Table of Contents
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
_______________________
FORM 10-Q
QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
FOR THE QUARTERLY PERIOD ENDEDJUNE 30, 20222023
OR
TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

FOR THE TRANSITION PERIOD FROM         TO       

Commission File Number 001-34223
_______________________
CLEAN HARBORS, INC.
(Exact name of registrant as specified in its charter)
Massachusetts04-2997780
(State or Other Jurisdiction of Incorporation or Organization)(IRS Employer Identification No.)
42 Longwater DriveNorwellMA02061-9149
(Address of Principal Executive Offices)(Zip Code)
Registrant’s Telephone Number, Including area code: (781) 792-5000
Securities registered pursuant to Section 12(b) of the Act:
Title of each classTrading SymbolName of each exchange on which registered
Common Stock, $0.01 par valueCLHNew York Stock Exchange
    Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports) and (2) has been subject to such filing requirements for the past 90 days. Yes   No 
Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes    No 
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and "emerging growth company" in Rule 12b-2 of the Exchange Act. (Check one):
Large accelerated filerAccelerated filer
Non-accelerated filerSmaller reporting company
Emerging growth company
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.
Indicate by check mark whether the registrant is a shell company (as defined by Rule 12b-2 of the Exchange Act). Yes   No 
The number of shares of Common Stock, $0.01 par value, of the registrant outstanding at July 29, 202228, 2023 was 54,103,226.54,150,830.



CLEAN HARBORS, INC.
QUARTERLY REPORT ON FORM 10-Q
TABLE OF CONTENTS
Page No.




Table of Contents
CLEAN.CLEAN HARBORS, INC. AND SUBSIDIARIES
CONSOLIDATED BALANCE SHEETS
(in thousands)
June 30, 2022December 31, 2021June 30, 2023December 31, 2022
ASSETSASSETS(unaudited)ASSETS(unaudited)
Current assets:Current assets:Current assets:
Cash and cash equivalentsCash and cash equivalents$344,631 $452,575 Cash and cash equivalents$238,776 $492,603 
Short-term marketable securitiesShort-term marketable securities70,797 81,724 Short-term marketable securities87,346 62,033 
Accounts receivable, net of allowances aggregating $49,817 and $40,140, respectively1,005,488 792,734 
Accounts receivable, net of allowances aggregating $43,393 and $45,253, respectivelyAccounts receivable, net of allowances aggregating $43,393 and $45,253, respectively981,233 964,603 
Unbilled accounts receivableUnbilled accounts receivable134,173 94,963 Unbilled accounts receivable122,679 107,010 
Inventories and suppliesInventories and supplies275,696 250,692 Inventories and supplies325,882 324,994 
Prepaid expenses and other current assetsPrepaid expenses and other current assets93,320 68,483 Prepaid expenses and other current assets92,559 82,518 
Total current assetsTotal current assets1,924,105 1,741,171 Total current assets1,848,475 2,033,761 
Property, plant and equipment, netProperty, plant and equipment, net1,913,145 1,863,175 Property, plant and equipment, net2,082,693 1,980,302 
Other assets:Other assets:Other assets:
Operating lease right-of-use assetsOperating lease right-of-use assets157,048 161,797 Operating lease right-of-use assets181,243 166,181 
GoodwillGoodwill1,244,655 1,227,042 Goodwill1,288,291 1,246,878 
Permits and other intangibles, netPermits and other intangibles, net637,254 644,912 Permits and other intangibles, net626,320 620,782 
OtherOther48,449 15,602 Other74,315 81,803 
Total other assetsTotal other assets2,087,406 2,049,353 Total other assets2,170,169 2,115,644 
Total assetsTotal assets$5,924,656 $5,653,699 Total assets$6,101,337 $6,129,707 
LIABILITIES AND STOCKHOLDERS' EQUITYLIABILITIES AND STOCKHOLDERS' EQUITYLIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:Current liabilities:Current liabilities:
Current portion of long-term debtCurrent portion of long-term debt$17,535 $17,535 Current portion of long-term debt$10,000 $10,000 
Accounts payableAccounts payable409,218 359,866 Accounts payable374,438 446,629 
Deferred revenueDeferred revenue94,531 83,749 Deferred revenue105,327 94,094 
Accrued expenses and other current liabilitiesAccrued expenses and other current liabilities387,047 391,414 Accrued expenses and other current liabilities348,857 396,716 
Current portion of closure, post-closure and remedial liabilitiesCurrent portion of closure, post-closure and remedial liabilities34,551 25,136 Current portion of closure, post-closure and remedial liabilities21,802 23,123 
Current portion of operating lease liabilitiesCurrent portion of operating lease liabilities47,176 47,614 Current portion of operating lease liabilities53,991 49,532 
Total current liabilitiesTotal current liabilities990,058 925,314 Total current liabilities914,415 1,020,094 
Other liabilities:Other liabilities:Other liabilities:
Closure and post-closure liabilities, less current portion of $12,379 and $12,015, respectively90,618 87,088 
Remedial liabilities, less current portion of $22,172 and $13,121, respectively101,484 98,752 
Closure and post-closure liabilities, less current portion of $12,186 and $13,205, respectivelyClosure and post-closure liabilities, less current portion of $12,186 and $13,205, respectively108,522 105,596 
Remedial liabilities, less current portion of $9,616 and $9,918, respectivelyRemedial liabilities, less current portion of $9,616 and $9,918, respectively102,560 106,372 
Long-term debt, less current portionLong-term debt, less current portion2,510,963 2,517,024 Long-term debt, less current portion2,294,306 2,414,828 
Operating lease liabilities, less current portionOperating lease liabilities, less current portion112,854 117,991 Operating lease liabilities, less current portion129,058 119,259 
Deferred tax liabilitiesDeferred tax liabilities322,108 314,853 Deferred tax liabilities346,328 350,389 
Other long-term liabilitiesOther long-term liabilities79,621 78,790 Other long-term liabilities96,262 90,847 
Total other liabilitiesTotal other liabilities3,217,648 3,214,498 Total other liabilities3,077,036 3,187,291 
Commitments and contingent liabilities (See Note 17)00
Commitments and contingent liabilities (See Note 16)Commitments and contingent liabilities (See Note 16)
Stockholders’ equity:Stockholders’ equity:Stockholders’ equity:
Common stock, $0.01 par value:Common stock, $0.01 par value:Common stock, $0.01 par value:
Authorized 80,000,000 shares; issued and outstanding 54,110,459 and 54,419,321 shares, respectively541 544 
Authorized 80,000,000 shares; issued and outstanding 54,090,202 and 54,064,797 shares, respectivelyAuthorized 80,000,000 shares; issued and outstanding 54,090,202 and 54,064,797 shares, respectively541 541 
Additional paid-in capitalAdditional paid-in capital512,662 536,377 Additional paid-in capital502,422 504,240 
Accumulated other comprehensive lossAccumulated other comprehensive loss(162,702)(196,012)Accumulated other comprehensive loss(165,966)(167,181)
Accumulated earningsAccumulated earnings1,366,449 1,172,978 Accumulated earnings1,772,889 1,584,722 
Total stockholders’ equityTotal stockholders’ equity1,716,950 1,513,887 Total stockholders’ equity2,109,886 1,922,322 
Total liabilities and stockholders’ equityTotal liabilities and stockholders’ equity$5,924,656 $5,653,699 Total liabilities and stockholders’ equity$6,101,337 $6,129,707 

The accompanying notes are an integral part of these unaudited consolidated financial statements.
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CLEAN HARBORS, INC. AND SUBSIDIARIES
UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS
(in thousands, except per share amounts)
Three Months EndedSix Months EndedThree Months EndedSix Months Ended
June 30,June 30,June 30,June 30,
20222021202220212023202220232022
Revenues:Revenues:Revenues:
Service revenuesService revenues$1,085,043 $734,563 $2,027,104 $1,397,271 Service revenues$1,159,090 $1,085,043 $2,212,323 $2,027,104 
Product revenuesProduct revenues271,269 191,895 498,317 337,335 Product revenues238,810 271,269 492,964 498,317 
Total revenuesTotal revenues1,356,312 926,458 2,525,421 1,734,606 Total revenues1,397,900 1,356,312 2,705,287 2,525,421 
Cost of revenues: (exclusive of items shown separately below)Cost of revenues: (exclusive of items shown separately below)Cost of revenues: (exclusive of items shown separately below)
Service revenuesService revenues736,560 492,662 1,429,984 943,000 Service revenues771,600 736,560 1,523,195 1,429,984 
Product revenuesProduct revenues161,909 125,224 311,874 235,422 Product revenues175,912 161,909 355,831 311,874 
Total cost of revenuesTotal cost of revenues898,469 617,886 1,741,858 1,178,422 Total cost of revenues947,512 898,469 1,879,026 1,741,858 
Selling, general and administrative expensesSelling, general and administrative expenses155,608 124,106 306,781 245,747 Selling, general and administrative expenses167,382 155,608 334,135 306,781 
Accretion of environmental liabilitiesAccretion of environmental liabilities3,197 2,873 6,353 5,826 Accretion of environmental liabilities3,486 3,197 6,893 6,353 
Depreciation and amortizationDepreciation and amortization87,868 71,592 172,166 143,755 Depreciation and amortization89,697 87,868 174,455 172,166 
Income from operationsIncome from operations211,170 110,001 298,263 160,856 Income from operations189,823 211,170 310,778 298,263 
Other income (expense), net1,265 (1,480)1,969 (2,708)
Other (expense) income, netOther (expense) income, net(1,283)1,265 (1,167)1,969 
Loss on early extinguishment of debtLoss on early extinguishment of debt— — (2,362)— 
Gain on sale of businessGain on sale of business8,864 — 8,864 — Gain on sale of business— 8,864 — 8,864 
Interest expense, net of interest income of $563, $580, $1,056 and $1,060, respectively(26,256)(18,051)(51,273)(35,969)
Interest expense, net of interest income of $2,001, $563, $4,956 and $1,056, respectivelyInterest expense, net of interest income of $2,001, $563, $4,956 and $1,056, respectively(30,072)(26,256)(50,704)(51,273)
Income before provision for income taxesIncome before provision for income taxes195,043 90,470 257,823 122,179 Income before provision for income taxes158,468 195,043 256,545 257,823 
Provision for income taxesProvision for income taxes46,886 23,395 64,352 33,368 Provision for income taxes42,702 46,886 68,378 64,352 
Net incomeNet income$148,157 $67,075 $193,471 $88,811 Net income$115,766 $148,157 $188,167 $193,471 
Earnings per share:Earnings per share:Earnings per share:
BasicBasic$2.73 $1.23 $3.56 $1.63 Basic$2.14 $2.73 $3.48 $3.56 
DilutedDiluted$2.71 $1.22 $3.54 $1.62 Diluted$2.13 $2.71 $3.46 $3.54 
Shares used to compute earnings per share - BasicShares used to compute earnings per share - Basic54,318 54,529 54,362 54,625 Shares used to compute earnings per share - Basic54,092 54,318 54,084 54,362 
Shares used to compute earnings per share - DilutedShares used to compute earnings per share - Diluted54,597 54,854 54,639 54,945 Shares used to compute earnings per share - Diluted54,448 54,597 54,422 54,639 

The accompanying notes are an integral part of these unaudited consolidated financial statements.
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CLEAN HARBORS, INC. AND SUBSIDIARIES
UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
(in thousands)
Three Months EndedSix Months Ended Three Months EndedSix Months Ended
June 30,June 30,June 30,June 30,
2022202120222021 2023202220232022
Net incomeNet income$148,157 $67,075 $193,471 $88,811 Net income$115,766 $148,157 $188,167 $193,471 
Other comprehensive (loss) income, net of tax:
Unrealized loss on available-for-sale securities(128)(48)(656)(122)
Other comprehensive income (loss), net of tax:Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on available-for-sale securitiesUnrealized gain (loss) on available-for-sale securities44 (128)218 (656)
Unrealized gain (loss) on fair value of interest rate hedge11,243 (349)35,924 2,759 
Unrealized gain on fair value of interest rate hedgesUnrealized gain on fair value of interest rate hedges12,556 11,243 7,727 35,924 
Reclassification adjustment for interest rate hedge amounts realized in net incomeReclassification adjustment for interest rate hedge amounts realized in net income2,164 2,494 5,358 4,942 Reclassification adjustment for interest rate hedge amounts realized in net income(4,930)2,164 (9,054)5,358 
Reclassification adjustment for settlement of interest rate hedgesReclassification adjustment for settlement of interest rate hedges— — (5,905)— 
Unfunded pension liabilityUnfunded pension liability20 — 10 — Unfunded pension liability(7)20 (7)10 
Foreign currency translation adjustmentsForeign currency translation adjustments(13,838)8,543 (7,326)15,009 Foreign currency translation adjustments7,898 (13,838)8,236 (7,326)
Other comprehensive (loss) income, net of tax(539)10,640 33,310 22,588 
Other comprehensive income (loss), net of taxOther comprehensive income (loss), net of tax15,561 (539)1,215 33,310 
Comprehensive incomeComprehensive income$147,618 $77,715 $226,781 $111,399 Comprehensive income$131,327 $147,618 $189,382 $226,781 

The accompanying notes are an integral part of these unaudited consolidated financial statements.
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CLEAN HARBORS, INC. AND SUBSIDIARIES
UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS
(in thousands)
Six Months EndedSix Months Ended
June 30,June 30,
2022202120232022
Cash flows from operating activities:Cash flows from operating activities:Cash flows from operating activities:
Net incomeNet income$193,471 $88,811 Net income$188,167 $193,471 
Adjustments to reconcile net income to net cash from operating activities:Adjustments to reconcile net income to net cash from operating activities:Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortizationDepreciation and amortization172,166 143,755 Depreciation and amortization174,455 172,166 
Allowance for doubtful accountsAllowance for doubtful accounts6,927 2,109 Allowance for doubtful accounts1,209 6,927 
Amortization of deferred financing costs and debt discountAmortization of deferred financing costs and debt discount3,135 1,806 Amortization of deferred financing costs and debt discount2,718 3,135 
Accretion of environmental liabilitiesAccretion of environmental liabilities6,353 5,826 Accretion of environmental liabilities6,893 6,353 
Changes in environmental liability estimatesChanges in environmental liability estimates1,232 445 Changes in environmental liability estimates387 1,232 
Deferred income taxesDeferred income taxes2,226 1,912 Deferred income taxes(356)2,226 
Other (income) expense, net(1,969)2,708 
Other expense (income), netOther expense (income), net1,167 (1,969)
Stock-based compensationStock-based compensation12,547 6,785 Stock-based compensation10,518 12,547 
Loss on early extinguishment of debtLoss on early extinguishment of debt2,362 — 
Gain on sale of businessGain on sale of business(8,864)— Gain on sale of business— (8,864)
Environmental expendituresEnvironmental expenditures(7,028)(6,594)Environmental expenditures(16,323)(7,028)
Changes in assets and liabilities, net of acquisitions:Changes in assets and liabilities, net of acquisitions:Changes in assets and liabilities, net of acquisitions:
Accounts receivable and unbilled accounts receivableAccounts receivable and unbilled accounts receivable(263,584)(51,285)Accounts receivable and unbilled accounts receivable(5,659)(263,584)
Inventories and suppliesInventories and supplies(23,888)765 Inventories and supplies(1,111)(23,888)
Other current and non-current assetsOther current and non-current assets(25,504)(12,043)Other current and non-current assets(22,749)(25,504)
Accounts payableAccounts payable45,748 49,880 Accounts payable(78,139)45,748 
Other current and long-term liabilitiesOther current and long-term liabilities19,002 30,552 Other current and long-term liabilities(27,966)19,002 
Net cash from operating activitiesNet cash from operating activities131,970 265,432 Net cash from operating activities235,573 131,970 
Cash flows used in investing activities:Cash flows used in investing activities:Cash flows used in investing activities:
Additions to property, plant and equipmentAdditions to property, plant and equipment(148,042)(91,988)Additions to property, plant and equipment(204,298)(148,042)
Proceeds from sale and disposal of fixed assetsProceeds from sale and disposal of fixed assets3,023 3,479 Proceeds from sale and disposal of fixed assets2,944 3,023 
Acquisitions, net of cash acquiredAcquisitions, net of cash acquired(68,766)(22,918)Acquisitions, net of cash acquired(120,636)(68,766)
Proceeds from sale of business, net of transaction costsProceeds from sale of business, net of transaction costs17,486 — Proceeds from sale of business, net of transaction costs— 17,486 
Additions to intangible assets including costs to obtain or renew permitsAdditions to intangible assets including costs to obtain or renew permits(836)(1,750)Additions to intangible assets including costs to obtain or renew permits(1,114)(836)
Purchases of available-for-sale securitiesPurchases of available-for-sale securities(74,451)(23,182)
Proceeds from sale of available-for-sale securitiesProceeds from sale of available-for-sale securities32,835 70,526 Proceeds from sale of available-for-sale securities50,290 32,835 
Purchases of available-for-sale securities(23,182)(89,689)
Net cash used in investing activitiesNet cash used in investing activities(187,482)(132,340)Net cash used in investing activities(347,265)(187,482)
Cash flows used in financing activities:Cash flows used in financing activities:Cash flows used in financing activities:
Change in uncashed checksChange in uncashed checks475 (2,895)Change in uncashed checks2,392 475 
Tax payments related to withholdings on vested restricted stockTax payments related to withholdings on vested restricted stock(2,571)(4,739)Tax payments related to withholdings on vested restricted stock(4,335)(2,571)
Repurchases of common stockRepurchases of common stock(33,694)(45,409)Repurchases of common stock(8,001)(33,694)
Deferred financing costs paidDeferred financing costs paid(321)(146)Deferred financing costs paid(6,346)(321)
Payments on finance leasesPayments on finance leases(6,552)(3,577)Payments on finance leases(7,588)(6,552)
Principal payments on debtPrincipal payments on debt(8,768)(3,768)Principal payments on debt(618,975)(8,768)
Proceeds from issuance of debtProceeds from issuance of debt500,000 — 
Borrowing from revolving credit facilityBorrowing from revolving credit facility114,000 — 
Payment on revolving credit facilityPayment on revolving credit facility(114,000)— 
Net cash used in financing activitiesNet cash used in financing activities(51,431)(60,534)Net cash used in financing activities(142,853)(51,431)
Effect of exchange rate change on cashEffect of exchange rate change on cash(1,001)3,915 Effect of exchange rate change on cash718 (1,001)
(Decrease) increase in cash and cash equivalents(107,944)76,473 
Decrease in cash and cash equivalentsDecrease in cash and cash equivalents(253,827)(107,944)
Cash and cash equivalents, beginning of periodCash and cash equivalents, beginning of period452,575 519,101 Cash and cash equivalents, beginning of period492,603 452,575 
Cash and cash equivalents, end of periodCash and cash equivalents, end of period$344,631 $595,574 Cash and cash equivalents, end of period$238,776 $344,631 
Supplemental information:Supplemental information:Supplemental information:
Cash payments for interest and income taxes:Cash payments for interest and income taxes:Cash payments for interest and income taxes:
Interest paidInterest paid$48,104 $34,164 Interest paid$49,257 $48,104 
Income taxes paid, net of refundsIncome taxes paid, net of refunds29,307 32,519 Income taxes paid, net of refunds92,494 29,307 
Non-cash investing activities:Non-cash investing activities:Non-cash investing activities:
Property, plant and equipment accruedProperty, plant and equipment accrued21,156 8,807 Property, plant and equipment accrued26,427 21,156 
Remedial liability assumed in acquisition of property, plant and equipmentRemedial liability assumed in acquisition of property, plant and equipment13,073 — Remedial liability assumed in acquisition of property, plant and equipment— 13,073 
ROU assets obtained in exchange for operating lease liabilitiesROU assets obtained in exchange for operating lease liabilities20,686 5,774 ROU assets obtained in exchange for operating lease liabilities38,474 20,686 
ROU assets obtained in exchange for finance lease liabilitiesROU assets obtained in exchange for finance lease liabilities7,646 18,704 ROU assets obtained in exchange for finance lease liabilities13,992 7,646 
The accompanying notes are an integral part of these unaudited consolidated financial statements.
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CLEAN HARBORS, INC. AND SUBSIDIARIES
UNAUDITED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY
(in thousands)
Common StockAccumulated
Other
Comprehensive Loss
Common StockAccumulated
Other
Comprehensive Loss
Number
of
Shares
$0.01
Par
Value
Additional
Paid-in
Capital
Accumulated
Earnings
Total
Stockholders’
Equity
Number
of
Shares
$0.01
Par
Value
Additional
Paid-in
Capital
Accumulated
Other
Comprehensive Loss
Total
Stockholders’
Equity
Balance at January 1, 202254,419 $544 $536,377 $(196,012)$1,172,978 $1,513,887 
Balance at January 1, 2023Balance at January 1, 202354,065 $541 $504,240 $(167,181)$1,584,722 $1,922,322 
Net incomeNet income— — — — 45,314 45,314 Net income— — — — 72,401 72,401 
Other comprehensive income— — — 33,849 — 33,849 
Other comprehensive lossOther comprehensive loss— — — (14,346)— (14,346)
Stock-based compensationStock-based compensation— — 5,712 — — 5,712 Stock-based compensation— — 6,018 — — 6,018 
Issuance of common stock for restricted share vesting, net of employee tax withholdingsIssuance of common stock for restricted share vesting, net of employee tax withholdings36 — (1,831)— — (1,831)Issuance of common stock for restricted share vesting, net of employee tax withholdings49 — (3,351)— — (3,351)
Repurchases of common stockRepurchases of common stock(41)— (3,694)— — (3,694)Repurchases of common stock(22)— (3,000)— — (3,000)
Balance at March 31, 202254,414 544 536,564 (162,163)1,218,292 1,593,237 
Balance at March 31, 2023Balance at March 31, 202354,092 541 503,907 (181,527)1,657,123 1,980,044 
Net incomeNet income— — — — 148,157 148,157 Net income— — — — 115,766 115,766 
Other comprehensive loss— — — (539)— (539)
Other comprehensive incomeOther comprehensive income— — — 15,561 — 15,561 
Stock-based compensationStock-based compensation— — 6,835 — — 6,835 Stock-based compensation— — 4,500 — — 4,500 
Issuance of common stock for restricted share vesting, net of employee tax withholdingsIssuance of common stock for restricted share vesting, net of employee tax withholdings31 — (740)— — (740)Issuance of common stock for restricted share vesting, net of employee tax withholdings34 — (984)— — (984)
Repurchases of common stockRepurchases of common stock(335)(3)(29,997)— — (30,000)Repurchases of common stock(36)— (5,001)— — (5,001)
Balance at June 30, 202254,110 $541 $512,662 $(162,702)$1,366,449 $1,716,950 
Balance at June 30, 2023Balance at June 30, 202354,090 $541 $502,422 $(165,966)$1,772,889 $2,109,886 

