging from $2 to $23, including interest ranging from 3.9% to 6.4%, maturing in April 2021 through December 2024. The notes are secured by equipment with a net book value of $1,295 as of December 31, 2022. 1,748 2,633 Various equipment notes entered in 2020, payable in monthly installments ranging from $9 to $10, including interest of 5.4%, maturing in August and September 2025. The notes are secured by equipment with a net book value of $1,098 as of December 31, 2022. 1,215 1,624 Various equipment notes entered into in 2021, payable in monthly installments ranging from $3 to $9, including interest ranging from 4.0% to 6.5%, maturing in February 2026 through August 2026. The notes are secured by equipment with a net book value of $1,696 as of December 31, 2022. 1,484 1,861 An equipment note entered into in 2022 with a customer, payable in monthly installments of $68 with no interest component, maturing with a balloon payment of the remaining outstanding balance in April 2023. The note is secured by equipment with a net book value of $3,784 as of December 31, 2022. 3,784 — Various commercial insurance premium financing agreements entered into in 2021, payable in monthly installments ranging from $24 to $117, including interest ranging from 3.0% to 3.9%, maturing in October 2021 through April 2022. — 467 Various commercial insurance premium financing agreements entered into in 2022, payable in monthly installments ranging from $19 to $143, including interest ranging from 4.2% to 5.3%, maturing in November 2022 through June 2023. 592 — A $10,000 equipment line with a bank, entered into in December 2017, secured by all equipment purchased with the proceeds of the loan. Interest is calculated on any outstanding amounts using a fixed rate of 4.5%. The equipment line converted to a term loan in September 2018, with a maturity date of June 22, 2023. The term loan is secured by equipment with a net book value of $459 as of December 31, 2022. 1,003 3,387 Term Loan Agreement, issued August 2022, and related amendments (see Note 10). After consideration of the amendment, the Term Loan Agreement bears interest at 12.0%, matures in April 2024 and is secured by land and land improvements with a book value of $13,404. 20,000 — Senior Unsecured Notes, issued August 2021 (see Note 10). The Notes are senior unsecured obligations of the Company, bearing stated interest at 8.50%, and rank equal in right of payment with the Company’s existing and future senior unsecured indebtedness. 135,000 135,000 Total 169,209 152,672 Less debt issuance costs (9,976) (11,444) 159,233 141,228 Less current maturities (9,649) (7,567) Notes payable due after one year $ 149,584 $ 133,661 Future maturities of notes payable at December 31 are as follows: For the Year Ending December 31, 2023 $ 9,649 2024 23,226 2025 1,122 2026 135,212 Total $ 169,209

Notes Payable

Notes Payable	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Notes Payable	Long-term Debt Senior Notes On August 25, 2021, the Company completed an offering of $135,000, in the aggregate, of the Company’s Notes, which amount includes the exercise by the underwriters of their option to purchase an additional $5,000 aggregate principal amount of Notes. The Notes were issued pursuant to the First Supplemental Indenture (the “First Supplemental Indenture”), dated as of August 25, 2021, between the Company and Wilmington Savings Fund Society, FSB, as trustee (the “Trustee”). The First Supplemental Indenture supplements the Indenture entered into by and between the Company and the Trustee, dated as of August 25, 2021 (the “Base Indenture” and, together with the First Supplemental Indenture, the “Indenture”). The public offering price of the Notes was 100.0% of the principal amount. The Company received proceeds before payment of expenses and other fees of $135,000. The Company used the proceeds, along with cash from the issuance of $13,000 of common stock, to fully repay and terminate the Company’s Credit Facility, as defined below. The Notes bear interest at the rate of 8.50% per annum. Interest on the Notes is payable quarterly in arrears on January 31, April 30, July 31 and October 31 of each year, commencing October 31, 2021. The Notes will mature on August 31, 2026. The Company may redeem the Notes for cash in whole or in part at any time (i) on or after August 31, 2023 and prior to August 31, 2024, at a price equal to 103% of their principal amount, plus accrued and unpaid interest to, but excluding, the date of redemption, (ii) on or after August 31, 2024 and prior to August 31, 2025, at a price equal to 102% of their principal amount, plus accrued and unpaid interest to, but excluding, the date of redemption, and (iii) on or after August 31, 2025 and prior to maturity, at a price equal to 100% of their principal amount, plus accrued and unpaid interest to, but excluding, the date of redemption. On and after any redemption date, interest will cease to accrue on the redeemed Notes. The Indenture also contains customary event of default and cure provisions. If an uncured default occurs and is continuing, the Trustee or the holders of not less than 25% in aggregate principal amount of the Notes may declare the Notes to be immediately due and payable. The Notes are senior unsecured obligations of the Company and rank equal in right of payment with the Company’s existing and future senior unsecured indebtedness. As a result of the issuance of the Notes, $12,116 of third-party fees were capitalized as debt issuance costs that will be amortized through interest expense, net in the Consolidated Statements of Operations using the effective interest method through the maturity date of the Notes. Asset-Based Lending Credit Agreement On November 9, 2021, the Company entered into a new Credit Agreement with JPMorgan Chase Bank, N.A. (“JPMorgan”), as administrative agent, the lenders party thereto and certain subsidiary guarantors named therein. The Credit Agreement provides for a four-year senior secured revolving credit facility with initial aggregate commitments from the lenders of $30,000, which includes $5,000 available for swingline loans, plus an additional $5,000 of capacity available for the issuance of letters of credit if supported by cash collateral provided by the Company (with a right to increase such amount by up to an additional $5,000) (“Aggregate Revolving Commitments”). Availability under the Credit Agreement is subject to a borrowing base calculated based on the value of certain eligible accounts receivable, inventory, and equipment of the Company and subject to redeterminations made in good faith and in the exercise of permitted discretion of JPMorgan. Proceeds of the Credit Agreements may be used for working capital and general corporate purposes. The Credit Agreement provides for borrowings of either base rate loans or Eurodollar loans. Principal amounts borrowed are payable on the maturity date with such borrowings bearing interest that is payable (i) with respect to base rate loans, monthly and (ii) with respect to Eurodollar loans, the last day of each Interest Period (as defined below); provided that if any Interest Period for a Eurodollar loan exceeds three months, interest will be payable on the respective dates that fall every three months after the beginning of such Interest Period. Eurodollar Loans bear interest at a rate per annum equal to the Adjusted LIBOR for one, three or six months (the “Interest Period”), plus an applicable margin of 2.25%. Base rate loans bear interest at a rate per annum equal to the greatest of (i) the agent bank’s reference rate, (ii) the federal funds effective rate plus 50 basis points and (iii) the rate for one month Adjusted LIBOR loans plus 100 basis points, plus an applicable rate of 125 basis points. The Credit Agreement contains a provision for sustainability adjustments annually that will impact the applicable margin by between positive 0.05% and negative 0.05% based on the achievement, or lack thereof, of certain metrics agreed upon between JPMorgan and the Company and publicly reported through the Company’s annual non-financial sustainability report. The Credit Agreement is guaranteed by certain of the Company’s subsidiaries and is secured by substantially all of the Company’s and such subsidiaries’ assets. The Credit Agreement contains customary restrictive covenants for asset-based loans that may limit the Company’s ability to, among other things: incur additional indebtedness, sell assets, make loans to others, make investments, enter into mergers, make certain restricted payments, incur liens, and engage in certain other transactions without the prior consent of the lenders. A covenant testing period (“Covenant Testing Period”) is a period in which excess availability (which is defined in the Credit Agreement as the sum of availability and an amount up to $1,000), is less than the greater of (a) 12.5% of the lesser of the aggregate revolving commitments and the borrowing base, (b) the lesser of $7,500 and the PP&E Component as defined in the Credit Agreement, and (c) $3,500, for three consecutive business days. During a Covenant Testing Period, the Credit Agreement requires the Company to maintain a fixed charge coverage ratio as defined in the Credit Agreement, determined for any period of twelve (12) consecutive months ending on the last day of each fiscal quarter, of at least 1.00 to 1.00. As of December 31, 2022, the Company had no borrowings outstanding on the Credit Agreement. Outstanding letters of credit were $10,687 as of December 31, 2022. As a result of entering into the Credit Agreement, $1,366 of third-party fees were capitalized as debt issuance costs that will be amortized through interest expense, net in the Consolidated Statements of Operations using the effective interest method through the maturity date of the Credit Agreement. On April 28, 2023, the Company entered into Consent and Amendment No. 3 to Credit Amendment ("Amendment No. 3") that, among other things, (i) provides consent to the Merger Agreement (as defined elsewhere herein), subject to certain conditions, provided that it occurs before October 16, 2023, is materially consistent with the terms of the Merger Agreement and related documents, and no event of default, as defined within the Credit Agreement, has occurred or will result from the acquisition; (ii) amends the definition of Progress Billings Cap Amount to be used in certain borrowing base certificates; (iii) amends the definition of the Applicable Rate; (iv) changes the maturity date from November 9, 2025 to January 31, 2024; and (v) consents to an extension of the deadline for certain financial deliverables for the fiscal year ended December 31, 2022. Term Loan Agreement On August 15, 2022, the Company, through its GCERG subsidiary (the “Term Loan Borrower”), entered into a term loan agreement (the “Term Loan Agreement”) with Charah Preferred Stock Aggregator, LP, an affiliate of Bernhard Capital Partners Management, LP (“BCP”). As a result of unexpected operating losses, an increase in contract assets and accelerated cash outflows for remediation activities on an ERT project that led to a decrease in cash during the six months ended June 30, 2022, the Company sought additional financing options to fund ongoing operations and project level investment. The Term Loan Agreement was executed to provide additional liquidity for the Company and accelerate the timing of the Company's cash flows for anticipated sales of the GCERG real estate parcels. The Term Loan Agreement provides for a delayed-draw term loan in an aggregate principal amount of $20,000. The Term Loan Agreement is scheduled to mature on the earlier of the sale of the remaining GCERG real estate parcels or April 15, 2024. The Company elected to draw down the full borrowing capacity available under the Term Loan Agreement by November 8, 2022 through separate funding requests in order to fund operating activities. Borrowings under the Term Loan Agreement accrue interest at a percentage per annum equal to 12.0%, with interest payments due on the first business day of each calendar quarter following the effective date of the Term Loan Agreement and on the maturity date. The Term Loan Borrower agreed to pay a commitment fee equal to $1,000 that is payable on the earliest of (i) April 15, 2024, (ii) the date on which the loans are redeemed in full and all commitments are terminated and (iii) the date on which all commitments are terminated in full. The Term Loan Agreement is secured by a lien on, and security interest in, substantially all of the Term Loan Borrower’s assets, including real property, and is guaranteed on an unsecured basis by the Company and Charah, LLC. Voluntary prepayments are permitted at any time, without premium or penalty. The Term Loan Agreement contains certain customary representations and warranties and affirmative and negative covenants. The negative covenants include, subject to customary exceptions, limitations on indebtedness, investments and acquisitions, mergers and consolidations, restricted payments, transactions with affiliates, liens and dispositions. The Term Loan Agreement allows the Term Loan Borrower to make distributions to its equity holders with the proceeds of the loans made thereunder. The Term Loan Agreement contains customary events of default. If an event of default occurs and is continuing, the lenders may declare all loans to be immediately due and payable. As a result of entering into the Term Loan Agreement, $598 of third-party fees were capitalized as debt issuance costs that will be amortized through interest expense, net in the consolidated statements of operations using the effective interest method through the maturity date of the Term Loan Agreement. On April 16, 2023, the Company entered into Amendment No. 2 to the Term Loan Amendment that, among other things, (i) waives the mandatory prepayment provisions with respect to certain asset sale proceeds, (ii) joins certain subsidiaries of the Company as guarantors under Term Loan Agreement, and (iii) consents to an extension of the deadline for certain financial deliverables for the fiscal year ended December 31, 2022. In connection with the Term Loan Amendment, ALERG, Cheswick Lefever LLC and Cheswick Plant Environmental Redevelopment Group LLC (collectively, the “Grantors”) entered in to a security agreement, dated as of April 16, 2023, with Charah Preferred Stock Aggregator, LP, an affiliate of BCP, as the secured party (the “Secured Party”), pursuant to which the Grantors granted liens over substantially all of their assets in favor of the Secured Party. Previous Credit Facility On September 21, 2018, we entered into a credit agreement (the “Credit Facility”) by and among us, the lenders party thereto from time to time and Bank of America, N.A., as administrative agent (the “Administrative Agent”). The Credit Facility included: • A revolving loan not to exceed $50,000 (the “Revolving Loan”); • A term loan of $205,000 (the “Closing Date Term Loan”); and • A commitment to loan up to a further $25,000 in term loans, which expired in March 2020 (the “Delayed Draw Commitment” and the term loans funded under such Delayed Draw Commitment, the “Delayed Draw Term Loan,” together with the Closing Date Term Loan, the “Term Loan”). Pursuant to the terms of the Credit Facility and its related amendments, all amounts associated with the Revolving Loan and the Term Loan under the Credit Facility were set to mature in July 2022. The interest rates per annum applicable to the loans under the Credit Facility were based on a fluctuating rate of interest measured by reference to, at our election, either (i) the Eurodollar rate, currently LIBOR, or (ii) an alternative base rate. Various margins were added to the interest rate based upon our consolidated net leverage ratio (as defined in the Credit Facility). Customary fees were payable regarding the Credit Facility and included (i) commitment fees for the unused portions of the Credit Facility and (ii) fees on outstanding letters of credit. Amounts borrowed under the Credit Facility were secured by substantially all of the assets of the Company. The Credit Facility contained various customary representations, warranties, restrictive covenants, certain affirmative covenants, including reporting requirements, and customary events of default. Outstanding letters of credit under the previous Credit Facility were $11,079 as of December 31, 2020. During the year ended December 31, 2021, using the proceeds from the Notes, along with cash from the issuance of $13,000 of common stock, to fully repay and terminate the Credit Facility, the Company paid $114,123 of outstanding principal on the Closing Date Loan and $12,340 of outstanding loans on the Revolver. Further, the Company paid $2,000 of previously accrued fees required as consideration for Amendment No. 3 to Credit Agreement that was otherwise due and payable on the maturity date. During the year ended December 31, 2021, the Company wrote off unamortized debt issuance costs of $638 as a result of extinguishment of debt , which is included in loss on extinguishment of debt in the Consolidated Statements of Operations. The following table summarizes the significant components of debt at each balance sheet date and provides maturities and interest rate ranges for each major category as of December 31, 2022 and 2021: December 31, 2022 2021 Various equipment notes entered into in November 2017, payable in monthly installments ranging from $6 to $24, including interest at 5.2%, maturing in December 2022 through December 2023. The notes are secured by equipment with a net book value of $0 as of December 31, 2022. $ 565 $ 1,748 Various equipment notes entered into in 2018, payable in monthly installments ranging from $1 to $39, including interest ranging from 5.6% to 6.8%, maturing in March 2023 through May 2025. The notes are secured by equipment with a net book value of $3,469 as of December 31, 2022. 3,818 5,952 Various equipment notes entered into in 2019, payable in monthly installments ranging from $2 to $23, including interest ranging from 3.9% to 6.4%, maturing in April 2021 through December 2024. The notes are secured by equipment with a net book value of $1,295 as of December 31, 2022. 1,748 2,633 Various equipment notes entered in 2020, payable in monthly installments ranging from $9 to $10, including interest of 5.4%, maturing in August and September 2025. The notes are secured by equipment with a net book value of $1,098 as of December 31, 2022. 1,215 1,624 Various equipment notes entered into in 2021, payable in monthly installments ranging from $3 to $9, including interest ranging from 4.0% to 6.5%, maturing in February 2026 through August 2026. The notes are secured by equipment with a net book value of $1,696 as of December 31, 2022. 1,484 1,861 An equipment note entered into in 2022 with a customer, payable in monthly installments of $68 with no interest component, maturing with a balloon payment of the remaining outstanding balance in April 2023. The note is secured by equipment with a net book value of $3,784 as of December 31, 2022. 3,784 — Various commercial insurance premium financing agreements entered into in 2021, payable in monthly installments ranging from $24 to $117, including interest ranging from 3.0% to 3.9%, maturing in October 2021 through April 2022. — 467 Various commercial insurance premium financing agreements entered into in 2022, payable in monthly installments ranging from $19 to $143, including interest ranging from 4.2% to 5.3%, maturing in November 2022 through June 2023. 592 — A $10,000 equipment line with a bank, entered into in December 2017, secured by all equipment purchased with the proceeds of the loan. Interest is calculated on any outstanding amounts using a fixed rate of 4.5%. The equipment line converted to a term loan in September 2018, with a maturity date of June 22, 2023. The term loan is secured by equipment with a net book value of $459 as of December 31, 2022. 1,003 3,387 Term Loan Agreement, issued August 2022, and related amendments (see Note 10). After consideration of the amendment, the Term Loan Agreement bears interest at 12.0%, matures in April 2024 and is secured by land and land improvements with a book value of $13,404. 20,000 — Senior Unsecured Notes, issued August 2021 (see Note 10). The Notes are senior unsecured obligations of the Company, bearing stated interest at 8.50%, and rank equal in right of payment with the Company’s existing and future senior unsecured indebtedness. 135,000 135,000 Total 169,209 152,672 Less debt issuance costs (9,976) (11,444) 159,233 141,228 Less current maturities (9,649) (7,567) Notes payable due after one year $ 149,584 $ 133,661 Future maturities of notes payable at December 31 are as follows: For the Year Ending December 31, 2023 $ 9,649 2024 23,226 2025 1,122 2026 135,212 Total $ 169,209

Sale-leaseback Transaction

Sale-leaseback Transaction	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Sale-leaseback Transaction	Sale-leaseback TransactionIn November 2020, we entered into a sale-leaseback transaction whereby we sold and leased back plant, machinery and equipment and vehicles. The transaction met the requirements of a sale in accordance with ASC 606, and the lease is classified as a finance lease under Leases (Topic 842) as of December 31, 2022 and a capital lease under Leases (Topic 840) as of December 31, 2021 and 2022. Proceeds from the sale were $7,000, and the cost and related accumulated depreciation of the plant, machinery and equipment and vehicles of $9,841 and $3,302, respectively, were removed from the Consolidated Balance Sheet at the time of the sale. The $461 gain realized on the sale and $88 in loan origination fees incurred at the time of the sale were included in the lease asset that is being depreciated over the life of the lease (three years). The lease obligation of $2,128 is recorded within current liabilities in the Consolidated Balance Sheet as of December 31, 2022. The lease obligation of $2,357 and $2,128 is recorded within current and long-term liabilities, respectively, in the Consolidated Balance Sheet as of December 31, 2021. The proceeds from the sale were recorded within investing activities in the Consolidated Cash Flow Statements in the year ended December 31, 2020.

Mezzanine Equity

Mezzanine Equity	12 Months Ended
	Dec. 31, 2022
Temporary Equity Disclosure [Abstract]
Mezzanine Equity	Mezzanine Equity Series A Preferred Stock In March 2020, the Company entered into an agreement with an investment fund affiliated with BCP to sell 26 (twenty-six thousand) shares of Series A Preferred Stock, par value $0.01 per share (the “Series A Preferred Stock”), with an initial aggregate liquidation preference of $26,000, net of a 3% Original Issue Discount (“OID”) of $780 for net proceeds of $25,220 in a private placement (the “Series A Preferred Stock Offering”). Proceeds from the Series A Preferred Stock Offering are being used for liquidity and general corporate purposes. In connection with the issuance of the Series A Preferred Stock, the Company incurred direct expenses of $966, including financial advisory fees, closing costs, legal expenses and other offering-related expenses. The Series A Preferred Stock was initially recorded net of OID and direct expenses, which are being accreted through paid-in-capital as a deemed dividend from the date of issuance through the first possible known redemption date, March 16, 2023. As of December 31, 2022, the Company had accrued dividends of $1,170 associated with the Series A Preferred Stock, which was recorded at a fair value of $689 using unobservable information for similar items and is classified as a level 3 fair value measurement. Dividend Rights The Series A Preferred Stock ranks senior to the Company’s common stock with respect to dividend rights and rights on the distribution of assets in any voluntary or involuntary liquidation, dissolution or winding up of the affairs of the Company. The Series A Preferred Stock had an initial liquidation preference of $1 (one thousand dollars) per share. The holders of the Series A Preferred Stock are entitled to a cumulative dividend paid in cash at the rate of 10.0% per annum, payable on a quarterly basis. If we do not declare and pay a dividend to the holders of the Series A Preferred Stock, the dividend rate will increase to 13.0% per annum and the dividends are paid-in-kind by adding such amount to the liquidation preference. Upon meeting certain "specified payment conditions," the Company has the ability under the Asset-Based Lending Credit Agreement to pay cash dividends on the Series A Preferred Stock. However, the Company’s intention is to pay dividends in-kind for the foreseeable future. The dividend rate will increase to 16.0% per annum upon the occurrence and during the continuance of an event of default. As of December 31, 2022, the liquidation preference of the Series A Preferred Stock, inclusive of dividends in-kind, was $37,176. Conversion Features The Series A Preferred Stock is convertible at the option of the holders at any time on and subsequent to the three-month anniversary of the date of issuance into shares of common stock at a conversion price of $27.70 per share (the “Conversion Price”), which represents a 30% premium to the 20-day volume-weighted average price ended March 4, 2020. As of December 31, 2022, the maximum number of common shares that could be required to be issued if converted is 1,342 (one million three hundred forty-two thousand). The conversion rate is subject to the following customary anti-dilution and other adjustments: • the issuance of common stock as a dividend or the subdivision, combination, or reclassification of common stock into a greater or lesser number of shares of common stock; • the dividend, distribution or other issuance of rights, options or warrants to holders of common stock entitling them to subscribe for or purchase shares of common stock at a price per share that is less than the market value for such issuance; • the issuance of a dividend or similar distribution in-kind, which can include shares of any class of capital stock, evidences of the Company’s indebtedness, assets or other property or securities, to holders of common stock; • a transaction in which a subsidiary of the Company ceases to be a subsidiary of the Company as a result of the distribution of the equity interests of the subsidiary to the holders of the Company’s common stock; and • the payment of a cash dividend to the holders of common stock. On or subsequent to the three-year anniversary of the date of issuance, if the holders have not elected to convert all their shares of Series A Preferred Stock, the Company may give 30 days’ notice to the holders giving the holders the option to choose, in their sole discretion, to have all outstanding shares of Series A Preferred Stock converted into shares of common stock or redeemed in cash at the then applicable Redemption Price (as defined below). The Company may not issue this conversion notice unless (i) the average volume-weighted average price per share of the Company’s common stock during each of the 20 consecutive trading days before the conversion is greater than 120% of the conversion price; (ii) the Company’s common stock is listed on a national securities exchange; (iii) a registration statement for the re-sale of the common stock is then effective; and (iv) the Company is not then in possession of material non-public information as determined by Regulation FD promulgated under the Exchange Act. The Series A Preferred Stock and the associated dividends during the year ended December 31, 2022 did not generate a beneficial conversion feature (“BCF”) upon issuance as the fair value of the Company’s common stock was less than the conversion price at the dividend dates. The Company will determine and, if required, measure a BCF based on the fair value of our stock price on the date dividends are declared for each subsequent dividend. If a BCF is recognized, a reduction to paid-in capital and the Series A Preferred Stock will be recorded and then subsequently accreted through the first redemption date. Additionally, the Company determined that the nature of the Series A Preferred Stock was more akin to an equity instrument and that the economic characteristics and risks of the embedded conversion options were clearly and closely related to the Series A Preferred Stock. As such, the conversion options were not required to be bifurcated from the host under ASC 815, Derivatives and Hedging . Redemption Rights If the Company undergoes certain change of control transactions, the Company will be required to immediately make an offer to repurchase all of the then-outstanding shares of Series A Preferred Stock for cash consideration per share equal to the greater of (i) 100% of the Liquidation Preference, plus accrued and unpaid dividends, if any, plus, if applicable for a transaction occurring before the third anniversary of the closing, a make-whole premium determined pursuant to a calculation of the present value of the dividends that would have accrued through such anniversary, discounted at a rate equal to the applicable treasury rate plus 0.50% (the “Make-Whole Premium”); provided that if the transaction occurs before the first anniversary of the closing, the Make-Whole Premium shall be no greater than $4,000 and (ii) the closing sale price of the common stock on the date of such redemption multiplied by the number of shares of common stock issuable upon conversion of the outstanding Series A Preferred Stock. On or subsequent to the three-year anniversary of the issuance of the Series A Preferred Stock, the Company may redeem the Series A Preferred Stock, in whole or in part, for an amount in cash equal to the greater of (i) the closing sale price of the common stock on the date the Company delivers such notice multiplied by the number of shares of common stock issuable upon conversion of the outstanding Series A Preferred Stock and (ii) (x) if the redemption occurs before the fourth anniversary of the date of the closing, 103% of the Liquidation Preference, plus accrued and unpaid dividends, or (y) if the redemption occurs on or after the fourth anniversary of the date of the closing, the Liquidation Preference plus accrued and unpaid dividends (the foregoing clauses (i) or (ii), as applicable, the “Redemption Price”). On or subsequent to the seven-year anniversary of the date of issuance, the holders have the right, subject to applicable law, to require the Company to redeem the Series A Preferred Stock, in whole or in part, into cash consideration equal to the liquidation preference, plus all accrued and unpaid dividends, from any source of funds legally available for such purpose. Since the redemption of the Series A Preferred Stock is contingently or optionally redeemable and therefore not certain to occur, the Series A Preferred Stock is not required to be classified as a liability under ASC 480, Distinguishing Liabilities from Equity . As the Series A Preferred Stock is redeemable in certain circumstances at the option of the holder and is redeemable in certain circumstances upon the occurrence of an event that is not solely within our control, we have classified the Series A Preferred Stock in mezzanine equity in the Consolidated Balance Sheets. Liquidation Rights In the event of any liquidation, winding-up or dissolution of the Company, whether voluntary or involuntary, the holders of the Series A Preferred Stock would receive an amount in cash equal to the greater of (i) 100% of the liquidation preference plus a Make-Whole Premium and (ii) the amount such holders would be entitled to receive at such time if the Series A Preferred Stock were converted into Company common stock immediately before the liquidation event. The Make-Whole Premium is removed from the calculation for a liquidation event occurring subsequent to the third anniversary of the issuance date. Voting Rights The holders of the Series A Preferred Stock are entitled to vote with the holders of the common stock on an as-converted basis in addition to voting as a separate class as provided by applicable Delaware law and the Company’s organizational documents. The holders, acting exclusively and as a separate class, shall have the right to appoint either a non-voting observer to the Company’s Board of Directors or one director to the Company’s Board of Directors. Registration Rights The holders of the Series A Preferred Stock have certain customary registration rights with respect to the Series A Preferred Stock and the shares of common stock into which they are converted, pursuant to the terms of a registration rights agreement. Series B Preferred Stock On November 14, 2022, the Company and an investment fund affiliated with BCP entered into (i) an agreement to sell 30 (thirty thousand) shares of Series B Preferred Stock, par value $0.01 per share (the “Series B Preferred Stock”), with an initial aggregate liquidation preference of $30,000, net of a 4% Original Issue Discount (“OID”) of $1,200 for net proceeds of $28,800 in a private placement (the “Series B Preferred Stock Investment”). The Series B Preferred Stock ranks senior to all classes or series of equity securities of the Company with respect to dividend rights and rights on liquidation. In the event of any liquidation or winding up of the Company, the holder of each share of the Series B Preferred Stock will receive in preference to the holders of the Company common stock a per share amount equal to the greater of (i) the stated value of the Series B Preferred Stock and (ii) the amount such holders would be entitled to receive at such time if the Series B Preferred Stock were converted into Company common stock. Proceeds from the Series B Preferred Stock Investment were used for liquidity and general corporate purposes. Conversion Features The holder of the Series B Preferred Stock may at any time following the 3-month anniversary of issuance convert all or a portion of the Series B Preferred Stock into common stock of the Company. Each share of Series B Preferred Stock will be convertible into a number of shares of common stock of the Company equal to the purchase price of such share divided by the conversion price, which will be set at an amount representing the volume-weighted average closing price of the Company common stock for the 20-trading days immediately preceding the public announcement of this transaction. At any time after the three-year anniversary of the date of issuance, if the holders have not elected to convert all their shares of Series B Preferred Stock, the Company will have the option to convert all of the then-outstanding shares of Series B Preferred Stock; provided that (i) the closing price of the Company’s common stock exceeds 120% of the conversion price for each of the 20 consecutive trading days prior to the date of conversion, (ii) the Company’s common stock is then listed on a national securities exchange, (iii) a registration statement for re-sale of the Company’s common stock is then effective and (iv) the Company is not then in possession of material non-public information. The Company will provide the holders with 30 days’ notice of its intention to convert the Series B Preferred Stock and the holders will then have the option, in their sole discretion, to have their Series B Preferred Stock converted at the then-applicable Conversion Price or redeemed in cash at the Company’s redemption price as defined in the agreement. In the event the holders elect to have the Series B Preferred Stock redeemed in cash and the Company is unable to redeem the Series B Preferred Stock in cash, then the holders shall not be required to participate in any conversion and shall retain their then-outstanding Series B Preferred Stock in all respects. Redemption Rights If a change of control of the Company occurs, subject to the payment in full of all obligations under the Credit Agreement, the Company will be required to immediately make an offer to repurchase all of the then-outstanding shares of Series B Preferred Stock for cash consideration per share equal to the Company’s redemption price as defined in the agreement. Unless the holders buy all or substantially all of the Company’s assets in a transaction or a series of related transactions approved by the Company’s board of directors, no acquisition or disposition of securities by the holders shall constitute a change of control hereunder. At any time after the 30-month anniversary of the date of closing, the holders will have the option to require the Company to redeem any or all of the then-outstanding shares of Series B Preferred Stock for cash consideration equal to the stated value provided that the Company has the financial means and subject to the approval of the Company's lender if required under a customary credit facility. At any time after the 30-month anniversary of the date of closing, and upon not less than 30 days prior written notice, if the holders have not elected to convert or redeem all their shares of Series B Preferred Stock, the Company may elect to redeem all shares of Series B Preferred Stock for an amount equal to the greater of (i) the closing sale price of the Common Stock on the date the Company delivers such notice multiplied by the number of shares of Common Stock issuable upon conversion of the outstanding Series B Preferred Stock and (ii) the stated value. Voting Rights The holders of the Series B Preferred Stock are entitled to vote with the holders of the common stock on an as-converted basis and not as a separate class. The voting power of the Series B Preferred Stock will be limited to 5.0% of the outstanding common stock of the Company. Registration Rights The holders of the Series B Preferred Stock will receive (i) customary transferable shelf registration rights pertaining to the Series B Preferred Stock and any shares of Company common stock issued upon the conversion thereof and (ii) customary piggyback and demand rights in respect of any Company common stock issued upon the conversion of any preferred stock, in each case, by amendment to the Company’s current registration rights agreement or otherwise and on terms consistent therewith.

Contract Assets and Liabilities

Contract Assets and Liabilities	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Contract Assets and Liabilities	Revenue We disaggregate our revenue from customers by customer arrangement and geographic region as we believe it best depicts how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors. See details in the tables below. Year Ended December 31, 2022 2021 2020 Construction contracts 140,798 160,632 80,805 Byproduct services 105,981 101,355 106,704 Raw material sales 46,388 31,232 44,868 Total revenue $ 293,167 $ 293,219 $ 232,377 Year Ended December 31, 2022 2021 2020 United States $ 293,167 $ 293,219 $ 231,032 Foreign — — 1,345 Total revenue $ 293,167 $ 293,219 $ 232,377 On December 31, 2022, we had $517,914 in transaction price for existing contracts allocated to remaining performance obligations. We expect to recognize approximately 19% of our remaining performance obligations as revenue during 2023, 13% in 2024, 11% in 2025 and 56% thereafter. Revenue associated with our remaining performance obligations relates to our construction contracts. The balance of remaining performance obligations does not include variable consideration that was determined to be constrained as of December 31, 2022. As of December 31, 2022, there were $2,923 in unapproved change orders associated with project scope changes included in estimated costs at completion on certain construction contracts, of which $2,330 were approved after year end. The timing of revenue recognition, billings and cash collections results in accounts receivable, contract assets, and contract liabilities on the Consolidated Balance Sheets. Our contract assets are as follows: December 31, 2022 2021 Costs and estimated earnings in excess of billings $ 11,700 $ 17,163 Retainage 9,281 9,681 Total contract assets $ 20,981 $ 26,844 The increase in contract assets in 2022 was primarily attributable to the timing of the billings for construction contracts. Our contract liabilities are as follows: December 31, 2022 2021 Deferred revenue $ 258 $ 483 Billings in excess of costs and estimated earnings 8,160 5,716 Total contract liabilities $ 8,418 $ 6,199 We recognized revenue of $5,941 for the year ended December 31, 2022, which was previously included in the contract liability balance at December 31, 2021. The following table sets forth the costs and estimated earnings on uncompleted contracts as of: December 31, 2022 2021 Costs incurred on uncompleted contracts $ 344,692 $ 227,195 Estimated earnings 20,267 22,331 Total costs and earnings 364,959 249,526 Less billings to date (361,419) (238,079) Costs and estimated earnings in excess of billings $ 3,540 $ 11,447 The following table sets forth the net balance in process as of: December 31, 2022 2021 Costs and estimated earnings in excess of billings $ 11,700 $ 17,163 Billings in excess of costs and estimated earnings (8,160) (5,716) Net balance in process $ 3,540 $ 11,447

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company adopted the Charah Solutions, Inc. 2018 Omnibus Incentive Plan (the “2018 Plan”), pursuant to which employees, consultants, and directors of the Company and its affiliates, including named executive officers, are eligible to receive awards. The 2018 Plan provides for the grant of stock options, stock appreciation rights, restricted stock, restricted stock units, bonus stock, dividend equivalents, other stock-based awards, substitute awards, annual incentive awards, and performance awards intended to align the interests of participants with those of Company's stockholders. The Company has reserved 301 shares of common stock for issuance under the 2018 Plan, and all future equity awards described above will be issued pursuant to the 2018 Plan. During the year ended December 31, 2022, the Company amended the 2018 Plan to reserve an additional 200 shares of common stock, for a total of 501 shares of common stock reserved for issuance under the 2018 Plan. Restricted share units (“RSUs”) During the years ended December 31, 2022, 2021 and 2020, the Company granted 90, 50 and 54, respectively, RSUs under the 2018 Plan that have time-based vesting requirements. Of the RSUs granted during the year ended December 31, 2022, 17 vest at the end of a one-year period, 56 vest in equal annual installments over three years, and 17 vest in equal annual installments over four years. The fair value of these RSUs is based on the market price of the Company’s shares on the grant date. As of December 31, 2022, 3 of the shares were vested and none had been forfeited. Of the RSUs granted during the year ended December 31, 2021, 9 vest at the end of a one-year period, and 41 vest in equal annual installments over three years. The fair value of these RSUs is based on the market price of the Company’s shares on the grant date. As of December 31, 2022, 251 of the shares were vested and 71 had been forfeited. Of the RSUs granted during the year ended December 31, 2020, 2 vested at the end of an eleven-month period, 9 vest after one year, 43 vest in equal installments over three years. The fair value of these RSUs is based on the market price of the Company's shares on the grant date. As of December 31, 2022, 491 of the shares were vested and 111 had been forfeited. Performance share units (“PSUs”) During the year ended December 31, 2022, 2021 and 2020, the Company granted 31, 24, and 23 PSUs, respectively, under the 2018 Plan that cliff vest after three years. The vesting of the PSUs is dependent upon the following performance goals during a specified period (the “Performance Period”): (i) the relative total stockholder return (“TSR”) percentile ranking of the Company as compared to the specified performance peer group and (ii) cumulative revenue. Each performance goal is weighted at 50% in determining the number of PSUs that become earned PSUs. The maximum number of earned PSUs for the Performance Period is 200% of the target number of PSUs. The total compensation cost we will recognize under the PSUs will be determined using the Monte Carlo valuation methodology, which factors in the value of the TSR market condition when determining the grant date fair value of the PSU. Compensation cost for each PSU is recognized during the Performance Period based on the probable achievement of the two performance criteria. The PSUs are converted into shares of our common stock at the time the PSU award value is finalized. Two shares granted during 2022 vested and 4 shares had been forfeited, 2 shares granted during 2021 vested and 2 shares had been forfeited, and 23 shares granted during 2019 were forfeited. A summary of the Company’s non-vested share activity for the year ended December 31, 2022 is as follows: Restricted Stock Performance Stock Total Shares Weighted-Average Grant Date Fair Value Shares Weighted-Average Grant Date Fair Value Shares Weighted-Average Grant Date Fair Value Balance as of December 31, 2021 89 $ 46.16 65 $ 42.40 154 $ 44.60 Granted 90 36.09 31 29.70 121 34.45 Forfeited (30) 44.28 (29) 56.45 (59) 50.24 Vested (61) 45.78 (4) 41.19 (65) 45.53 Balance as of December 31, 2022 88 $ 36.90 63 $ 30.21 151 $ 34.08 Restricted Stock Performance Stock Total Weighted Average Remaining Contractual Terms (Years) Aggregate Intrinsic Value Weighted Average Remaining Contractual Terms (Years) Aggregate Intrinsic Value Weighted Average Remaining Contractual Terms (Years) Aggregate Intrinsic Value Balance as of December 31, 2021 0.88 $ 4,072 1.26 $ 2,979 1.04 $ 7,051 Balance as of December 31, 2022 1.08 $ 476 1.33 $ 346 1.18 $ 822 Stock-based compensation expense related to the restricted stock issued was $1,936, $1,945 and $1,839 during the years ended December 31, 2022, 2021, and 2020, respectively. As of December 31, 2022, total unrecognized stock-based compensation expense related to non-vested awards of restricted stock, net of estimated forfeitures, was $1,576, and is expected to be recognized over a weighted-average period of 1.18 years. The total fair value of awards vested for the year ended December 31, 2022 was $2,133. Stock-based compensation expense related to the performance stock issued was $724, $757 and $555 during the years ended December 31, 2022, 2021, and 2020, respectively. As of December 31, 2022, total unrecognized stock-based compensation expense related to non-vested awards of performance stock, net of estimated forfeitures, was $853, and is expected to be recognized over a weighted-average period of 1.83 years.

Defined Contribution Retirement

Defined Contribution Retirement Plan	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
Defined Contribution Retirement Plan	Defined Contribution Retirement PlanCharah and its operating subsidiary, Ash Management Services (“AMS”), provide a defined contribution employee benefit plan (the “Charah and AMS 401(k) Plan”) qualified under Section 401(k) of the Code to employees who have completed 90 days of service and have attained age 18. Participants may contribute up to the lesser of 90% of eligible compensation or the maximum allowed under the Code. Charah and AMS make matching safe harbor contributions to participant accounts of up to 3% of the participant’s annual compensation. During the year ended December 31, 2022, 2021 and 2020, Charah and AMS contributed $968, $940 and $393, respectively, to the Charah and AMS 401(k) Plan.Multiemployer Pension Plan AMS contributes to union-sponsored multiemployer retirement defined benefit pension plans (the “multiemployer plans”) under the terms of collective bargaining agreements that cover its union-represented employees. The risks of participating in multiemployer plans are different from single-employer plans in the following aspects: • Assets contributed to the multiemployer plans by one employer may be used to provide benefits to employees of other participating employers. • If a participating employer stops contributing to the multiemployer plans, the unfunded obligations of the multiemployer plans may be borne by the remaining participating employers. • If AMS chooses to stop participating in the multiemployer plans, AMS may be required to pay the multiemployer plans an amount based on the underfunded status of the multiemployer plans, referred to as a withdrawal liability. The primary multiemployer plan to which AMS made contributions for the year ended December 31, 2022, 2021 and 2020 is outlined in the table below. The “EIN/Pension Plan Number” column provides the Employer Identification Number (“EIN”). The most recent Pension Protection Act zone status available in 2022 is for the respective multiemployer plan’s year-end within those years, unless otherwise noted. The zone status is based on information that AMS received from the multiemployer plans and is certified by the respective multiemployer plan’s actuary. Among other factors, multiemployer plans in the red zone (critical) are generally less than 65% funded, multiemployer plans in the yellow zone (endangered) are less than 80% funded, and multiemployer plans in the green zone (neither critical and declining, critical, or endangered) are at least 80% funded. The “FIP/RP Status Pending/Implemented” column indicates multiemployer plans for which a financial improvement plan (“FIP”) or a rehabilitation plan (“RP”) is either pending or has been implemented. The last column lists the expiration dates of the collective bargaining agreements to which the multiemployer plans are subject. Year ended December 31, 2022 Year ended December 31, 2021 Year ended December 31, 2020 Pension Fund EIN/Pension Pension Protection FIP/RP Status Contributions Contributions Contributions Surcharge Expiration Central states, southeast and southwest areas pension plan 36-6044243 Red - Critical and declining Progress under FIP or RP $ 59 $ 111 $ 55 No Continuous with notice period by either party Operating Engineers Local 324 Pension Fund 38-1900637 Red - Critical Progress under FIP or RP $ — $ — $ 27 Yes 2021 Employer Teamsters Locals 175 & 505 pension trust fund 55-6021850 Red - Critical Progress under FIP or RP $ 111 $ 81 $ 74 Yes 2023

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and ContingenciesIn December 2022, the Company was notified by a whistleblower that certain employees had engaged in improper spending activities at one of our project sites. In response, the Company conducted an internal investigation that substantiated the whistleblower's allegations. The Company engaged external legal counsel and a forensic accounting investigation team to thoroughly assess the extent of the fraudulent activities. Based on specific assumptions and limitations, we determined a range of $1,140 to $2,670 of possible loss related to potentially fraudulent transactions believed to have been billed to the customer from 2018 through 2022. The investigation will continue to proceed through the legal process, which includes examining the extent of involvement of the customer, its representatives or any third parties in contributory responsibility, evaluating the extent of insurance coverage available for reimbursement of the Company's losses, and collaborating with external law enforcement agencies to ascertain the full scope and magnitude of the overall fraudulent scheme. The Company has reversed revenue of $2,476 for these fraudulent activities during the year ended December 31, 2022, representing management's best estimate of the probable loss, irrespective of potential recoveries from third parties or insurance policies. In September 2022, TMPA served GCERG in the District Court of Travis County, Texas with a lawsuit alleging improper calculation of costs attributed to the remediation of the Site F Landfill on our Gibbons Creek project. In our APA with TMPA, GCERG agreed that if aggregate costs actually incurred to remediate the Site F Landfill did not exceed $13,600, then the cash and restricted cash received would be reduced on a dollar-for-dollar basis. In May 2023, the two parties held an unsuccessful mediation. This lawsuit is in the discovery phase and the Company intends to continue to defend the case vigorously . From time to time the Company is a party to various lawsuits, claims and other legal proceedings that arise in the ordinary course of our business. For all such lawsuits, claims and proceedings, we record reserves when it is probable a liability has been incurred and the amount of loss can be reasonably estimated. Although it is difficult to predict the ultimate outcome of these lawsuits, claims and proceedings, we do not believe that the ultimate disposition of any of these matters, individually or in the aggregate, would have a material adverse effect on our results of operations, financial position or cash flows. We maintain liability insurance for certain risks that is subject to certain self-insurance limits. We believe amounts previously recorded are sufficient to cover any liabilities arising from the proceedings with all outstanding legal claims. Except as reflected in such accruals, we are currently unable to estimate a range of reasonably possible loss or a range of reasonably possible loss in excess of the amount accrued for outstanding legal matters.