Common StockAccumulated
Other
Comprehensive Loss
Number
of
Shares
$0.01
Par
Value
Additional
Paid-in
Capital
Accumulated
Earnings
Total
Stockholders’
Equity
Balance at January 1, 202154,773 $548 $582,749 $(211,477)$969,731 $1,341,551 
Net income— — — — 21,736 21,736 
Other comprehensive income— — — 11,948 — 11,948 
Stock-based compensation— — 3,480 — — 3,480 
Issuance of common stock for restricted share vesting, net of employee tax withholdings78 (3,720)— — (3,719)
Repurchases of common stock(300)(3)(26,543)— — (26,546)
Balance at March 31, 202154,551 546 555,966 (199,529)991,467 1,348,450 
Net income— — — — 67,075 67,075 
Other comprehensive income— — — 10,640 — 10,640 
Stock-based compensation— — 3,305 — — 3,305 
Issuance of common stock for restricted share vesting, net of employee tax withholdings42 — (1,020)— — (1,020)
Repurchases of common stock(200)(2)(18,861)— — (18,863)
Balance at June 30, 202154,393 $544 $539,390 $(188,889)$1,058,542 $1,409,587 

Common StockAccumulated
Other
Comprehensive Loss
Number
of
Shares
$0.01
Par
Value
Additional
Paid-in
Capital
Accumulated
Earnings
Total
Stockholders’
Equity
Balance at January 1, 202254,419 $544 $536,377 $(196,012)$1,172,978 $1,513,887 
Net income— — — — 45,314 45,314 
Other comprehensive income— — — 33,849 — 33,849 
Stock-based compensation— — 5,712 — — 5,712 
Issuance of common stock for restricted share vesting, net of employee tax withholdings36 — (1,831)— — (1,831)
Repurchases of common stock(41)— (3,694)— — (3,694)
Balance at March 31, 202254,414 544 536,564 (162,163)1,218,292 1,593,237 
Net income— — — — 148,157 148,157 
Other comprehensive loss— — — (539)— (539)
Stock-based compensation— — 6,835 — — 6,835 
Issuance of common stock for restricted share vesting, net of employee tax withholdings31 — (740)— — (740)
Repurchases of common stock(335)(3)(29,997)— — (30,000)
Balance at June 30, 202254,110 $541 $512,662 $(162,702)$1,366,449 $1,716,950 

The accompanying notes are an integral part of these unaudited consolidated financial statements.
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CLEAN HARBORS, INC. AND SUBSIDIARIES
NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS

(1) BASIS OF PRESENTATION
The accompanying consolidated interim financial statements are unaudited and include the accounts of Clean Harbors, Inc. and its subsidiaries (collectively, “Clean Harbors” or the “Company”) and have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) and, in the opinion of management, include all adjustments which are of a normal recurring nature and are necessary for a fair presentation of the financial position, results of operations and cash flows for the periods presented. Management has made estimates and assumptions affecting the amounts reported in the Company's consolidated interim financial statements and accompanying footnotes; actual results could differ from those estimates and judgments. The results for interim periods are not necessarily indicative of results for the entire year or any other interim periods. The financial statements presented herein should be read in conjunction with the financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021.2022.

(2) SIGNIFICANT ACCOUNTING POLICIES
The Company's significant accounting policies are described in Note 2, "Significant Accounting Policies," in the Company's Annual Report on Form 10-K for the year ended December 31, 2021.2022. There have been no material changes in these policies or their application duringexcept for the periods presented.change described below.
Segment Reporting and Goodwill
Pursuant to the previous succession announcement, effective March 31, 2023, Michael L. Battles and Eric W. Gerstenberg, former Chief Financial Officer and Chief Operating Officer of the Company, respectively, were appointed co-CEOs. As a result, the Company’s new Chief Operating Decision Maker (“CODM”) is a committee comprised of both co-CEOs, who, going forward, will manage the business, make operating decisions and assess performance. The Company does not expect that the new CODM structure will change how the Company is managed and as such will continue to report as two operating segments; (i) the Environmental Services segment and (ii) the Safety-Kleen Sustainability Solutions segment and assess the recoverability of goodwill under three reporting units; (i) Environmental Sales and Service, (ii) Environmental Facilities and (iii) Safety-Kleen Sustainability Solutions.

(3) REVENUES
The Company’sCompany generates revenues through the following operating segments: Environmental Services and Safety-Kleen Sustainability Solutions. The Company's Environmental Services operating segment generally has four sources of revenue and the Safety-Kleen Sustainability Solutions operating segment has two sources of revenue. The Company disaggregates third-party revenues are disaggregated by geographic location and source of revenue as management believes these categories depict how revenue and cash flows are affected by economic factors. The Company's significant sources of revenue include:
Technical Services—Technical Services contribute to the revenues of the Environmental Services operating segment. Revenues for these services are generated from fees charged for waste material management and disposal services including onsite environmental management services, large remediation projects, collection and transportation, packaging, recycling, treatment and disposal of waste. Revenue is primarily generated by short-term projects, most of which are governed by master service agreements that are long-term in nature. These master service agreements are typically entered into with the Company's larger customers and outline the pricing and legal frameworks for such arrangements. Services are provided based on purchase orders or agreements with the customer and include prices based upon units of volume of waste, material and personnel costs as well as transportation and other fees. Collection and transportation revenues are recognized over time, as the customer receives and consumes the benefits of the services as they are being performed and the Company has a right to payment for performance completed to date. The Company uses the input method to recognize revenue over time, based on time and materials incurred as a basis for measuring the satisfaction of the performance obligation. Revenues for treatment and disposal of waste are recognized upon completion of treatment, final disposition in a landfill or incineration,incinerator, or when the waste is shipped to a third-party for processing and disposal. The Company periodically enters into bundled arrangements for the collection and transportation and disposal of waste. For such arrangements, transportation and disposal are considered distinct performance obligations and the Company allocates revenue to each based on the relative standalone selling price (i.e., the estimated price that a customer would pay for the services on a standalone basis). Revenues and the related costs from waste that is not yet completely processed and disposed of are deferred. The deferred revenues and costs are recognized when the services are completed. The period between collection and transportation and the final processing and disposal ranges depending on the location of the customer, but generally is measured in days.
Field and Emergency Response Services—Field and Emergency Response Services contribute to the revenues of the Environmental Services operating segment. Field Services revenues are generated from cleanup services at customer sites, including those managed by municipalities and utility providers, or other locations on a scheduled or emergency response basis. Services include confined space entry for tank cleaning, site decontamination, remediation, railcar cleaning, manhole/vault clean outs, product recovery and transfer and vacuum services. Additional services include filtration and water treatment services. Response services for environmental emergencies of any scale range from man-made disasters such as oil spills to natural disasters such as hurricanes. Emergency response services also include spill cleanup on land and water, contagion disinfection, decontamination and disposal services most recently in response to the COVID-19 pandemic. Field and emergency response services are provided based on purchase orders or agreements with customers and include prices generally based upon daily, hourly or job rates for equipment, materials and personnel. The Company recognizes revenue for these services over time, as the customer receives and consumes the benefits of the services as they are being performed and the Company has a right to payment for performance completed to date. The
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Company uses the input method to recognize revenue over time, based on time and materials incurred. The duration of such services can be over a number of hours, several days or even months for larger scale projects.
Industrial Services and Other—Industrial Services contribute to the revenues of the Environmental Services operating segment. These revenues are primarily generated from industrial and specialty services provided to refineries, mines, upgraders, chemical plants, manufacturing facilities, power generation companies, pulp and paper mills, manufacturing facilities, power generation facilitiesmines and other industrial customers throughout North America. Services include in-plant cleaning and maintenance services, plant outage and turnaround services, specialty cleaning services including chemical cleaning, pigging and high and ultra-high pressure water cleaning, leak detection and repair, daylighting, production services and upstream energy services. Services are provided based on purchase orders or agreements with the customer and include prices based upon daily, hourly or job rates for equipment, materials and personnel. The Company recognizes revenue for these services over time, as the customer receives and consumes the benefits of the services as they are being performed and the Company has a right to payment for performance completed to date. The Company uses the input method to recognize revenue over time, based on time and materials incurred.
Field and Emergency Response Services—Field and Emergency Response Services contribute to the revenues of the Environmental Services operating segment. Field Services revenues are generated from cleanup services at customer sites, including those managed by municipalities and utility providers, or other locations on a scheduled or emergency response basis. Services include confined space entry for tank cleaning, site decontamination, remediation, railcar cleaning, manhole/vault clean outs, product recovery and transfer and vacuum services. Additional services include filtration and water treatment services. Response services for environmental emergencies of any scale range from man-made disasters such as oil spills to natural disasters like hurricanes. Emergency response services also include spill cleanup on land and water, as well as contagion disinfection, decontamination and disposal services. Field and emergency response services are provided based on purchase orders or agreements with customers and include prices generally based upon daily, hourly or job rates for equipment, materials and personnel. The Company recognizes revenue for these services over time, as the customer receives and consumes the benefits of the services as they are being performed and the Company has a right to payment for performance completed to date. The Company uses the input method to recognize revenue over time, based on time and materials incurred. The duration of such services can be over a number of hours, several days or even months for larger scale projects.
Safety-Kleen Environmental Services—Safety-Kleen Environmental Services revenues contribute both to the Environmental Services operating segment and the Safety-Kleen Sustainability Solutions operating segment depending upon the nature of such revenues and operating responsibilities relative to executing the revenue contracts. Revenues from providing containerized waste handling and disposal services, parts washer services and vacuum services, referred to collectively as the Safety-Kleen branches' core service offerings, contribute to the revenues of the Environmental Services operating segment. In addition, sales of packaged blended oil products and other complementary product sales contribute to the revenues of the Environmental Services operating segment. Revenues generated from waste oil, anti-freeze and oil filter collection services, sales of bulk blended oil products and sales of bulk automotive fluids contribute to the Safety-Kleen Sustainability Solutions operating segment.
Generally, the revenue from services is recognized over time, as the customer receives and consumes the benefits of the services as they are being performed and the Company has a right to payment for performance completed to date. The duration of such services can be over a number of hours or several days. The Company uses the input method to recognize revenue over time, based on time and materials incurred. Product revenue is recognized upon the transfer of control whereby control transfers when the products are delivered to the customer. Containerized waste services consist of profiling, collecting, transporting and recycling or disposing of a wide variety of waste. Related collection and transportation revenues are recognized over time, as the customer receives and consumes the benefits of the services as they are being performed and the Company has a right to payment for performance completed to date. Parts washer services include customer use of ourthe Company's parts washer equipment, cleaning and maintenance of the parts washer equipment and removal and replacement of used cleaning fluids. Parts washer services are considered a single performance obligation due to the highly integrated and interdependent nature of the arrangement. Revenue from parts washer services is recognized over the service interval as the customer receives the benefit of the services.
Safety-Kleen Oil—Safety-Kleen Oil related sales contribute to the revenues of the Safety-Kleen Sustainability Solutions segment. These revenues are generated from sales of high-quality base and blended lubricating oils to third-party distributors, government agencies, fleets, railroads and industrial customers. The business also sells recycled fuel oil to asphalt plants, industrial plants and pulp and paper companies. The used oil is also processed into vacuum gas oil which can be further re-refined into lubricant base oils or sold directly into the marine diesel oil fuel market. Revenue for oil products is recognized at a point in time, upon the transfer of control. Control transfers when the products are delivered to the customer.
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The following tables present the Company's third-party revenue disaggregated by source of revenue and geography (in thousands):
For the Three Months Ended June 30, 2022For the Three Months Ended June 30, 2023
Environmental ServicesSafety-Kleen Sustainability SolutionsCorporateTotalEnvironmental ServicesSafety-Kleen Sustainability SolutionsCorporateTotal
Primary Geographical MarketsPrimary Geographical MarketsPrimary Geographical Markets
United StatesUnited States$945,579 $236,879 $79 $1,182,537 United States$1,041,739 $212,994 $116 $1,254,849 
CanadaCanada138,927 34,848 — 173,775 Canada119,743 23,308 — 143,051 
Total third-party revenuesTotal third-party revenues$1,084,506 $271,727 $79 $1,356,312 Total third-party revenues$1,161,482 $236,302 $116 $1,397,900 
Sources of RevenueSources of RevenueSources of Revenue
Technical ServicesTechnical Services$387,019 $— $— $387,019 Technical Services$389,908 $— $— $389,908 
Field and Emergency Response Services (1)
144,860 — — 144,860 
Industrial Services and Other (2)
360,870 — 79 360,949 
Industrial Services and OtherIndustrial Services and Other399,545 — 116 399,661 
Field and Emergency Response ServicesField and Emergency Response Services154,359 — — 154,359 
Safety-Kleen Environmental ServicesSafety-Kleen Environmental Services191,757 49,381 — 241,138 Safety-Kleen Environmental Services217,670 62,452 — 280,122 
Safety-Kleen OilSafety-Kleen Oil— 222,346 — 222,346 Safety-Kleen Oil— 173,850 — 173,850 
Total third-party revenuesTotal third-party revenues$1,084,506 $271,727 $79 $1,356,312 Total third-party revenues$1,161,482 $236,302 $116 $1,397,900 
_____________
(1) Includes approximately $34.2 million of third-party revenues from the operations of the HydroChemPSC business
For the Three Months Ended June 30, 2022
Environmental ServicesSafety-Kleen Sustainability SolutionsCorporateTotal
Primary Geographical Markets
United States$945,579 $236,879 $79 $1,182,537 
Canada138,927 34,848 — 173,775 
Total third-party revenues$1,084,506 $271,727 $79 $1,356,312 
Sources of Revenue
Technical Services$387,019 $— $— $387,019 
Industrial Services and Other360,870 — 79 360,949 
Field and Emergency Response Services144,860 — — 144,860 
Safety-Kleen Environmental Services191,757 49,381 — 241,138 
Safety-Kleen Oil— 222,346 — 222,346 
Total third-party revenues$1,084,506 $271,727 $79 $1,356,312 
(2) Includes approximately $173.7 million of third-party revenues from the operations of the HydroChemPSC business
For the Three Months Ended June 30, 2021For the Six Months Ended June 30, 2023
Environmental ServicesSafety-Kleen Sustainability SolutionsCorporateTotalEnvironmental ServicesSafety-Kleen Sustainability SolutionsCorporateTotal
Primary Geographical MarketsPrimary Geographical MarketsPrimary Geographical Markets
United StatesUnited States$616,585 $180,216 $79 $796,880 United States$2,000,323 $434,765 $223 $2,435,311 
CanadaCanada106,562 23,016 — 129,578 Canada222,141 47,835 — 269,976 
Total third-party revenuesTotal third-party revenues$723,147 $203,232 $79 $926,458 Total third-party revenues$2,222,464 $482,600 $223 $2,705,287 
Sources of RevenueSources of RevenueSources of Revenue
Technical ServicesTechnical Services$306,865 $— $— $306,865 Technical Services$756,417 $— $— $756,417 
Industrial Services and OtherIndustrial Services and Other735,924 — 223 736,147 
Field and Emergency Response ServicesField and Emergency Response Services106,986 — — 106,986 Field and Emergency Response Services302,445 — — 302,445 
Industrial Services and Other150,367 — 79 150,446 
Safety-Kleen Environmental ServicesSafety-Kleen Environmental Services158,929 40,453 — 199,382 Safety-Kleen Environmental Services427,678 112,011 — 539,689 
Safety-Kleen OilSafety-Kleen Oil— 162,779 — 162,779 Safety-Kleen Oil— 370,589 — 370,589 
Total third-party revenuesTotal third-party revenues$723,147 $203,232 $79 $926,458 Total third-party revenues$2,222,464 $482,600 $223 $2,705,287 
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For the Six Months Ended June 30, 2022
Environmental ServicesSafety-Kleen Sustainability SolutionsCorporateTotal
Primary Geographical Markets
United States$1,780,257 $439,409 $151 $2,219,817 
Canada245,047 60,557 — 305,604 
Total third-party revenues$2,025,304 $499,966 $151 $2,525,421 
Sources of Revenue
Technical Services$710,675 $— $— $710,675 
Field and Emergency Response Services (1)
277,219 — — 277,219 
Industrial Services and Other (2)
669,708 — 151 669,859 
Safety-Kleen Environmental Services367,702 93,769 — 461,471 
Safety-Kleen Oil— 406,197 — 406,197 
Total third-party revenues$2,025,304 $499,966 $151 $2,525,421 
_____________
(1) Includes approximately $62.2 million of third-party revenues from the operations of the HydroChemPSC business
(2) Includes approximately $329.8 million of third-party revenues from the operations of the HydroChemPSC business
For the Six Months Ended June 30, 2021For the Six Months Ended June 30, 2022
Environmental ServicesSafety-Kleen Sustainability SolutionsCorporateTotalEnvironmental ServicesSafety-Kleen Sustainability SolutionsCorporateTotal
Primary Geographical MarketsPrimary Geographical MarketsPrimary Geographical Markets
United StatesUnited States$1,192,093 $319,206 $158 $1,511,457 United States$1,780,257 $439,409 $151 $2,219,817 
CanadaCanada183,932 39,217 — 223,149 Canada245,047 60,557 — 305,604 
Total third-party revenuesTotal third-party revenues$1,376,025 $358,423 $158 $1,734,606 Total third-party revenues$2,025,304 $499,966 $151 $2,525,421 
Sources of RevenueSources of RevenueSources of Revenue
Technical ServicesTechnical Services$578,905 $— $— $578,905 Technical Services$710,675 $— $— $710,675 
Industrial Services and OtherIndustrial Services and Other669,708 — 151 669,859 
Field and Emergency Response ServicesField and Emergency Response Services212,154 — — 212,154 Field and Emergency Response Services277,219 — — 277,219 
Industrial Services and Other270,177 — 158 270,335 
Safety-Kleen Environmental ServicesSafety-Kleen Environmental Services314,789 79,431 — 394,220 Safety-Kleen Environmental Services367,702 93,769 — 461,471 
Safety-Kleen OilSafety-Kleen Oil— 278,992 — 278,992 Safety-Kleen Oil— 406,197 — 406,197 
Total third-party revenuesTotal third-party revenues$1,376,025 $358,423 $158 $1,734,606 Total third-party revenues$2,025,304 $499,966 $151 $2,525,421 
Contract Balances
(in thousands)(in thousands)June 30, 2022December 31, 2021(in thousands)June 30, 2023December 31, 2022
ReceivablesReceivables$1,005,488 $792,734 Receivables$981,233 $964,603 
Contract assets (unbilled receivables)Contract assets (unbilled receivables)134,173 94,963 Contract assets (unbilled receivables)122,679 107,010 
Contract liabilities (deferred revenue)Contract liabilities (deferred revenue)94,531 83,749 Contract liabilities (deferred revenue)105,327 94,094 