Multiemployer Pension Plan

Multiemployer Pension Plan	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
Multiemployer Pension Plan	Defined Contribution Retirement PlanCharah and its operating subsidiary, Ash Management Services (“AMS”), provide a defined contribution employee benefit plan (the “Charah and AMS 401(k) Plan”) qualified under Section 401(k) of the Code to employees who have completed 90 days of service and have attained age 18. Participants may contribute up to the lesser of 90% of eligible compensation or the maximum allowed under the Code. Charah and AMS make matching safe harbor contributions to participant accounts of up to 3% of the participant’s annual compensation. During the year ended December 31, 2022, 2021 and 2020, Charah and AMS contributed $968, $940 and $393, respectively, to the Charah and AMS 401(k) Plan.Multiemployer Pension Plan AMS contributes to union-sponsored multiemployer retirement defined benefit pension plans (the “multiemployer plans”) under the terms of collective bargaining agreements that cover its union-represented employees. The risks of participating in multiemployer plans are different from single-employer plans in the following aspects: • Assets contributed to the multiemployer plans by one employer may be used to provide benefits to employees of other participating employers. • If a participating employer stops contributing to the multiemployer plans, the unfunded obligations of the multiemployer plans may be borne by the remaining participating employers. • If AMS chooses to stop participating in the multiemployer plans, AMS may be required to pay the multiemployer plans an amount based on the underfunded status of the multiemployer plans, referred to as a withdrawal liability. The primary multiemployer plan to which AMS made contributions for the year ended December 31, 2022, 2021 and 2020 is outlined in the table below. The “EIN/Pension Plan Number” column provides the Employer Identification Number (“EIN”). The most recent Pension Protection Act zone status available in 2022 is for the respective multiemployer plan’s year-end within those years, unless otherwise noted. The zone status is based on information that AMS received from the multiemployer plans and is certified by the respective multiemployer plan’s actuary. Among other factors, multiemployer plans in the red zone (critical) are generally less than 65% funded, multiemployer plans in the yellow zone (endangered) are less than 80% funded, and multiemployer plans in the green zone (neither critical and declining, critical, or endangered) are at least 80% funded. The “FIP/RP Status Pending/Implemented” column indicates multiemployer plans for which a financial improvement plan (“FIP”) or a rehabilitation plan (“RP”) is either pending or has been implemented. The last column lists the expiration dates of the collective bargaining agreements to which the multiemployer plans are subject. Year ended December 31, 2022 Year ended December 31, 2021 Year ended December 31, 2020 Pension Fund EIN/Pension Pension Protection FIP/RP Status Contributions Contributions Contributions Surcharge Expiration Central states, southeast and southwest areas pension plan 36-6044243 Red - Critical and declining Progress under FIP or RP $ 59 $ 111 $ 55 No Continuous with notice period by either party Operating Engineers Local 324 Pension Fund 38-1900637 Red - Critical Progress under FIP or RP $ — $ — $ 27 Yes 2021 Employer Teamsters Locals 175 & 505 pension trust fund 55-6021850 Red - Critical Progress under FIP or RP $ 111 $ 81 $ 74 Yes 2023

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company is a “C” Corporation under the Code and, as a result, is subject to U.S. federal, state, and local income taxes. The Company’s subsidiaries previously operated as partnerships for income tax purposes. Before the contribution of assets and liabilities to the Company on June 18, 2018, the subsidiaries passed through their taxable income to their owners for U.S. federal and other state and local income tax purposes and, thus, the subsidiaries were not subject to U.S. federal income taxes or other state or local income taxes, except for franchise tax at the state level. The total income tax (benefit) expense on (loss) income before income taxes was allocated as follows: Year Ended December 31, 2022 2021 2020 Continuing operations $ (57) $ 661 $ (914) Discontinued operations — — 94 Total $ (57) $ 661 $ (820) The components of the provision for income taxes attributable to continuing operations for the year ended December 31, 2022, 2021, and 2020 is as follows: Year Ended December 31, 2022 2021 2020 Current income tax expense (benefit): Federal $ 72 $ — $ — State — 80 (80) 72 80 (80) Deferred income tax expense (benefit): Federal (280) 500 (843) State 151 81 9 (129) 581 (834) Total income tax expense (benefit) $ (57) $ 661 $ (914) The items accounting for differences between income taxes computed at the federal statutory rate and the (benefit) provision recorded for income taxes for continuing operations were as follows: Year Ended December 31, 2022 2021 2020 Income tax benefit at the federal statutory rate (21%) $ (26,914) $ (1,079) $ (13,537) State income tax (benefit) expense, net of federal tax benefit 119 127 (70) Non-controlling interest 55 (3) (251) Stock compensation 164 (164) 277 Valuation allowance 26,151 1,578 12,328 Foreign income tax differential 23 — — Permanent items 345 202 339 Total income tax (benefit) expense $ (57) $ 661 $ (914) The Company accounts for income taxes in accordance with ASC 740, which requires an asset and liability approach for measuring deferred taxes based on temporary differences between the financial statement and tax basis of assets and liabilities existing at each balance sheet date using enacted tax rates for the years in which taxes are expected to be paid or recovered. The components of the Company’s deferred tax assets and liabilities as of December 31, 2022 and 2021 are as follows: As of December 31, 2022 2021 Deferred tax assets: Loss carryovers $ 29,749 $ 14,333 Intangible assets 13,834 3,431 Other accrued expenses and reserves 2,056 2,326 Right-of-use liability 8,771 — Finance leases 517 1,091 Deferred asset sale 1,018 226 Accrued bonus 1,471 1,195 Asset retirement obligations 16,655 10,222 Capitalized cost 4,903 819 Deferred tax assets 78,974 33,643 Valuation allowance (50,311) (19,937) Net deferred tax asset 28,663 13,706 Deferred tax liabilities: Fixed assets, including land 12,433 9,757 Restricted cash from ERT projects 9,089 4,838 Right-of-use assets 7,955 — Prepaid expenses 5 60 Deferred tax liabilities 29,482 14,655 Net deferred tax liability $ 819 $ 949 The Company has net operating loss carryforwards of $90,241 for federal income tax purposes as of December 31, 2022. The increase in the net operating loss carryforward from 2021 is due to operating losses in 2022. Additionally, capital losses of $3,793 were recognized in 2022 which may be carried back to increase the net operating loss carryforward. Deferred interest expense carried forward to 2023 is $25,773. Net operating losses have unlimited carryover periods. Net operating losses and deferred interest expense for state tax purposes vary by state due mainly to apportionment. Most states allow net operating loss carryovers for a limited number of years. The Company’s utilization of net operating losses and deferred interest expense in the future will be limited due to the provisions of Section 382 of the Internal Revenue Code. This will limit the utilization of carryover losses in 2023 and thereafter to approximately $2,700 per year plus an increased amount for certain built-in gains recognized over the next five years. Net deferred tax liabilities were $819 and $949 at December 31, 2022 and 2021, respectively. We consider both positive and negative evidence when measuring the need for a valuation allowance. The weight given to the evidence is commensurate with the extent to which it may be objectively verified. Current and cumulative financial reporting results are a source of objectively verifiable evidence. We give operating results during the most recent three-year period a significant weight in our analysis. We typically only consider forecasts of future profitability when positive cumulative operating results exist in the most recent three-year period. We perform scheduling exercises to determine if sufficient taxable income of the appropriate character exists in the periods required in order to realize our deferred tax assets with limited lives before their expiration. Realization of net operating losses and other carryforwards is dependent upon generating sufficient taxable income in the appropriate jurisdiction before the expiration of the carryforward periods, which involves business plans, planning opportunities and expectations about future outcomes. Furthermore, we consider tax planning strategies available to accelerate taxable amounts if required to utilize expiring deferred tax assets. A valuation allowance is not required to the extent that, in our judgment, positive evidence exists with a magnitude and duration sufficient to result in a conclusion that it is more likely than not that our deferred tax assets will be realized. A valuation allowance is recorded if it is more likely than not that a portion of our deferred tax assets will not be realized. The change in the valuation allowance for deferred tax assets is as follows: As of December 31, 2022 2021 Beginning balance $ (19,937) $ (17,158) Current additions recorded in income tax (benefit) or expense (32,023) (2,708) Current reductions recorded in income tax (benefit) or expense 1,338 837 Other adjustments 311 (908) Ending balance $ (50,311) $ (19,937) Based on the available evidence as of December 31, 2022 and 2021 we were not able to conclude it was more likely than not certain deferred tax assets would be realized. Therefore, a valuation allowance of $50,311 and $19,937, respectively, was recorded against our deferred tax assets. We will continue to evaluate the need for a valuation allowance on our deferred tax assets in future periods. The Company classifies any interest and penalties related to income taxes assessed as part of income tax expense. The Company has concluded that there are no significant uncertain tax positions requiring recognition in the financial statements, nor has the Company been assessed any significant interest or penalties by any major tax jurisdiction to any open tax periods.

Leases

Leases	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Leases	eases The Company leases equipment, vehicles, and real estate under various arrangements which are classified as either operating or finance leases. A lease exists when a contract or part of a contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. In determining whether a lease exists, we consider whether a contract provides us with both: (a) the right to obtain substantially all of the economic benefits from the use of the identified asset and (b) the right to direct the use of the identified asset. Our leases typically include a combination of fixed and variable payments. Fixed payments are generally included when measuring the right-of-use asset and lease liability. Variable payments, which primarily represent payments based on usage of the underlying asset, are generally excluded from such measurement and expensed as incurred. In addition, certain of our lease arrangements may contain a lease coupled with an arrangement to provide other services, such as maintenance, or may require us to make other payments on behalf of the lessor related to the leased asset, such as payments for taxes or insurance. We elected the practical expedient to not separate lease and non-lease components for all leases entered into after the date of adoption. The Company has elected the short-term lease exemption for all underlying asset classes. Accordingly, leases with an initial term of 12 months or less which are not expected to be renewed beyond one year, are not recorded on the balance sheet and are recognized as a lease expense on a straight-line basis over the lease term. The measurement of right-of-use assets and lease liabilities requires us to estimate appropriate discount rates. To the extent the rate implicit in the lease is readily determinable, such rate is utilized. However, based on information available at lease commencement for our leases, the rate implicit in the lease is not known. As such, we utilize an incremental borrowing rate, which represents the rate of interest that we would pay to borrow on a collateralized basis, over a similar term, an amount equal to the lease payments. Lease position as of December 31, 2022 The following table presents the lease-related assets and liabilities reported in the Consolidated Balance Sheet as of December 31, 2022: Classification on the Consolidated Balance Sheet December 31, 2022 Assets Operating lease assets Operating lease right-of-use assets $ 32,748 Finance lease assets Real estate, property and equipment, net 49,306 Total lease assets $ 82,054 Liabilities Current Operating Operating lease liabilities, current $ 12,483 Finance Finance lease obligations, current 10,592 Non-current Operating Operating lease liabilities, long-term 23,621 Finance Finance lease obligations, less current portion 24,585 Total lease liabilities $ 71,281 Lease costs The following table presents information related to our lease expense for the years ended December 31, 2022: December 31, 2022 Finance lease costs: Amortization expense $ 9,785 Interest expense 2,483 Operating lease costs 13,893 Short-term lease expense 464 Total lease expense $ 26,625 The total rent expense included in the Consolidated Statements of Operations for the years ended December 31, 2021 and 2020 was $26,990 and $19,406, respectively. Lease term and Discount rate The following table presents certain information related to the lease terms and discount rates for our leases as of December 31, 2022: December 31, 2022 Weighted-average remaining term in years Operating leases 3.68 Finance leases 4.41 Weighted-average discount rate Operating leases 7.4 % Finance leases 7.2 % Other Information The following table presents supplemental cash flow information related to our leases for the years ended December 31, 2022: December 31, 2022 Cash paid amounts included in the measurement of lease liabilities: Operating cash flows used for operating leases $ 14,118 Operating cash flows used for finance leases 2,453 Financing cash flows used for finance leases 9,381 Total $ 25,952 Right-of-use assets obtained in exchange for: New operating lease liabilities $ 15,866 New finance lease liabilities 18,134 Total $ 34,000 Maturity of Lease Liabilities The following table reconciles our future minimum lease payments on an undiscounted cash flow basis to our lease liabilities reported in the Consolidated Balance Sheet as of December 31, 2022: For the Years Ending December 31, Operating Leases Finance Leases 2023 $ 14,583 $ 12,825 2024 9,354 10,628 2025 5,150 9,172 2026 3,935 6,500 2027 3,069 939 Thereafter 6,122 — Total minimum lease payments $ 42,213 $ 40,064 Less: Amount of lease payments representing interest (6,109) (4,887) Present value of future minimum lease payments $ 36,104 $ 35,177 Current portion of lease liabilities $ 12,483 $ 10,592 Noncurrent portion of lease liabilities 23,621 24,585 Total lease liabilities $ 36,104 $ 35,177 The Company's future minimum lease payments for operating leases as of December 31, 2021 are as follows: For the Years Ending December 31, Operating Leases 2022 $ 10,216 2023 9,271 2024 5,646 2025 2,151 2026 1,003 Thereafter 819 Total $ 29,106
Leases	eases The Company leases equipment, vehicles, and real estate under various arrangements which are classified as either operating or finance leases. A lease exists when a contract or part of a contract conveys the right to control the use of an identified asset for a period of time in exchange for consideration. In determining whether a lease exists, we consider whether a contract provides us with both: (a) the right to obtain substantially all of the economic benefits from the use of the identified asset and (b) the right to direct the use of the identified asset. Our leases typically include a combination of fixed and variable payments. Fixed payments are generally included when measuring the right-of-use asset and lease liability. Variable payments, which primarily represent payments based on usage of the underlying asset, are generally excluded from such measurement and expensed as incurred. In addition, certain of our lease arrangements may contain a lease coupled with an arrangement to provide other services, such as maintenance, or may require us to make other payments on behalf of the lessor related to the leased asset, such as payments for taxes or insurance. We elected the practical expedient to not separate lease and non-lease components for all leases entered into after the date of adoption. The Company has elected the short-term lease exemption for all underlying asset classes. Accordingly, leases with an initial term of 12 months or less which are not expected to be renewed beyond one year, are not recorded on the balance sheet and are recognized as a lease expense on a straight-line basis over the lease term. The measurement of right-of-use assets and lease liabilities requires us to estimate appropriate discount rates. To the extent the rate implicit in the lease is readily determinable, such rate is utilized. However, based on information available at lease commencement for our leases, the rate implicit in the lease is not known. As such, we utilize an incremental borrowing rate, which represents the rate of interest that we would pay to borrow on a collateralized basis, over a similar term, an amount equal to the lease payments. Lease position as of December 31, 2022 The following table presents the lease-related assets and liabilities reported in the Consolidated Balance Sheet as of December 31, 2022: Classification on the Consolidated Balance Sheet December 31, 2022 Assets Operating lease assets Operating lease right-of-use assets $ 32,748 Finance lease assets Real estate, property and equipment, net 49,306 Total lease assets $ 82,054 Liabilities Current Operating Operating lease liabilities, current $ 12,483 Finance Finance lease obligations, current 10,592 Non-current Operating Operating lease liabilities, long-term 23,621 Finance Finance lease obligations, less current portion 24,585 Total lease liabilities $ 71,281 Lease costs The following table presents information related to our lease expense for the years ended December 31, 2022: December 31, 2022 Finance lease costs: Amortization expense $ 9,785 Interest expense 2,483 Operating lease costs 13,893 Short-term lease expense 464 Total lease expense $ 26,625 The total rent expense included in the Consolidated Statements of Operations for the years ended December 31, 2021 and 2020 was $26,990 and $19,406, respectively. Lease term and Discount rate The following table presents certain information related to the lease terms and discount rates for our leases as of December 31, 2022: December 31, 2022 Weighted-average remaining term in years Operating leases 3.68 Finance leases 4.41 Weighted-average discount rate Operating leases 7.4 % Finance leases 7.2 % Other Information The following table presents supplemental cash flow information related to our leases for the years ended December 31, 2022: December 31, 2022 Cash paid amounts included in the measurement of lease liabilities: Operating cash flows used for operating leases $ 14,118 Operating cash flows used for finance leases 2,453 Financing cash flows used for finance leases 9,381 Total $ 25,952 Right-of-use assets obtained in exchange for: New operating lease liabilities $ 15,866 New finance lease liabilities 18,134 Total $ 34,000 Maturity of Lease Liabilities The following table reconciles our future minimum lease payments on an undiscounted cash flow basis to our lease liabilities reported in the Consolidated Balance Sheet as of December 31, 2022: For the Years Ending December 31, Operating Leases Finance Leases 2023 $ 14,583 $ 12,825 2024 9,354 10,628 2025 5,150 9,172 2026 3,935 6,500 2027 3,069 939 Thereafter 6,122 — Total minimum lease payments $ 42,213 $ 40,064 Less: Amount of lease payments representing interest (6,109) (4,887) Present value of future minimum lease payments $ 36,104 $ 35,177 Current portion of lease liabilities $ 12,483 $ 10,592 Noncurrent portion of lease liabilities 23,621 24,585 Total lease liabilities $ 36,104 $ 35,177 The Company's future minimum lease payments for operating leases as of December 31, 2021 are as follows: For the Years Ending December 31, Operating Leases 2022 $ 10,216 2023 9,271 2024 5,646 2025 2,151 2026 1,003 Thereafter 819 Total $ 29,106

Loss Per Share

Loss Per Share	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Loss Per Share	Loss Per Share Basic loss per share is computed by dividing loss attributable to the Company’s stockholders by the weighted average number of shares outstanding during the period. Diluted loss per share reflects all potential dilutive ordinary shares outstanding during the period and is computed by dividing loss available to the Company’s stockholders by the weighted average number of shares outstanding during the period increased by the number of additional shares that would have been outstanding as dilutive securities. Basic and diluted loss per share is determined using the following information: Year Ended December 31, 2022 2021 2020 Numerator: Net loss from continuing operations $ (127,843) $ (5,814) $ (64,746) Deemed and imputed dividends on Series A Preferred Stock (599) (592) (461) Series A Preferred Stock dividends (5,307) (8,156) (4,064) Net loss from continuing operations attributable to common stockholders (133,749) (14,562) (69,271) Net income from discontinued operations — — 8,883 Net loss attributable to common stockholders $ (133,749) $ (14,562) $ (60,388) Denominator: Weighted average shares outstanding 3,363 3,157 2,990 Dilutive share-based awards — — — Total weighted average shares outstanding, including dilutive shares 3,363 3,157 2,990 Net loss from continuing operations per common share Basic $ (39.77) $ (4.61) $ (23.17) Diluted $ (39.77) $ (4.61) $ (23.17) Net income from discontinued operations per common share Basic $ — $ — $ 2.97 Diluted $ — $ — $ 2.97 Net loss attributable to common stockholders per common share Basic $ (39.77) $ (4.61) $ (20.20) Diluted $ (39.77) $ (4.61) $ (20.20) The holders of the Series A and Series B Preferred Stock have non-forfeitable rights to common stock dividends or common stock dividend equivalents. Accordingly, the Series A and Series B Preferred Stock qualify as participating securities. As a result of the net loss from continuing operations per share for the years ended December 31, 2022, 2021, and 2019, the inclusion of all potentially dilutive shares would be anti-dilutive. Therefore, dilutive shares (in thousands) of 1,647, 1,224, and 925 were excluded from the computation of the weighted average shares for diluted net loss per share for the years ended December 31, 2022, 2021, and 2020 respectively. A summary of securities excluded from the computation of diluted earnings per share is presented below: Year Ended December 31, 2022 2021 2020 Diluted earnings per share: Anti-dilutive restricted and performance stock units 180 132 151 Anti-dilutive Series A and Series B Preferred Stock convertible into common stock 1,467 1,092 774 Potentially dilutive securities, excluded as anti-dilutive 1,647 1,224 925 Reverse Stock Split

Major Customers

Major Customers	12 Months Ended
	Dec. 31, 2022
Risks and Uncertainties [Abstract]
Major Customers	Major Customers Revenues from certain customers in excess of 10% of total consolidated revenues for the years ended December 31 are as follows: December 31, 2022 Revenue % of Total % of A/R, net Customer 1 $ 64,484 22.0 % 28.9 % December 31, 2021 Revenue % of Total % of A/R, net Customer 1 $ 40,590 13.8 % 4.6 % Customer 2 34,788 11.9 % 11.1 % Customer 3 29,670 10.1 % 2.4 % During the year ended December 31, 2020, no customers accounted for greater than 10% of total consolidated revenue or trade accounts receivable, net.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Agreement and Plan of Merger On April 16, 2023, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Acquisition Parent 0423 Inc., a Delaware corporation (the “Parent”), and Acquisition Sub April 2023, Inc., a Delaware corporation and a direct, wholly owned subsidiary of Parent (“Acquisition Sub”), pursuant to which, and subject to the terms and conditions therein, Acquisition Sub will be merged with and into the Company, with the Company continuing as the surviving corporation in the merger (the “Merger”). Following the consummation of the Merger, the Company will be a wholly owned subsidiary of Parent. Parent is a wholly owned subsidiary of investment funds affiliated with SER Capital Partners (“SER”), a private investment firm focused on sustainable investment. Pursuant to the terms of the Merger Agreement, at the effective time of the Merger (the “Effective Time”), each share of common stock, par value $0.01 per share, of the Company issued and outstanding immediately prior to the Effective Time will be cancelled and each share will be converted into the right to receive $6.00 per share in cash, without interest (the “Common Per Share Merger Consideration”). In addition, at the Effective Time, each share of Series A Preferred Stock of the Company and Series B Preferred Stock of the Company that is issued and outstanding immediately prior to the Effective Time shall be purchased and redeemed by Parent pursuant to Section 8 of the Certificate of Designations of Series A Preferred Stock and Section 7 of the Certificate of Designations of Series B Preferred Stock in exchange for the Series A Redemption Price of $40,061 (as such term is defined in the Merger Agreement) or the Series B Redemption Price of $30,000 (as such term is defined in the Merger Agreement), respectively (the “Redemption”). The parties to the Merger Agreement have made certain customary representations and warranties and have agreed to certain covenants. The Merger Agreement between Parent and the Company may be terminated by mutual consent of both parties or under certain conditions as detailed within the Merger Agreement. The closing of the transactions contemplated by the Merger Agreement is subject to (i) receipt of the Requisite Stockholder Approval, (ii) consent from the FCC under section 310 of the Communications Act of 1934, and (iii) consent from JPMorgan Chase Bank, N.A. to the Merger and the Redemption, to the extent the Existing Debt Agreement (as such term is defined in the Merger Agreement) remains outstanding. The Parent has obtained certain equity financing commitments pursuant to an equity commitment letter (the “Equity Commitment Letter”) for the purpose of financing the transactions contemplated by the Merger Agreement and paying related fees and expenses. Certain affiliates of SER Capital Partners (collectively, “Guarantors”) committed to contribute to Parent an equity contribution equal to $88,054 prior to or at the closing, on the terms and subject to the conditions set forth under those certain commitments. On April 16, 2023, the Guarantors and the Company executed a guarantee (the “Guarantee”) in favor of the Company in which the Guarantors have guaranteed the due and punctual payment of any and all payment obligations of Parent and Acquisition Sub, including Parent’s and/or Acquisition Sub’s obligations to pay actual damages incurred as a result of any knowing or intentional breach of the Merger Agreement prior to the valid termination of the Merger Agreement. In connection with the execution of the Merger Agreement, BCP, the Parent and the Company entered into a voting and support agreement (the “Letter Agreement”). Subject to the terms and conditions set forth in the Letter Agreement, BCP agreed, among other things, to vote their shares in favor of the adoption of the Merger Agreement, the Merger and the other transactions contemplated thereby, and against any agreement, transaction or proposal that relates to a competing proposal. The Letter Agreement also includes restrictions on the transfer of the Holder's shares and a waiver of appraisal rights. The Letter Agreement will terminate under certain circumstances as defined in the Letter Agreement.

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2022
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	Quarterly Financial Data (Unaudited) The following table summarizes the unaudited quarterly results of operations for the year ended December 31, 2022 and 2021: First Quarter Second Quarter Third Quarter Fourth Quarter (a) 2022 Revenue $ 66,051 $ 77,110 $ 81,540 $ 68,466 Operating income (loss) (7,392) (4,795) (8,902) (88,499) Income (loss) from continuing operations, net of tax and non-controlling interest (12,040) (9,603) (13,359) (92,841) Deemed and imputed dividends on Series A Preferred Stock (149) (150) (150) (150) Series A Preferred Stock dividends (2,090) (1,571) (956) (690) Net loss from continuing operations attributable to common stockholders (14,279) (11,324) (14,465) (93,681) Income from discontinued operations, net of tax — — — — Net loss attributable to common stockholders (14,279) (11,324) (14,465) (93,681) Net loss from continuing operations per common share Basic $ (4.30) $ (3.40) $ (4.30) $ (27.72) Diluted $ (4.30) $ (3.40) $ (4.30) $ (27.72) Net loss attributable to common stockholders per common share Basic $ (4.30) $ (3.40) $ (4.30) $ (27.72) Diluted $ (4.30) $ (3.40) $ (4.30) $ (27.72) First Quarter (b) Second Quarter Third Quarter Fourth Quarter (c) 2021 Revenue $ 52,107 $ 63,518 $ 84,161 $ 93,433 Operating loss 1,978 (770) 2,661 6,669 Deemed and imputed dividends on Series A Preferred Stock (147) (148) (148) (149) Series A Preferred Stock dividends (2,067) (2,148) (1,946) (1,995) Income from discontinued operations, net of tax — — — — Net loss attributable to common stockholders (3,501) (6,462) (3,771) (828) Net loss from continuing operations per common share Basic $ (1.20) $ (2.10) $ (1.16) $ (0.15) Diluted $ (1.20) $ (2.10) $ (1.16) $ (0.15) Net loss attributable to common stockholders per common share Basic $ (1.20) $ (2.10) $ (1.16) $ (0.15) Diluted $ (1.20) $ (2.10) $ (1.16) $ (0.15) (a) Fourth-quarter of 2022 includes a $2,112 reversal of revenue associated with the legal investigation discussed in Note 17. The reversal of revenue corrects errors identified for the period from January 2018 through September 2022, which were not material to the consolidated financial statements for any of the affected unaudited or audited periods. In addition, the Company recognized a $62,271 impairment of intangible assets, equipment and construction in process. (b) First-quarter of 2021 includes a $5,568 gain on sales-type lease in operating income (loss). (c) Fourth-quarter of 2021 includes a $14,669 gain on the sale of real estate and $4,750 in accrued bonus.

Valuation and Qualifying Accoun

Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2022
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation and Qualifying Accounts	Valuation and Qualifying Accounts The table below presents valuation and qualifying accounts: Balance at Beginning of Period Charged to Expense Deductions Balance at End of Period Year ended December 31, 2022: Allowance for doubtful accounts $ 146 $ 990 $ (6) $ 1,130 Valuation allowance for deferred taxes 19,937 31,712 (1,338) 50,311 Year ended December 31, 2021: Allowance for doubtful accounts $ 467 $ 62 $ (383) $ 146 Valuation allowance for deferred taxes 17,158 3,616 (837) 19,937

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Description of Business Operations	Description of Business Operations The Company is a leading national service provider of mission-critical environmental services and byproduct recycling to the power generation industry, enabling our customers to address challenges related to the remediation of coal ash ponds and landfills at open and closed power plant sites while continuously operating and providing necessary electric power to communities nationwide. Services offered include a suite of remediation and compliance services, byproduct services, raw material sales and Environmental Risk Transfer (“ERT”) services. The Company has corporate offices in Kentucky and North Carolina and principally operates in the eastern and mid-central United States. The accompanying consolidated financial statements include the assets, liabilities, stockholders’ equity, members’ equity, and results of operations of the Company and its consolidated subsidiaries. Intercompany transactions and balances have been eliminated in consolidation. Under the Jumpstart Our Business Startups Act (the “JOBS Act”), the Company meets the definition of an “emerging growth company,” which allows the Company to have an extended transition period for complying with new or revised accounting standards pursuant to Section 107(b) of the JOBS Act. The Company intends to take advantage of all of the reduced reporting requirements and exemptions, including the longer phase-in periods for the adoption of new or revised financial accounting standards under Section 107 of the JOBS Act until the Company is no longer an emerging growth company. Among other things, we are not required to provide an auditor attestation report on the assessment of the internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act of 2002 and our disclosure obligations regarding executive compensation may be reduced. We may take advantage of these provisions until the last day of our fiscal year following the fifth anniversary of the IPO, or December 31, 2023. However, if certain events occur before the end of such five-year period, including if we become a “large accelerated filer,” our annual gross revenue exceeds $1.07 billion, or we issue more than $1.0 billion of non-convertible debt in any three-year period, we will cease to be an emerging growth company before the end of such five-year period.
Discontinued Operations	Discontinued Operations On November 19, 2020, the Company sold its Allied subsidiary engaged in maintenance, modification and repair services to the nuclear and fossil power generation industry to an affiliate of BCP (the “Purchaser”), the Company’s majority shareholder, in an all-cash deal for $40,000 (the “Allied Transaction”), subject to adjustments for working capital and certain other adjustments as set forth in the purchase agreement (the "Purchase Agreement").
Segment Information	Segment Information After the Allied Transaction, the Company operates as one reportable segment, reflecting the suite of end-to-end services we offer our utility partners and how our Chief Operating Decision Maker (“CODM”) reviews consolidated financial information to evaluate results of operations, assess performance and allocate resources. Due to the nature of the Company’s business, the Company's Chief Executive Officer, who is also the CODM, evaluates the performance of the Company and allocates resources of the Company based on consolidated gross profit, general and administrative expenses, balance sheet, liquidity, capital spending, safety statistics and business development reports for the Company as a whole. Since the Company has a single operating segment, all required financial segment information can be found in the consolidated financial statements. We provide the following services through our one segment: remediation and compliance services, byproduct services, raw material sales and ERT transfer services. Remediation and compliance services are associated with our customers’ need for multi-year environmental improvement and sustainability initiatives, whether driven by regulatory requirements, power generation customer initiatives or consumer expectations and standards. Byproduct services consist of recurring and mission-critical coal ash management and operations for coal-fired power generation facilities while also supporting both our power generation customers’ desire to recycle their recurring and legacy volumes of coal combustion residuals (“CCRs”), commonly known as coal ash, and our ultimate end customers’ need for high-quality, cost-effective supplemental cementitious materials (SCMs) that provide a sustainable, environmentally-friendly substitute for Portland cement in concrete. Our raw materials sales provide customers with the materials essential to their business while also providing the sourcing, logistics, and management needed to facilitate these raw materials transactions around the globe. ERT services represent an innovative solution designed to meet the evolving and increasingly complex needs of utility customers' evolving and increasingly complex plant closure and environmental remediation needs. These customers need to retire and decommission older or underutilized assets while maximizing the asset's value and improving the environment. Our ERT services manage the sites' environmental remediation requirements, benefiting the communities and lowering the utility customers' costs
Management's Use of Estimates	Management’s Use of Estimates The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions, in particular estimates of legal reserves, remediation costs for asset retirement obligations (“ARO”), costs to complete contracts in process, contract modifications and unapproved change orders, that affect the reported amounts in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates.
Balance Sheet Classification	alance Sheet ClassificationThe Company includes in current assets and liabilities contract assets, contract liabilities and retainage amounts payable, which may extend beyond one year. One year is used as the basis for classifying all other assets and liabilities.
Reclassification	ReclassificationResulting from the increase in significance of the Company's raw material sales, revenue and cost of sales amounts reported in prior years have been reclassified to conform to the current year’s presentation.
Cash	Cash The Company maintains cash in bank deposit accounts which, at times, may exceed federally insured limits. The Company has not experienced any losses in such accounts. The Company believes it is not exposed to any significant credit risk on cash.
Restricted Cash	Restricted CashWe maintain restricted cash in non-interest bearing escrow accounts for specific remediation and compliance projects, cash collateral for letters of credit, and insurance-related items. This cash becomes unrestricted as project milestones are completed in accordance with each project's defined project schedule, or when credit agreements requiring cash collateral are terminated.
Trade Accounts Receivable, Net	Trade Accounts Receivable, NetTrade accounts receivable, net consist of amounts due from customers. An allowance for doubtful accounts is recorded to the extent it is probable that a portion of a particular account will not be collected. Management determines the allowance for doubtful accounts by evaluating individual customer receivables and considering a customer’s financial condition, credit history, and current economic conditions. Trade accounts receivable balances are considered past due based upon contract or invoice terms and are charged off when deemed uncollectible. The Company does not charge interest on customer accounts and generally does not require collateral on sales and services during the normal course of business. The Company has the right to file liens on the owner’s property with regard to certain construction contracts.
Inventory	Inventory Inventories, mainly comprising ash for resale, are valued using the first-in, first-out (“FIFO”) method. Inventories are stated at the lower of cost or net realizable value.
Property and Equipment	Property and Equipment Property and equipment are stated at cost. Construction-in-progress represents costs incurred on the construction of assets that have not been completed or placed in service as of the end of the year. We evaluate the long-lived assets each reporting period to determine whether events and circumstances continue to support the asset's carrying value. Depreciation is provided principally by the straight-line method over the estimated useful lives of the assets as follows: Plant, machinery and equipment 2 - 15 years Vehicles 2 - 10 years Office equipment 2 - 10 years Buildings and leasehold improvements 5 - 40 years Finance lease assets 3 - 7 years Repair and maintenance costs are expensed as incurred and expenditures for improvements are capitalized.
Asset Retirement Obligations	Asset Retirement Obligations AROs associated with retiring long-lived assets are recognized as a liability in the period in which a legal obligation is incurred and becomes determinable. The ARO liability reflects the estimated present value of the closure and post-closure activities associated with the Company’s land and structural fill assets. The Company utilizes current retirement costs to estimate the expected cash outflows for retirement obligations. Inherent in the present value calculation are numerous assumptions and judgments, including the ultimate settlement amounts, inflation factors, credit-adjusted discount rates, timing of settlement, and changes in the legal, regulatory, environmental and political environments. To the extent future revisions to these assumptions impact the present value of the existing ARO liability, a corresponding adjustment is made to the land and/or structural fill balance. Accretion expense is recognized over time as the discounted liability is accreted to its expected settlement value. Gains and losses on ARO settlement are recognized as specific remediation tasks are performed. These gains and losses are determined based on the differences between the estimated costs used in the measurement of the fair value of the Company's AROs and the actual costs incurred for specific remediation tasks recognized on a proportionate basis.
Goodwill and Indefinite Lived Intangible Assets	Goodwill and Indefinite Lived Intangible Assets Goodwill represents the excess purchase price over the estimated fair value of net assets acquired in a business combination. Our intangible assets in the Consolidated Balance Sheets as of December 31, 2021 included a trade name that was considered to have an indefinite life. All intangible assets were impaired to zero during the year ended December 31, 2022. Goodwill and indefinite-lived intangible assets are not amortized but instead are tested for impairment at least annually or more often if events or changes in circumstances indicate that the fair value of the asset may have decreased below its carrying value. Goodwill is tested at the reporting unit level, which has been determined to be the Company. When performing its goodwill impairment test, the Company considers a qualitative assessment, when appropriate, and a quantitative assessment using the market approach and its market capitalization when determining the fair value of the reporting unit. We evaluate the indefinite-lived trade name each reporting period to determine whether events and circumstances continue to support an indefinite useful life. When performing its indefinite-lived intangible asset impairment test, the Company considers a qualitative assessment, when appropriate, and a quantitative assessment using the relief-from-royalty method, an income approach, that estimates the present value of royalty income that could be hypothetically earned by licensing the brand name to a third party over the remaining useful life. The assets will be written down to their implied fair value if the carrying value exceeds its fair value.
Definite-Lived Intangible Assets	Definite-lived intangible assets are comprised of our customer relationships. We evaluate our definite-lived intangible asset each reporting period to determine whether events and circumstances indicate that a triggering event has occurred that suggests that the fair value of the asset is below its carrying value.
Fair Value Disclosure	Fair Value Disclosure The Company follows Accounting Standards Codification (“ASC”) 820, Fair Value Measurements , which provides a framework for measuring and disclosing fair value under generally accepted accounting principles. ASC 820 requires disclosures about the fair value of assets and liabilities recognized in the balance sheet in periods subsequent to initial recognition, whether the measurements are made on a recurring basis or on a nonrecurring basis. ASC 820 defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. ASC 820 also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard describes three levels of inputs that may be used to measure fair value. Fair Value Hierarchy Level 1 - Valuation is based on quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 1 assets and liabilities generally include debt and equity securities that are traded in an active exchange market. Valuations are obtained from readily available pricing sources for market transactions involving identical assets and liabilities. Level 2 - Valuation is based on inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. The valuation may be based on quoted prices for similar assets and liabilities; quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability. Level 3 - Valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which determination of fair value requires significant management judgment or estimation. In determining the appropriate levels, the Company performs a detailed analysis of assets and liabilities that are subject to ASC 820. The Company's contingent payments for acquisitions and interest rate swap are the only assets or liabilities subject to fair value measurements on a recurring basis. The Company may also be required, from time to time, to measure certain other financial and non-financial assets and liabilities at fair value on a non-recurring basis in accordance with GAAP. There have been no transfers between levels of the fair value hierarchy during the years ended December 31, 2022 and 2021 . The fair value of the Company's 8.50% Senior Notes due 2026 (the "Notes") were valued using quoted prices in active markets for the Notes, which is considered to be a Level 1 measurement. The Notes had a fair value of $54,594 and $131,760 as of December 31, 2022 and 2021, respectively, and a carrying value of $135,000 as of December 31, 2022 and 2021. The book value of our outstanding equipment and other notes of $14,209 approximated fair value as December 31, 2022 based on consideration of recently executed transactions for similar debt, which are considered to be Level 2 measurements. Our outstanding debt as of December 31, 2020 primarily bore interest at variable rates and book value approximated fair value, which were considered to be Level 2 measurements. The carrying amounts and fair values of the Company’s recurring fair value measurements as of December 31, 2022 and 2021 are presented in the following table: December 31, 2022 Level 1 Level 2 Level 3 Total Fair Value Total Carrying Value Recurring: Contingent payments for acquisitions (1) $ — $ — $ 1,950 $ 1,950 $ 1,950 December 31, 2021 Level 1 Level 2 Level 3 Total Fair Value Total Carrying Value Recurring: Contingent payments for acquisitions (1) — — 1,950 1,950 1,950 1. As of December 31, 2022 and 2021, t he fair value of the contingent payments for acquisitions was estimated at the acquisition date using the present value of future payments. This analysis is updated at each reporting date to determine if any changes to the fair value are required and is considered to be a Level 3 measurement.
Debt Issuance costs	Debt Issuance Costs Debt issuance costs associated with our various credit agreements are amortized as interest expense over the term of the applicable agreement. Debt issuance costs related to the Notes are presented as a direct deduction from the carrying amount
Freight Costs	Freight Costs Freight costs charged to customers are included in construction and service revenue and raw material sales. Costs incurred by the Company for freight are included in construction and service cost of sales and raw material cost of sales.
Leases	Leases We lease equipment, vehicles, and real estate under various arrangements which are classified as either operating or finance leases. We recognize operating lease right-of-use assets and operating lease liabilities for operating leases and finance lease assets and liabilities for finance leases based on the present value of the lease payments over the lease term. The present value is based on our incremental borrowing rate, which represents the rate of interest that we would pay to borrow on a collateralized basis, over a similar term, an amount equal to the lease payments. See note 20 for further discussion of leases.
Income Taxes	Income Taxes Income taxes are accounted for in accordance with ASC 740. Income tax expense, or benefit, is calculated using the asset and liability method under which deferred tax assets and liabilities are recorded based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The Company assesses its deferred tax assets each quarter to determine whether the assets are more likely than not (probability of more than 50%) realizable under ASC 740. The Company is required to record a valuation allowance for any portion of the tax assets that, based on the assessment, are not more likely than not realizable. The assessment considers, among other things, earnings in prior periods, forecasts of future taxable income, statutory carryforward periods, and tax planning strategies, to the extent feasible. The realization of deferred tax assets largely depends part on the generation of future taxable income during the periods in which the differences become deductible. The value of the deferred tax assets will also depend on applicable income tax rates. Judgment is required in determining the future tax consequences of events that have been recognized in the financial statements. Differences between anticipated and actual outcomes of these future tax consequences could have a material impact on the financial statements. Changes in existing tax laws and tax rates also affect actual tax results and the valuation of deferred tax assets over time.
Stock-Based Compensation Plans	Stock-Based Compensation Plans The Company accounts for its stock-based compensation plans as equity-classified plans, in accordance with the fair value recognition provisions of ASC 718, Compensation-Stock Compensation . The Company utilizes the Black-Scholes model, which requires the input of subjective assumptions. These assumptions include estimating (i) the volatility of the common stock price over the expected term, (ii) the expected term, and (iii) expected dividends. Where the vesting of the stock is also based upon performance measures, management determines the likelihood of meeting such measures. Changes in the subjective assumptions can materially affect the estimate of the fair value of stock-based compensation and, consequently, the related amounts recognized on the Consolidated Statements of Operations. Stock-based compensation expense is recognized in general and administrative expenses.
Revenue from Contracts with Customers	Revenue from Contracts with Customers Revenue is measured based on the amount of consideration specified in a contract with a customer. Revenue is recognized when our performance obligations under the terms of the contract are satisfied, which generally occurs with the transfer of control of the goods or services to the customer. Contract Combination To determine revenue recognition for contracts, we evaluate whether two or more contracts should be combined and accounted for as one single contract and whether the combined or single contract should be accounted for as more than one performance obligation. This evaluation requires significant judgment, and the decision to combine a group of contracts or separate a combined or single contract into multiple performance obligations could change the amount of revenue and profit recorded in a given period. Contracts are considered to have a single performance obligation if the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts primarily because we provide a service that involves multiple inter-related and integrated tasks to achieve the completion of a specific, single project. We allocate the transaction price to each performance obligation for contracts with multiple performance obligations using our best estimate of the stand-alone selling price of each distinct good or service in the contract. Sales and Services Contracts For sales and service contracts where we have the right to consideration from the customer in an amount that corresponds directly with the unit price for the product and the value received by the customer based on our performance to date, revenue is recognized at a point in time when product is delivered to the customer and services are performed and contractually billable. Certain service contracts contain provisions dictating fluctuating rates per unit for the certain services in which the rates are not directly related to changes in the Company’s effort to perform under the contract. We recognize revenue based on the stand-alone selling price per unit for such contracts, calculated as the average rate per unit over the term of those contractual rates. This creates a contract asset or liability for the difference between the revenue recognized and the amount billed to the customer. Under the typical payment terms of our services contracts, amounts are billed as work progresses in accordance with agreed-upon contractual terms, at periodic intervals ( e.g. , weekly, biweekly or monthly). Construction Contracts We recognize revenue over time, as performance obligations are satisfied, for substantially all of our construction contracts due to the continuous transfer of control to the customer. For most of our construction contracts, the customer contracts with us to provide a service that involves multiple inter-related and integrated tasks to complete a specific, single project and is therefore accounted for as a single performance obligation. We recognize revenue using the cost-to-cost input method, based primarily on contract costs incurred to date compared to total estimated contract costs. This method is the most accurate measure of our contract performance because it depicts the company’s performance in transferring control of goods or services promised to customers according to a reasonable measure of progress toward complete satisfaction of the performance obligation. Contract costs include all direct material, labor and subcontractor costs and indirect costs related to contract performance. The costs incurred that do not relate directly to transferring a service to the customer are excluded from the input method used to recognize revenue. Project mobilization costs are generally charged to the project as incurred when they are an integrated part of the performance obligation being transferred to the client. Pre-contract costs are expensed as incurred unless they are expected to be recovered from the client. The payment terms of our construction contracts from time to time require the customer to make advance payments as well as interim payments as work progresses. The advance payment generally is not considered a significant financing component as we expect to recognize those amounts in revenue within a year of receipt as work progresses on the related performance obligation. Variable Consideration It is common for our contracts to contain contract provisions that give rise to variable consideration such as unpriced change orders or volume discounts that may either increase or decrease the transaction price. We estimate the amount of variable consideration at the expected value or most likely amount, depending on which is determined to be more predictive of the amount to which the Company will be entitled. Variable consideration is included in the transaction price when it is probable that a significant reversal of cumulative revenue recognized will not occur or when the uncertainty associated with the variable consideration is resolved. Our estimates of variable consideration and determination of whether to include such amounts in the transaction price are based largely on our assessment of legal enforceability, anticipated performance, industry business practices, and any other information (historical, current or forecasted) that is reasonably available to us. Variable consideration associated with unapproved change orders is included in the transaction price only to the extent of costs incurred. We provide limited warranties to customers for work performed under our contracts. Such warranties are not sold separately, assure that the services comply with the agreed-upon specifications and legal requirements and do not provide customers with a service in addition to assurance of compliance with agreed-upon specifications. Accordingly, these types of warranties are not considered to be separate performance obligations. Historically, warranty claims have not resulted in material costs incurred. Contract Estimates and Modifications Due to the nature of the work required to be performed on many of our performance obligations, the estimation of total revenue and cost at completion is complex, subject to many variables and requires significant judgment. As a significant change in one or more of these estimates could affect the profitability of our contracts, we routinely review and update our contract-related estimates through a disciplined project review process in which management reviews the progress and execution of our performance obligations and the estimated costs at completion. As part of this process, management reviews information including, but not limited to, outstanding contract matters, progress towards completion, program schedule and the associated changes in estimates of revenue and costs. Management must make assumptions and estimates regarding the availability and productivity of labor, the complexity of the work to be performed, the availability and cost of materials, the performance of subcontractors, and the availability and timing of funding from the customer, along with other risks inherent in performing services under all contracts where we recognize revenue over-time using the cost-to-cost method. We recognize changes in contract estimates on a cumulative catch-up basis in the period in which the changes are identified. Such changes in contract estimates can result in the recognition of revenue in a current period for performance obligations that were satisfied or partially satisfied in prior periods. Changes in contract estimates may also result in the reversal of previously recognized revenue if the current estimate differs from the previous estimate. If at any time the estimate of contract profitability indicates an anticipated loss on the contract, we recognize the total loss in the period it is identified. Contracts are often modified to account for changes in contract specifications and requirements. Most of our contract modifications are for goods or services that are not distinct from existing contracts due to the significant integration provided in the context of the contract and are accounted for as if they were part of the original contract. The effect of a contract modification on the transaction price and our measure of progress for the performance obligation to which it relates is recognized as an adjustment to revenue (either as an increase in or a reduction of revenue) on a cumulative catch-up basis. We account for contract modifications when the modification results in the promise to deliver additional goods or services that are distinct and the increase in the price of the contract is for the same amount as the stand-alone selling price of the additional goods or services included in the modification. We evaluate our contracts whether we are acting as the principal or as the agent when providing services, which we consider in determining if revenue should be reported on a gross or net basis. We determine the Company to be a principal if we control the specified service before that service is transferred to a customer. Contract Assets and Liabilities Billing practices are governed by each project's contract terms based upon costs incurred, achievement of the milestones or predetermined schedules. Billings do not necessarily correlate with revenue recognized over time using the cost-to-cost input method. Contract assets include unbilled amounts typically resulting from revenue under long-term contracts when the revenue recognized exceeds the amount billed to the customer. Contract liabilities consist of billings in excess of revenue recognized as well as deferred revenue. Contract assets also include retainage, which represents amounts withheld by our clients from billings according to provisions in the contracts and may not be paid to us until the completion of specific tasks or the completion of the project and, in some instances, for even longer periods. Our contract assets and liabilities are reported in a gross position on a contract-by-contract basis at the end of each reporting period. We include in current assets and liabilities contract assets and liabilities, which may extend beyond one year.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) , requiring all leases to be recognized on the balance sheet as a right-of-use asset and a lease liability unless the lease is a short-term lease (generally a lease with a term of 12 months or less). On January 1, 2022, we adopted ASC 842. As further described in Note 20, we lease equipment and vehicles primarily used at our project sites. We adopted ASC 842 using a modified retrospective approach (Comparatives Under 840 Option). The Comparatives Under 840 Option requires recognition under the new standard in ASC 842, Leases (“Leases (Topic 842)”) to be applied as of the date of adoption (January 1, 2022) with all prior periods being presented under Accounting Standards Codification (ASC) 840, Leases (“Leases (Topic 840)”). As a result, the comparative financial information has not been updated and the required disclosures prior to the date of adoption have not been updated and continue to be reported under the accounting standards in effect for those periods. ASC 842 also permitted the election of certain practical expedients upon adoption. We elected the transition package of practical expedients which allowed us to carryforward the historical lease classification. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) - Measurement of Credit Losses on Financial Instruments , which introduces a new model for recognizing credit losses on financial instruments based on an estimate of current expected credit losses. The new model will apply to: (1) loans, accounts receivable, trade receivables, and other financial assets measured at amortized cost, (2) loan commitments and certain other off-balance sheet credit exposures, (3) debt securities and other financial assets measured at fair value through other comprehensive income, and (4) beneficial interests in securitized financial assets. The amendments contained in this ASU will be applied through a modified retrospective approach through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. In November 2018, the FASB issued ASU No. 2018-19, which amended the effective date of ASU No. 2016-13 and clarified that receivables arising from operating leases are not within the scope of Subtopic 326-20. In October 2019, the FASB delayed the effective date of this ASU, extending the effective date for non-public business entities and making the ASU effective for the Company for the fiscal year ending December 31, 2023, and interim periods therein, with early adoption permitted. The adoption of this ASU is not expected to have a material impact on the Company's consolidated financial statements. In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848) Facilitation of the Effects of Reference Rate Reform on Financial Reporting . The ASU provides optional expedients and exceptions for applying GAAP to contract modifications and hedging relationships, subject to meeting certain criteria, that reference LIBOR or another rate that is expected to be discontinued. In January 2021, the FASB issued ASU No. 2021-01, Reference Rate Reform (Topic 848) . This ASU provides supplemental guidance and clarification to ASU No. 2020-04, and these updates must be adopted concurrently, cumulatively referred to as “Topic 848.” The amendments in Topic 848 are currently effective for all entities and upon adoption may be applied prospectively to contract modifications made on or before December 31, 2022. The adoption of this ASU is not expected to have a material impact on the Company's consolidated financial statements. In August 2020, the FASB issued ASU No. 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815 – 40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity . This ASU eliminates the current models that require separation of beneficial conversion and cash conversion features from convertible instruments and simplifies the derivative scope exception guidance pertaining to equity classification of contracts in an entity’s own equity. The new standard also introduces additional disclosures for convertible debt and freestanding instruments that are indexed to and settled in an entity’s own equity. ASU No. 2020-06 amends the diluted earnings per share guidance, including the requirement to use the if-converted method for all convertible instruments. The Company adopted ASU No. 2020-06 effective as of January 1, 2022. The adoption of ASU No. 2020-06 did not have an impact on the Company’s consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Schedule of Property and Equipment, Net	Property and equipment are stated at cost. Construction-in-progress represents costs incurred on the construction of assets that have not been completed or placed in service as of the end of the year. We evaluate the long-lived assets each reporting period to determine whether events and circumstances continue to support the asset's carrying value. Depreciation is provided principally by the straight-line method over the estimated useful lives of the assets as follows: Plant, machinery and equipment 2 - 15 years Vehicles 2 - 10 years Office equipment 2 - 10 years Buildings and leasehold improvements 5 - 40 years Finance lease assets 3 - 7 years The following table shows the components of property and equipment, net: December 31, 2022 2021 Plant, machinery and equipment $ 60,377 $ 63,937 Structural fill site improvements 55,760 55,760 Vehicles 11,619 11,718 Office equipment 600 600 Buildings and leasehold improvements 267 267 Land, land improvements and structural fill sites 44,790 12,231 Finance lease assets 49,306 31,172 Construction in progress — 1,522 Total property and equipment $ 222,719 $ 177,207 Less: accumulated depreciation (128,779) (106,734) Property and equipment, net $ 93,940 $ 70,473
Schedule of Finite-Lived Intangible Assets	Definite-lived intangible assets are comprised of our customer relationships. We evaluate our definite-lived intangible asset each reporting period to determine whether events and circumstances indicate that a triggering event has occurred that suggests that the fair value of the asset is below its carrying value. These assets are amortized on a straight-line basis over their estimated useful lives, as shown in the table below. Definite Lived Intangible Useful Life Customer relationships 10 years
Fair Value, Liabilities Measured on Recurring Basis	The carrying amounts and fair values of the Company’s recurring fair value measurements as of December 31, 2022 and 2021 are presented in the following table: December 31, 2022 Level 1 Level 2 Level 3 Total Fair Value Total Carrying Value Recurring: Contingent payments for acquisitions (1) $ — $ — $ 1,950 $ 1,950 $ 1,950 December 31, 2021 Level 1 Level 2 Level 3 Total Fair Value Total Carrying Value Recurring: Contingent payments for acquisitions (1) — — 1,950 1,950 1,950 1. As of December 31, 2022 and 2021, t he fair value of the contingent payments for acquisitions was estimated at the acquisition date using the present value of future payments. This analysis is updated at each reporting date to determine if any changes to the fair value are required and is considered to be a Level 3 measurement.