The timing of revenue recognition, billings and cash collections results in billed accounts receivable, unbilled receivables (contract assets) and customer advances and deposits or deferred revenue (contract liabilities) on the consolidated balance sheet. Generally, billing occurs subsequent to revenue recognition, as a right to payment is not just subject to passage of time, resulting in contract assets. Contract assets, which are generally classified as current. The Company sometimes receives advances or deposits from its customers before revenue is recognized, resulting in contract liabilities. These assets and liabilities are reported on the consolidated balance sheet on a contract-by-contract basis at the end of each reporting period. The contract liability balances at the beginning of each period presented were generally fully recognized in the subsequent three-month period.
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(4) BUSINESS COMBINATIONS
20222023 Acquisition
On June 17, 2022,March 31, 2023, the Company acquired a privately-owned companyThompson Industrial Services, LLC ("Thompson Industrial") for an all-cash purchase price of approximately $73.8$111.9 million, net of cash acquired and subject to the final settlement of working capital adjustments.capital. The operations of the newly acquired companyThompson Industrial expand the Safety-Kleen Sustainability SolutionsEnvironmental Services segment's waste oil collection capabilities and re-refining business throughoutindustrial service operations in the southeastsoutheastern region of the United States, including the addition of a re-refinery in Georgia.States.
The preliminary allocation of the purchase price is provisional and was based on estimates of the fair value of assets acquired and liabilities assumed as of June 17, 2022.the acquisition date. The Company continues to obtain information to complete the valuation of these balances and the associated income tax accounting. Measurement period adjustments will reflect new information obtained
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about facts and circumstances that existed as of the acquisition date. The following table summarizes the preliminary determination and recognition of assets acquired and liabilities assumed (in thousands):
At June 17, 2022
Accounts receivable$1,079 
Inventories and supplies5,737 
Prepaid expenses and other current assets269 
Property, plant and equipment23,270 
Permits and other intangibles16,750 
Operating lease right-of-use assets585 
Other non-current assets42 
Current liabilities(2,756)
Current portion of operating lease liabilities(186)
Operating lease liabilities, less current portion(399)
Total identifiable net assets44,391 
Goodwill29,375 
Total purchase price$73,766 
At Acquisition Date As Reported March 31, 2023Measurement Period Adjustments
At Acquisition Date
As Reported June 30, 2023
Accounts receivable$25,793 $(563)$25,230 
Inventories and supplies233 — 233 
Prepaid expenses and other current assets1,150 154 1,304 
Property, plant and equipment28,030 (1,301)26,729 
Permits and other intangibles28,100 800 28,900 
Operating lease right-of-use assets4,716 — 4,716 
Other non-current assets36 36 72 
Current liabilities(11,514)1,586 (9,928)
Current portion of operating lease liabilities(1,653)— (1,653)
Operating lease liabilities, less current portion(3,063)— (3,063)
Other long-term liabilities— (570)(570)
Total identifiable net assets71,828 142 71,970 
Goodwill40,092 (167)39,925 
Total purchase price$111,920 $(25)$111,895 
IntangiblePermits and other intangible assets acquired include customer relationships, trademarks/tradenames and non-compete agreements and are anticipated to have estimated useful lives of between five and 15 years with a weighted average useful life of approximately 13 years. The excess of the total purchase price, which includes the aggregate cash consideration paid in excess of the fair value of the tangible and intangible assets acquired and liabilities assumed, was recorded as goodwill. The goodwill recognized is attributable to the expected operating synergies, assembled workforce and growth potential that the Company expects to realize from the acquisition. Goodwill generated from the acquisition is deductible for tax purposes.
The operations included in the Company's financial statements for the three and six months ended June 30, 2023, and pro forma revenue and earnings amounts on a combined basis as if this acquisition had been completed on January 1, 2022 are immaterial to the consolidated financial statements of the Company.
2022 Acquisitions
On June 17, 2022, the Company acquired a privately-owned company for an all-cash purchase price of approximately $78.9 million, net of cash acquired. The operations of the newly acquired company expand the Safety-Kleen Sustainability Solutions segment's waste oil collection capabilities and re-refining business throughout the southeastern region of the United States, including the addition of a re-refinery in Georgia.
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The Company has finalized the purchase accounting for this acquisition. The allocation of the purchase price was based on estimates of the fair value and assets acquired and liabilities assumed as of June 17, 2022. The following table summarizes the final determination and recognition of assets acquired and liabilities assumed (in thousands):
At Acquisition Date As Reported December 31, 2022Measurement Period AdjustmentsFinal Allocation At Acquisition Date As Reported June 30, 2023
Accounts receivable$1,111 $(22)$1,089 
Inventories and supplies5,816 (71)5,745 
Prepaid expenses and other current assets144 — 144 
Property, plant and equipment19,605 2,626 22,231 
Permits and other intangibles23,500 — 23,500 
Operating lease right-of-use assets585 — 585 
Other non-current assets13 — 13 
Current liabilities(3,271)(104)(3,375)
Current portion of operating lease liabilities(186)— (186)
Operating lease liabilities, less current portion(399)— (399)
Other long-term liabilities(55)(2,626)(2,681)
Total identifiable net assets46,863 (197)46,666 
Goodwill32,015 197 32,212 
Total purchase price$78,878 $— $78,878 
Permits and other intangible assets acquired include supplier relationships, permits, customer relationships and trademarks/tradenames and are anticipated to have estimated useful lives of between five and 20 years with a weighted average useful life of approximately 1718 years. The excess of the total purchase price, which includes the aggregate cash consideration paid in excess of the fair value of the tangible and intangible assets acquired, was recorded as goodwill. The goodwill recognized is attributable to the expected operating synergies, assembled workforce and growth potential that the Company expects to realize from the acquisition. Goodwill generated from the acquisition is deductible for tax purposes.
The operations included in the Company's financial statements for the period ended June 30, 2022 and pro forma revenue and earnings amounts on a combined basis as if this acquisition had been completed on January 1, 2021 are immaterial to the consolidated financial statements of the Company.
2021 Acquisitions
On October 8, 2021, the Company completed the acquisition of LJ Energy Services Intermediate Holding Corp. and its subsidiaries (collectively, “HydroChemPSC”), a privately-owned company, for an all-cash purchase price of approximately $1.23 billion. HydroChemPSC is a leading U.S. provider of industrial cleaning, specialty maintenance and utilities services. These operations enhance and have been integrated into the Company's Environmental Services segment. In the first quarter ofDecember 9, 2022, the Company received $5.0 million after finalizing the acquisition date working capital balances, which decreased the overall purchase price.
The allocation of the purchase price was based on estimates of the fair value of assets acquired and liabilities assumed as of October 8, 2021. The Company continues to obtain information to complete the valuation of these balances and the associated income tax accounting. Measurement period adjustments reflect new information obtained about facts and circumstances that existed
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as of the acquisition date, including the adjustment for the monies received for the working capital finalization noted above. The components and allocation of the purchase price consist of the following amounts (in thousands):
At Acquisition Date As Reported December 31, 2021Measurement Period Adjustments
At Acquisition Date
As Reported
 June 30, 2022
Accounts receivable, including unbilled receivables$131,924 $(395)$131,529 
Inventories and supplies3,162 — 3,162 
Prepaid expenses and other current assets16,016 363 16,379 
Property, plant and equipment313,540 — 313,540 
Other intangibles289,000 — 289,000 
Operating lease right-of-use assets34,347 68 34,415 
Other non-current assets1,045 (60)985 
Current liabilities(115,704)(883)(116,587)
Current portion of operating lease liabilities(11,659)382 (11,277)
Operating lease liabilities, less current portion(26,128)(216)(26,344)
Deferred tax liabilities(85,908)2,436 (83,472)
Other long-term liabilities(2,685)(242)(2,927)
Total identifiable net assets546,950 1,453 548,403 
Goodwill (i)
683,463 (6,453)677,010 
Total purchase price$1,230,413 $(5,000)$1,225,413 
_____________
(i) Goodwill represents the excess of the fair value of the net assets acquired over the purchase price. Goodwill of $677.0 million was assigned to the Environmental Sales & Service reporting unit and is attributable to the future economic benefits arising from the acquired operations, synergies and the acquired workforce of HydroChemPSC. None of the goodwill related to this acquisition will be deductible for tax purposes.
HydroChemPSC's results of operations have been included in the Company's financial statements for the period subsequent to the completion of the acquisition on October 8, 2021. The following unaudited supplemental pro-forma data presents consolidated information as if the acquisition had occurred on January 1, 2021 (in thousands):
Three Months Ended June 30, 2021Six Months Ended June 30, 2021
Pro forma combined revenues$1,121,121 $2,107,309 
Pro forma combined net income74,526 102,078 
The pro forma results do not include any costs incurred directly attributable to the acquisition of HydroChemPSC. The pro forma results do reflect impacts resulting from the issuance of $1.0 billion senior secured term loans issued in connection with the acquisition assuming interest rates in effect at the time of the acquisition.
This pro forma financial information is not necessarily indicative of the Company's consolidated operating results that would have been reported had the transactions been completed as described herein, nor is such information necessarily indicative of the Company's consolidated results for any future period. Interest expense used in calculating the pro forma net income did not contemplate the interest rate swaps that the Company put in place in early 2022.
On March 27, 2021, the Company also acquired a privately-owned business for $22.8$12.6 million cash consideration. The acquired company increasesexpands the Safety-Kleen Sustainability Solutions segment's network withinoil collection operations in the south centralsoutheastern region of the United States. In connection with this acquisition, a final goodwill amount of $16.3$2.6 million was recognized. The results of operations for the acquired business were not material in 2022.

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(5) DISPOSITION OF BUSINESS
On June 30, 2022, the Company completed the sale of a line of business as part of its continuous focus on divesting certain non-core operations. The divested line of business was previously included within the Environmental Sales & ServicesService reporting unit of the Environmental Services segment. The Company determined that the disposition did not constitute a strategic shift and that the impact on the Company's overall operations and financial results will not be material. Accordingly, the operations associated with the disposal are not reported in discontinued operations. The final purchase price for the line of business was sold for $19.5$18.8 million, and is subject to customary post-closing conditions.after settling working capital. The gain on sale of $8.9 million, after accounting for the assets sold, liabilities transferred upon sale and transaction costs, is included in gain on sale of business in the Company’sCompany's consolidated statement of operations for the three and six months ended June 30, 2022.

(6) INVENTORIES AND SUPPLIES
Inventories and supplies consisted of the following (in thousands):
June 30, 2022December 31, 2021June 30, 2023December 31, 2022
Oil and oil related productsOil and oil related products$112,656 $101,965 Oil and oil related products$129,575 $151,519 
SuppliesSupplies136,038 126,602 Supplies162,788 143,743 
Solvent and solutionsSolvent and solutions11,304 8,099 Solvent and solutions13,004 11,994 
OtherOther15,698 14,026 Other20,515 17,738 
Total inventories and suppliesTotal inventories and supplies$275,696 $250,692 Total inventories and supplies$325,882 $324,994 
Supplies inventories consist primarily of critical spare parts to support the Company's incinerator and re-refinery operations
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and other general supplies used in our normal day-to-day operations. Other inventories consist primarily of parts washer components, cleaning fluids, absorbents and automotive fluids, such as windshield washer fluid and antifreeze.

(7) PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment consisted of the following (in thousands):
June 30, 2022December 31, 2021June 30, 2023December 31, 2022
LandLand$174,744 $165,010 Land$174,235 $172,579 
Asset retirement costs (non-landfill)Asset retirement costs (non-landfill)19,598 19,105 Asset retirement costs (non-landfill)27,164 22,001 
Landfill assetsLandfill assets214,558 205,873 Landfill assets244,639 232,872 
Buildings and improvements (1)
Buildings and improvements (1)
571,078 551,795 
Buildings and improvements (1)
617,189 591,397 
Camp equipment124,672 127,680 
Vehicles (2)
Vehicles (2)
950,754 912,836 
Vehicles (2)
1,174,004 1,112,188 
Equipment (3)
Equipment (3)
2,136,376 2,092,395 
Equipment (3)
2,307,666 2,195,064 
Furniture and fixtures6,574 6,444 
Construction in progressConstruction in progress98,189 60,447 Construction in progress170,120 140,328 
4,296,543 4,141,585 4,715,017 4,466,429 
Less - accumulated depreciation and amortizationLess - accumulated depreciation and amortization2,383,398 2,278,410 Less - accumulated depreciation and amortization2,632,324 2,486,127 
Total property, plant and equipment, netTotal property, plant and equipment, net$1,913,145 $1,863,175 Total property, plant and equipment, net$2,082,693 $1,980,302 
________________
(1) Balances inclusive of gross right-of-use ("ROU") assets classified as finance leases of $8.0 million and $8.9 million respectively. in both periods.
(2) Balances inclusive of gross ROU assets classified as finance leases of $85.3$120.8 million and $77.7$106.7 million, respectively.
(3) Balances inclusive of gross ROU assets classified as finance leases of $9.3 $9.2 million in both periods.
Depreciation expense, inclusive of landfill and finance lease amortization, was $77.2 million and $149.2 million for the three and six months ended June 30, 2023, respectively. Depreciation expense, inclusive of landfill and finance lease amortization, was $75.6 million and $147.7 million for the three and six months ended June 30, 2022, respectively. Depreciation expense, inclusive of landfill and finance lease amortization, was $63.8The Company recorded $1.4 million and $128.4$2.7 million forof capitalized interest during the three and six months ended June 30, 2021,2023, respectively. The Company recorded $0.7 million and $1.1 million of capitalized interest during the three and six months ended June 30, 2022, respectively. The capitalized interest in the periods is mainly due to the construction of a new incinerator in Kimball, Nebraska.

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(8) GOODWILL AND OTHER INTANGIBLE ASSETS
The changes in goodwill by segment for the six months ended June 30, 20222023 were as follows (in thousands):
Environmental ServicesSafety-Kleen Sustainability SolutionsTotals
Balance at January 1, 2022$1,085,534 $141,508 $1,227,042 
Increase from current period acquisition— 29,375 29,375 
Measurement period adjustments from prior period acquisition(6,453)— (6,453)
Decrease from disposition of business(4,412)— (4,412)
Foreign currency translation(659)(238)(897)
Balance at June 30, 2022$1,074,010 $170,645 $1,244,655 
Environmental ServicesSafety-Kleen Sustainability SolutionsTotals
Balance at January 1, 2023$1,071,846 $175,032 $1,246,878 
Increase from current period acquisition39,925 — 39,925 
Measurement period adjustments from prior period acquisitions— 340 340 
Foreign currency translation818 330 1,148 
Balance at June 30, 2023$1,112,589 $175,702 $1,288,291 
The decrease from disposition of business relates to the divestiture discussed in Note 5, "Disposition of Business." The Company assesses goodwill on an annual basis as of December 31 or at an interim date when events or changes in the business environment (“triggering events”) would more likely than not reduce the fair value of a reporting unit below its carrying value. During the period ended June 30, 2022,2023, no such triggering events were identified.
As of June 30, 20222023 and December 31, 2021,2022, the Company's intangible assets consisted of the following (in thousands):
June 30, 2022December 31, 2021June 30, 2023December 31, 2022
CostAccumulated
Amortization
NetCostAccumulated
Amortization
NetCostAccumulated
Amortization
NetCostAccumulated
Amortization
Net
PermitsPermits$189,675 $105,957 $83,718 $187,519 $102,408 $85,111 Permits$190,209 $113,404 $76,805 $188,373 $109,036 $79,337 
Customer and supplier relationshipsCustomer and supplier relationships589,192 229,277 359,915 576,474 214,776 361,698 Customer and supplier relationships604,992 244,537 360,455 583,709 229,368 354,341 
Other intangible assetsOther intangible assets95,688 25,100 70,588 94,271 19,359 74,912 Other intangible assets100,068 31,291 68,777 89,388 24,818 64,570 
Total amortizable permits and other intangible assetsTotal amortizable permits and other intangible assets874,555 360,334 514,221 858,264 336,543 521,721 Total amortizable permits and other intangible assets895,269 389,232 506,037 861,470 363,222 498,248 
Trademarks and trade namesTrademarks and trade names123,033 — 123,033 123,191 — 123,191 Trademarks and trade names120,283 — 120,283 122,534 — 122,534 
Total permits and other intangible assetsTotal permits and other intangible assets$997,588 $360,334 $637,254 $981,455 $336,543 $644,912 Total permits and other intangible assets$1,015,552 $389,232 $626,320 $984,004 $363,222 $620,782 
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Amortization expense of permits, customer and supplier relationships and other intangible assets was $12.5 million and $25.2 million in the three and six months ended June 30, 2023, respectively. Amortization expense of permits, customer and supplier relationships and other intangible assets was $12.3 million and $24.5 million in the three and six months ended June 30, 2022, respectively. Amortization expense of permits, customer and supplier relationships and other intangible assets was $7.8 million and $15.4 million in the three and six months ended June 30, 2021, respectively.
The expected amortization of the net carrying amount of finite-lived intangible assets at June 30, 20222023 was as follows (in thousands):
Years Ending December 31,Years Ending December 31,Expected AmortizationYears Ending December 31,Expected Amortization
2022 (six months)$24,966 
202345,728 
2023 (six months)2023 (six months)$24,894 
2024202440,256 202446,461 
2025202539,051 202543,036 
2026202637,167 202641,146 
2027202739,067 
ThereafterThereafter327,053 Thereafter311,433 
$514,221 $506,037 

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(9) ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES
Accrued expenses and other current liabilities consisted of the following (in thousands):
June 30, 2022December 31, 2021
Accrued insurance$96,642 $102,853 
Accrued interest19,763 19,785 
Accrued compensation and benefits113,575 133,604 
Accrued income, real estate, sales and other taxes66,071 29,954 
Interest rate swap liability— 17,383 
Accrued other90,996 87,835 
$387,047 $391,414 
The decrease in the interest rate swap liability balance from December 31, 2021 is due to changes in future interest rate
expectations. As of June 30, 2022, the interest rate swap derivatives are in an asset position and therefore are included within Other Assets on the consolidated balance sheet. For additional information relating to the interest rate swaps, see Note 12, "Financing Arrangements."
June 30, 2023December 31, 2022
Accrued insurance$96,132 $92,909 
Accrued interest33,611 20,033 
Accrued compensation and benefits83,680 123,226 
Accrued income, real estate, sales and other taxes41,839 61,442 
Accrued other93,595 99,106 
$348,857 $396,716 

(10) CLOSURE AND POST-CLOSURE LIABILITIES
The changes to closure and post-closure liabilities (also referred to as “asset retirement obligations”) from January 1, 20222023 through June 30, 20222023 were as follows (in thousands):
Landfill
Retirement
Liability
Non-Landfill
Retirement
Liability
TotalLandfill
Retirement
Liability
Non-Landfill
Retirement
Liability
Total
Balance at January 1, 2022$53,425 $45,678 $99,103 
Balance at January 1, 2023Balance at January 1, 2023$62,251 $56,550 $118,801 
Liabilities assumed in acquisitionsLiabilities assumed in acquisitions— 584 584 
Measurement period adjustments from prior period acquisitionsMeasurement period adjustments from prior period acquisitions— 3,015 3,015 
New asset retirement obligationsNew asset retirement obligations1,657 — 1,657 New asset retirement obligations1,348 — 1,348 
AccretionAccretion2,250 1,993 4,243 Accretion2,555 2,182 4,737 
Changes in estimates recorded to consolidated statement of operationsChanges in estimates recorded to consolidated statement of operations329 47 376 Changes in estimates recorded to consolidated statement of operations— 135 135 
Changes in estimates recorded to consolidated balance sheetChanges in estimates recorded to consolidated balance sheet— 504 504 Changes in estimates recorded to consolidated balance sheet(260)1,531 1,271 
ExpendituresExpenditures(2,126)(622)(2,748)Expenditures(5,408)(4,093)(9,501)
Currency translation and otherCurrency translation and other(100)(38)(138)Currency translation and other169 149 318 
Balance at June 30, 2022$55,435 $47,562 $102,997 
Balance at June 30, 2023Balance at June 30, 2023$60,655 $60,053 $120,708 
During the first quarter of 2023, the Company's non-commercial landfill at the Deer Park, Texas incineration facility reached its permitted capacity, as expected. The Company has commenced closure activities; however, there have been no changes to the liabilities related to this location. In the six months ended June 30, 2022,2023, there were no significant chargesbenefits or benefitscharges resulting from changes in estimates for closure and post-closure liabilities.
New asset retirement obligations incurred during the first six months of 2022 were discounted at the credit-adjusted risk-free rate of 5.37%.

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(11) REMEDIAL LIABILITIES 
The changes to remedial liabilities from January 1, 20222023 through June 30, 20222023 were as follows (in thousands):
Remedial
Liabilities for
Landfill Sites
Remedial
Liabilities for
Inactive Sites
Remedial
Liabilities
(Including
Superfund) for
Non-Landfill
Operations
TotalRemedial
Liabilities for
Landfill Sites
Remedial
Liabilities for
Inactive Sites
Remedial
Liabilities
(Including
Superfund) for
Non-Landfill
Operations
Total
Balance at January 1, 2022$1,780 $59,787 $50,306 $111,873 
Liability assumed in acquisition of real estate— — 13,073 13,073 
Measurement period adjustment from a prior period acquisition— — 242 242 
Balance at January 1, 2023Balance at January 1, 2023$1,824 $59,749 $54,717 $116,290 
AccretionAccretion42 1,264 804 2,110 Accretion44 1,304 808 2,156 
Changes in estimates recorded to consolidated statement of operationsChanges in estimates recorded to consolidated statement of operations731 124 856 Changes in estimates recorded to consolidated statement of operations386 (140)252 
ExpendituresExpenditures(25)(1,676)(2,579)(4,280)Expenditures(26)(1,966)(4,830)(6,822)
Currency translation and otherCurrency translation and other— (9)(209)(218)Currency translation and other— 12 288 300 
Balance at June 30, 2022$1,798 $60,097 $61,761 $123,656 
Balance at June 30, 2023Balance at June 30, 2023$1,848 $59,485 $50,843 $112,176 
In the six months ended June 30, 2022,2023, there were no significant benefits or charges resulting from changes in estimates for remedial liabilities. The $13.1 million liability assumed in acquisition relates to real estate that the Company acquired in the first quarter of 2022. In purchasing the property, the Company assumed a known associated remedial liability, which was contemplated in the purchase price.

(12) FINANCING ARRANGEMENTS
Long-term Debt
The following table is a summary of the Company’s long-term debt (in thousands):
Current Portion of Long-Term Debt:Current Portion of Long-Term Debt:June 30, 2022December 31, 2021Current Portion of Long-Term Debt:June 30, 2023December 31, 2022
Secured senior term loansSecured senior term loans$17,535 $17,535 Secured senior term loans$10,000 $10,000 
Long-Term Debt:Long-Term Debt:Long-Term Debt:
Secured senior term loans due June 30, 2024 ("2024 Term Loans")Secured senior term loans due June 30, 2024 ("2024 Term Loans")$708,323 $712,091 Secured senior term loans due June 30, 2024 ("2024 Term Loans")$— $613,975 
Secured senior term loans due October 8, 2028 ("2028 Term Loans")Secured senior term loans due October 8, 2028 ("2028 Term Loans")985,000 990,000 Secured senior term loans due October 8, 2028 ("2028 Term Loans")975,000 980,000 
Unsecured senior notes, at 4.875%, due July 15, 2027 ("2027 Notes")Unsecured senior notes, at 4.875%, due July 15, 2027 ("2027 Notes")545,000 545,000 Unsecured senior notes, at 4.875%, due July 15, 2027 ("2027 Notes")545,000 545,000 
Unsecured senior notes, at 5.125%, due July 15, 2029 ("2029 Notes")Unsecured senior notes, at 5.125%, due July 15, 2029 ("2029 Notes")300,000 300,000 Unsecured senior notes, at 5.125%, due July 15, 2029 ("2029 Notes")300,000 300,000 
Unsecured senior notes, at 6.375%, due February 1, 2031 ("2031 Notes")Unsecured senior notes, at 6.375%, due February 1, 2031 ("2031 Notes")500,000 — 
Long-term debt, at parLong-term debt, at par$2,538,323 $2,547,091 Long-term debt, at par$2,320,000 $2,438,975 
Unamortized debt issuance costs and discount, netUnamortized debt issuance costs and discount, net(27,360)(30,067)Unamortized debt issuance costs and discount, net(25,694)(24,147)
Long-term debt, at carrying valueLong-term debt, at carrying value$2,510,963 $2,517,024 Long-term debt, at carrying value$2,294,306 $2,414,828 
Financing Activities
The Company's significant financing arrangements are described in Note 12, "Financing Arrangements," in the Company's Annual Report on Form 10-K for the year ended December 31, 2022 and there have been no material changes to the arrangements described therein. As previously disclosed, on January 24, 2023, the Company completed a private placement of $500.0 million aggregate principal amount of unsecured senior notes which mature on February 1, 2031 (collectively referred to with the 2027 and 2029 Notes as the "Notes"). The proceeds from the 2031 Notes, along with a $114.0 million borrowing on the Company's revolving credit facility and available cash, were used to repay the $614.0 million outstanding principal amount of the 2024 Term Loans. In connection with the repayment, the Company recognized a loss on early extinguishment of debt of $2.4 million in the first quarter of 2023.
The Company maintains a $400.0 million revolving credit facility under which the Company had no outstanding loan balance as of June 30, 2023 and December 31, 2022. During the three months ended March 31, 2023, the Company borrowed $114.0 million on the revolving credit facility to repay the outstanding principal amount of the 2024 Term Loans. The Company repaid the full amount of the borrowing on May 26, 2023. As of June 30, 2023, the Company had $274.8 million available to borrow under the revolving credit facility and outstanding letters of credit were $125.2 million. Subject to certain conditions, this credit facility will expire in October 2025.
As of June 30, 20222023 and December 31, 2021,2022, the estimated fair value of the Company’s outstanding long-term debt, including the current portion, was $2.5$2.3 billion and $2.6$2.4 billion, respectively. The Company’s estimates of fair value of its long-term debt, including the current portion, are based on quoted market prices or other available market data which are considered Level 2
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measures according to the fair value hierarchy. Level 2 utilizes quoted market prices in markets that are not active, broker or dealer quotationsquotation or alternative pricing sources with reasonable levels of price transparency for similar assets and liabilities.
The Company maintainsUpon the phase-out of LIBOR as a $400.0 million revolving credit facility under whichreferenced rate, the Company had no outstanding loan balances ashas transitioned all of June 30, 2022 and December 31, 2021.its variable rate debt to a successor rate, namely Term SOFR. As of June 30, 2022,2023, after taking into account the interest rate swaps discussed under the "Cash Flow Hedges" header below, the Company's variable rate debt consists of $385.0 million of the 2028 Term Loans and any borrowings under the revolving credit facility.
In accordance with the October 8, 2021 amendment to the credit agreement, the 2028 Term Loan will generally bear interest at a rate of Term SOFR plus an adjustment of 0.11448%, based upon one-month Term SOFR. The Term Loan Agreement also provides for Term SOFR adjustments for other interest periods, however the Company had $290.6 million availableexpects to borrowelect the one-month Term SOFR for interest payments on that debt. The 2.00% margin applicable to the 2028 Term Loans prior to the phase-out of LIBOR also remains applicable to the interest payments under Term SOFR, so in total, the 2028 Term Loan will bear interest at Term SOFR plus 2.11448%. The Company expects these changes will not be material to future financial results.
On April 28, 2023, the Company entered into an amendment to the credit agreement for the revolving credit facility. As amended, the terms of the agreement are substantially the same as prior to the amendment except for certain updates required to transition the agreement to include a defined LIBOR successor rate. Under the amended agreement, borrowings under the revolving credit facility will bear interest at a rate, at the Company’s option, of either (i) “Term SOFR” (as defined in the amended agreement) plus an applicable margin ranging from 1.50% to 1.75% per annum based primarily on the level of the Company’s average liquidity for the most recent 30 day period or (ii) Bank of America's base rate plus an applicable margin ranging from 0.50% to 0.75% per annum based primarily on such average liquidity. The amended agreement also continues to provide (i) for an unused line fee payable to the lenders, calculated on the then unused portion of the lenders’ $400.0 million maximum commitments, ranging from 0.25% to 0.375% per annum of the unused commitment, and (ii) for outstanding letters of credit, were $109.4 million. Subjecta fee payable to certain conditions, this credit facilitythe lenders equal to the then applicable margin for Term SOFR borrowings described above, and to the issuing banks a standard fronting fee and customary fees and charges in connection with all amendments, extensions, draws and other actions with respect to letters of credit. The Company expects these changes will expire in October 2025.not be material to future financial results.
Cash Flow Hedges
The Company’sCompany's strategy to hedge against fluctuations in variable interest rates involves entering into interest rate derivative agreements.
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Although the interest rates on the Term Loans are variable, theThe Company has effectively fixed the interest rate on $350.0 million principal of the previously outstanding 2024 Term Loans by entering into interest rate swap agreements in 2018 with a notional amount of $350.0 million ("2018 Swaps"). UnderOn January 24, 2023, concurrently with the termsrepayment of the 2018 Swaps,2024 Term Loans, the Company receivesreceived a settlement payment of $8.3 million from the counterparties. As a result of the settlement, the Company also reclassified the amounts previously deferred in accumulated other comprehensive loss and recognized a settlement gain of $8.3 million in interest based onexpense during the one-month LIBOR index and pays interest at a weighted average rate of approximately 2.92%, resulting in a fixed effective annual interest rate of approximately 4.67%.three months ended March 31, 2023.
In January 2022, the Company entered into interest rate swap agreements ("2022 Swaps") with a notional amount of $600.0 million ("2022 Swaps") to effectively fix the interest rate on $600.0 million principal of the outstanding 2028 Term Loans. Under the terms of the 2022 Swaps' agreements, the Company will receivereceives interest based upon the variable rates on the 2028 Term Loans and paypays a fixed amount of interest. The fixed rate on these instruments is 0.931% through June 30, 2023 and then increases to 1.9645% from July 1, 2023 through September 30, 2027. The variablewhich, together with the 2.00% interest rate margin for borrowings on these instruments is designed to both mirror the current 2028 Term Loan interest payments and the successor rate upon the eventual sunsetting of the LIBOR rate. Under the terms of the 2022 Swaps, the Company currently receives interest based on the one-month LIBOR index and pays interest at a weighted average rate of 0.931%, resultingLoans, results in a fixedan effective annual interest rate of approximately 2.931%. The fixed rate on these instruments increased to 1.9645% on July 1, 2023 and the variable rate became linked to Term SOFR to mirror the variable interest payments for the 2028 Term Loans. Including the 2.00% interest rate margin for borrowings on the 2028 Term Loans and the 0.11448% SOFR adjustment per the 2028 Term Loans, the effective annual interest rate of this $600.0 million is now 4.07898%. The 2022 Swaps expire September 30, 2027.
TheAt the inception of these instruments, the Company has designated both the 2018 Swaps and the 2022 Swaps (collectively referred to as the “Swaps”) as cash flow hedges. The Company recognizes the fair value of the derivative instruments by counterparty as either a net asset, included in Other Assets, or net liability, included in Accrued expenses and other current liabilities, on the consolidated balance sheets. As of June 30, 2022,2023, the Company recorded a related derivative asset with a fair value of $33.7 million. As$49.1 million comprised only of the 2022 Swaps as the 2018 Swaps were settled during the period, as noted above. The balance of the derivative asset as of December 31, 2021, the derivative liability totaled $17.4 million. The change in the fair value2022 was $60.6 million, which included both of the interest rate swap liability is mainly due to the passage of time and changes in future interest rate expectations.
The fair value of the Swaps are measured using discounted cash flow valuation methodologies based upon the yield curves of the relevant variable rate indexes that are observable at commonly quoted intervals for the term of the Swaps and as such is considered a Level 2 measure according to the fair value hierarchy.Swaps.
No ineffectiveness has been identified on the Swaps and, therefore the change in fair value is recorded in stockholders' equity as a component of accumulated other comprehensive loss. Amounts are reclassified from accumulated other comprehensive loss into interest expense on the consolidated statement of operations in the same period or periods during which the hedged transactions affect earnings.

(13) INCOME TAXES
The Company records a tax provision or benefit on an interim basis using an estimated annual effective tax rate. This rate is applied to the current period ordinary income or loss to determine the income tax provision or benefit allocated to the interim period. Losses from jurisdictions for which no benefit can be recognized and the income tax effects of unusual or infrequent items are excluded from the estimated annual effective tax rate and are recognized in the impacted interim period. The estimated annual effective tax rate may be significantly impacted by projected earnings mix by tax jurisdiction. Adjustments to the estimated annual effective income tax rate are recognized in the period when such estimates are revised. The Company’s effective tax rate for the three and six months ended June 30, 2022 was 24.0% and 25.0%, compared to 25.9% and 27.3%, respectively, for the comparable periods in 2021.
As of June 30, 2022 and December 31, 2021, the Company had recorded $3.6 million and $5.5 million, respectively, of gross liabilities for unrecognized tax benefits and $1.9 million and $2.3 million, respectively, of accrued interest.
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(14)(13) EARNINGS PER SHARE     
The following are computations of basic and diluted earnings per share (in thousands, except per share amounts):
Three Months EndedSix Months EndedThree Months EndedSix Months Ended
June 30,June 30, June 30,June 30,
2022202120222021 2023202220232022
Numerator for basic and diluted earnings per share:Numerator for basic and diluted earnings per share:Numerator for basic and diluted earnings per share:
Net incomeNet income$148,157 $67,075 $193,471 $88,811 Net income$115,766 $148,157 $188,167 $193,471 
Denominator:Denominator:Denominator:
Weighted-average basic shares outstandingWeighted-average basic shares outstanding54,318 54,529 54,362 54,625 Weighted-average basic shares outstanding54,092 54,318 54,084 54,362 
Dilutive effect of outstanding stock awardsDilutive effect of outstanding stock awards279 325 277 320 Dilutive effect of outstanding stock awards356 279 338 277 
Dilutive shares outstandingDilutive shares outstanding54,597 54,854 54,639 54,945 Dilutive shares outstanding54,448 54,597 54,422 54,639 
Basic earnings per share:Basic earnings per share:$2.73 $1.23 $3.56 $1.63 Basic earnings per share:$2.14 $2.73 $3.48 $3.56 
Diluted earnings per share:Diluted earnings per share:$2.71 $1.22 $3.54 $1.62 Diluted earnings per share:$2.13 $2.71 $3.46 $3.54 
For the three months ended June 30, 2023 and 2022, and 2021, all then outstanding performance awards and restricted stock awards were included in the calculation of diluted earnings per share except for 104,700105,560 and 33,708,104,700, respectively, of performance stock awards for which the performance criteria were not attained at the reporting dates anddates. For the three months ended June 30, 2023 there were no restricted stock awards excluded from the calculation of diluted earnings per share. For the three months ended June 30, 2022 there were 8,376 and 500, respectively, of restricted stock awards which were excluded from the calculation of diluted earnings per share as their inclusion would have an antidilutive effect.
For the six months ended June 30, 2023 and 2022, and 2021, all then outstanding performance awards and restricted stock awards were included in the calculation of diluted earnings per share except for 104,700105,560 and 33,708,104,700, respectively, of performance stock awards for which the performance criteria were not attained at the reporting dates and 25,87619,839 and 12,604,25,876, respectively, of restricted stock awards which were excluded as their inclusion would have an antidilutive effect.

(15)(14) ACCUMULATED OTHER COMPREHENSIVE LOSS
The changes in accumulated other comprehensive loss by component and related tax impacts for the six months ended June 30, 20222023 were as follows (in thousands):
Foreign Currency TranslationUnrealized (Loss) Gain on Available-For-Sale SecuritiesUnrealized (Loss) Gain on Interest Rate HedgeUnrealized Loss on Unfunded Pension LiabilityTotal
Balance at January 1, 2022$(177,824)$(150)$(17,383)$(655)$(196,012)
Other comprehensive (loss) income before reclassifications(7,326)(830)45,685 10 37,539 
Amounts reclassified out of accumulated other comprehensive loss— — 5,358 — 5,358 
Tax benefit (provision)— 174 (9,761)— (9,587)
Other comprehensive (loss) income(7,326)(656)41,282 10 33,310 
Balance at June 30, 2022$(185,150)$(806)$23,899 $(645)$(162,702)
Foreign Currency Translation
Adjustments
Unrealized Loss on Available-For-Sale SecuritiesUnrealized Gain on Fair Value of Interest Rate HedgesUnrealized Loss on Unfunded Pension LiabilityTotal
Balance at January 1, 2023$(209,339)$(563)$43,058 $(337)$(167,181)
Other comprehensive income (loss) before reclassifications8,236 276 8,607 (7)17,112 
Amounts reclassified out of accumulated other comprehensive loss— — (20,175)— (20,175)
Tax (provision) benefit— (58)4,336 — 4,278 
Other comprehensive income (loss)8,236 218 (7,232)(7)1,215 
Balance at June 30, 2023$(201,103)$(345)$35,826 $(344)$(165,966)
The amount realizedrealized in the consolidatedconsolidated statement of operations during the three and six months ended June 30, 20222023 which was reclassified out of accumulatedaccumulated other comprehensivecomprehensive loss was as follows (in thousands):
Other Comprehensive (Loss) Income ComponentFor the Three Months Ended June 30, 2022For the Six Months Ended June 30, 2022Location
Unrealized loss on interest rate hedge$(2,164)$(5,358)Interest expense, net of interest income
Component of Accumulated Other Comprehensive LossFor the Three Months Ended June 30, 2023For the Six Months Ended June 30, 2023Location
Unrealized Gain on Fair Value of Interest Rate Hedges (1)
$6,049 $20,175 Interest expense, net of interest income
________________
(1) For the six months ended June 30, 2023, the balance is inclusive of an $8.3 million gain realized in connection with the settlement of the 2018 Swaps. For more information on this transaction, see Note 12, "Financing Arrangements."

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(15) STOCK-BASED COMPENSATION
Total stock-based compensation cost charged to selling, general and administrative expenses for the three and six months ended June 30, 2023 was $4.5 million and $10.5 million, respectively. Total stock-based compensation cost charged to selling, general and administrative expenses for the three and six months ended June 30, 2022 was $6.8 million and $12.5 million, respectively. TotalThe total income tax benefit recognized in the consolidated statements of operations from stock-based compensation cost charged to selling, general and administrative expensesexpense for the three and six months ended June 30, 20212023 was $3.3$0.6 million and $6.8$1.7 million,
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respectively. The total income tax benefit recognized in the consolidated statements of operations from stock-based compensation expense for the three and six months ended June 30, 2022 was $1.2 million and $2.3 million, respectively. The total income tax benefit recognized in the consolidated statements of operations from stock-based compensation expense for the three and six months ended June 30, 2021 was $0.8 million and $1.5 million, respectively.
Restricted Stock Awards
The following table summarizes information about restricted stock awards for the six months ended June 30, 2022:2023:
Restricted StockRestricted StockNumber of SharesWeighted Average
Grant-Date
Fair Value
Restricted StockNumber of SharesWeighted Average
Grant-Date
Fair Value
Balance at January 1, 2022452,197 $76.88 
Balance at January 1, 2023Balance at January 1, 2023427,142 $84.64 
GrantedGranted137,697 93.00 Granted151,318 134.07 
VestedVested(56,068)75.94 Vested(57,657)85.30 
ForfeitedForfeited(15,487)82.65 Forfeited(33,119)102.51 
Balance at June 30, 2022518,339 81.09 
Balance at June 30, 2023Balance at June 30, 2023487,684 $98.69 
As of June 30, 2022,2023, there was $30.4$34.9 million of total unrecognized compensation cost arising from restricted stock awards. This cost is expected to be recognized over a weighted average period of 2.83.1 years. The total fair value of restricted stock vested during the three and six months ended June 30, 2023 was $5.9 million and $8.1 million, respectively. The total fair value of restricted stock vested during the three and six months ended June 30, 2022 was $3.9 million and $5.6 million, respectively. The total fair value of restricted stock vested during the three and six months ended June 30, 2021 was $4.9 million and $8.9 million, respectively.
Performance Stock Awards
Performance stock awards are subject to performance criteria established by the Compensation Committee of the Company's Board of Directors prior to or at the date of grant. The vesting of the performance stock awards is based on achieving targets currently based on revenue, Adjusted EBITDA Adjusted EBITDA Margin, Return on Invested Capital and Total Recordable Incident Rate. In addition, performance stock awards include continued service conditions.
The following table summarizes information about performance stock awards for the six months ended June 30, 2022:2023:
Performance StockPerformance StockNumber of SharesWeighted Average
Grant-Date
Fair Value
Performance StockNumber of SharesWeighted Average
Grant-Date
Fair Value
Balance at January 1, 2022169,757 $85.56 
Balance at January 1, 2023Balance at January 1, 2023213,679 $91.62 
GrantedGranted154,172 92.64 Granted119,382 130.77 
VestedVested(35,718)86.14 Vested(58,636)92.49 
ForfeitedForfeited(5,722)87.14 Forfeited(26,584)114.37 
Balance at June 30, 2022282,489 89.32 
Balance at June 30, 2023Balance at June 30, 2023247,841 $107.83 
As of June 30, 2022,2023, there was $13.1$5.1 million of total unrecognized compensation cost arising from unvested performance stock awards deemed probable of vesting. No performance awards vested during the three months ended June 30, 20222023 and June 30, 2021.2022. The total fair value of performance awards vested during the six months ended June 30, 20222023 and June 30, 20212022 was $3.8$7.8 million and $6.4$3.8 million, respectively.