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2022
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Derecognized Assets and Liabilities	The Company derecognized the following assets and liabilities through this Allied Transaction: Restricted cash $ 240 Trade accounts receivable, net 25,752 Prepaid expenses and other current assets 1,453 Property and equipment, net 1,112 Goodwill (a) 12,020 Accounts payable (8,681) Accrued liabilities (26,367) Carrying value of Allied $ 5,529 (a) Goodwill was allocated to discontinued operations on a relative fair value basis.
Schedule of Discontinued Operations On Our Consolidated & Combined Statements of Operations	The following amounts related to discontinued operation were derived from historical financial information and have been segregated from continuing operations and reported as discontinued operations in our Consolidated Statements of Operations: Year Ended December 31, 2020 Revenue $ 314,251 Cost of sales 295,423 Gross profit 18,828 General and administrative expenses 7,106 Operating income 11,722 Interest expense, net (b) (2,745) Income from discontinued operations before income taxes 8,977 Income tax expense 94 Income from discontinued operations $ 8,883 (b) Interest expense was allocated to discontinued operations due to a requirement in our amended Credit Agreement that cash generated from the Allied Transaction was to be used to reduce our borrowings.
Schedule of Cash and Cash Equivalents	The following table provides supplemental cash and restricted cash information related to discontinued operations: Year Ended December 31, 2020 Cash and restricted cash: Cash and restricted cash - continuing operations $ 29,211 Cash and restricted cash - discontinued operations — Total cash and restricted cash $ 29,211
Schedule of Depreciation and Amortization, Capital Expenditures and Significant Operating Noncash Items	The depreciation and amortization, capital expenditures and significant operating noncash items of Allied were as follows: Year Ended December 31, 2020 Cash flows from discontinued operating activities: Depreciation and amortization $ 755 Loss on disposal of fixed assets 22 Non-cash shared-based compensation 145 Cash flows from discontinued investing activities: Purchase of property and equipment $ 93

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	Year Ended December 31, 2022 2021 2020 Construction contracts 140,798 160,632 80,805 Byproduct services 105,981 101,355 106,704 Raw material sales 46,388 31,232 44,868 Total revenue $ 293,167 $ 293,219 $ 232,377 Year Ended December 31, 2022 2021 2020 United States $ 293,167 $ 293,219 $ 231,032 Foreign — — 1,345 Total revenue $ 293,167 $ 293,219 $ 232,377

Asset Acquisition (Tables)

Asset Acquisition (Tables)	12 Months Ended
	Dec. 31, 2022
Business Combination and Asset Acquisition [Abstract]
Schedule of Asset Acquisitions	The assets acquired and liabilities assumed as recognized within the Company's consolidated balance sheet upon closing on the APA consisted of the following: Consideration and direct transaction costs: Asset retirement obligations $ (34,300) Direct transaction costs (1,345) Total consideration and transaction costs incurred $ (35,645) Assets Acquired: Restricted Cash $ 2,900 Land, land improvements and structural fill sites 32,109 Plant, machinery and equipment 623 Vehicles 13 Total allocated value of assets acquired $ 35,645 A summary of the other assumptions included in the fair value measurement of the asset retirement obligations to be recognized upon closing of the APA consisted of the following: Other Assumptions: Inflation rate 2.50 % Weighted average rate applicable to our long-term asset retirement obligations 7.35 % Consideration and direct transaction costs: Asset retirement obligations $ (30,179) Direct transaction costs and accrued expenses (684) Total consideration and transaction costs incurred $ (30,863) Assets Acquired: Cash $ 5,577 Restricted cash 29,762 Total allocated value of assets acquired $ 35,339 Excess of fair value of assets acquired over total consideration – deferred gain $ (4,476) A summary of the other assumptions included in the fair value measurement of the asset retirement obligations to be recognized upon closing of the APA consisted of the following: Other Assumptions: Inflation rate 2.50 % Weighted average rate applicable to our long-term asset retirement obligations 7.45 % The assets acquired and liabilities assumed as recognized within the Company's Consolidated Balance Sheet upon closing on the APA consisted of the following: Consideration and direct transaction costs: Asset retirement obligations $ (50,590) Bond and insurance accrued expenses, net (2,229) Direct transaction costs (2,336) Total consideration and transaction costs incurred $ (55,155) Asset Received: Cash $ 6,354 Restricted cash 28,546 Water rights 5,196 Land 14,385 Plant, machinery and equipment 610 Vehicles 64 Total allocated value of assets acquired $ 55,155 A summary of the other assumptions included in the fair value measurement of the asset retirement obligations to be recognized upon closing of the APA consisted of the following: Other Assumptions: Inflation rate 3.00 % Weighted average rate applicable to our long-term asset retirement obligations 4.50 %

Balance Sheet Items (Tables)

Balance Sheet Items (Tables)	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Property and Equipment, Net	Property and equipment are stated at cost. Construction-in-progress represents costs incurred on the construction of assets that have not been completed or placed in service as of the end of the year. We evaluate the long-lived assets each reporting period to determine whether events and circumstances continue to support the asset's carrying value. Depreciation is provided principally by the straight-line method over the estimated useful lives of the assets as follows: Plant, machinery and equipment 2 - 15 years Vehicles 2 - 10 years Office equipment 2 - 10 years Buildings and leasehold improvements 5 - 40 years Finance lease assets 3 - 7 years The following table shows the components of property and equipment, net: December 31, 2022 2021 Plant, machinery and equipment $ 60,377 $ 63,937 Structural fill site improvements 55,760 55,760 Vehicles 11,619 11,718 Office equipment 600 600 Buildings and leasehold improvements 267 267 Land, land improvements and structural fill sites 44,790 12,231 Finance lease assets 49,306 31,172 Construction in progress — 1,522 Total property and equipment $ 222,719 $ 177,207 Less: accumulated depreciation (128,779) (106,734) Property and equipment, net $ 93,940 $ 70,473
Schedule Of Lease Receivable	The following table reflects the classification of the lease receivable within our Consolidated Balance Sheet: December 31, 2022 Lease receivable $ 5,872 Less: current portion in prepaid expenses and other current assets (68) Non-current portion in other assets $ 5,804
Schedule of Notes Receivable	The following table reflects the classification of the note receivable within our Consolidated Balance Sheet: December 31, 2022 Note receivable $ 852 Less: current portion in prepaid expenses and other current assets (500) Non-current portion in other assets $ 352
Schedule of Accrued Liabilities	The following table shows the components of accrued liabilities: December 31, 2022 2021 Accrued expenses $ 17,022 $ 25,074 Accrued payroll and bonuses 5,732 7,798 Accrued preferred stock dividends 689 1,994 Accrued interest 2,853 2,008 Accrued liabilities $ 26,296 $ 36,874
Schedule of Changes in the Contingent Payments for Acquisitions	The following table presents the changes in the contingent payments for acquisitions: December 31, 2022 2021 Balance, beginning of period $ 1,950 $ 1,950 Add: interest accreted on contingent payments for acquisition — — Less: gain on change in contingent payment liability — — Balance, end of period $ 1,950 $ 1,950

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2022
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Asset Retirement Obligations	The following table reflects the activity for our asset retirement obligations: December 31, 2022 2021 Balance, beginning of period $ 42,413 $ 5,159 Liabilities incurred 64,479 50,590 Liabilities settled (37,901) (11,725) Accretion 4,359 2,012 Gain on ARO settlement, net (4,789) (3,623) Balance, end of period 68,561 42,413 Less: current portion (37,982) (27,534) Non-current portion $ 30,579 $ 14,879

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Goodwill	The Company’s intangible assets consist of the following as of: December 31, 2022 December 31, 2021 Gross Carrying Amount Accumulated Amortization and Impairment Net Carrying Amount Gross Carrying Amount Accumulated Amortization and Impairment Net Carrying Amount Definite-lived intangibles Customer relationships $ 78,942 $ (78,942) $ — $ 78,942 $ (38,727) $ 40,215 Indefinite-lived intangibles Charah trade name 13,316 (13,316) — 13,316 — 13,316 Total $ — $ 53,531

Notes Payable (Tables)

Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Schedule of Debt	The following table summarizes the significant components of debt at each balance sheet date and provides maturities and interest rate ranges for each major category as of December 31, 2022 and 2021: December 31, 2022 2021 Various equipment notes entered into in November 2017, payable in monthly installments ranging from $6 to $24, including interest at 5.2%, maturing in December 2022 through December 2023. The notes are secured by equipment with a net book value of $0 as of December 31, 2022. $ 565 $ 1,748 Various equipment notes entered into in 2018, payable in monthly installments ranging from $1 to $39, including interest ranging from 5.6% to 6.8%, maturing in March 2023 through May 2025. The notes are secured by equipment with a net book value of $3,469 as of December 31, 2022. 3,818 5,952 Various equipment notes entered into in 2019, payable in monthly installments ranging from $2 to $23, including interest ranging from 3.9% to 6.4%, maturing in April 2021 through December 2024. The notes are secured by equipment with a net book value of $1,295 as of December 31, 2022. 1,748 2,633 Various equipment notes entered in 2020, payable in monthly installments ranging from $9 to $10, including interest of 5.4%, maturing in August and September 2025. The notes are secured by equipment with a net book value of $1,098 as of December 31, 2022. 1,215 1,624 Various equipment notes entered into in 2021, payable in monthly installments ranging from $3 to $9, including interest ranging from 4.0% to 6.5%, maturing in February 2026 through August 2026. The notes are secured by equipment with a net book value of $1,696 as of December 31, 2022. 1,484 1,861 An equipment note entered into in 2022 with a customer, payable in monthly installments of $68 with no interest component, maturing with a balloon payment of the remaining outstanding balance in April 2023. The note is secured by equipment with a net book value of $3,784 as of December 31, 2022. 3,784 — Various commercial insurance premium financing agreements entered into in 2021, payable in monthly installments ranging from $24 to $117, including interest ranging from 3.0% to 3.9%, maturing in October 2021 through April 2022. — 467 Various commercial insurance premium financing agreements entered into in 2022, payable in monthly installments ranging from $19 to $143, including interest ranging from 4.2% to 5.3%, maturing in November 2022 through June 2023. 592 — A $10,000 equipment line with a bank, entered into in December 2017, secured by all equipment purchased with the proceeds of the loan. Interest is calculated on any outstanding amounts using a fixed rate of 4.5%. The equipment line converted to a term loan in September 2018, with a maturity date of June 22, 2023. The term loan is secured by equipment with a net book value of $459 as of December 31, 2022. 1,003 3,387 Term Loan Agreement, issued August 2022, and related amendments (see Note 10). After consideration of the amendment, the Term Loan Agreement bears interest at 12.0%, matures in April 2024 and is secured by land and land improvements with a book value of $13,404. 20,000 — Senior Unsecured Notes, issued August 2021 (see Note 10). The Notes are senior unsecured obligations of the Company, bearing stated interest at 8.50%, and rank equal in right of payment with the Company’s existing and future senior unsecured indebtedness. 135,000 135,000 Total 169,209 152,672 Less debt issuance costs (9,976) (11,444) 159,233 141,228 Less current maturities (9,649) (7,567) Notes payable due after one year $ 149,584 $ 133,661
Schedule of Maturities of Long-term Debt	Future maturities of notes payable at December 31 are as follows: For the Year Ending December 31, 2023 $ 9,649 2024 23,226 2025 1,122 2026 135,212 Total $ 169,209

Contract Assets and Liabiliti_2

Contract Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Schedule of Asset and Liabilities	Our contract assets are as follows: December 31, 2022 2021 Costs and estimated earnings in excess of billings $ 11,700 $ 17,163 Retainage 9,281 9,681 Total contract assets $ 20,981 $ 26,844 Our contract liabilities are as follows: December 31, 2022 2021 Deferred revenue $ 258 $ 483 Billings in excess of costs and estimated earnings 8,160 5,716 Total contract liabilities $ 8,418 $ 6,199
Costs in Excess of Billings and Billings in Excess of Costs	The following table sets forth the costs and estimated earnings on uncompleted contracts as of: December 31, 2022 2021 Costs incurred on uncompleted contracts $ 344,692 $ 227,195 Estimated earnings 20,267 22,331 Total costs and earnings 364,959 249,526 Less billings to date (361,419) (238,079) Costs and estimated earnings in excess of billings $ 3,540 $ 11,447 The following table sets forth the net balance in process as of: December 31, 2022 2021 Costs and estimated earnings in excess of billings $ 11,700 $ 17,163 Billings in excess of costs and estimated earnings (8,160) (5,716) Net balance in process $ 3,540 $ 11,447

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	A summary of the Company’s non-vested share activity for the year ended December 31, 2022 is as follows: Restricted Stock Performance Stock Total Shares Weighted-Average Grant Date Fair Value Shares Weighted-Average Grant Date Fair Value Shares Weighted-Average Grant Date Fair Value Balance as of December 31, 2021 89 $ 46.16 65 $ 42.40 154 $ 44.60 Granted 90 36.09 31 29.70 121 34.45 Forfeited (30) 44.28 (29) 56.45 (59) 50.24 Vested (61) 45.78 (4) 41.19 (65) 45.53 Balance as of December 31, 2022 88 $ 36.90 63 $ 30.21 151 $ 34.08 Restricted Stock Performance Stock Total Weighted Average Remaining Contractual Terms (Years) Aggregate Intrinsic Value Weighted Average Remaining Contractual Terms (Years) Aggregate Intrinsic Value Weighted Average Remaining Contractual Terms (Years) Aggregate Intrinsic Value Balance as of December 31, 2021 0.88 $ 4,072 1.26 $ 2,979 1.04 $ 7,051 Balance as of December 31, 2022 1.08 $ 476 1.33 $ 346 1.18 $ 822