(17)(16) COMMITMENTS AND CONTINGENCIES
Legal and Administrative Proceedings
The Company and its subsidiaries are subject to legal proceedings and claims arising in the ordinary course of business. Actions filed against the Company arise from commercial and employment-related claims including alleged class actions related to sales practices and wage and hour claims. The plaintiffs in these actions may be seeking damages or injunctive relief or both. These actions are in various jurisdictions and stages of proceedings, and some are covered in part by insurance. In addition, the Company’s waste management services operations are regulated by federal, state, provincial and local laws enacted to regulate discharge of
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materials into the environment, remediation of contaminated soil and groundwater or otherwise protect the environment. This ongoing regulation results in the Company frequently becoming a party to legal or administrative proceedings involving all levels of governmentalgovernment authorities and other interested parties. The issues involved in such proceedings generally relate to alleged violations of
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existing permits and licenses or alleged responsibility under federal or state Superfund laws to remediate contamination at properties owned either by the Company or by other parties (“third-party sites”) to which either the Company or the prior owners of certain of the Company’s facilities shipped waste.
At June 30, 20222023 and December 31, 2021,2022, the Company had recorded reserves of $36.8$29.4 million and $36.1$37.1 million, respectively, in the Company's financial statements for actual or probable liabilities related to the legal and administrative proceedings in which the Company was then involved, the principal of which are described below. As of June 30, 2023 and December 31, 2022, the $29.4 million and $37.1 million, respectively, of reserves consisted of (i) $22.8 million and $24.1 million, respectively, related to pending legal or administrative proceedings, including Superfund liabilities, which were included in remedial liabilities on the consolidated balance sheets, and (ii) $6.6 million and $13.0 million, respectively, primarily related to federal, state and provincial enforcement actions, which were included in accrued expenses on the consolidated balance sheets.
In management's opinion, it is not reasonably possible that the potential liability beyond what has been recorded, if any, that may result from these actions, either individually or collectively, will have a material effect on ourthe Company's financial position, results of operations or cash flows. The Company periodically adjusts the aggregate amount of these reserves when actual or probable liabilities are paid or otherwise discharged, new claims arise, or additional relevant information about existing or probable claims becomes available. As of June 30, 2022 and December 31, 2021, the $36.8 million and $36.1 million, respectively, of reserves consisted of (i) $24.1 million for both periods, related to pending legal
Legal or administrative proceedings, including Superfund liabilities, which were included in remedial liabilities on the consolidated balance sheets, and (ii) $12.7 million and $12.0 million, respectively, primarily related to federal, state and provincial enforcement actions, which were included in accrued expenses and other current liabilities on the consolidated balance sheets.Administrative Proceedings
As of June 30, 2022,2023, the Company's principal legal and administrative proceedings were as follows:
Ville Mercier. In September 2002,in which the Company acquired the stock of a subsidiary (the "Mercier Subsidiary")was involved, or which owns a hazardous waste incinerator in Ville Mercier, Quebec (the "Mercier Facility"). The property adjacenthad been terminated during 2023, relate to the Mercier Facility, which is also owned by the Mercier Subsidiary, is now contaminated as a result of actions dating back to 1968, when the Government of Quebec issued 2 permits to dump organic liquids into lagoons on the property to a company unrelated to the Mercier Subsidiary. In 1999, Ville MercierSafety-Kleen product liability cases and 3 neighboring municipalities filed separate legal proceedings against the Mercier Subsidiary and the Government of Quebec. In 2012, the municipalities amended their existing statement of claim to seek $2.9 million (CAD) in general damages and $10.0 million (CAD) in punitive damages, plus interest and costs, as well as injunctive relief. Both the Government of Quebec and the Company have filed summary judgment motions against the municipalities. The parties are attempting to negotiate a resolution and hearings on the motions have been delayed. In September 2007, the Quebec Minister of Sustainable Development, Environment and Parks issued a notice pursuant to Section 115.1 of the Environment Quality Act, superseding notices issued in 1992, which are the subject of the pending litigation. The more recent notice notifies the Mercier Subsidiary that, if the Mercier Subsidiary does not take certain remedial measures at the site, the Minister intends to undertake those measures at the site and claim direct and indirect costs related to such measures. The Company has accrued for costs expected to be incurred relative to the resolution of this matter and believes this matter will not have future material effect on its financial position, results of operations or cash flows.Superfund proceedings.
Safety-Kleen Product Liability Cases.Cases: On December 28, 2012, the Company acquired Safety-Kleen, Inc. ("Safety-Kleen") and thereby became subject to, which is a legal entity acquired by the legal proceedingsCompany in which Safety-Kleen was a party on that date. In addition to certain Superfund proceedings in which Safety-Kleen has been named as a potentially responsible party as described below under “Superfund Proceedings,” Safety-Kleen2012, has been named as a defendant in variouscertain product liability lawsuitscases that are currently pending in various courts and jurisdictions throughout the United States. As of June 30, 2022, Safety-Kleen has been named in2023, there were approximately 60 outstanding63 proceedings (excluding cases which have been settled but not formally dismissed), wherein persons claim personal injury resulting from the use of Safety-Kleen's parts washercleaning equipment or cleaning products. These proceedings typically involve allegations that the solvent used in Safety-Kleen's parts washercleaning equipment contains contaminants and/or that Safety-Kleen's recycling process does not effectively remove the contaminants that become entrained in the solvent during their use. In addition, certain claimants assert that Safety-Kleen failed to warn adequately warn the product user of potential risks, including a historic failure to warn that solvent contains trace amounts of toxic or hazardous substances such as benzene.
The Company maintains insurance that it believes will provide coverage for these product liability claims (over amounts accrued for self-insured retentions and deductibles in certain limited cases), except for punitive damages to the extent not insurable under state law or excluded from insurance coverage. The Company also believes that these claims lack merit and historically has historically vigorously defended, and intends to continue to vigorously defend itself and the safety of its products against all of these claims. Such matters are subject to many uncertainties and outcomes are not predictable with assurance. Consequently, the Company is unable to ascertain the ultimate aggregate amount of monetary liability or financial impact with respect to these matters as of June 30, 2022.2023. From January 1, 20222023 to June 30, 2022, 82023, 14 product liability claims were settled or dismissed. Due to the nature of these claims and the related insurance, the Company did not incur any expense as insurance provided coverage in full for all such claims. Safety-Kleen may be named in similar, additional lawsuits in the future, including claims for which insurance coverage may not be available.
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Superfund Proceedings
Proceedings:The Company has been notified that either the Company (which, since December 28, 2012, has included Safety-Kleen) or the prior owners of certain of the Company's facilities for which the Company may have certain indemnification obligations have been identified as potentially responsible parties ("PRPs") or potential PRPs in connection with 131 sites which are subject to or are proposed to become subject to proceedings under federal or state Superfund laws. Of the 131 Superfund related sites, 6 (including the BR Facility described below)six involve facilities that are now owned or leased by the Company and 125 involve third-party sites to which either the Company or the prior owners of certain of the Company’s facilities shipped wastes.waste. Of the 125 third-party sites, 30 are now settled, 15 are currently requiring expenditures on remediation and 80 are not currently requiring expenditures on remediation.
In connection with each site, the Company has estimated the extent, if any, to which it may be subject, either directly or as a result of any indemnification obligations, for cleanup and remediation costs, related legal and consulting costs associated with PRP investigations, settlements and related legal and administrative proceedings. The amount of such actual and potential liability is inherently difficult to estimate because of, among other relevant factors, uncertainties as to the legal liability if any,(if any) of the Company
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or the prior owners of certain of the Company's facilities to contribute a portion of the cleanup costs, the assumptions that must be made in calculating the estimated cost and timing of remediation, the identification of other PRPs and their respective capability and obligation to contribute to remediation efforts and the existence and legal standing of indemnification agreements if any,(if any) with prior owners, which may either benefit the Company or subject the Company to potential indemnification obligations. The Company believes its potential monetary liability could exceed $1.0 million at 3three of the 131 Superfund related sites.
BR Facility. The Company acquired in 2002 a former hazardous waste incinerator and landfill in Baton Rouge (the "BR Facility"), for which operations had been previously discontinued by the prior owner. In September 2007, the U.S. Environmental Protection Agency ("EPA") issued a special notice letter to the Company related to the Devil's Swamp Lake Site ("Devil's Swamp") in East Baton Rouge Parish, Louisiana. Devil's Swamp includes a lake located downstream of an outfall ditch where wastewater and storm water have been discharged, and Devil's Swamp is proposed to be included on the National Priorities List due to the presence of Contaminants of Concern ("COC") cited by the EPA. These COCs include substances of the kind found in wastewater and storm water discharged from the BR Facility in past operations. The EPA originally requested COC generators to submit a good faith offer to conduct a remedial investigation feasibility study directed towards the eventual remediation of the site. In 2018, the Company completed performing corrective actions at the BR Facility under an order issued by the Louisiana Department of Environmental Quality and has also completed conducting the remedial investigation feasibility study for Devil's Swamp under the order issued by the EPA at which point the feasibility study, with several remedial alternatives, was submitted to the EPA for review. During 2020, the EPA signed a Record of Decision which defined the remediation alternative selected and approved by the EPA and in return, the Company increased the estimated remedial liability for this inactive site by $3.3 million. Changes in the natural landscape and/or new information identified during the remediation could impact this estimate; however, any such changes are not expected to have a future material effect on the Company's financial position, liquidity or results of operation.
Third-Party Sites. Of the 125 third-party Superfund sites at which the Company has been notified it is a PRP or potential PRP or may have indemnification obligations, the Company has an indemnification agreementagreements at a total of 17 sites. These agreements indemnify the Company (which now includes Safety-Kleen) with respect to any liability at the 17 sites for waste disposed prior to the Company's (or Safety-Kleen's) acquisition of the former subsidiaries of Waste Management and McKesson.McKesson which had shipped waste to those sites. Accordingly, the indemnifying parties are paying all costs of defending those subsidiaries in those 17 cases, including legal fees and settlement costs. However, there can be no guarantee that the Company's ultimate liabilities for those sites will not exceed the amount recorded or that indemnities applicable to any of these sites will be available to pay all or a portion of related costs. Except for thethose indemnification agreements which the Company holds from ChemWaste and McKesson,discussed, the Company does not have an indemnity agreement with respect to any of the 125 third-party sites discussed above.
Federal, State and Provincial Enforcement Actions
From time to time, the Company pays fines or penalties in regulatory proceedings relating primarily to waste treatment, storage or disposal facilities. As of June 30, 2022 and December 31, 2021,2023 there were 2no proceedings for which the Company reasonably believes it is possible that the sanctions could equal or exceed $1.0 million. As of December 31, 2022, there was one proceeding for which the Company believed it was possible that the sanctions could equal or exceed $1.0 million. The Company believes that the fines or other penalties in thesethis or any of the other regulatory proceedings will, not, individually or in the aggregate, not have a material effect on its financial condition, results of operations or cash flows.

(18)(17) SEGMENT REPORTING 
Segment reporting is prepared on the same basis that the Company's chief executive officer, whooperating decision maker, which is a committee comprised of the Company's chief operating decision maker,co-Chief Executive Officers, manages the business, makes operating decisions and assesses performance. The Company is managed and
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reports as 2two operating segments; (i) the Environmental Services segment and (ii) the Safety-Kleen Sustainability Solutions segment.
Third-party revenue is revenue billed to outside customers by a particular segment. Direct revenues is revenue allocated to the segment providing the product or service. Intersegment revenues represent the sharing of third-party revenues among the segments based on products and services provided by each segment as if the products and services were sold directly to the third-party. Transactions between the segments are accounted for at the Company’s best estimate based on similar transactions with outside customers. The intersegment revenues are shown net. The operations not managed through the Company’s operating segments described above are recorded as “Corporate Items.”
The following table reconcilestables reconcile third-party revenues to direct revenues for the three and six months ended June 30, 20222023 and 20212022 (in thousands):
For the Three Months EndedFor the Three Months Ended
For the Three Months Ended June 30, 2022For the Three Months Ended June 30, 2021June 30, 2023June 30, 2022
Third-party revenuesIntersegment revenues, netDirect revenuesThird-party revenuesIntersegment revenues, netDirect revenuesThird-Party RevenuesIntersegment Revenues (Expenses), netDirect RevenuesThird-Party RevenuesIntersegment Revenues (Expenses), netDirect Revenues
Environmental ServicesEnvironmental Services$1,084,506 $6,237 $1,090,743 $723,147 $950 $724,097 Environmental Services$1,161,482 $10,554 $1,172,036 $1,084,506 $6,237 $1,090,743 
Safety-Kleen Sustainability SolutionsSafety-Kleen Sustainability Solutions271,727 (6,237)265,490 203,232 (950)202,282 Safety-Kleen Sustainability Solutions236,302 (10,554)225,748 271,727 (6,237)265,490 
Corporate ItemsCorporate Items79 — 79 79 — 79 Corporate Items116 — 116 79 — 79 
TotalTotal$1,356,312 $— $1,356,312 $926,458 $— $926,458 Total$1,397,900 $— $1,397,900 $1,356,312 $— $1,356,312 
For the Six Months Ended June 30, 2022For the Six Months Ended June 30, 2021
Third-party revenuesIntersegment revenues, netDirect revenuesThird-party revenuesIntersegment revenues, netDirect revenues
Environmental Services$2,025,304 $12,884 $2,038,188 $1,376,025 $2,674 $1,378,699 
Safety-Kleen Sustainability Solutions499,966 (12,884)487,082 358,423 (2,674)355,749 
Corporate Items151 — 151 158 — 158 
Total$2,525,421 $— $2,525,421 $1,734,606 $— $1,734,606 

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For the Six Months EndedFor the Six Months Ended
June 30, 2023June 30, 2022
Third-Party RevenuesIntersegment Revenues (Expenses), netDirect RevenuesThird-Party RevenuesIntersegment Revenues (Expenses), netDirect Revenues
Environmental Services$2,222,464 $20,313 $2,242,777 $2,025,304 $12,884 $2,038,188 
Safety-Kleen Sustainability Solutions482,600 (20,313)462,287 499,966 (12,884)487,082 
Corporate Items223 — 223 151 — 151 
Total$2,705,287 $— $2,705,287 $2,525,421 $— $2,525,421 
The primary financial measure by which the Company evaluates the performance of its segments is "AdjustedAdjusted EBITDA," which consists of net income plus accretion of environmental liabilities, stock-based compensation, depreciation and amortization, net interest expense, loss on early extinguishment of debt and provision for income taxes and excludes other gains, losses orand non-cash charges not deemed representative of fundamental segment results and other (income) expense,income (expense), net. Transactions between the segments are accounted for at the Company’s best estimate based on similar transactions with outside customers.
The following table presents Adjusted EBITDA information used by management by reported segment (in thousands):
For the Three Months EndedFor the Six Months Ended For the Three Months EndedFor the Six Months Ended
June 30,June 30,June 30,June 30,
2022202120222021 2023202220232022
Adjusted EBITDA:Adjusted EBITDA:  Adjusted EBITDA:  
Environmental ServicesEnvironmental Services$269,341 $176,041 $452,943 $316,295 Environmental Services$305,622 $269,341 $533,967 $452,943 
Safety-Kleen Sustainability SolutionsSafety-Kleen Sustainability Solutions97,010 63,314 148,887 94,946 Safety-Kleen Sustainability Solutions53,415 97,010 94,878 148,887 
Corporate ItemsCorporate Items(57,281)(51,584)(112,501)(94,019)Corporate Items(71,531)(57,281)(126,201)(112,501)
TotalTotal309,070 187,771 489,329 317,222 Total287,506 309,070 502,644 489,329 
Reconciliation to Consolidated Statements of Operations:Reconciliation to Consolidated Statements of Operations:  Reconciliation to Consolidated Statements of Operations:  
Accretion of environmental liabilitiesAccretion of environmental liabilities3,197 2,873 6,353 5,826 Accretion of environmental liabilities3,486 3,197 6,893 6,353 
Stock-based compensationStock-based compensation6,835 3,305 12,547 6,785 Stock-based compensation4,500 6,835 10,518 12,547 
Depreciation and amortizationDepreciation and amortization87,868 71,592 172,166 143,755 Depreciation and amortization89,697 87,868 174,455 172,166 
Income from operationsIncome from operations211,170 110,001 298,263 160,856 Income from operations189,823 211,170 310,778 298,263 
Other (income) expense, net(1,265)1,480 (1,969)2,708 
Other expense (income), netOther expense (income), net1,283 (1,265)1,167 (1,969)
Loss on early extinguishment of debtLoss on early extinguishment of debt— — 2,362 — 
Gain on sale of businessGain on sale of business(8,864)— (8,864)— Gain on sale of business— (8,864)— (8,864)
Interest expense, net of interest incomeInterest expense, net of interest income26,256 18,051 51,273 35,969 Interest expense, net of interest income30,072 26,256 50,704 51,273 
Income before provision for income taxesIncome before provision for income taxes$195,043 $90,470 $257,823 $122,179 Income before provision for income taxes$158,468 $195,043 $256,545 $257,823 