Multiemployer Pension Plan (Tab

Multiemployer Pension Plan (Tables)	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
Schedule of Multiemployer Plans	The primary multiemployer plan to which AMS made contributions for the year ended December 31, 2022, 2021 and 2020 is outlined in the table below. The “EIN/Pension Plan Number” column provides the Employer Identification Number (“EIN”). The most recent Pension Protection Act zone status available in 2022 is for the respective multiemployer plan’s year-end within those years, unless otherwise noted. The zone status is based on information that AMS received from the multiemployer plans and is certified by the respective multiemployer plan’s actuary. Among other factors, multiemployer plans in the red zone (critical) are generally less than 65% funded, multiemployer plans in the yellow zone (endangered) are less than 80% funded, and multiemployer plans in the green zone (neither critical and declining, critical, or endangered) are at least 80% funded. The “FIP/RP Status Pending/Implemented” column indicates multiemployer plans for which a financial improvement plan (“FIP”) or a rehabilitation plan (“RP”) is either pending or has been implemented. The last column lists the expiration dates of the collective bargaining agreements to which the multiemployer plans are subject. Year ended December 31, 2022 Year ended December 31, 2021 Year ended December 31, 2020 Pension Fund EIN/Pension Pension Protection FIP/RP Status Contributions Contributions Contributions Surcharge Expiration Central states, southeast and southwest areas pension plan 36-6044243 Red - Critical and declining Progress under FIP or RP $ 59 $ 111 $ 55 No Continuous with notice period by either party Operating Engineers Local 324 Pension Fund 38-1900637 Red - Critical Progress under FIP or RP $ — $ — $ 27 Yes 2021 Employer Teamsters Locals 175 & 505 pension trust fund 55-6021850 Red - Critical Progress under FIP or RP $ 111 $ 81 $ 74 Yes 2023

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit) Attributable to Continuing Operations	The total income tax (benefit) expense on (loss) income before income taxes was allocated as follows: Year Ended December 31, 2022 2021 2020 Continuing operations $ (57) $ 661 $ (914) Discontinued operations — — 94 Total $ (57) $ 661 $ (820) The components of the provision for income taxes attributable to continuing operations for the year ended December 31, 2022, 2021, and 2020 is as follows: Year Ended December 31, 2022 2021 2020 Current income tax expense (benefit): Federal $ 72 $ — $ — State — 80 (80) 72 80 (80) Deferred income tax expense (benefit): Federal (280) 500 (843) State 151 81 9 (129) 581 (834) Total income tax expense (benefit) $ (57) $ 661 $ (914)
Schedule of Effective Income Tax Rate Reconciliation	The items accounting for differences between income taxes computed at the federal statutory rate and the (benefit) provision recorded for income taxes for continuing operations were as follows: Year Ended December 31, 2022 2021 2020 Income tax benefit at the federal statutory rate (21%) $ (26,914) $ (1,079) $ (13,537) State income tax (benefit) expense, net of federal tax benefit 119 127 (70) Non-controlling interest 55 (3) (251) Stock compensation 164 (164) 277 Valuation allowance 26,151 1,578 12,328 Foreign income tax differential 23 — — Permanent items 345 202 339 Total income tax (benefit) expense $ (57) $ 661 $ (914)
Schedule of Deferred Tax Assets and Liabilities	The components of the Company’s deferred tax assets and liabilities as of December 31, 2022 and 2021 are as follows: As of December 31, 2022 2021 Deferred tax assets: Loss carryovers $ 29,749 $ 14,333 Intangible assets 13,834 3,431 Other accrued expenses and reserves 2,056 2,326 Right-of-use liability 8,771 — Finance leases 517 1,091 Deferred asset sale 1,018 226 Accrued bonus 1,471 1,195 Asset retirement obligations 16,655 10,222 Capitalized cost 4,903 819 Deferred tax assets 78,974 33,643 Valuation allowance (50,311) (19,937) Net deferred tax asset 28,663 13,706 Deferred tax liabilities: Fixed assets, including land 12,433 9,757 Restricted cash from ERT projects 9,089 4,838 Right-of-use assets 7,955 — Prepaid expenses 5 60 Deferred tax liabilities 29,482 14,655 Net deferred tax liability $ 819 $ 949
Summary of Valuation Allowance	The change in the valuation allowance for deferred tax assets is as follows: As of December 31, 2022 2021 Beginning balance $ (19,937) $ (17,158) Current additions recorded in income tax (benefit) or expense (32,023) (2,708) Current reductions recorded in income tax (benefit) or expense 1,338 837 Other adjustments 311 (908) Ending balance $ (50,311) $ (19,937)

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Schedule Of Lease-Related Assets And Liabilities and Weighted-Average Lease Terms and Discount Rates	The following table presents the lease-related assets and liabilities reported in the Consolidated Balance Sheet as of December 31, 2022: Classification on the Consolidated Balance Sheet December 31, 2022 Assets Operating lease assets Operating lease right-of-use assets $ 32,748 Finance lease assets Real estate, property and equipment, net 49,306 Total lease assets $ 82,054 Liabilities Current Operating Operating lease liabilities, current $ 12,483 Finance Finance lease obligations, current 10,592 Non-current Operating Operating lease liabilities, long-term 23,621 Finance Finance lease obligations, less current portion 24,585 Total lease liabilities $ 71,281 December 31, 2022 Weighted-average remaining term in years Operating leases 3.68 Finance leases 4.41 Weighted-average discount rate Operating leases 7.4 % Finance leases 7.2 %
Schedule of Supplemental Cash Flow and Other Information Related to Leases Expense	The following table presents information related to our lease expense for the years ended December 31, 2022: December 31, 2022 Finance lease costs: Amortization expense $ 9,785 Interest expense 2,483 Operating lease costs 13,893 Short-term lease expense 464 Total lease expense $ 26,625 The following table presents supplemental cash flow information related to our leases for the years ended December 31, 2022: December 31, 2022 Cash paid amounts included in the measurement of lease liabilities: Operating cash flows used for operating leases $ 14,118 Operating cash flows used for finance leases 2,453 Financing cash flows used for finance leases 9,381 Total $ 25,952 Right-of-use assets obtained in exchange for: New operating lease liabilities $ 15,866 New finance lease liabilities 18,134 Total $ 34,000
Schedule of Finance Lease Payments	The following table reconciles our future minimum lease payments on an undiscounted cash flow basis to our lease liabilities reported in the Consolidated Balance Sheet as of December 31, 2022: For the Years Ending December 31, Operating Leases Finance Leases 2023 $ 14,583 $ 12,825 2024 9,354 10,628 2025 5,150 9,172 2026 3,935 6,500 2027 3,069 939 Thereafter 6,122 — Total minimum lease payments $ 42,213 $ 40,064 Less: Amount of lease payments representing interest (6,109) (4,887) Present value of future minimum lease payments $ 36,104 $ 35,177 Current portion of lease liabilities $ 12,483 $ 10,592 Noncurrent portion of lease liabilities 23,621 24,585 Total lease liabilities $ 36,104 $ 35,177
Schedule of Operating Lease Payments	The following table reconciles our future minimum lease payments on an undiscounted cash flow basis to our lease liabilities reported in the Consolidated Balance Sheet as of December 31, 2022: For the Years Ending December 31, Operating Leases Finance Leases 2023 $ 14,583 $ 12,825 2024 9,354 10,628 2025 5,150 9,172 2026 3,935 6,500 2027 3,069 939 Thereafter 6,122 — Total minimum lease payments $ 42,213 $ 40,064 Less: Amount of lease payments representing interest (6,109) (4,887) Present value of future minimum lease payments $ 36,104 $ 35,177 Current portion of lease liabilities $ 12,483 $ 10,592 Noncurrent portion of lease liabilities 23,621 24,585 Total lease liabilities $ 36,104 $ 35,177
Schedule of Future Minimum Rental Payments for Operating Leases	The Company's future minimum lease payments for operating leases as of December 31, 2021 are as follows: For the Years Ending December 31, Operating Leases 2022 $ 10,216 2023 9,271 2024 5,646 2025 2,151 2026 1,003 Thereafter 819 Total $ 29,106

Loss Per Share (Tables)

Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Schedule of Loss Per Share, Basic and Diluted	Basic and diluted loss per share is determined using the following information: Year Ended December 31, 2022 2021 2020 Numerator: Net loss from continuing operations $ (127,843) $ (5,814) $ (64,746) Deemed and imputed dividends on Series A Preferred Stock (599) (592) (461) Series A Preferred Stock dividends (5,307) (8,156) (4,064) Net loss from continuing operations attributable to common stockholders (133,749) (14,562) (69,271) Net income from discontinued operations — — 8,883 Net loss attributable to common stockholders $ (133,749) $ (14,562) $ (60,388) Denominator: Weighted average shares outstanding 3,363 3,157 2,990 Dilutive share-based awards — — — Total weighted average shares outstanding, including dilutive shares 3,363 3,157 2,990 Net loss from continuing operations per common share Basic $ (39.77) $ (4.61) $ (23.17) Diluted $ (39.77) $ (4.61) $ (23.17) Net income from discontinued operations per common share Basic $ — $ — $ 2.97 Diluted $ — $ — $ 2.97 Net loss attributable to common stockholders per common share Basic $ (39.77) $ (4.61) $ (20.20) Diluted $ (39.77) $ (4.61) $ (20.20)
Schedule of Antidilutive Securities Excluded from Computation	A summary of securities excluded from the computation of diluted earnings per share is presented below: Year Ended December 31, 2022 2021 2020 Diluted earnings per share: Anti-dilutive restricted and performance stock units 180 132 151 Anti-dilutive Series A and Series B Preferred Stock convertible into common stock 1,467 1,092 774 Potentially dilutive securities, excluded as anti-dilutive 1,647 1,224 925

Major Customers (Tables)

Major Customers (Tables)	12 Months Ended
	Dec. 31, 2022
Risks and Uncertainties [Abstract]
Schedules of Concentration of Risk, by Risk Factor	Revenues from certain customers in excess of 10% of total consolidated revenues for the years ended December 31 are as follows: December 31, 2022 Revenue % of Total % of A/R, net Customer 1 $ 64,484 22.0 % 28.9 % December 31, 2021 Revenue % of Total % of A/R, net Customer 1 $ 40,590 13.8 % 4.6 % Customer 2 34,788 11.9 % 11.1 % Customer 3 29,670 10.1 % 2.4 %

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2022
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following table summarizes the unaudited quarterly results of operations for the year ended December 31, 2022 and 2021: First Quarter Second Quarter Third Quarter Fourth Quarter (a) 2022 Revenue $ 66,051 $ 77,110 $ 81,540 $ 68,466 Operating income (loss) (7,392) (4,795) (8,902) (88,499) Income (loss) from continuing operations, net of tax and non-controlling interest (12,040) (9,603) (13,359) (92,841) Deemed and imputed dividends on Series A Preferred Stock (149) (150) (150) (150) Series A Preferred Stock dividends (2,090) (1,571) (956) (690) Net loss from continuing operations attributable to common stockholders (14,279) (11,324) (14,465) (93,681) Income from discontinued operations, net of tax — — — — Net loss attributable to common stockholders (14,279) (11,324) (14,465) (93,681) Net loss from continuing operations per common share Basic $ (4.30) $ (3.40) $ (4.30) $ (27.72) Diluted $ (4.30) $ (3.40) $ (4.30) $ (27.72) Net loss attributable to common stockholders per common share Basic $ (4.30) $ (3.40) $ (4.30) $ (27.72) Diluted $ (4.30) $ (3.40) $ (4.30) $ (27.72) First Quarter (b) Second Quarter Third Quarter Fourth Quarter (c) 2021 Revenue $ 52,107 $ 63,518 $ 84,161 $ 93,433 Operating loss 1,978 (770) 2,661 6,669 Deemed and imputed dividends on Series A Preferred Stock (147) (148) (148) (149) Series A Preferred Stock dividends (2,067) (2,148) (1,946) (1,995) Income from discontinued operations, net of tax — — — — Net loss attributable to common stockholders (3,501) (6,462) (3,771) (828) Net loss from continuing operations per common share Basic $ (1.20) $ (2.10) $ (1.16) $ (0.15) Diluted $ (1.20) $ (2.10) $ (1.16) $ (0.15) Net loss attributable to common stockholders per common share Basic $ (1.20) $ (2.10) $ (1.16) $ (0.15) Diluted $ (1.20) $ (2.10) $ (1.16) $ (0.15) (a) Fourth-quarter of 2022 includes a $2,112 reversal of revenue associated with the legal investigation discussed in Note 17. The reversal of revenue corrects errors identified for the period from January 2018 through September 2022, which were not material to the consolidated financial statements for any of the affected unaudited or audited periods. In addition, the Company recognized a $62,271 impairment of intangible assets, equipment and construction in process. (b) First-quarter of 2021 includes a $5,568 gain on sales-type lease in operating income (loss). (c) Fourth-quarter of 2021 includes a $14,669 gain on the sale of real estate and $4,750 in accrued bonus.

Nature of Business and Basis _2

Nature of Business and Basis of Presentation (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 segment	Nov. 19, 2020 USD ($)
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Number of reportable segments | segment	1
Discontinued Operations, Disposed of by Sale | Allied Transaction
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Consideration | $		$ 40,000
Charah Solutions | BCP
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Ownership percentage by noncontrolling owners	73%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Restricted cash	$ 40,100	$ 34,908	$ 4,424

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Trade Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Allowance for accounts receivable	$ 1,130	$ 146

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Property, Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2022
Plant, machinery and equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Plant, machinery and equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	15 years
Vehicles | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Vehicles | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Office equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Office equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Buildings and leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Buildings and leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	40 years
Finance lease assets | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Finance lease assets | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	7 years

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Goodwill and Intangible Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	$ 0	$ 53,531,000
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	10 years

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Fair Value Disclosure (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Aug. 25, 2021
Finite-Lived Intangible Assets [Line Items]
Long-term debt, carrying value	$ 169,209	$ 152,672
Contingent payments for acquisitions	1,950	1,950
Recurring
Finite-Lived Intangible Assets [Line Items]
Contingent payments for acquisitions	1,950	1,950
Level 1 | Recurring
Finite-Lived Intangible Assets [Line Items]
Contingent payments for acquisitions	0	0
Level 2 | Recurring
Finite-Lived Intangible Assets [Line Items]
Contingent payments for acquisitions	0	0
Level 3 | Recurring
Finite-Lived Intangible Assets [Line Items]
Contingent payments for acquisitions	1,950	1,950
Notes Payable
Finite-Lived Intangible Assets [Line Items]
Long-term debt, carrying value	$ 169,209
8.50% Senior Notes Due 2026 | Senior Notes
Finite-Lived Intangible Assets [Line Items]
Interest rate	8.50%		8.50%
Long-term debt, fair value	$ 54,594	131,760
Long-term debt, carrying value	135,000	$ 135,000
Various Equipment Financing Notes | Notes Payable
Finite-Lived Intangible Assets [Line Items]
Long-term debt, carrying value	14,209
Various Equipment Financing Notes | Notes Payable | Level 2
Finite-Lived Intangible Assets [Line Items]
Long-term debt, fair value	$ 14,209

Discontinued Operations - Narra

Discontinued Operations - Narrative (Details) - USD ($) $ in Thousands		12 Months Ended
	Nov. 19, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contribution from sale of subsidiary to entity under common control				$ 25,506
Proceeds from the sale of subsidiary, net of subsidiary cash		$ 0	$ 0	$ 37,860
Discontinued Operations, Disposed of by Sale | Allied Transaction
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration	$ 40,000
Contribution from sale of subsidiary to entity under common control	25,506
Recognized credit cost of sales		0	60
Accounts receivable outstanding	25,752	$ 0	0
Proceeds from the sale of subsidiary, net of subsidiary cash			37,860
Discontinued operation transaction costs			1,900
Restricted cash	$ 240		240
Liabilities assumed			3,500
Adjustments to additional paid in capital other			301
Accrued on working capital adjustments			6,954
Other transaction costs			$ 413

Discontinued Operations - Derec

Discontinued Operations - Derecognized Assets and Liabilities (Details) - Discontinued Operations, Disposed of by Sale - Allied Transaction - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Nov. 19, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restricted cash		$ 240	$ 240
Trade accounts receivable, net	$ 0	$ 0	25,752
Prepaid expenses and other current assets			1,453
Real estate, property and equipment, net			1,112
Goodwill			12,020
Accounts payable			(8,681)
Accrued liabilities			(26,367)
Carrying value of Allied			$ 5,529

Discontinued Operations - Conti

Discontinued Operations - Continuing Operations and Discontinued Operations in Our Consolidated & Combined Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax expense									$ 0	$ 0	$ 94
Income from discontinued operations	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	8,883
Discontinued Operations, Disposed of by Sale | Allied Transaction
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue											314,251
Cost of sales											295,423
Gross (loss) profit											18,828
General and administrative expenses											7,106
Operating (loss) income											11,722
Interest expense, net											(2,745)
Income from discontinued operations before income taxes											8,977
Income tax expense											94
Income from discontinued operations											$ 8,883

Discontinued Operations - Suppl

Discontinued Operations - Supplemental Cash, Cash Equivalent and Restricted Cash Information Related to Discontinued Operations (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash and restricted cash:
Cash and restricted cash - continuing operations			$ 29,211
Cash and restricted cash - discontinued operations			0
Total cash and restricted cash	$ 61,659	$ 59,174	$ 29,211	$ 6,128

Discontinued Operations - Depre

Discontinued Operations - Depreciation and Amortization, Capital Expenditures and Significant Operating Noncash Items (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from discontinued operating activities:
Non-cash share-based compensation	$ 2,660	$ 2,702	$ 2,539
Discontinued Operations, Disposed of by Sale | Allied Transaction
Cash flows from discontinued operating activities:
Depreciation and amortization			755
Loss on disposal of fixed assets			22
Non-cash share-based compensation			145
Cash flows from discontinued investing activities:
Purchases of property and equipment, including costs of demolition			$ 93

Revenue - Schedule of Disaggreg

Revenue - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenue	$ 68,466	$ 81,540	$ 77,110	$ 66,051	$ 93,433	$ 84,161	$ 63,518	$ 52,107	$ 293,167	$ 293,219	$ 232,377
United States
Disaggregation of Revenue [Line Items]
Total revenue									293,167	293,219	231,032
Foreign
Disaggregation of Revenue [Line Items]
Total revenue									0	0	1,345
Construction contracts
Disaggregation of Revenue [Line Items]
Total revenue									140,798	160,632	80,805
Byproduct services
Disaggregation of Revenue [Line Items]
Total revenue									105,981	101,355	106,704
Raw material sales
Disaggregation of Revenue [Line Items]
Total revenue									$ 46,388	$ 31,232	$ 44,868

Revenue - Performance Obligatio

Revenue - Performance Obligations (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation, amount	$ 517,914
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue from Contract with Customer [Abstract]
Expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage	19%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue from Contract with Customer [Abstract]
Expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage	13%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue from Contract with Customer [Abstract]
Expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage	11%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue from Contract with Customer [Abstract]
Expected timing of satisfaction, period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage	56%

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Thousands	5 Months Ended
	May 26, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Unapproved change orders		$ 2,923
Subsequent Event
Disaggregation of Revenue [Line Items]
Changes orders amount approved	$ 2,330

Asset Acquisition - Narrative (

Asset Acquisition - Narrative (Details)		1 Months Ended	3 Months Ended	12 Months Ended
	Apr. 06, 2022 USD ($) a ashPond	Feb. 28, 2021 a	Dec. 31, 2021 USD ($)	Dec. 31, 2022 USD ($) a acquisition	Dec. 31, 2021 USD ($) acquisition	Dec. 31, 2020 USD ($)	Apr. 04, 2022 a	Jan. 31, 2021 USD ($)
Schedule of Asset Acquisition [Line Items]
Number of acquisitions during period | acquisition				2	1
Gains on sales of real estate, property and equipment, net			$ 14,669,000	$ 12,245,000	$ 23,543,000	$ 0
Number of ash ponds | ashPond	2
Realization of deferred gain on ERT project performance				284,000	$ 0	$ 0
Property redevelopment term		34 months
Real Property Acreage
Schedule of Asset Acquisition [Line Items]
Net proceeds from sale of property, plant, and equipment				0
Asset Purchase Agreement
Schedule of Asset Acquisition [Line Items]
Asset acquisition deferred gain	$ 4,476,000
Decommissioning and redevelopment period, after acquisition	42 months
Post closure monitoring period	30 years
Sale Of Plant, Machinery And Equipment And Vehicles
Schedule of Asset Acquisition [Line Items]
Book value of assets held for sale sold				505,000
Net proceeds from sale of property, plant, and equipment				1,565,000
Gains on sales of real estate, property and equipment, net	$ 526,000			$ 1,060,000
Avon Lake Property
Schedule of Asset Acquisition [Line Items]
Area of land | a							40
Cheswick Generating Station Asset Acquisition Primary Generating Station Site
Schedule of Asset Acquisition [Line Items]
Area of land | a	56
Cheswick Generating Station Asset Acquisition
Schedule of Asset Acquisition [Line Items]
Area of land | a	27
Cheswick Generating Station In Cheswick, PA
Schedule of Asset Acquisition [Line Items]
Area of land | a	182
Cheswick Generating Station Asset Acquisition Landfill Facility
Schedule of Asset Acquisition [Line Items]
Area of land | a	50
Texas Municipal Power Agency
Schedule of Asset Acquisition [Line Items]
Area of land | a		6,166
Gibbons Creek Steam Reservoir, Dam and Floodway
Schedule of Asset Acquisition [Line Items]
Area of land | a		3,500		3,500
Gibbons Creek Steam Electric Station And Reservoir
Schedule of Asset Acquisition [Line Items]
Area of land | a				4,860
Net proceeds from sale of property, plant, and equipment				$ 23,575,000
Gains on sales of real estate, property and equipment, net				$ 14,669,000
Sale of property percentage				80%
Gibbons Creek Steam Electric Station And Reservoir | Sale Of Plant, Machinery And Equipment And Vehicles
Schedule of Asset Acquisition [Line Items]
Book value of assets held for sale sold								$ 193,000