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ITEM 2.    MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS 
Forward-Looking Statements 
In addition to historical information, this Quarterly Report on Form 10-Q contains forward-looking statements, which are generally identifiable by use of the words "believes," "expects," "intends," "anticipates," "plans to," "seeks," "should," "estimates," "projects," "may," "likely" or similar expressions. Such statements may include, but are not limited to, statements about future financial and operating results, the Company's plans, objectives, expectations and intentions and other statements that are not historical facts. Forward-looking statements are neither historical facts nor assurances of future performance. Such statements are based upon the beliefs and expectations of Clean Harbors' management as of this date only and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, without limitation, those items identified as "Risk Factors,” in this report under Item 1A and in our Annual Report on Form 10-K filed with the Securities and Exchange Commission ("SEC") on February 23, 2022,March 1, 2023, and in other documents we file from time to time with the SEC. Therefore, readers are cautioned not to place undue reliance on these forward-looking statements, which reflect management’s opinions only as of the date hereof. Our actual results and financial condition may differ materially from those indicated in the forward-looking statements. Clean Harbors undertakes no obligation to revise or publicly release the results of any revision to these forward-looking statements other than through its filings with the SEC, which may be viewed in the "Investors" section of the Clean Harbors website.
Overview
We are North America’s leading provider of environmental and industrial services supporting our customers in finding environmentally responsible solutions to further their sustainability goals in today's world. Everywhere industry meets the environment, we strive to provide eco-friendly products and services that protect and restore North America's natural environment. We believe we operate, in the aggregate, the largest number of hazardous waste incinerators, landfills and treatment, storage and disposal facilities ("TSDFs") in North America. We serve over 300,000 customers, including the majority of Fortune 500 companies. This diverse customer base includes thecompanies, across various markets including chemical energy,and manufacturing, and additional markets, as well as numerous government agencies. These customers rely on us to deliver a broad range of services including but not limited to end-to-end hazardous waste management, emergency response, industrial cleaning and maintenance and recycling services. We are also the largest re-refiner and recycler of used oil in North America and the largest provider of parts washercleaning and related environmental services to commercial, industrial and automotive customers in North America.
Performance of our segments is evaluated on several factors of which the primary financial measure is Adjusted EBITDA, as reconciled to our net income and described more fully below. The following is a discussion of how management evaluates its segments in regards to other factors including key performance indicators that management uses to assess the segments’ results, as well as certain macroeconomic trends and influences that impact each reportable segment:
Environmental Services - Environmental Services segment results are predicated upon customerthe demand by our customers for wasteour wide variety of services, waste volumes generatedmanaged by delivering such services and project work for which responsible waste handling and/or disposal is required. Environmental Services results are also impacted by the demand for planned and unplanned industrial related cleaning and maintenance services at customer sites, and environmental cleanup services on a scheduled or emergency basis, including response to nationallarge scale events such as major chemical spills, natural disasters, or other eventsinstances where immediate and specialized services are required, including our contagion disinfection, decontamination and disposal services. With the addition ofrequired. The Environmental Services segment results include the Safety-Kleen branches' core environmental service offerings (e.g.of containerized waste disposal, parts washer and vacuum services), the Environmental Servicesservices. These results are further impacteddriven by the volumes of waste collected from these customers, the overall number of parts washers placed at customer sites and the demand for and frequency of other offered services. In managing the business and evaluating performance, management tracks the volumes and mix of waste handled and disposed of or recycled, generally through our incinerators, TSDFs and landfills, the utilization rates of our incinerators, equipment and workforce, including billable hours, and the number of parts washer services performed, amongand pricing realized by our business and peer companies as well as other key metrics. Levels of activity and ultimate performance associated with this segment can be impacted by several factors including overall U.S. GDP, U.S. industrial production, economic conditions in the automotive,chemical, manufacturing and other industrialautomotive markets including efforts and economic incentives to reshore operations to the U.S., available capacity at waste disposal outlets, weather conditions, efficiency of our operations, technology, changing regulations, competition, market pricing of our services, costs incurred to deliver our services and the management of our related operating costs.
Safety-Kleen Sustainability Solutions - Safety-Kleen Sustainability Solutions segment results are impacted by our customers' demand for high-quality, environmentally responsible recycled oil products and their demand for our related service offerings and products.product offerings. Safety-Kleen Sustainability Solutions offers high quality recycled base and blended oil
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products, including our KLEEN+ brand of Group II+ base oils, and various blended oil products to end users including fleet customers, distributors and manufacturers of oil products.
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Segment results are impacted by market pricing, overall demand as well as productand the mix as it relates to theseof our oil products.products sales. Segment results are also predicated on the demand for the Safety-Kleen Sustainability SolutionsSolutions' other product and service offerings including collection services for used oil, used oil filters and other automotive fluids. These fluid collections are used as feedstock in our oil re-refining to makeproduce our base and blended oil products and our recycled automotive related fluid products or are integrated into the Clean Harbors' recycling and disposal network. In operating the business and evaluating performance, management tracks the volumes and relative percentages of base and blended oil sales along with various pricing metrics associated with the commodity driven margin. Management also tracksmargin between product pricing and the volumes and pricingoverall costs associated with the collection of used oil and automotive fluid collections.oil. Levels of activity and ultimate performance associated with this segment can be impacted by economic conditions in the automotive services and manufacturing markets, efficiency of our operations, technology, weather conditions, changing regulations, competition and the management of our related operating costs and the availability of raw materials including used oil and additives.costs. Costs incurred in connection with the collection of used oil and other raw materials associated with the segment’s oil related products can also be volatile.volatile and can be impacted by global events and their relative impact on commodity products and pricing. The overall market price of oil and regulations that change the possible usage of used oil including the International Maritime Organization's 2020 regulation ("IMO 2020") and other regulations related to theor burning of used motor oil as a fuel, both impact the premium the segment can charge for used oil collections.
Highlights
Total direct revenues for the three and six months ended June 30, 20222023 were $1,397.9 million and $2,705.3 million, compared with $1,356.3 million and $2,525.4 million, compared with $926.5 million and $1,734.6 million for the three and six months ended June 30, 2021.2022. Our Environmental Services segment direct revenues increased $366.6$81.3 million and $659.5$204.6 million or 50.6%7.5% and 47.8%10.0% from the comparable periods in 2021. Our2022 driven by continued demand for our services and growth from the recent acquisition of HydroChemPSCThompson Industrial Services, LLC ("Thompson Industrial") on October 8, 2021, contributed to increases in both our industrial services and field and emergency response service offerings within the Environmental Services segment. The sales and operations of HydroChemPSC have been fully integrated into the Environmental Services segment and we estimate that for the three and six months ended June 30, 2022, total revenues from the HydroChemPSC business were approximately $207.9 million and $392.0 million, respectively. Core organic growth within the Environmental Services segment also contributed to the overall increases in direct revenues for the segment in 2022 as compared to the comparable periods in 2021.March 31, 2023. In the three and six months ended June 30, 2022,2023, our Safety-Kleen Sustainability Solutions segment direct revenues increased $63.2decreased $39.7 million and $131.3$24.8 million or 31.2%15.0% and 36.9%5.1% from the comparable periods in 2021 predominately2022, due to higherlower market-based pricing ofon our base and blended oil products.product sales. The segment has increased the pricing on our collection of used oil services. Foreign currency translation of our Canadian operations negatively impacted our consolidated direct revenues by $7.3$8.5 million and $18.6 million in the three and six months ended June 30, 2022.2023.
In the three and six months ended June 30, 2022, costs have increased in both the Environmental Services and Safety-Kleen Sustainability Solutions segments when comparing to the prior year given the increase in business levels, revenue mix, inflationary pressures seen across several cost categories and supply chain constraints. Our business began seeing the impact of macroeconomic factors including inflationary pressures and supply chain constraints in 2021 and these factors continue to impact the business operations. Supply chain challenges for additives and other materials used in the oil re-refining process have delayed production, added costs and shifted the product mix within our Safety-Kleen Sustainability Solutions segment. Similarly within the Environmental Services segment, supply chain challenges have delayed fleet and equipment delivery, increasing rental and external transportation costs.
Both segments have seen the impact of inflationary pressures, most notably in labor and the cost of certain supplies used in the operations of our businesses, including fuel related costs. In recent quarters, we have executed upon pricing strategies, including fuel surcharges, and cost control initiatives to mitigate, to the greatest extent possible, the impact of these inflationary pressures. As a result of these focused efforts, costs as a percentage of direct revenues for the three months ended June 30, 2022 improved when compared to previous quarters also impacted by these inflationary pressures.
We reported incomeIncome from operations for the three and six months ended June 30, 2022 of2023 was $189.8 million and $310.8 million, compared with $211.2 million and $298.3 million, compared with $110.0 million and $160.9 million in the three and six months ended June 30, 2021,2022, representing increasesa decrease of $101.2 million10.1% and $137.4 million.an increase of 4.2%, respectively. Net income for the three and six months ended June 30, 20222023 was $148.2$115.8 million and $193.5$188.2 million, compared with net income of $67.1$148.2 million and $88.8$193.5 million in the three and six months ended June 30, 2021,2022, representing increasesdecreases of $81.1 million21.9% and $104.7 million.2.7%, respectively.
Adjusted EBITDA, which is the primary financial measure by which we evaluate our segments, are evaluated, increased 64.6%decreased 7.0% to $287.5 million in the three months ended June 30, 2023 from $309.1 million in the three months ended June 30, 2022 from $187.8 millionpredominately due to lower revenue in the threeSafety-Kleen Sustainability Solutions segment. For the six months ended June 30, 2021 and2023, Adjusted EBITDA increased 54.3% to2.7% from $489.3 million in the six months ended June 30, 2022 from $317.2to $502.6 million in the six months ended June 30, 2021. This improved performance was driven by2023 due to the increased revenue levels in both segments noted above,and focused pricing initiatives in the Environmental Services segment's disposal network, strong spread management as it relates to the pricing of base oil products and used motor oil collection services in the Safety-Kleen Sustainability Solutions segment and cost control initiatives across the entire
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business.segment. Additional information regarding Adjusted EBITDA, which is a non-GAAP measure, including a reconciliation of Adjusted EBITDA to net income, appears below under "Adjusted EBITDA."
Net cash from operating activities for the six months ended June 30, 2022 was2023 increased $103.6 million from $132.0 million as comparedin 2022 to net cash from operating activities of $265.4$235.6 million in the comparable period of 2021.2023. Adjusted free cash flow, which management uses to measure our financial strength and ability to generate cash, was an outflowinflow of $13.0$34.2 million in the six months ended June 30, 20222023 as compared to positive adjusted free cash flowan outflow of $176.9$13.0 million in the comparable period of 2021. These expected decreases2022. This change is due to increases in ournet cash flows were the result of an increase in working capital arising from our significant growth in the business, comparatively higher incentive compensation and interest payments and higher levels of cash spendingoperating activities, partially offset by incremental spend on the acquisition of property, plant and equipment partially offset by higher operating income.net of proceeds from sale and disposal of fixed assets. Additional information regarding adjusted free cash flow, which is a non-GAAP measure, including a reconciliation of adjusted free cash flow to net cash from operating activities, appears below under ""Adjusted Free Cash Flow.Flow."
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Segment Performance
The primary financial measure by which we evaluate the performance of our segments is Adjusted EBITDA, as described below under "Adjusted EBITDA".EBITDA. The following table sets forth certain financial information associated with our results of operations for the three and six months ended June 30, 20222023 and June 30, 20212022 (in thousands, except percentages):
Summary of Operations Summary of Operations
For the Three Months EndedFor the Six Months Ended For the Three Months EndedFor the Six Months Ended
June 30, 2022June 30, 2021
Change
%
Change
June 30, 2022June 30, 2021Change% Change June 30, 2023June 30, 2022
Change
%
Change
June 30, 2023June 30, 2022Change% Change
Direct Revenues(1):
Direct Revenues(1):
    
Direct Revenues (1):
    
Environmental ServicesEnvironmental Services$1,090,743 $724,097 $366,646 50.6%$2,038,188 $1,378,699 $659,489 47.8%Environmental Services$1,172,036 $1,090,743 $81,293 7.5%$2,242,777 $2,038,188 $204,589 10.0%
Safety-Kleen Sustainability SolutionsSafety-Kleen Sustainability Solutions265,490 202,282 63,208 31.2487,082 355,749 131,333 36.9Safety-Kleen Sustainability Solutions225,748 265,490 (39,742)(15.0)462,287 487,082 (24,795)(5.1)
Corporate ItemsCorporate Items79 79 — N/M151 158 (7)N/MCorporate Items116 79 37 N/M223 151 72 N/M
TotalTotal1,356,312 926,458 429,854 46.42,525,421 1,734,606 790,815 45.6Total1,397,900 1,356,312 41,588 3.12,705,287 2,525,421 179,866 7.1
Cost of Revenues(2):
Cost of Revenues(2):
      
Cost of Revenues (2):
      
Environmental ServicesEnvironmental Services743,659 487,257 256,402 52.61,428,995 938,512 490,483 52.3Environmental Services781,251 743,659 37,592 5.11,534,611 1,428,995 105,616 7.4
Safety-Kleen Sustainability SolutionsSafety-Kleen Sustainability Solutions151,020 123,025 27,995 22.8303,037 231,401 71,636 31.0Safety-Kleen Sustainability Solutions153,901 151,020 2,881 1.9329,758 303,037 26,721 8.8
Corporate ItemsCorporate Items3,790 7,604 (3,814)N/M9,826 8,509 1,317 N/MCorporate Items12,360 3,790 8,570 N/M14,657 9,826 4,831 N/M
TotalTotal898,469 617,886 280,583 45.41,741,858 1,178,422 563,436 47.8Total947,512 898,469 49,043 5.51,879,026 1,741,858 137,168 7.9
Selling, General & Administrative Expenses:Selling, General & Administrative Expenses:     Selling, General & Administrative Expenses:     
Environmental ServicesEnvironmental Services77,743 60,799 16,944 27.9156,250 123,892 32,358 26.1Environmental Services85,163 77,743 7,420 9.5174,199 156,250 17,949 11.5
Safety-Kleen Sustainability SolutionsSafety-Kleen Sustainability Solutions17,460 15,943 1,517 9.535,158 29,402 5,756 19.6Safety-Kleen Sustainability Solutions18,432 17,460 972 5.637,651 35,158 2,493 7.1
Corporate ItemsCorporate Items60,405 47,364 13,041 27.5115,373 92,453 22,920 24.8Corporate Items63,787 60,405 3,382 5.6122,285 115,373 6,912 6.0
TotalTotal155,608 124,106 31,502 25.4306,781 245,747 61,034 24.8Total167,382 155,608 11,774 7.6334,135 306,781 27,354 8.9
Adjusted EBITDA:Adjusted EBITDA:      Adjusted EBITDA:      
Environmental ServicesEnvironmental Services269,341 176,041 93,300 53.0452,943 316,295 136,648 43.2Environmental Services305,622 269,341 36,281 13.5533,967 452,943 81,024 17.9
Safety-Kleen Sustainability SolutionsSafety-Kleen Sustainability Solutions97,010 63,314 33,696 53.2148,887 94,946 53,941 56.8Safety-Kleen Sustainability Solutions53,415 97,010 (43,595)(44.9)94,878 148,887 (54,009)(36.3)
Corporate ItemsCorporate Items(57,281)(51,584)(5,697)(11.0)(112,501)(94,019)(18,482)(19.7)Corporate Items(71,531)(57,281)(14,250)(24.9)(126,201)(112,501)(13,700)(12.2)
TotalTotal$309,070 $187,771 $121,299 64.6%$489,329 $317,222 $172,107 54.3%Total$287,506 $309,070 $(21,564)(7.0)%$502,644 $489,329 $13,315 2.7%
Adjusted EBITDA as a % of Direct Revenues:Adjusted EBITDA as a % of Direct Revenues:Adjusted EBITDA as a % of Direct Revenues:
Environmental Services24.7 %24.3 %0.4 %22.2 %22.9 %(0.7)%
Safety-Kleen Sustainability Solutions36.5 %31.3 %5.2 %30.6 %26.7 %3.9 %
Corporate ItemsN/MN/MN/MN/MN/MN/M
Environmental Services (3)
Environmental Services (3)
26.1 %24.7 %1.4 %23.8 %22.2 %1.6 %
Safety-Kleen Sustainability Solutions(3)
Safety-Kleen Sustainability Solutions(3)
23.7 %36.5 %(12.8)%20.5 %30.6 %(10.1)%
Corporate Items (4)
Corporate Items (4)
(5.1)%(4.2)%(0.9)%(4.7)%(4.5)%(0.2)%
TotalTotal22.8 %20.3 %2.5 %19.4 %18.3 %1.1 %Total20.6 %22.8 %(2.2)%18.6 %19.4 %(0.8)%
_____________________
N/M = not meaningful
(1)Direct revenue is revenuerevenues are revenues allocated to the segment performing the provided service.
(2)Cost of revenue isrevenues are shown exclusive of items presented separately on the consolidated statements of operations which consist of (i) accretion of environmental liabilities and (ii) depreciation and amortization.
(3)Calculated as a percentage of individual segment direct revenue.
(4)Calculated as a percentage of total Company revenue.
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Direct Revenues
There are many factors which have impacted and continue to impact our revenues including, but not limited to: overall levels of industrial activity and economic growth in North America, existence or non-existence of large scale environmental waste and remediation projects, competitive industry pricing, overall market incineration capacity including captive incinerator closures, miles driven and related lubricant demand, impacts of acquisitions and divestitures, the level of emergency response services, government infrastructure investment, weather related events, the number of parts washers placed at customer sites, base and blended oil pricing, market supply for base oil products, market changes relative to the collection of used oil, our ability to manage the spread between oil product prices and prices for the collection of used oil the number of parts washers placed at customer sites and foreign currency translation. In addition, customer efforts to minimize hazardous waste and changes in regulation can also impact our revenues.
Environmental Services     
For the Three Months EndedFor the Six Months EndedFor the Three Months EndedFor the Six Months Ended
June 30,2022 over 2021June 30,2022 over 2021June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)(in thousands, except percentages)20222021
Change
%
Change
20222021Change% Change(in thousands, except percentages)20232022
Change
%
Change
20232022Change% Change
Direct revenuesDirect revenues$1,090,743 $724,097 $366,646 50.6 %$2,038,188 $1,378,699 $659,489 47.8 %Direct revenues$1,172,036 $1,090,743 $81,293 7.5 %$2,242,777 $2,038,188 $204,589 10.0 %

Environmental Services direct revenues for the three months ended June 30, 20222023 increased $366.6$81.3 million from the comparable period in 2021 driven2022 primarily by the incremental business from the HydroChemPSC operations within industrial service and field and emergency response service revenues coupled with organicdue to growth across our other waste disposal service offerings. Direct revenues ofin our industrial service offerings increased $203.8and Safety-Kleen core service offerings. The $38.7 million of which approximately $173.7 million was generated by HydroChemPSC, while the remainder was primarily due to increased demand and pricing for our core industrial services. Technical services revenues increased $91.6 million largely due to higher throughput at our facilities and higher value waste streams coupled with pricing initiatives across the business. Higher volumes at our incinerators drove an increase in utilization from 87% in the second quarter of 2021 to 90% in the second quarter of 2022. We also saw an increase in landfill volumes in the second quarter of 2022 as compared to the second quarter of 2021. Field and emergency response services revenues increased approximately $40.1 million despite a $6.3 million decrease in COVID-19 decontaminationour industrial service revenues. This overall increaseofferings revenue was both related todriven by contributions from the HydroChemPSC businessacquisition of $34.2 millionThompson Industrial on March 31, 2023, as well as organic growth fromin the legacy field servicesindustrial operations. Direct revenues for the Safety-Kleen core service offerings increased $31.1$25.9 million from the comparable period in 20212022 due to improved pricing and greater demand for our containerized waste, parts washer and vacuum services. Field and emergency response service revenues increased $9.5 million. Within our technical services operations, utilization at our incinerators for the three months ended June 30, 2023 was 84% as compared to 90% in the prior year due to outages for required maintenance early in the second quarter of 2023. The Canadian operations of the Environmental Services segment were negatively impacted by $5.8$7.0 million due to foreign currency translation.
Environmental Services direct revenues for the six months ended June 30, 20222023 increased $659.5$204.6 million from the comparable period in 2021. Consistent with the discussion above, a significant portion of this increase is2022 due to the incremental business from the HydroChemPSC operations within industrial service and field and emergency response service revenues and organic growth across our service offerings. Direct revenues ofRevenue from our industrial service offerings increased $388.2services operations grew $66.2 million of which approximately $329.8 million was generated by HydroChemPSC while the remainder was primarily due to increased demand and pricing for ourorganic growth as well as contributions from the acquisition of Thompson Industrial. Safety-Kleen core industrial services. Technical services revenues increased $155.4offerings contributed $60.0 million largely due to higher throughput at our facilities and higher value waste streams coupled with pricing initiatives. Utilization at our incinerators increased to 88%the overall growth of the Environmental Services segment in the first six months of 2022 largely driven by increased volume and fewer down days as compared to utilization of 83% in the six months ended June 30, 2021 which was impacted by significant weather events in the first quarter of 2021. We also saw an increase in landfill volumes in the six months of 20222023 as compared to the first six months of 2021.2022. This increase was generally due to greater demand and improved pricing for our containerized waste, parts washer and vacuum services. Technical services revenue increased $45.7 million with contributions across our portfolio of waste disposal facilities more than offsetting slightly lower revenues at our incinerators. Utilization at our incinerators for the six months ended June 30, 2023 was 82% as compared to 88% in the prior year due to unplanned outages for required maintenance and significant weather events early in the year. Pricing at the incinerators for the six months ended June 30, 2023 improved when compared to 2022 partially offsetting this lower utilization. Field and emergency response servicesservice revenues increased approximately $67.4 million despite a $25.8 million decrease in COVID-19 decontamination service revenues. This overall increase was both related to contributions from the HydroChemPSC business of $62.2 million as well as organic growth from increased demand in the legacy field services operations. Direct revenues for the Safety-Kleen core service offerings increased $48.0$25.2 million from the comparable period in 2021 due to improved pricing and greater demand for our containerized waste and vacuum services.2022. The Canadian operations of the Environmental Services segment were negatively impacted by $5.8$14.7 million due to foreign currency translation.
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Safety-Kleen Sustainability Solutions
For the Three Months EndedFor the Six Months EndedFor the Three Months EndedFor the Six Months Ended
June 30,2022 over 2021June 30,2022 over 2021June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)(in thousands, except percentages)20222021Change%
Change
20222021Change% Change(in thousands, except percentages)20232022Change%
Change
20232022Change% Change
Direct revenuesDirect revenues$265,490 $202,282 $63,208 31.2 %$487,082 $355,749 $131,333 36.9 %Direct revenues$225,748 $265,490 $(39,742)(15.0)%$462,287 $487,082 $(24,795)(5.1)%
Safety-Kleen Sustainability Solutions direct revenues for the three and six months ended June 30, 2022 increased $63.2 million and $131.3 million respectively from the comparable periods in 2021 predominately due to higher pricing of our base and blended oil products. ForIn the three months ended June 30, 2022, base oil sales revenues increased $47.8 million and blended oil sales revenues increased $6.72023, Safety-Kleen Sustainability Solutions direct revenue decreased $39.7 million from the comparable period in 2021 both due to pricing increases which more than offset lower volumes sold. Pricing increases also drove increases2022. This decrease was driven by a $42.8 million decrease in base oil sales revenuesdue to lower pricing despite increased volumes sold. Revenues from the collection of $98.2 millionused oil and blended oil sales revenuepartially offset this decrease by $4.1 million and $2.3 million respectively. The increase in revenues from the collection of $17.7 millionused oil was driven by higher collection volumes and pricing increases for these services, while the six months ended June 30, 2022 when compared with the six months ended June 30, 2021.increase in blended oil sales was driven by higher volume which offset a lower price for these products. The Canadian operations of the Safety-Kleen Sustainability Solutions segment were negatively impacted by $1.5 million in both the three andmonths ended June 30, 2023 due to foreign currency translation.
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In the six months ended June 30, 2023, Safety-Kleen Sustainability Solutions direct revenues decreased $24.8 million from the comparable period in 2022 largely due to a $31.7 million reduction in revenues from base oil sales due to lower pricing despite increased volumes sold. Revenues from contract packaging and blending decreased $7.6 million and blended oil revenues decreased $3.1 million. Partially offsetting these decreases were incremental revenues of $12.4 million from our recycled fuel oil and refinery byproducts driven by operations acquired in mid-2022 and an increase of $2.7 million in revenues from the collection of used oil due to higher collection volumes and pricing increases for these services. The Canadian operations of the Safety-Kleen Sustainability Solutions segment were negatively impacted by $3.9 million in the six months ended June 30, 2023 due to foreign currency translation.
Cost of Revenues 
We believe that our ability to manage operating costscost management is importantvital to our ability to remain price competitive. We continue toAs we experience the currentcost increases, including those driven by macroeconomic inflationary pressures across several cost categories, but most notably related tosuch as internal and external labor, transportation, general supplies and energy related costs. We continue tocosts, we manage these increasescosts through constantdiligent cost monitoring as well as ourand overall customer pricing strategies designed to offset the negative inflationary impacts on our margins.
We also continue to upgrade the quality and efficiency of our services through the development of new technology and continued modifications and expansion at our facilities, invest in new business opportunities and aggressively implement strategic sourcing and logistics solutions in the face of these inflationary pressures, while also continuing to optimize our management and operating structure in an effort to manage our operating margins.
Environmental Services
For the Three Months EndedFor the Six Months Ended
June 30,2022 over 2021June 30,2022 over 2021
(in thousands, except percentages)20222021
Change
%
Change
20222021Change% Change
Cost of revenues$743,659 $487,257 $256,402 52.6 %$1,428,995$938,512$490,483 52.3 %
As a % of Direct revenues68.2 %67.3 %0.9 %70.1 %68.1 %2.0 %
For the Three Months EndedFor the Six Months Ended
June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)20232022
Change
%
Change
20232022Change% Change
Cost of revenues$781,251 $743,659 $37,592 5.1 %$1,534,611$1,428,995$105,616 7.4 %
As a % of Direct revenues66.7 %68.2 %(1.5)%68.4 %70.1 %(1.7)%
Environmental Services cost of revenues for the three months ended June 30, 20222023 increased $256.4$37.6 million from the comparable period in 2021, primarily due to the increase in direct revenues noted above, including additional costs from the HydroChemPSC operations. Cost of revenues2022, however as a percentage of direct revenues for the three months ended June 30, 2022 remained relatively consistent with the three months ended June 30, 2021 despite lower COVID-19 decontamination services and higher industrial services which typically operate at a lower margin than our waste disposal focused offerings.revenue these costs decreased 1.5%. Overall, labor and benefit related costs increased $124.8$32.4 million and equipment and supply costs increased $61.2$7.1 million, and externalcommensurate with the revenue growth in the business. External transportation, vehicle and fuel related costs increased $51.1 million.decreased $4.4 million which, along with the pricing increases noted above, drove the improvement in these total costs as a percentage of revenues.
Environmental Services cost of revenues for the six months ended June 30, 20222023 increased $490.5$105.6 million from the comparable period in 2021, primarily due to the increase in direct revenues noted above, including additional costs from the HydroChemPSC operations. Cost of revenues2022, however as a percentage of direct revenues increased 2.0% fromrevenue these costs decreased 1.7%. Overall, commensurate with the comparable periodrevenue growth in the prior year mainly due to the mix of services, including lower COVID-19 decontamination services and the growth of our industrial services offerings which typically operate at margins lower than our waste disposal focused offerings. Inflationary pressures across several cost categories including labor, transportation, equipment and supply costs have also contributed to the increase of these costs as a percentage of revenues. Overall,business, labor and benefit related costs increased $234.9$74.0 million and equipment and supply costs increased $128.5 million and external$27.3 million. External transportation, vehicle and fuel related costs also increased $91.5 million.
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Table$2.1 million, however these costs improved as a percentage of Contents
revenue driving overall improvement in the segment's costs as a percentage of revenue.
Safety-Kleen Sustainability Solutions
For the Three Months EndedFor the Six Months EndedFor the Three Months EndedFor the Six Months Ended
June 30,2022 over 2021June 30,2022 over 2021June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)(in thousands, except percentages)20222021
Change
%
Change
20222021Change% Change(in thousands, except percentages)20232022
Change
%
Change
20232022Change% Change
Cost of revenuesCost of revenues$151,020 $123,025 $27,995 22.8 %$303,037$231,401$71,636 31.0 %Cost of revenues$153,901 $151,020 $2,881 1.9 %$329,758$303,037$26,721 8.8 %
As a % of Direct revenuesAs a % of Direct revenues56.9 %60.8 %(3.9)%62.2 %65.0 %(2.8)%As a % of Direct revenues68.2 %56.9 %11.3 %71.3 %62.2 %9.1 %
Safety-Kleen Sustainability Solutions cost of revenues for the three months ended June 30, 20222023 increased $28.0$2.9 million from the comparable period in 2021.2022. As a percentage of revenues, these costs increased by 11.3% predominately due to the market related pricing decreases discussed in the revenue section above. Overall, labor and benefit related expense increased $5.2 million, transportation, vehicle and fuel costs increased $4.8 million and equipment and supply costs increased $2.0 million. These cost increases were driven by the increased collection and production volumes and the additional costs from businesses acquired in mid-2022. The cost of used oil as the primary raw materials usedmaterial in production of our recycled base and blended oil products increased $17.8decreased by $9.7 million driven mainly by increased costsour efforts to obtain usedmanage the spread between the pricing of base oil throughproducts and our used oil collection services. The increase in base oil pricingWe expect these raw material costs to continue to decrease in the secondthird quarter of 2022 as compared to the same period in 2021 has resulted in a correlating increase in the cost we now pay for used oil feedstock. Increased external transportation, vehicle and fuel costs2023.
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Table of $5.1 million also contributed to the overall increase in cost of revenues, with fuel being the largest component of this increase.Contents
Safety-Kleen Sustainability Solutions cost of revenues for the six months ended June 30, 20222023 increased $71.6$26.7 million from the comparable period in 2021. The cost2022 and as a percentage of raw materials used in production of our oil productsrevenues, these costs increased $49.5 million, more than half of which wasby 9.1% mainly due to increased costs to obtain used oil through our used oil collection services. As noted above, the increase in base oilmarket related pricing has resulted in a correlating increasedecreases discussed in the cost we now pay for used oil feedstock. Other costs that contributed to the overall increase include the cost ofrevenue section above. Overall, external transportation, vehicle and fuel costs which increased $9.6$13.6 million, and labor and benefit related expense increased $10.9 million and equipment and supply costs which increased $2.8 million.
As a percentage of revenues, Safety-Kleen Sustainability Solutions$3.3 million also driven by increased collection and production volumes and the incremental costs from businesses acquired mid-2022. Similar to the discussion in the preceding paragraph, costs of revenuesoil additives and other raw materials decreased by 3.9% and 2.8% in the three and six months ended June 30, 2022 as compared to the comparable periods in 2021. This margin improvement was largely driven by the increased pricing of our products which outpaced the increase in cost of revenues as the business continued to capitalize on the favorable market conditions and efficient management of the spread between the pricing of products and the rising costs to obtain oil feedstock, including labor and fuel costs, in this inflationary environment.$2.6 million.
Selling, General and Administrative Expenses
We strive to manage our selling, general and administrative ("SG&A") expenses commensurate with the overall performance of our segments and corresponding revenue levels. We believe our ability to properly align these costs with business performance is reflective of our strong management of the businesses and further promotes our ability to remain competitive in the marketplace.
Environmental Services
For the Three Months EndedFor the Six Months EndedFor the Three Months EndedFor the Six Months Ended
June 30,2022 over 2021June 30,2022 over 2021June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)(in thousands, except percentages)20222021
Change
%
Change
20222021Change% Change(in thousands, except percentages)20232022
Change
%
Change
20232022Change% Change
SG&A expensesSG&A expenses$77,743 $60,799 $16,944 27.9 %$156,250$123,892$32,358 26.1 %SG&A expenses$85,163 $77,743 $7,420 9.5 %$174,199$156,250$17,949 11.5 %
As a % of Direct revenuesAs a % of Direct revenues7.1 %8.4 %(1.3)%7.7 %9.0 %(1.3)%As a % of Direct revenues7.3 %7.1 %0.2 %7.8 %7.7 %0.1 %
Environmental Services SG&A expenses for the three and six months ended June 30, 20222023 increased $16.9$7.4 million and $17.9 million, respectively, from the comparable periodperiods in 2021, most predominately2022 however, as a percentage of revenues, these costs remained relatively consistent as a result of cost control initiatives. The overall cost increases were due to a $12.9 million increase inhigher labor and benefitbenefits related costs. Environmental Services SG&A expenses forcosts of $6.9 million in the three months ended June 30, 2023 and $18.2 million in the six months ended June 30, 2022 increased $32.4 million from the comparable period in 2021, also2023 predominately due to increased laborinvestments in our employees and benefit related costs of $23.9 million. Increased costshigher incentive compensation resulting from the HydroChemPSC business operations drove approximately $12.0 millionrevenue growth and $24.2 million of the labor and benefit cost increases, respectively. As a percentage of revenue, the Environmental Services SG&A improved by 1.3% in both the three and six months ended June 30, 2022, driven both by the HydroChemPSC business operations which have lower SG&A expenses when compared to the business's related revenues and overall improved leverage of SG&A in the legacy Environmental Services business. The improved leverage of our SG&A spending significantly contributed to the overall increase in profitability of the segment.
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profitability.
Safety-Kleen Sustainability Solutions
For the Three Months EndedFor the Six Months EndedFor the Three Months EndedFor the Six Months Ended
June 30,2022 over 2021June 30,2022 over 2021June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)(in thousands, except percentages)20222021
Change
%
Change
20222021Change% Change(in thousands, except percentages)20232022
Change
%
Change
20232022Change% Change
SG&A expensesSG&A expenses$17,460 $15,943 $1,517 9.5 %$35,158$29,402$5,756 19.6 %SG&A expenses$18,432 $17,460 $972 5.6 %$37,651$35,158$2,493 7.1 %
As a % of Direct revenuesAs a % of Direct revenues6.6 %7.9 %(1.3)%7.2 %8.3 %(1.1)%As a % of Direct revenues8.2 %6.6 %1.6 %8.1 %7.2 %0.9 %
Safety-Kleen Sustainability Solutions SG&A expenses for the three and six months ended June 30, 20222023 increased $1.5$1.0 million and $5.8$2.5 million from the comparable periods in 20212022 and as a percentage of revenues, these costs increased from the prior period, mainly due to the revenue reductions discussed above. The overall cost increases were primarily attributabledue to higher labor and benefit cost increases of $1.2 million and $4.6 million, respectively. As a percentage of revenue, these costs improved in both the three and six months ended June 30, 2022 when compared to2023, as we expanded our sales team for the same periodssegment in the prior year.mid-2022.
Corporate Items
For the Three Months EndedFor the Six Months EndedFor the Three Months EndedFor the Six Months Ended
June 30,2022 over 2021June 30,2022 over 2021June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)(in thousands, except percentages)20222021
Change
%
Change
20222021Change% Change(in thousands, except percentages)20232022
Change
%
Change
20232022Change% Change
SG&A expensesSG&A expenses$60,405 $47,364 $13,041 27.5 %$115,373 $92,453 $22,920 24.8 %SG&A expenses$63,787 $60,405 $3,382 5.6 %$122,285 $115,373 $6,912 6.0 %
As a % of Total Clean Harbors' Direct revenues4.5 %5.1 %(0.6)%4.6 %5.3 %(0.7)%
As a % of Total Company Direct revenuesAs a % of Total Company Direct revenues4.6 %4.5 %0.1 %4.5 %4.6 %(0.1)%
We manage our Corporate Items SG&A expenses commensurate with the overall total Company performance and direct revenue levels. Generally, as revenues increase, we would expect some increase in these costs. Corporate Items SG&A expenses for the three and six months ended June 30, 2022 increased from the comparable periods in 2021, but decreased in both periods2023 remained consistent as a percentage of total Clean Harbors' direct revenues which has also contributedwhen compared to Clean Harbors' overall profitability.the
For the three months ended June 30, 2022, the overall cost increase
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Table of $13.0 million included a $6.8 million increaseContents
same periods in labor and benefits related costs, including higher stock-based compensation costs and human resource related costs. The higher stock-based compensation costs are primarily driven by the timing of grants in 2022. Overall we expect the stock-based grants in the current year to remain relatively consistent with the prior year. The remaining net increase is spread across various cost categories.
ForSG&A expenses for the six months ended June 30, 2022 the overall increaseincludes a benefit of $22.9$3.0 million included a $13.3 million increase in labor and benefits related costs, including higher stock-based compensation costs, incentive costs and human resource related costs. Similar to the discussion above, the increase in stock-based compensation is mainly due to the timing of grants in 2022, though we expect the overall grants for 2022 to be relatively consistent with 2021. Both bad debt expense and information technology/cyber-security related technology costs increased $4.0 million, respectively. These increases were partially offset by the $3.0 million breakup fee received related tofrom Vertex Energy, Inc. for the termination of the proposed asset acquisition from Vertex Energy, Inc. The remaining net increase is spread across various cost categories.acquisition.
Adjusted EBITDA
Management considers Adjusted EBITDA to be a measurement of performance which provides useful information to both management and investors. Adjusted EBITDA should not be considered an alternative to net income or other measurements under GAAP.generally accepted accounting principles ("GAAP"). Adjusted EBITDA is not calculated identically by all companies and therefore our measurements of Adjusted EBITDA, while defined consistently and in accordance with our existing credit agreement, may not be comparable to similarly titled measures reported by other companies.
 For the Three Months EndedFor the Six Months Ended
June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)20232022Change%
Change
20232022Change% Change
Adjusted EBITDA:    
Environmental Services$305,622 $269,341 $36,281 13.5 %$533,967 $452,943 $81,024 17.9 %
Safety-Kleen Sustainability Solutions53,415 97,010 (43,595)(44.9)94,878 148,887 (54,009)(36.3)
Corporate Items(71,531)(57,281)(14,250)(24.9)(126,201)(112,501)(13,700)(12.2)
Total$287,506 $309,070 $(21,564)(7.0)%$502,644 $489,329 $13,315 2.7 %
Adjusted EBITDA as a % of Direct Revenues (1):
Environmental Services26.1 %24.7 %1.4 %23.8 %22.2 %1.6 %
Safety-Kleen Sustainability Solutions23.7 %36.5 %(12.8)%20.5 %30.6 %(10.1)%
Corporate Items(5.1)%(4.2)%(0.9)%(4.7)%(4.5)%(0.2)%
Total20.6 %22.8 %(2.2)%18.6 %19.4 %(0.8)%
______________
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Table(1) Environmental Services and Safety-Kleen Sustainability Solutions calculated as a percentage of Contents
 For the Three Months EndedFor the Six Months Ended
June 30,2022 over 2021June 30,2022 over 2021
(in thousands, except percentages)20222021Change%
Change
20222021Change% Change
Adjusted EBITDA:    
Environmental Services$269,341 $176,041 $93,300 53.0 %$452,943 $316,295 $136,648 43.2 %
Safety-Kleen Sustainability Solutions97,010 63,314 33,696 53.2 148,887 94,946 53,941 56.8 
Corporate Items(57,281)(51,584)(5,697)(11.0)(112,501)(94,019)(18,482)(19.7)
Total$309,070 $187,771 $121,299 64.6 %$489,329 $317,222 $172,107 54.3 %
individual segment revenues. Corporate Items calculated as a percentage of total Company revenues.
We use Adjusted EBITDA to enhance our understanding of our operating performance, which represents our views concerning our performance in the ordinary, ongoing and customary course of our operations. We historically have found it helpful, and believe that investors have found it helpful, to consider an operating measure that excludes certain expenses relating to transactions not reflective of our core operations. Adjusted EBITDA margin for the Environmental Services segment improved due to the revenue pricing increases and cost management in both cost of revenues and SG&A expenses. Adjusted EBITDA margin in Safety-Kleen Sustainability Solutions segment decreased mainly due to the reduced revenue amounts. Corporate Items Adjusted EBITDA margin remained relatively consistent as a percentage of total Company revenues with the slight increase due to insurance related charges in cost of revenues.
The information about our operating performance provided by this financial measureAdjusted EBITDA is used by our management for a variety of purposes. We regularly communicate Adjusted EBITDA results to our lenders since our loan covenants are based upon levels of Adjusted EBITDA achieved and to our board of directors, and we discuss with the board our interpretation of such results with the board.results. We also compare our Adjusted EBITDA performance against internal targets as a key factor in determining cash and stockequity bonus compensation for executives and other employees, largely because we believe that this measure is indicative of how the fundamental business is performing and is being managed.
We also provide information relating to our Adjusted EBITDA so that analysts, investors and other interested persons have the same data that we use to assess our core operating performance. We believe that Adjusted EBITDA should be viewed only as a supplement to the GAAP financial information. We also believe, however, that providing this information in addition to, and together with, GAAP financial information permits the users of our financial statements to obtainprovides a better understanding of our core operating performance and to evaluate the efficacyhow management evaluates and measures our performance.
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Table of the methodology and information used by management to evaluate and measure such performance on a standalone and a comparative basis.Contents
The following is a reconciliation of net income to Adjusted EBITDA for the following periods (in thousands, except percentages):
For the Three Months EndedFor the Six Months Ended
 June 30,June 30,
 2022202120222021
Net income$148,157 $67,075 $193,471 $88,811 
Accretion of environmental liabilities3,197 2,873 6,353 5,826 
Stock-based compensation6,835 3,305 12,547 6,785 
Depreciation and amortization87,868 71,592 172,166 143,755 
Other (income) expense, net(1,265)1,480 (1,969)2,708 
Gain on sale of business(8,864)— (8,864)— 
Interest expense, net of interest income26,256 18,051 51,273 35,969 
Provision for income taxes46,886 23,395 64,352 33,368 
Adjusted EBITDA$309,070 $187,771 $489,329 $317,222 
As a % of Direct revenues22.8 %20.3 %19.4 %18.3 %
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For the Three Months EndedFor the Six Months Ended
 June 30,June 30,
 2023202220232022
Net income$115,766 $148,157 $188,167 $193,471 
Accretion of environmental liabilities3,486 3,197 6,893 6,353 
Stock-based compensation4,500 6,835 10,518 12,547 
Depreciation and amortization89,697 87,868 174,455 172,166 
Other expense (income), net1,283 (1,265)1,167 (1,969)
Loss on early extinguishment of debt— — 2,362 — 
Gain on sale of business— (8,864)— (8,864)
Interest expense, net of interest income30,072 26,256 50,704 51,273 
Provision for income taxes42,702 46,886 68,378 64,352 
Adjusted EBITDA$287,506 $309,070 $502,644 $489,329 
As a % of Direct revenues20.6 %22.8 %18.6 %19.4 %
Depreciation and Amortization
For the Three Months EndedFor the Six Months EndedFor the Three Months EndedFor the Six Months Ended
June 30,2022 over 2021June 30,2022 over 2021June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)(in thousands, except percentages)20222021Change%
Change
20222021Change% Change(in thousands, except percentages)20232022Change%
Change
20232022Change% Change
Depreciation of fixed assets and amortization of landfills and finance leasesDepreciation of fixed assets and amortization of landfills and finance leases$75,616 $63,828 $11,788 18.5 %$147,674 $128,402 $19,272 15.0 %Depreciation of fixed assets and amortization of landfills and finance leases$77,194 $75,616 $1,578 2.1 %$149,226 $147,674 $1,552 1.1 %
Permits and other intangibles amortizationPermits and other intangibles amortization12,252 7,764 4,488 57.8 24,492 15,353 9,139 59.5 Permits and other intangibles amortization12,503 12,252 251 2.0 25,229 24,492 737 3.0 
Total depreciation and amortizationTotal depreciation and amortization$87,868 $71,592 $16,276 22.7 %$172,166 $143,755 $28,411 19.8 %Total depreciation and amortization$89,697 $87,868 $1,829 2.1 %$174,455 $172,166 $2,289 1.3 %
Depreciation and amortization for the three and six months ended June 30, 20222023 increased by $16.3$1.8 million and $28.4$2.3 million from the comparable periods in 20212022 due to theincreased depreciation and amortization offrom new finance leases in the HydroChemPSCperiod and the Thompson Industrial tangible and intangible assets which were acquired on March 31, 2023.
Loss on Early Extinguishment of Debt
For the Three Months EndedFor the Six Months Ended
June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)20232022Change%
Change
20232022Change% Change
Loss on early extinguishment of debt$— $— $— — %$(2,362)$— $(2,362)100.0 %
During the six months ended June 30, 2023, we recorded a $2.4 million loss on early extinguishment of debt in inconnection with the fourth quarterrepayment of 2021.the remaining $614.0 million principal amount of the 2024 Term Loans. For additional information regarding this repayment, see Note 12, "Financing Arrangements," to the accompanying financial statements.
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Gain on Sale of Business
For the Three Months EndedFor the Six Months Ended
June 30,2022 over 2021June 30,2022 over 2021
20222021Change%
Change
20222021Change%
Change
Gain on sale of business$8,864 $— $8,864 100.0 %$8,864 $— $8,864 100.0 %
For the Three Months EndedFor the Six Months Ended
June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)20232022Change%
Change
20232022Change% Change
Gain on sale of business$— $8,864 $(8,864)100.0 %$— $8,864 $(8,864)(100.0)%
During the three and six months ended June 30, 2022, we recorded aan $8.9 million gain on the sale of a non-core line of business within our Environmental Services segment. For additional information regarding this gain on sale of business, see Note 5, "Disposition of Business," to the accompanying financial statements.
ProvisionInterest Expense, Net of Interest Income
For the Three Months EndedFor the Six Months Ended
June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)20232022Change%
Change
20232022Change% Change
Interest expense, net of interest income$(30,072)$(26,256)$(3,816)14.5 %$(50,704)$(51,273)$569 (1.1)%
Interest expense, net of interest income for Income Taxes
For the Three Months EndedFor the Six Months Ended
June 30,2022 over 2021June 30,2022 over 2021
(in thousands, except percentages)20222021Change%
Change
20222021Change%
Change
Provision for income taxes$46,886 $23,395 $23,491 100.4 %$64,352 $33,368 $30,984 92.9 %
Effective tax rate24.0 %25.9 %(1.9)%25.0 %27.3 %(2.3)%
the three months ended June 30, 2023 increased $3.8 million from the comparable period in 2022 due to higher interest rates on our portfolio of debt obligations. Interest expense, net of interest income for the six months ended June 30, 2023 decreased $0.6 million from the comparable period in 2022 due to the $8.3 million benefit recognized from settling interest rate swaps in connection with repaying certain of our variable rate debt in January 2023. Absent this benefit, interest expense, net of interest income, increased $7.7 million due to higher interest rates on our portfolio of debt obligations. The provision for income taxeseffective interest rates on our long-term debt for the three and six months ended June 30, 2022 increased $23.5 million2023 were 5.52% and $31.0 million from the5.30%, respectively. The comparable periods in 2021, due to an increase in income before provision for income taxes. Our effective tax rates for the three and six months ended June 30, 2022 were 4.24% and 3.90% respectively.
For the remainder of 2023, we anticipate the effective rate will be approximately 5.96% given the current interest rate environment and our portfolio of long-term debt. For additional information regarding the financing events during 2023 and our current portfolio of long-term debt, see Note 12, "Financing Arrangements," to the accompanying financial statements.
Provision for Income Taxes
For the Three Months EndedFor the Six Months Ended
June 30,2023 over 2022June 30,2023 over 2022
(in thousands, except percentages)20232022Change%
Change
20232022Change% Change
Provision for income taxes$42,702 $46,886 $(4,184)(8.9)%$68,378 $64,352 $4,026 6.3 %
Effective tax rate26.9 %24.0 %2.9 %26.7 %25.0 %1.7 %
For the three months ended June 30, 2023, the provision for income taxes decreased 1.9%$4.2 million from the comparable period in 2022 due to a decrease in income before provision for income taxes. For the six months ended June 30, 2023, the provision for income taxes increased $4.0 million from the comparable period in 2022 due to the utilization of unbenefited losses in certain of our Canadian entities which benefitted the expense in 2022. Our effective tax rate for the three and 2.3%, respectively,six months ended June 30, 2023 increased 2.9% and 1.7% when compared to the three and six months ended June 30, 2021. The decrease in our effective tax rate is largely2022 also due to the utilization of previous unbenefited losses in certain of our Canadian entities.2022.
In recent periods, certain Canadian entities which have historically generated net operating losses and for which we have recognized valuation allowances, have been operating at a profit. This recent profitability and associated utilization of previous unbenefited losses is due to operational improvements and tax strategies as well as government subsidies and the gain on sale of a line of business. As of June 30, 2022, we do not yet believe that sufficient positive evidence exists to support that this return to profitability will continue for a sustained period. We will continue to evaluate this on an ongoing basis to determine when, if at all, to release some or all of the associated remaining valuation allowances.
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Liquidity and Capital Resources 
We assess our liquidity in terms of our ability to generate cash to fund our operating, investing, and financing activities. Our primary ongoing cash requirements will be to fund operations, capital expenditures, interest payments and investments in line with our business strategy. We believe our future operating cash flows will be sufficient to meet our future operating and internal investing cash needs. We monitor our actual needs and forecasted cash flows, our liquidity and our capital resources, enabling us to plan our present needs and fund items that may arise during the year as a result of changing business conditions or opportunities. Furthermore, our existing cash balance and the availability of additional borrowings under our revolving credit facility provide additional potential sources of liquidity should they be required.
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Summary of Cash Flow Activity
Six Months EndedSix Months Ended
June 30,June 30,
(in thousands)(in thousands)20222021(in thousands)20232022
Net cash from operating activitiesNet cash from operating activities$131,970 $265,432 Net cash from operating activities$235,573 $131,970 
Net cash used in investing activitiesNet cash used in investing activities(187,482)(132,340)Net cash used in investing activities(347,265)(187,482)
Net cash used in financing activitiesNet cash used in financing activities(51,431)(60,534)Net cash used in financing activities(142,853)(51,431)
Net cash from operating activities
Net cash from operating activities for the six months ended June 30, 20222023 was $132.0$235.6 million as compared to $265.4$132.0 million in the comparable period of 2021. The decrease2022. This $103.6 million increase in operating cash flows from the comparable period of 2021 was attributable to improved working capital balances and increased income from operations, partially offset by an increase in working capital caused by the significant growthincome taxes paid and an increase in the business, and higher incentive compensation and interest payments in the first six months of 2022, partially offset by greater levels of operating income.environmental expenditures.
Net cash used in investing activities
Net cash used in investing activities for the six months ended June 30, 20222023 was $187.5$347.3 million, an increase of $55.1$159.8 million from the comparable period in 2021. The increase in net cash used in investing activities as compared to the same prior year period was primarily due to a $56.1 million increase in additions2022. Additions to property, plant and equipment, inclusivenet of $13.5proceeds from the sale and disposal of fixed assets increased $56.3 million, oflargely driven by incremental capital spending for our new incinerator construction in Kimball, Nebraska and a $45.8Nebraska. Cash used for acquisitions increased $51.9 million, increase in acquisitions, net ofwhile cash acquired. These increases were partially offset by a $28.8 million cash increase relatedpaid relative to the timing of investment transactions within our wholly owned captive insurance company and aincreased $33.8 million. Additionally, during the six months ended June 30, 2022 we received $17.5 million cash inflowin proceeds from the disposition of a line of business.
Net cash used in financing activities
Net cash used in financing activities for the six months ended June 30, 2022 was2023 increased $91.4 million from $51.4 million as comparedin 2022 to $60.5$142.9 million in 2023. During the comparable periodsix months ended June 30, 2023, the Company repaid $614.0 million of secured senior term loans with the proceeds from issuing $500.0 million of unsecured senior notes. Associated with this refinancing the Company also paid an additional $6.0 million of additional finance costs in 2021. This decrease of $9.1 million was primarily due to an $11.7 million decrease in repurchases of common stock during the first six months of 2022 partially offset by a $5.02023. Partially offsetting this the Company spent $25.7 million increase in debt principal payments required by the new term loans executed in the fourth quarterless for repurchases of 2021.common stock.
Adjusted Free Cash Flow
Management considers adjusted free cash flow to be a measure of liquidity which provides useful information to both management, creditors and investors about our financial strength and our ability to generate cash. Additionally, adjusted free cash flow is a metric on which a portion of management incentive compensation is based. We define adjusted free cash flow as net cash from operating activities excluding cash impacts of items derived from non-operating activities, such as taxes paid in connection with divestitures, less additions to property, plant and equipment plus proceeds from sales or disposals of fixed assets. Adjusted free cash flow should not be considered an alternative to net cash from operating activities or other measurements under GAAP. Adjusted free cash flow is not calculated identically by all companies, and therefore our measurements of adjusted free cash flow may not be comparable to similarly titled measures reported by other companies.
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The following is a reconciliation from net cash from operating activities to adjusted free cash flow for the following periods (in thousands):
Six Months EndedSix Months Ended
June 30, June 30,
20222021 20232022
Net cash from operating activitiesNet cash from operating activities$131,970 $265,432 Net cash from operating activities$235,573 $131,970 
Additions to property, plant and equipmentAdditions to property, plant and equipment(148,042)(91,988)Additions to property, plant and equipment(204,298)(148,042)
Proceeds from sale and disposal of fixed assetsProceeds from sale and disposal of fixed assets3,023 3,479 Proceeds from sale and disposal of fixed assets2,944 3,023 
Adjusted free cash flowAdjusted free cash flow$(13,049)$176,923 Adjusted free cash flow$34,219 $(13,049)
Summary of Capital Resources
At June 30, 2022,2023, cash and cash equivalents and marketable securities totaled $415.4$326.1 million, compared to $534.3$554.6 million at December 31, 2021.2022. This reduction was primarily attributable to the net reduction of $114.0 million in long-term debt obligations and the payment of $111.9 million for the acquisition of Thompson Industrial in 2023. At June 30, 2022,2023, cash and cash equivalents held by our foreignCanadian subsidiaries totaled $52.3$29.3 million. The cash and cash equivalents and marketable securities balance for our U.S. operations was $363.1$296.9 million at June 30, 2022.2023. Our U.S. operations had net operating cash inflows of $139.6$226.0 million for the six months ended June 30, 2022.2023.
We also maintain a $400.0 million revolving credit facility of which, as of June 30, 2022,2023, approximately $290.6$274.8 million was available to borrow andunder the facility, with letters of credit under the credit facility in the amount of $109.4$125.2 million were outstanding.
Material Capital Requirements
Capital Expenditures
Capital expenditures during the first six months of 20222023 were $148.0$204.3 million as compared to $92.0$148.0 million during the first six months of 2021.2022. We anticipate that 20222023 capital spending, net of disposals, will be in the range of $320.0$400.0 million to $340.0 million. This includes approximately $45.0$420.0 million, including $85.0 million to $50.0$90.0 million of capital spending for our new incinerator construction in Kimball, Nebraska, of which $13.5 million has been spent duringNebraska.
We anticipate that the first six months of 2022.
As always, unanticipatedcapital spending will be funded by cash from our operations. Unanticipated changes in environmental regulations could require us to make significant capital expenditures for our facilities and could adversely affect our results of operations and cash flow.
During the first six months of 2023, capital spending on the construction of our new incinerator at our Kimball, Nebraska facility was approximately $35.4 million. The current capital expenditure estimate for this project is approximately $180.0 million and we anticipate the project to be complete in early 2025. As of June 30, 2023, a total of $87.5 million has been spent on the project.
Financing Arrangements
In January 2023, we issued $500.0 million principal amount of 6.375% unsecured senior notes due 2031. The net proceeds of the issuance, along with a $114.0 million borrowing under our existing revolving credit facility and cash on hand, were used to repay the aggregate principal balance of our 2024 Term Loans. In the three months ended June 30, 2023, we repaid the $114.0 million borrowing on the revolving credit facility.
As of June 30, 2022,2023, our financing arrangements include (i) $715.9 million of senior secured term loans due 2024, (ii) $545.0 million of 4.875% senior unsecured notes due 2027, (iii) $995.0(ii) $985.0 million of senior secured term loans due 2028, and (iv)(iii) $300.0 million of 5.125% senior unsecured notes due 2029. We2029 and (iv) $500.0 million of 6.375% senior unsecured notes due 2031. As noted above, we also maintain our $400.0 million revolving credit facility. Asfacility with no amounts owed as of June 30, 2022, under the revolving credit facility, we had no outstanding loan balance, $290.6 million available to borrow and outstanding letters of credit of $109.4 million. We obtain standby letters of credit as security for financial assurances we have been required to provide to regulatory bodies for our hazardous waste facilities and which would be called only in the event that we fail to satisfy closure, post-closure and other obligations under the permits issued by those regulatory bodies for such licensed facilities.2023.
The material terms of these arrangements are discussed further in Note 12, “Financing Arrangements,” to our consolidatedthe accompanying financial statements included in Item 8 of this report.statements.
As of December 31, 2021,June 30, 2023, we were in compliance with the covenants of all of our debt agreements, and we believe we will continue to meet such covenants.
Common Stock Repurchases Pursuant to Publicly Announced Plan
The Company's common stock repurchases are made pursuant to the previously authorized board approved plan to repurchase up to $600.0 million of the Company's common stock. During the three and six months ended June 30, 2023, the Company repurchased and retired a total of approximately 36.5 thousand and 58.7 thousand shares of the Company's common stock, respectively, for total expenditures of approximately $5.0 million and $8.0 million, respectively. During the three and six months
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ended June 30, 2022, the Company repurchased and retired a total of approximately 0.3 million and 0.4 million shares of the Company's common stock, respectively, for total expenditures of approximately $30.0 million and $33.7 million, respectively. During the three and six months ended June 30, 2021, the Company repurchased and retired a total of approximately 0.2 million and 0.5 million shares of the Company's common stock, respectively, for total expenditures of approximately $18.9 million and $45.4 million, respectively.
Through June 30, 2022,2023, the Company has repurchased and retired a total of approximately 8.08.3 million shares of its common stock for approximately $478.3$502.7 million under this program. As of June 30, 2022,2023, an additional $121.7$97.3 million remained available for repurchase of shares under this program.
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Environmental Liabilities
(in thousands, except percentages)(in thousands, except percentages)June 30, 2022December 31, 2021Change% Change(in thousands, except percentages)June 30, 2023December 31, 2022Change% Change
Closure and post-closure liabilitiesClosure and post-closure liabilities$102,997 $99,103 $3,894 3.9 %Closure and post-closure liabilities$120,708 $118,801 $1,907 1.6 %
Remedial liabilitiesRemedial liabilities123,656 111,873 11,783 10.5 Remedial liabilities112,176 116,290 (4,114)(3.5)
Total environmental liabilitiesTotal environmental liabilities$226,653 $210,976 $15,677 7.4 %Total environmental liabilities$232,884 $235,091 $(2,207)(0.9)%
Total environmental liabilities as of June 30, 20222023 were $226.7$232.9 million, an increaserelatively consistent with the balance as of $15.7 million compared to December 31, 2021, primarily due2022. During the six months ended June 30, 2023, expenditures of $16.3 million were partially offset by accretion of $6.9 million, changes in estimates for the environmental liabilities, including those related to liabilities assumed in prior period acquisitions, of $4.7 million, and new liabilities of $1.9 million, including those assumed in acquisition, of $14.7 million and accretion of $6.4 million, partially offset by expenditures of $7.0 million. The majority of the new liabilities relate to a real estate acquisition in 2022 for which we are assuming a remedial liability. The remedial liability was contemplated when arriving at the amount paid to acquire the property.current period acquisitions.
We anticipate our environmental liabilities, substantially all of which we assumed in connection with our acquisitions, will be payable over many years and that cash flow from operations will generally be sufficient to fund the payment of such liabilities when required.
Events not anticipated (such as future changes in environmental laws and regulations) could require that payments to satisfy our environmental liabilities be made earlier or in greater amounts than currently anticipated, which could adversely affect our results of operations, cash flow and financial condition. Conversely, the development of new treatment technologies or other circumstances may arise in the future which may reduce amounts ultimately paid.
Letters of Credit
We obtain standby letters of credit as security for financial assurances we have been required to provide to regulatory bodies for our hazardous waste facilities and which would be called only in the event that we fail to satisfy closure, post-closure and other obligations under the permits issued by those regulatory bodies for such licensed facilities. As of June 30, 2023, there were $125.2 million outstanding letters of credit. See Note 12, "Financing Arrangements," to the accompanying financial statements.
Critical Accounting Policies and Estimates
Other than as described below, there were no material changes in the first six months of 20222023 to the information provided under the heading “Critical Accounting Policies and Estimates” included in our Annual Report on Form 10-K for the year ended December 31, 2021.2022.
Goodwill and Other Long-Lived Assets. Pursuant to the previous succession announcement, effective March 31, 2023, Michael L. Battles and Eric W. Gerstenberg, were appointed co-CEOs and as a result, the Company’s new Chief Operating Decision Maker (“CODM”) is a committee comprised of both co-CEOs, who, going forward, will manage the business, make operating decisions and assess performance. The Company does not expect that the new CODM structure will change how the Company is managed and as such will continue to report as two operating segments; (i) the Environmental Services segment and (ii) the Safety-Kleen Sustainability Solutions segment and assess the recoverability of goodwill under three reporting units; (i) Environmental Sales and Service, (ii) Environmental Facilities and (iii) Safety-Kleen Sustainability Solutions.