Asset Acquisition - Assets acqu

Asset Acquisition - Assets acquired and liabilities assumed (Details) - USD ($) $ in Thousands			1 Months Ended
	Apr. 06, 2022	Apr. 04, 2022	Feb. 28, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Consideration and direct transaction costs:
Asset retirement obligations				$ (68,561)	$ (42,413)	$ (5,159)
Asset Purchase Agreement
Consideration and direct transaction costs:
Asset retirement obligations	$ (30,179)	$ (34,300)	$ (50,590)
Bond and insurance accrued expenses, net			(2,229)
Direct transaction costs	(684)	(1,345)	(2,336)
Total consideration and transaction costs incurred	(30,863)	(35,645)	(55,155)
Asset Received:
Cash	5,577		6,354
Restricted cash	29,762	2,900	28,546
Water rights			5,196
Land			14,385
Land, land improvements and structural fill sites		32,109
Plant, machinery and equipment		623	610
Vehicles		13	64
Total allocated value of assets acquired	35,339	$ 35,645	$ 55,155
Excess of fair value of assets acquired over total consideration – deferred gain	$ (4,476)
Other Assumptions:
Inflation rate	2.50%	2.50%	3%
Weighted average rate applicable to our long-term asset retirement obligations	7.45%	7.35%	4.50%

Balance Sheet Items - Schedule

Balance Sheet Items - Schedule of Property and equipment, net (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Finance lease assets	$ 49,306	$ 31,172
Total property and equipment	222,719	177,207
Less: accumulated depreciation	(128,779)	(106,734)
Property and equipment, net	93,940	70,473
Plant, machinery and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	60,377	63,937
Structural fill site improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	55,760	55,760
Vehicles
Property, Plant and Equipment [Line Items]
Total property and equipment	11,619	11,718
Office equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	600	600
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	267	267
Land, land improvements and structural fill sites
Property, Plant and Equipment [Line Items]
Total property and equipment	44,790	12,231
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 0	$ 1,522

Balance Sheet Items - Narrative

Balance Sheet Items - Narrative (Details) - USD ($)		1 Months Ended			12 Months Ended
	Mar. 30, 2018	Jun. 30, 2021	Mar. 31, 2021	Nov. 30, 2018	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Demolition cost capitalized					$ 3,129,000
Cost basis on scrap sold					2,679,000
Depreciation					19,363,000	$ 16,718,000	$ 17,659,000
Impairment of long-lived assets					10,484,000
Long-lived assets impaired, fair value					20,003,000
Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration]							Impairment expense
Impairment expense					62,271,000	827,000	$ 40,772,000
Inventory impairment on remaining fair value					8,000		1,090,000
Sale leaseback transaction, terms			30 years
Discount rate			3.90%
Gain on sales-type lease					0	5,568,000	0
Non-current assets held for sale		$ 2,852,000
Proceeds from sale of assets		$ 1,250,000
Asset sale agreement, final payment to be received, term		36 months
Gain on disposition of fixed asset						1,187,000
Gain on change in contingent payment liability					0	0	9,702,000
Contingent payments for acquisitions					1,950,000	1,950,000
Gibbons Creek Transaction
Property, Plant and Equipment [Line Items]
Real property acquired being demolished					$ 19,107,000
SBC Materials International, Inc.
Property, Plant and Equipment [Line Items]
Purchase price	$ 35,000
Payment at closing	20,000
Additional payment to be paid based on certain performance metrics	$ 15,000			$ 15,000
Gain on change in contingent payment liability				$ 3,300,000
Cost of Sales
Property, Plant and Equipment [Line Items]
Impairment expense							2,757,000
Certain Technology-Related Equipment
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets						673,000
Long-lived assets impaired, fair value						$ 0
Structural Fill Sites
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets							6,399,000
Long-lived assets impaired, fair value							711,000
Construction in progress
Property, Plant and Equipment [Line Items]
Impairment expense							$ 9,150,000

Balance Sheet Items - Lease Rec

Balance Sheet Items - Lease Receivable (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Lease receivable	$ 5,872
Less: current portion in prepaid expenses and other current assets	(68)
Non-current portion in other assets	$ 5,804

Balance Sheet Items - Note Rece

Balance Sheet Items - Note Receivable (Details) - Notes Receivable $ in Thousands	Dec. 31, 2022 USD ($)
Related Party Transaction [Line Items]
Note receivable	$ 852
Less: current portion in prepaid expenses and other current assets	(500)
Non-current portion in other assets	$ 352

Balance Sheet Items - Schedul_2

Balance Sheet Items - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued expenses	$ 17,022	$ 25,074
Accrued payroll and bonuses	5,732	7,798
Accrued preferred stock dividends	689	1,994
Accrued interest	2,853	2,008
Accrued liabilities	$ 26,296	$ 36,874

Balance Sheet Items - Schedul_3

Balance Sheet Items - Schedule of Changes in the Contingent Payments for Acquisitions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration [Roll Forward]
Balance, beginning of period	$ 1,950	$ 1,950
Add: interest accreted on contingent payments for acquisition	0	0
Less: gain on change in contingent payment liability	0	0	$ (9,702)
Balance, end of period	$ 1,950	$ 1,950	$ 1,950

Asset Retirement Obligations -

Asset Retirement Obligations - Narrative (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) tract_of_real_property site	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Property, Plant and Equipment [Line Items]
Number of structural sites owned and operated | site	2
Number of tracts of real property | tract_of_real_property	8
Asset retirement obligations	$ 68,561,000	$ 42,413,000	$ 5,159,000
Structural fill site, required period to maintain and monitor	30 years
Gain on ARO settlement, net	$ 4,789,000	$ 3,623,000	0
Structural Fill Sites
Property, Plant and Equipment [Line Items]
Asset retirement obligations			0
ARO, downward revision of estimate			2,127,000
Asset retirement obligation, period decrease			279,000
Asset retirement obligation, reduction			$ 1,848,000
Land, land improvements and structural fill sites
Property, Plant and Equipment [Line Items]
Inflation rate	3%
Weighted average rate applicable to our long-term asset retirement obligations	5.25%

Asset Retirement Obligations _2

Asset Retirement Obligations - Schedule of Asset Retirement Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance, beginning of period	$ 42,413	$ 5,159
Liabilities incurred	64,479	50,590
Liabilities settled	(37,901)	(11,725)
Accretion	4,359	2,012
Gain on ARO settlement, net	(4,789)	(3,623)	$ 0
Balance, end of period	68,561	42,413	$ 5,159
Less: current portion	(37,982)	(27,534)
Non-current portion	$ 30,579	$ 14,879

Distributions to Stockholders_2

Distributions to Stockholders, Receivable from Affiliates, and Related Party Transactions (Details) - USD ($)	1 Months Ended		12 Months Ended
	Nov. 30, 2022	Mar. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Aug. 25, 2021
Related Party Transaction [Line Items]
Payments of debt issuance costs			$ 861,000	$ 13,380,000	$ 1,623,000
Issuance of Series A & B Preferred Stock, net of issuance costs (in shares)					26,000
Series A Preferred Stock
Related Party Transaction [Line Items]
Series A Preferred Stock, shares issued (in shares)			26,000
Series B Preferred Stock
Related Party Transaction [Line Items]
Series A Preferred Stock, shares issued (in shares)			30,000	30,000
Issuance of Series A & B Preferred Stock, net of issuance costs (in shares)			30,000	0
8.50% Senior Notes Due 2026 | Senior Notes
Related Party Transaction [Line Items]
Debt instrument						$ 135,000,000
Additional purchase amount						5,000,000
Amendment No. 3 to Credit Agreement | Series A Preferred Stock
Related Party Transaction [Line Items]
Issuance of Series A & B Preferred Stock, net of issuance costs (in shares)		26,000
Charah, LLC | 8.50% Senior Notes Due 2026 | Senior Notes
Related Party Transaction [Line Items]
Debt instrument						17,852,000
Affiliated Entity | BCP | Series A Preferred Stock
Related Party Transaction [Line Items]
Issuance of Series A & B Preferred Stock, net of issuance costs (in shares)		26,000
Affiliated Entity | BCP | Series B Preferred Stock
Related Party Transaction [Line Items]
Issuance of Series A & B Preferred Stock, net of issuance costs (in shares)	30,000
Affiliated Entity | Environmental Consulting and Engineering Services | ATC Group Services, LLC
Related Party Transaction [Line Items]
Expenses from transactions with related party			$ 55,000	$ 100,000	$ 288,000
Receivable due from equity method investment			0	0
Payable to related parties			$ 14,000	4,000
B. Riley Securities, Inc | 8.50% Senior Notes Due 2026 | Senior Notes
Related Party Transaction [Line Items]
Debt instrument						$ 80,325,000
Payments of debt issuance costs				$ 7,914,000

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Line Items]
Goodwill	$ 62,193,000	$ 62,193,000
Goodwill, impairment loss	0	0
Amortization of intangible assets	$ 5,921,000	7,894,000	$ 8,582,000
Impairment, Intangible Asset, Finite-Lived, Statement of Income or Comprehensive Income [Extensible Enumeration]	Impairment expense
Impairment, Intangible Asset, Indefinite-Lived (Excluding Goodwill), Statement of Income or Comprehensive Income [Extensible Enumeration]			Impairment expense
Impairment charges	$ 34,295,000	$ 1,452,000
Charah trade name
Goodwill [Line Items]
Impairment of intangible assets	$ 13,316,000		$ 21,014,000
Impairment, Intangible Asset, Indefinite-Lived (Excluding Goodwill), Statement of Income or Comprehensive Income [Extensible Enumeration]	Impairment expense		Impairment expense

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Goodwill and Intangible Assets (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Roll Forward]
Gross Carrying Amount	$ 13,316,000	$ 13,316,000
Indefinite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	13,316,000	13,316,000
Accumulated Amortization and Impairment	(13,316,000)	0
Intangible Assets, Gross (Including Goodwill) [Roll Forward]
Intangible assets, net	0	53,531,000
Charah trade name
Indefinite-Lived Intangible Assets [Line Items]
Net Carrying Amount	0	13,316,000
Customer Relationships [Member]
Finite-Lived Intangible Assets [Roll Forward]
Gross Carrying Amount	78,942,000	78,942,000
Accumulated Amortization and Impairment	(78,942,000)	(38,727,000)
Net Carrying Amount	$ 0	$ 40,215,000

Long-term Debt (Details)

Long-term Debt (Details)				12 Months Ended
	Aug. 15, 2022 USD ($)	Nov. 09, 2021 USD ($) trading_day	Aug. 25, 2021 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Sep. 21, 2018 USD ($)
Debt Instrument [Line Items]
Proceeds from issuance of common stock			$ 13,000	$ 0	$ 13,000,000	$ 0
Debt issuance costs				9,976,000	11,444,000
Repayments of debt				0	128,083,000	46,397,000
Write off of debt issue costs					638,000
Term Loan Agreement | Affiliated Entity
Debt Instrument [Line Items]
Debt issuance costs	$ 598,000
Face amount of delayed-draw term loan	$ 20,000,000
Interest rate	12%
Commitment fee	$ 1,000,000
Letter of Credit
Debt Instrument [Line Items]
Letters of credit outstanding				$ 10,687,000
8.50% Senior Notes Due 2026 | Senior Notes
Debt Instrument [Line Items]
Debt instrument			$ 135,000,000
Debt instrument, redemption price, percentage			100%
Interest rate			8.50%	8.50%
Percentage of principal amount, minimum			25%
Debt issuance costs			$ 12,116,000
8.50% Senior Notes Due 2026 | Senior Notes | Period 1
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage			103%
8.50% Senior Notes Due 2026 | Senior Notes | Period 2
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage			102%
8.50% Senior Notes Due 2026 | Senior Notes | Period 3
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage			100%
8.50% Senior Notes Due 2026, Additional Borrowings | Senior Notes
Debt Instrument [Line Items]
Debt instrument			$ 5,000,000
Credit Agreement | Senior Notes
Debt Instrument [Line Items]
Debt issuance costs				$ 1,366,000
Credit Agreement | Line of Credit | Minimum
Debt Instrument [Line Items]
Provision for sustainability adjustment, percentage		0.05%
Credit Agreement | Line of Credit | Maximum
Debt Instrument [Line Items]
Provision for sustainability adjustment, percentage		(0.05%)
Credit Agreement | Line of Credit | Adjusted LIBOR
Debt Instrument [Line Items]
Basis spread		2.25%
Additional basis spread on basis spread		1.25%
Credit Agreement | Line of Credit | Fed Funds Effective Rate Overnight Index Swap Rate
Debt Instrument [Line Items]
Basis spread		0.50%
Credit Agreement | Line of Credit | One Month Adjusted LIBOR
Debt Instrument [Line Items]
Basis spread		1%
Credit Agreement | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt, term		4 years
Maximum borrowing capacity		$ 30,000,000
Accordion feature, higher borrowing capacity option		5,000,000
Maximum availability		$ 1,000,000
Percentage of Lesser of the aggregate revolving commitments and the borrowing base		0.125
PP&E component		$ 7,500,000
Line of credit facility, consecutive business days, maximum borrowing capacity		$ 3,500,000
Line of credit facility, consecutive business day | trading_day		3
Line of credit facility, threshold consecutive months | trading_day		12
Line of credit facility, fixed charge coverage ratio		1
Long-term line of credit				$ 0
Credit Agreement | Line of Credit | Bridge Loan
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 5,000,000
Credit Agreement | Line of Credit | Letter of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 5,000,000
Syndicated Credit Facility | Line of Credit
Debt Instrument [Line Items]
Interest rate				12%
Repayments of debt					114,123,000
Payment of debt accrued fees					2,000,000
Syndicated Credit Facility | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity							$ 50,000,000
Letters of credit outstanding						$ 11,079,000
Repayments of debt					$ 12,340,000
Syndicated Credit Facility | Line of Credit | Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity							205,000,000
Syndicated Credit Facility | Line of Credit | Loan Commitment
Debt Instrument [Line Items]
Accordion feature, higher borrowing capacity option							$ 25,000,000

Notes Payable - Schedule of Deb

Notes Payable - Schedule of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Aug. 25, 2021
Debt Instrument [Line Items]
Total	$ 169,209	$ 152,672
Less debt issuance costs	(9,976)	(11,444)
Total	159,233	141,228
Less current maturities	(9,649)	(7,567)
Notes payable due after one year	149,584	133,661
Notes Payable
Debt Instrument [Line Items]
Total	169,209
Equipment Notes Payable, 5.2 % Due December 2022 and 2023 | Notes Payable
Debt Instrument [Line Items]
Total	$ 565	1,748
Interest rate	5.20%
Equipment net book value	$ 0
Equipment Notes Payable, 5.2 % Due December 2022 and 2023 | Notes Payable | Minimum
Debt Instrument [Line Items]
Monthly installments	6
Equipment Notes Payable, 5.2 % Due December 2022 and 2023 | Notes Payable | Maximum
Debt Instrument [Line Items]
Monthly installments	24
Equipment Notes Payable, 5.6% and 6.8% Due March 2023 Through May 2025 | Notes Payable
Debt Instrument [Line Items]
Total	3,818	5,952
Equipment net book value	3,469
Equipment Notes Payable, 5.6% and 6.8% Due March 2023 Through May 2025 | Notes Payable | Minimum
Debt Instrument [Line Items]
Monthly installments	$ 1
Interest rate	5.60%
Equipment Notes Payable, 5.6% and 6.8% Due March 2023 Through May 2025 | Notes Payable | Maximum
Debt Instrument [Line Items]
Monthly installments	$ 39
Interest rate	6.80%
Equipment Notes Payable, 3.9% and 6.4% Due April 2021 Through December 2024 | Notes Payable
Debt Instrument [Line Items]
Total	$ 1,748	2,633
Equipment net book value	1,295
Equipment Notes Payable, 3.9% and 6.4% Due April 2021 Through December 2024 | Notes Payable | Minimum
Debt Instrument [Line Items]
Monthly installments	$ 2
Interest rate	3.90%
Equipment Notes Payable, 3.9% and 6.4% Due April 2021 Through December 2024 | Notes Payable | Maximum
Debt Instrument [Line Items]
Monthly installments	$ 23
Interest rate	6.40%
Equipment Notes Payable, 5.4 % Due August and September 2025 | Notes Payable
Debt Instrument [Line Items]
Total	$ 1,215	1,624
Interest rate	5.40%
Equipment net book value	$ 1,098
Equipment Notes Payable, 5.4 % Due August and September 2025 | Notes Payable | Minimum
Debt Instrument [Line Items]
Monthly installments	9
Equipment Notes Payable, 5.4 % Due August and September 2025 | Notes Payable | Maximum
Debt Instrument [Line Items]
Monthly installments	10
Equipment Notes Payable 4.0% to 6.5% Percent Due February 2026 through August 2026 | Term Loan
Debt Instrument [Line Items]
Total	1,484	1,861
Equipment net book value	1,696
Equipment Notes Payable 4.0% to 6.5% Percent Due February 2026 through August 2026 | Term Loan | Minimum
Debt Instrument [Line Items]
Monthly installments	$ 3
Interest rate	4%
Equipment Notes Payable 4.0% to 6.5% Percent Due February 2026 through August 2026 | Term Loan | Maximum
Debt Instrument [Line Items]
Monthly installments	$ 9
Interest rate	6.50%
Equipment Notes Payable Due 2022 Through April 2023 | Notes Payable
Debt Instrument [Line Items]
Monthly installments	$ 68
Equipment net book value	3,784
Equipment Notes Payable Due 2022 Through April 2023 | Line of Credit
Debt Instrument [Line Items]
Total	3,784	0
Commercial Insurance Premium Financing Agreement 3.0% to 3.9% Due October through April 2022 | Line of Credit
Debt Instrument [Line Items]
Total	0	467
Commercial Insurance Premium Financing Agreement 3.0% to 3.9% Due October through April 2022 | Line of Credit | Minimum
Debt Instrument [Line Items]
Monthly installments		$ 24
Interest rate		3%
Commercial Insurance Premium Financing Agreement 3.0% to 3.9% Due October through April 2022 | Line of Credit | Maximum
Debt Instrument [Line Items]
Monthly installments		$ 117
Interest rate		0.039%
Commercial Insurance Premium Financing Agreement 4.2 % to 5.3% Due November 2022 | Line of Credit
Debt Instrument [Line Items]
Total	592	$ 0
Commercial Insurance Premium Financing Agreement 4.2 % to 5.3% Due November 2022 | Line of Credit | Minimum
Debt Instrument [Line Items]
Monthly installments	$ 19
Interest rate	4.20%
Commercial Insurance Premium Financing Agreement 4.2 % to 5.3% Due November 2022 | Line of Credit | Maximum
Debt Instrument [Line Items]
Monthly installments	$ 143
Interest rate	5.30%
4.5% Equipment Line Of Credit | Line of Credit
Debt Instrument [Line Items]
Total	$ 1,003	3,387
Total	$ 459
Interest rate	4.50%
Initial commitment	$ 10,000
Syndicated Credit Facility | Line of Credit
Debt Instrument [Line Items]
Total	$ 20,000	0
Interest rate	12%
Equipment net book value	$ 13,404
8.50% Senior Notes Due 2026 | Senior Notes
Debt Instrument [Line Items]
Total	$ 135,000	$ 135,000
Less debt issuance costs			$ (12,116)
Interest rate	8.50%		8.50%

Notes Payable - Maturities of N

Notes Payable - Maturities of Notes Payable (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Total	$ 169,209	$ 152,672
Notes Payable
Debt Instrument [Line Items]
2023	9,649
2024	23,226
2025	1,122
2026	135,212
Total	$ 169,209

Sale-leaseback Transaction (Det

Sale-leaseback Transaction (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Nov. 30, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Sale Leaseback Transaction [Line Items]
Proceeds from sale-leaseback transaction	$ 7,000	$ 0	$ 0	$ 7,000
Proceeds from sale-leaseback transaction	461
Loan origination fees	88
Sale leaseback transaction, lease term		3 years
Sale leaseback transaction obligation, current		$ 2,128	2,357
Sale leaseback transaction obligation, noncurrent			$ 2,128
Plant and Machinery
Sale Leaseback Transaction [Line Items]
Accumulated depreciation	9,841
Equipment and Vehicles
Sale Leaseback Transaction [Line Items]
Accumulated depreciation	$ 3,302

Mezzanine Equity (Details)