ITEM 3.    QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK 
There were no material changes in the first six months of 20222023 to the information provided under Item 7A. “Quantitative and Qualitative Disclosures about Market Risk” in the Company's Annual Report on Form 10-K for the year ended December 31, 2021.2022.

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ITEM 4.    CONTROLS AND PROCEDURES
Evaluation of Disclosure Controls and Procedures
Based on an evaluation under the supervision and with the participation of our ChiefCo-Chief Executive OfficerOfficers and Chief Financial Officer, as of the end of the period covered by this Quarterly Report on Form 10-Q, our ChiefCo-Chief Executive OfficerOfficers and Chief Financial Officer have concluded that our disclosure controls and procedures (as defined under Rule 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) were effective as of June 30, 20222023 to ensure that information required to be disclosed by us in reports that we file or submit under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in Securities and Exchange Commission rules and forms and is accumulated and communicated to our management, including our ChiefCo-Chief Executive OfficerOfficers and Chief Financial Officer, as appropriate to allow timely decisions regarding required disclosure.
Changes in Internal Control over Financial Reporting
There were no changes in the Company's internal control over financial reporting identified in connection with the evaluation required by paragraph (d) of Exchange Act Rules 13a-15 or 15d-15 that was conducted during the six months ended June 30, 20222023 that have materially affected, or are reasonably likely to materially affect, the Company’s internal control over financial reporting.
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CLEAN HARBORS, INC. AND SUBSIDIARIES
PART II��II—OTHER INFORMATION
ITEM 1.    LEGAL PROCEEDINGS
See Note 17,16, “Commitments and Contingencies,” to the unaudited consolidated financial statements included in Item 1 of this report, which description is incorporated herein by reference.

ITEM 1A.     RISK FACTORS
There have been no material changes to the risk factors from the information provided in Item 1A. in the Company's Annual Report on Form 10-K for the year ended December 31, 2021.2022.

ITEM 2.     UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS
Common Stock Repurchase Program
The following table provides information with respect to the shares of common stock repurchased by us for the periods indicated.
Period
Total Number of Shares Purchased (1)
Average Price Paid Per Share (2)
Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs
Approximate Dollar Value of Shares that May Yet Be Purchased Under the Plans or Programs
(in thousands) (3)
April 1, 2022 through April 30, 20226,481 $112.93 — $151,748 
May 1, 2022 through May 31, 2022183,132 90.97 183,089 135,093 
June 1, 2022 through June 30, 2022151,817 87.94 151,768 121,748 
Total341,430 90.04 334,857 
Period
Total Number of Shares Purchased (1)
Average Price Paid Per Share (2)
Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs
Approximate Dollar Value of Shares that May Yet Be Purchased Under the Plans or Programs
(in thousands) (3)
April 1, 2023 through April 30, 20235,040 $142.56 — $102,265 
May 1, 2023 through May 31, 202336,820 137.17 36,473 97,265 
June 1, 2023 through June 30, 20231,500 143.49 — 97,265 
Total43,360 $138.02 36,473 
________________
(1)    Includes 6,5736,887 shares withheld by us from employees to satisfy employee tax obligations upon vesting of restricted stock granted to our employees under the Company's equity incentive plans.
(2)    The average price paid per share of common stock repurchased under the stock repurchase program includes the commissions paid to brokers.
(3)    Our board of directors has authorized the repurchase of up to $600.0 million of our common stock. We have funded and intend to fund the repurchases through available cash resources. The stock repurchase program authorizes us to purchase our common stock on the open market or in privately negotiated transactions periodically in a manner that complies with applicable U.S. securities laws. The number of shares purchased and the timing of the purchases has depended and will depend on several factors, including share price, cash required for business plans, trading volume and other conditions. We maintain a repurchase plan in accordance with Rule 10b5-1 promulgated under the Securities Exchange Act of 1934, as amended. During the three months ended June 30, 2022,2023, no shares were repurchased under the Rule 10b5-1 plan. Future repurchases may be made as open market or privately negotiated transactions as described above. We have no obligation to repurchase stock under this program and may suspend or terminate the repurchase program at any time.

ITEM 3.     DEFAULTS UPON SENIOR SECURITIES
    None

ITEM 4.    MINE SAFETY DISCLOSURE
    Not applicable

ITEM 5.    OTHER INFORMATION
    NoneDuring the quarter ended June 30, 2023, no director or “officer” (as defined in Rule 16a-1(f)) of Clean Harbors, Inc. adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408(a) of Regulation S-K.
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ITEM 6.    EXHIBITS
Item No. Description Location
31.1  Filed herewith
31.2Filed herewith
31.3  Filed herewith
32  Filed herewith
4.43EFiled herewith
101 Interactive Data Files Pursuant to Rule 405 of Regulation S-T: Financial statements from the quarterly report on Form 10-Q of Clean Harbors, Inc. for the quarterly period ended June 30, 2022,2023, formatted in iXBRL (Inline eXtensible Business Reporting Language): (i) Consolidated Balance Sheets, (ii) Unaudited Consolidated Statements of Operations, (iii) Unaudited Consolidated Statements of Comprehensive Income, (iv) Unaudited Consolidated Statements of Cash Flows, (v) Unaudited Consolidated Statements of Stockholders’ Equity and (vi) Notes to Unaudited Consolidated Financial Statements. *
104The cover page from the Company's Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2022,2023, formatted in iXBRL and contained in Exhibit 101.
_______________________
*    Interactive data files are furnished and deemed not filed or part of a registration statement or prospectus for purposes of Sections 11 or 12 of the Securities Act of 1933, as amended, are deemed not filed for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, and otherwise are not subject to liability under those sections.
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CLEAN HARBORS, INC. AND SUBSIDIARIES
SIGNATURES
    Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. 
 CLEAN HARBORS, INC.
 Registrant
 By:/s/ ALAN S. MCKIM
Alan S. McKim
Chairman, President and Chief Executive Officer
Date:August 3, 2022
By:/s/ MICHAEL L. BATTLES
  Michael L. Battles
  Co-Chief Executive Officer and Co-President
Date:August 2, 2023
By:/s/ ERIC W. GERSTENBERG
Eric W. Gerstenberg
Co-Chief Executive Officer and Co-President
Date:August 2, 2023
By:/s/ ERIC J. DUGAS
Eric J. Dugas
Executive Vice President and Chief Financial Officer
Date:August 3, 20222, 2023

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