Mezzanine Equity (Details)		1 Months Ended	12 Months Ended
	Nov. 14, 2022 USD ($) trading_day $ / shares	Mar. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) trading_day $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 shares	Mar. 04, 2020 $ / shares
Temporary Equity [Line Items]
Issuance of Series A Preferred Stock, net of issuance costs (in shares) | shares					26,000
Accrued preferred stock dividends			$ 689,000	$ 1,994,000
Conversion term	3 months
Threshold trading days | trading_day	30
Threshold consecutive trading days | trading_day	20
Conversion price, percentage	120%
Series A Preferred Stock
Temporary Equity [Line Items]
Series A & B Preferred Stock, par value (in dollars per share) | $ / shares			$ 0.01	$ 0.01
Liquidation preference (in dollars per share) | $ / shares			$ 1,000
Dividend in cash, liquidation preference percentage			10%
Dividend other than cash, liquidation preference percentage			13%
Dividend other than cash, liquidation preference percentage, upon default			16%
Series A Preferred Stock, aggregate liquidation preference			$ 37,176,000	$ 28,783,000
Conversion price (in dollars per share) | $ / shares						$ 27.70
Weighted average price percentage of preferred stock						30%
Common stock issuable if preferred stock is converted (in shares) | shares			1,342,000
Threshold trading days | trading_day			30
Threshold consecutive trading days | trading_day			20
Conversion price, percentage			120%
Conversion price, upon change of control			100%
Dividend discount spread on treasury rate			0.50%
Make whole payment, maximum			$ 4,000,000
Conversion price, upon early redemption			103%
Series A Preferred Stock | Stock Conversion, Three-Month Anniversary
Temporary Equity [Line Items]
Conversion term			3 months
Series A Preferred Stock | Stock Conversion, Three-Year Anniversary
Temporary Equity [Line Items]
Conversion term			3 years
Series A Preferred Stock | Period 1
Temporary Equity [Line Items]
Conversion term			3 years
Series A Preferred Stock | Period 2
Temporary Equity [Line Items]
Conversion term			7 years
Series B Preferred Stock
Temporary Equity [Line Items]
Issuance of Series A Preferred Stock, net of issuance costs (in shares) | shares			30,000	0
Series A & B Preferred Stock, par value (in dollars per share) | $ / shares			$ 0.01	$ 0.01
Series A Preferred Stock, aggregate liquidation preference			$ 30,000,000	$ 30,000,000
Conversion term	3 years
Preferred stock, number of trading days for conversion price	20 days
Preferred stock, period after which company may be required to redeem for cash	30 months
Preferred stock, intent to convert notice period	30 days
Preferred stock, maximum voting power as percentage of outstanding common stock	5%
Amendment No. 3 to Credit Agreement | Series A Preferred Stock
Temporary Equity [Line Items]
Issuance of Series A Preferred Stock, net of issuance costs (in shares) | shares		26,000
Series A & B Preferred Stock, par value (in dollars per share) | $ / shares		$ 0.01
Original issue discount, rate		3%
Amendment No. 3 to Credit Agreement | Series A Preferred Stock | Private Placement
Temporary Equity [Line Items]
Proceeds from issuance, net of discount		$ 26,000,000
Original issue discount, amount		780,000
Proceeds from private placement		25,220,000
Payments of stock issuance costs		$ 966,000
Series A preferred stock dividends payable included in accrued expenses			1,170,000
Accrued preferred stock dividends			$ 689,000
Amendment No. 3 to Credit Agreement | Series B Preferred Stock
Temporary Equity [Line Items]
Series A & B Preferred Stock, par value (in dollars per share) | $ / shares	$ 0.01
Original issue discount, rate	4%
Amendment No. 3 to Credit Agreement | Series B Preferred Stock | Private Placement
Temporary Equity [Line Items]
Proceeds from issuance, net of discount	$ 30,000,000
Original issue discount, amount	1,200,000
Proceeds from private placement	$ 28,800,000

Contract Assets and Liabiliti_3

Contract Assets and Liabilities - Schedule of Asset and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Contract with Customer, Asset, Net, Current [Abstract]
Costs and estimated earnings in excess of billings	$ 11,700	$ 17,163
Retainage	9,281	9,681
Total contract assets	20,981	26,844
Contract with Customer, Liability [Abstract]
Deferred revenue	258	483
Billings in excess of costs and estimated earnings	8,160	5,716
Contract liabilities	8,418	$ 6,199
Revenue recognized	$ 5,941

Contract Assets and Liabiliti_4

Contract Assets and Liabilities - Activity (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Costs incurred on uncompleted contracts	$ 344,692	$ 227,195
Estimated earnings	20,267	22,331
Total costs and earnings	364,959	249,526
Less billings to date	(361,419)	(238,079)
Costs and estimated earnings in excess of billings	$ 3,540	$ 11,447

Contract Assets and Liabiliti_5

Contract Assets and Liabilities - Balance Sheet Classification (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Costs and estimated earnings in excess of billings	$ 11,700	$ 17,163
Billings in excess of costs and estimated earnings	(8,160)	(5,716)
Net balance in process	3,540	11,447
Long-term contracts, loss accrual	$ 120	$ 159

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted in period (in units)	121
Vested (in shares)	65
Forfeited (in shares)	59
Fair value of awards vested	$ 2,133
Common Stock | 2018 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized to be issued (in units)	501			301
Additional shares issued (in shares)	200
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted in period (in units)	90
Vested (in shares)	61		9
Forfeited (in shares)	30
Compensation expense	$ 1,936	$ 1,945	$ 1,839
Unrecognized compensation cost	$ 1,576
Unrecognized compensation cost, period for recognition	1 year 2 months 4 days
Restricted Stock | 2018 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted in period (in units)	90	50	54
Vested (in shares)			2
Vesting period	4 years		1 year
Restricted Stock | 2018 Omnibus Incentive Plan | Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	17	9	43
Vesting period	1 year	1 year	3 years
Restricted Stock | 2018 Omnibus Incentive Plan | Share-based Payment Arrangement, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	56	41
Vesting period	3 years	3 years
Restricted Stock | 2018 Omnibus Incentive Plan | Share-based Payment Arrangement, Tranche Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	17
Restricted Stock | 2018 Omnibus Incentive Plan, 2022 Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized to be issued (in units)	3
Forfeited (in shares)	0
Restricted Stock | 2018 Omnibus Incentive Plan, 2021 Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	251
Forfeited (in shares)	71
Restricted Stock | 2018 Omnibus Incentive Plan, 2019 Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	491
Forfeited (in shares)	111
Performance Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted in period (in units)	31	24	23
Vested (in shares)	4
Vesting period	3 years
Forfeited (in shares)	29
Maximum number of earned PSUs for the performance period, target number of PSUs	200%
Compensation expense	$ 724	$ 757	$ 555
Unrecognized compensation cost	$ 853
Unrecognized compensation cost, period for recognition	1 year 9 months 29 days
Performance Stock | Charah Management LLC
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance goal weight	50%
Performance Stock | 2018 Omnibus Incentive Plan, 2022 Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	2
Forfeited (in shares)	4
Performance Stock | 2018 Omnibus Incentive Plan, 2021 Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	2
Forfeited (in shares)	2
Performance Stock | 2018 Omnibus Incentive Plan, 2019 Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)	23

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Awards (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Shares
Beginning balance (in shares)	154
Granted (in shares)	121
Forfeited (in shares)	(59)
Vested (in shares)	(65)
Ending balance (in shares)	151	154
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share)	$ 44.60
Granted (in dollars per share)	34.45
Forfeited (in dollars per share)	50.24
Vested (in dollars per share)	45.53
Ending balance (in dollars per share)	$ 34.08	$ 44.60
Weighted Average Remaining Contractual Terms (Years)	1 year 2 months 4 days	1 year 14 days
Aggregate Intrinsic Value	$ 822	$ 7,051
Restricted Stock
Shares
Beginning balance (in shares)	89
Granted (in shares)	90
Forfeited (in shares)	(30)
Vested (in shares)	(61)		(9)
Ending balance (in shares)	88	89
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share)	$ 46.16
Granted (in dollars per share)	36.09
Forfeited (in dollars per share)	44.28
Vested (in dollars per share)	45.78
Ending balance (in dollars per share)	$ 36.90	$ 46.16
Weighted Average Remaining Contractual Terms (Years)	1 year 29 days	10 months 17 days
Aggregate Intrinsic Value	$ 476	$ 4,072
Performance Stock
Shares
Beginning balance (in shares)	65
Granted (in shares)	31	24	23
Forfeited (in shares)	(29)
Vested (in shares)	(4)
Ending balance (in shares)	63	65
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share)	$ 42.40
Granted (in dollars per share)	29.70
Forfeited (in dollars per share)	56.45
Vested (in dollars per share)	41.19
Ending balance (in dollars per share)	$ 30.21	$ 42.40
Weighted Average Remaining Contractual Terms (Years)	1 year 3 months 29 days	1 year 3 months 3 days
Aggregate Intrinsic Value	$ 346	$ 2,979

Defined Contribution Retireme_2

Defined Contribution Retirement Plan (Details) - Pension Plan - Qualified Plan - 401(k) Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Contribution Plan Disclosure [Line Items]
Maximum annual contributions percentage	90%
Employer matching contribution percentage	3%
Defined contribution plan, employer discretionary contribution amount	$ 968	$ 940	$ 393

Commitment and Contingencies (D

Commitment and Contingencies (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2022
Loss Contingencies [Line Items]
Revenue reversal due to legal investigation		$ 2,112	$ 2,476
Aggregate costs to remediate, threshold	$ 13,600
Minimum
Loss Contingencies [Line Items]
Potential amount due to fraudulent transactions		1,140	1,140
Maximum
Loss Contingencies [Line Items]
Potential amount due to fraudulent transactions		$ 2,670	$ 2,670

Multiemployer Pension Plan (Det

Multiemployer Pension Plan (Details) - AMS - Pension Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Central states, southeast and southwest areas pension plan
Multiemployer Plans [Line Items]
Contributions to funds	$ 59	$ 111	$ 55
Operating Engineers Local 324 Pension Fund
Multiemployer Plans [Line Items]
Contributions to funds	0	0	27
Employer Teamsters Locals 175 & 505 pension trust fund
Multiemployer Plans [Line Items]
Contributions to funds	$ 111	$ 81	$ 74

Income Taxes - Schedule of Tota

Income Taxes - Schedule of Total Income Tax (Benefit) Expense On (Loss) Income Before Income Allocated (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Continuing operations	$ (57)	$ 661	$ (914)
Discontinued operations	0	0	94
Total	$ (57)	$ 661	$ (820)

Income Taxes - Current and Defe

Income Taxes - Current and Deferred (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current income tax expense (benefit):
Federal	$ 72	$ 0	$ 0
State	0	80	(80)
Current income tax (benefit) expense	72	80	(80)
Deferred income tax expense (benefit):
Federal	(280)	500	(843)
State	151	81	9
Deferred income tax expense (benefit)	(129)	581	(834)
Total income tax expense (benefit)	$ (57)	$ 661	$ (914)

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income tax benefit at the federal statutory rate (21%)	$ (26,914)	$ (1,079)	$ (13,537)
State income tax (benefit) expense, net of federal tax benefit	119	127	(70)
Non-controlling interest	55	(3)	(251)
Stock compensation	164	(164)	277
Valuation allowance	26,151	1,578	12,328
Foreign income tax differential	23	0	0
Permanent items	345	202	339
Total income tax expense (benefit)	$ (57)	$ 661	$ (914)

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Loss carryovers	$ 29,749	$ 14,333
Intangible assets	13,834	3,431
Other accrued expenses and reserves	2,056	2,326
Right-of-use liability	8,771	0
Finance leases	517	1,091
Deferred asset sale	1,018	226
Accrued bonus	1,471	1,195
Asset retirement obligations	16,655	10,222
Capitalized cost	4,903	819
Deferred tax assets	78,974	33,643
Valuation allowance	(50,311)	(19,937)	$ (17,158)
Net deferred tax asset	28,663	13,706
Deferred tax liabilities:
Fixed assets, including land	12,433	9,757
Restricted cash from ERT projects	9,089	4,838
Right-of-use assets	7,955	0
Prepaid expenses	5	60
Deferred tax liabilities	29,482	14,655
Net deferred tax liability	$ 819	$ 949

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, federal income tax	$ 90,241,000
Deferred interest expense	25,773,000
Carryover losses annual utilization limit	2,700,000
Net deferred tax liability	819,000	$ 949,000
Valuation allowance	50,311,000	$ 19,937,000	$ 17,158,000
Unrecognized tax benefits that would impact effective tax rate	0
Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, federal income tax	$ 3,793,000

Income Taxes - Summary of Valua

Income Taxes - Summary of Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Deferred Tax Asset, Valuation Allowance [Roll Forward]
Beginning balance	$ (19,937)	$ (17,158)
Current additions recorded in income tax (benefit) or expense	(32,023)	(2,708)
Current reductions recorded in income tax (benefit) or expense	1,338	837
Other adjustments	311	(908)
Ending balance	$ (50,311)	$ (19,937)

Leases - Lease Assets and Liabi

Leases - Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets
Operating lease assets	$ 32,748	$ 0
Finance lease assets	49,306
Total lease assets	82,054
Current
Operating lease, liability, current	12,483	0
Finance lease, liability, current	10,592	6,979
Non-current
Operating lease, liability, noncurrent	23,621	0
Finance lease, liability, noncurrent	24,585	$ 19,444
Total lease liabilities	$ 71,281
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property and equipment, net

Leases - Lease Costs (Details)

Leases - Lease Costs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Finance Lease Costs [Abstract]
Amortization expense	$ 9,785
Interest expense	2,483
Operating lease costs	13,893
Short-term lease expense	464
Total lease expense	$ 26,625

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Rent expense, net	$ 26,990	$ 19,406

Leases - Lease Term and Discoun

Leases - Lease Term and Discount Rate (Details)	Dec. 31, 2022
Weighted-average remaining term in years
Operating leases	3 years 8 months 4 days
Finance leases	4 years 4 months 28 days
Weighted-average discount rate
Operating leases	7.40%
Finance leases	7.20%

Leases - Other Information (Det

Leases - Other Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash paid amounts included in the measurement of lease liabilities:
Operating cash flows used for operating leases	$ 14,118
Operating cash flows used for finance leases	2,453
Financing cash flows used for finance leases	9,381	$ 4,768	$ 316
Total	25,952
Right-of-use assets obtained in exchange for:
New operating lease liabilities	15,866	0	0
New finance lease liabilities	18,134	$ 24,508	$ 0
Total	$ 34,000

Leases - Maturity of Lease Liab

Leases - Maturity of Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Operating Leases
2023	$ 14,583
2024	9,354
2025	5,150
2026	3,935
2027	3,069
Thereafter	6,122
Total minimum lease payments	42,213
Less: Amount of lease payments representing interest	(6,109)
Current portion of lease liabilities	12,483	$ 0
Noncurrent portion of lease liabilities	23,621	0
Total lease liabilities	36,104
Finance Leases [Abstract]
2023	12,825
2024	10,628
2025	9,172
2026	6,500
2027	939
Thereafter	0
Total minimum lease payments	40,064
Less: Amount of lease payments representing interest	(4,887)
Current portion of lease liabilities	10,592	6,979
Noncurrent portion of lease liabilities	24,585	19,444
Total lease liabilities	$ 35,177
Operating Leases (Topic 840) [Abstract]
2022		10,216
2023		9,271
2024		5,646
2025		2,151
2026		1,003
Thereafter		819
Total		$ 29,106

Loss Per Share - Calculation of

Loss Per Share - Calculation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss from continuing operations									$ (127,843)	$ (5,814)	$ (64,746)
Deemed and imputed dividends on Series A Preferred Stock	$ (150)	$ (150)	$ (150)	$ (149)	$ (149)	$ (148)	$ (148)	$ (147)	(599)	(592)	(461)
Series A Preferred Stock dividends	(690)	(956)	(1,571)	(2,090)	(1,995)	(1,946)	(2,148)	(2,067)	(5,307)	(8,156)	(4,064)
Net loss from continuing operations attributable to common stockholders	(93,681)	(14,465)	(11,324)	(14,279)					(133,749)	(14,562)	(69,271)
Net income from discontinued operations									0	0	8,883
Net loss attributable to common stockholders									(133,749)	(14,562)	(60,388)
Net loss attributable to common stockholders	$ (93,681)	$ (14,465)	$ (11,324)	$ (14,279)	$ (828)	$ (3,771)	$ (6,462)	$ (3,501)	$ (133,749)	$ (14,562)	$ (60,388)
Denominator:
Weighted average shares outstanding (in shares)									3,363	3,157	2,990
Dilutive share-based awards (in shares)									0	0	0
Total weighted average shares outstanding, including dilutive shares (in shares)									3,363	3,157	2,990
Net loss from continuing operations per common share
Basic (in dollars per share)	$ (27.72)	$ (4.30)	$ (3.40)	$ (4.30)	$ (0.15)	$ (1.16)	$ (2.10)	$ (1.20)	$ (39.77)	$ (4.61)	$ (23.17)
Diluted (in dollars per share)	(27.72)	(4.30)	(3.40)	(4.30)	(0.15)	(1.16)	(2.10)	(1.20)	(39.77)	(4.61)	(23.17)
Net income from discontinued operations per common share
Basic (in dollars per share)									0	0	2.97
Diluted (in dollars per share)									0	0	2.97
Net loss attributable to common stockholders per common share
Basic (in dollars per share)	(27.72)	(4.30)	(3.40)	(4.30)	(0.15)	(1.16)	(2.10)	(1.20)	(39.77)	(4.61)	(20.20)
Diluted (in dollars per share)	$ (27.72)	$ (4.30)	$ (3.40)	$ (4.30)	$ (0.15)	$ (1.16)	$ (2.10)	$ (1.20)	$ (39.77)	$ (4.61)	$ (20.20)

Loss Per Share - Antidilutive S

Loss Per Share - Antidilutive Securities (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive restricted and performance stock units (in shares)	1,647	1,224	925
Anti-dilutive restricted and performance stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive restricted and performance stock units (in shares)	180	132	151
Anti-dilutive Series A and Series B Preferred Stock convertible into common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive restricted and performance stock units (in shares)	1,467	1,092	774

Loss Per Share - Reverse Stock

Loss Per Share - Reverse Stock Split (Details)	Dec. 29, 2022 $ / shares shares	Dec. 31, 2022 $ / shares shares	Dec. 30, 2022 shares	Dec. 31, 2021 $ / shares shares
Earnings Per Share [Abstract]
Stock split ratio, common stock	0.10
Common stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01		$ 0.01
Common stock, shares outstanding (in shares) | shares	33,889,000	3,379,605	3,389,000	3,340,782

Major Customers (Details)

Major Customers (Details) - Customer Concentration Risk - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer Benchmark | Customer 1
Concentration Risk [Line Items]
Revenue	$ 64,484	$ 40,590
Concentration risk, percentage	22%	13.80%
Revenue from Contract with Customer Benchmark | Customer 2
Concentration Risk [Line Items]
Revenue		$ 34,788
Concentration risk, percentage		11.90%
Revenue from Contract with Customer Benchmark | Customer 3
Concentration Risk [Line Items]
Revenue		$ 29,670
Concentration risk, percentage		10.10%
Accounts Receivable | Customer 1
Concentration Risk [Line Items]
Concentration risk, percentage	28.90%	4.60%
Accounts Receivable | Customer 2
Concentration Risk [Line Items]
Concentration risk, percentage		11.10%
Accounts Receivable | Customer 3
Concentration Risk [Line Items]
Concentration risk, percentage		2.40%

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 16, 2023	Dec. 31, 2022	Dec. 29, 2022	Dec. 31, 2021
Subsequent Event [Line Items]
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01	$ 0.01
Forecast
Subsequent Event [Line Items]
Cash to be received upon merger (in dollars per share)	$ 6
Forecast | Series A Preferred Stock
Subsequent Event [Line Items]
Preferred stock redemption amount	$ 40,061
Forecast | Series B Preferred Stock
Subsequent Event [Line Items]
Preferred stock redemption amount	$ 30,000
Subsequent Event
Subsequent Event [Line Items]
Common stock, par value (in dollars per share)	$ 0.01
Equity contribution commitment from third party	$ 88,054

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 68,466	$ 81,540	$ 77,110	$ 66,051	$ 93,433	$ 84,161	$ 63,518	$ 52,107	$ 293,167	$ 293,219	$ 232,377
Operating income (loss)	(88,499)	(8,902)	(4,795)	(7,392)	6,669	2,661	(770)	1,978	(109,588)	10,538	(39,569)
Loss before income taxes and non-controlling interest	(92,841)	(13,359)	(9,603)	(12,040)					(127,843)	(5,814)	(55,863)
Deemed and imputed dividends on Series A Preferred Stock	(150)	(150)	(150)	(149)	(149)	(148)	(148)	(147)	(599)	(592)	(461)
Series A Preferred Stock dividends	(690)	(956)	(1,571)	(2,090)	(1,995)	(1,946)	(2,148)	(2,067)	(5,307)	(8,156)	(4,064)
Net loss from continuing operations attributable to common stockholders	(93,681)	(14,465)	(11,324)	(14,279)					(133,749)	(14,562)	(69,271)
Net loss from continuing operations attributable to common stockholders	(93,681)	(14,465)	(11,324)	(14,279)					(133,749)	(14,562)	(69,271)
Income from discontinued operations, net of tax	0	0	0	0	0	0	0	0	0	0	8,883
Net loss attributable to common stockholders	$ (93,681)	$ (14,465)	$ (11,324)	$ (14,279)	$ (828)	$ (3,771)	$ (6,462)	$ (3,501)	$ (133,749)	$ (14,562)	$ (60,388)
Net loss from continuing operations per common share
Basic (in dollars per share)	$ (27.72)	$ (4.30)	$ (3.40)	$ (4.30)	$ (0.15)	$ (1.16)	$ (2.10)	$ (1.20)	$ (39.77)	$ (4.61)	$ (23.17)
Diluted (in dollars per share)	(27.72)	(4.30)	(3.40)	(4.30)	(0.15)	(1.16)	(2.10)	(1.20)	(39.77)	(4.61)	(23.17)
Net loss attributable to common stockholders per common share
Basic (in dollars per share)	(27.72)	(4.30)	(3.40)	(4.30)	(0.15)	(1.16)	(2.10)	(1.20)	(39.77)	(4.61)	(20.20)
Diluted (in dollars per share)	$ (27.72)	$ (4.30)	$ (3.40)	$ (4.30)	$ (0.15)	$ (1.16)	$ (2.10)	$ (1.20)	$ (39.77)	$ (4.61)	$ (20.20)

Quarterly Financial Data (Una_4

Quarterly Financial Data (Unaudited) - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Revenue reversal due to legal investigation	$ 2,112			$ 2,476
Impairment expense				62,271	$ 827	$ 40,772
Gain on sales-type lease			$ 5,568	0	5,568	0
Gains on sales of real estate, property and equipment, net		$ 14,669		12,245	$ 23,543	$ 0
Accrued bonuses	$ 4,750			$ 4,750

Valuation and Qualifying Acco_2

Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 146	$ 467
Charged to Expense	990	62
Deductions	(6)	(383)
Balance at End of Period	1,130	146
Valuation allowance for deferred taxes
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	19,937	17,158
Charged to Expense	31,712	3,616
Deductions	(1,338)	(837)
Balance at End of Period	$ 50,311	$ 19,937