| Commitments and Contingencies | Commitments and Contingencies Overview There are various claims and lawsuits pending against the Company. In addition, the Company is subject to federal, state, and local environmental laws and regulations and periodically participates in the investigation and remediation of various sites. In addition, the Company periodically enters into financial commitments in connection with its business operations. Also, the Company is involved in various legal and regulatory proceedings in the normal course of its business (Note 12). It is not possible at this time for the Company to determine fully the effect of all litigation and other legal and regulatory proceedings on its financial position, results of operations, or cash flows. With respect to some of the items listed below, the Company has determined that a loss is not probable or that, to the extent probable, cannot be reasonably estimated. In some cases, the Company is not able to predict with any degree of certainty the range of possible loss that could be incurred. The Company assesses legal and regulatory matters based on current information and makes judgments concerning their potential outcome, giving due consideration to the nature of the claim, the amount and nature of any damages sought, and the probability of success. Such judgments are made with the understanding that the outcome of any litigation, investigation, or other legal proceeding is inherently uncertain. In accordance with GAAP, the Company records liabilities for matters where it is probable a loss has been incurred and the amount of loss is reasonably estimable. The actual outcomes of the items listed below could ultimately differ from the judgments made and the differences could be material. The Company cannot make any assurances that the amount of reserves or potential insurance coverage will be sufficient to cover the cash obligations that might be incurred as a result of litigation or regulatory proceedings. Except as otherwise disclosed, the Company does not expect that any known lawsuits, environmental costs, and commitments will have a material effect on its financial condition, results of operations, or cash flows. Additional information concerning commitments and contingencies is contained in Note 16 of the Notes to Consolidated Financial Statements in the 2018 Annual Reports on Form 10-K. Commitments and Contingencies Related to the Environment Nuclear Spent Fuel and Waste Disposal Nuclear power plant operators are required to enter into spent fuel disposal contracts with the DOE that require the DOE to accept and dispose of all spent nuclear fuel and other high-level radioactive wastes generated by domestic power reactors. Although the Nuclear Waste Policy Act required the DOE to develop a permanent repository for the storage and disposal of spent nuclear fuel by 1998, the DOE announced that it would not be able to open the repository by 1998 and sought to excuse its performance of these requirements. In November 1997, the DC Circuit issued a decision preventing the DOE from excusing its own delay but refused to order the DOE to begin accepting spent nuclear fuel. Based on this decision and the DOE’s delay, a number of utilities, including APS (on behalf of itself and the other PVNGS owners, including PNM), filed damages actions against the DOE in the Court of Federal Claims. The lawsuits filed by APS alleged that damages were incurred due to DOE’s continuing failure to remove spent nuclear fuel and high-level waste from PVNGS. In August 2014, APS and the DOE entered into a settlement agreement that establishes a process for the payment of claims for costs incurred through December 31, 2019. Under the settlement agreement, APS must submit claims annually for payment of allowable costs. PNM records estimated claims on a quarterly basis. The benefit from the claims is passed through to customers under the FPPAC to the extent applicable to NMPRC regulated operations. PNM estimates that it will incur approximately $57.7 million (in 2016 dollars) for its share of the costs related to the on-site interim storage of spent nuclear fuel at PVNGS during the term of the operating licenses. PNM accrues these costs as a component of fuel expense as the nuclear fuel is consumed. At June 30, 2019 and December 31, 2018 , PNM had a liability for interim storage costs of $12.7 million and $12.4 million , which is included in other deferred credits. PVNGS has sufficient capacity at its on-site Independent Spent Fuel Storage Installation (“ISFSI”) to store all of the nuclear fuel that will be irradiated during the initial operating license period, which ends in December 2027. Additionally, PVNGS has sufficient capacity at its on-site ISFSI to store a portion of the fuel that will be irradiated during the period of extended operation, which ends in November 2047. If uncertainties regarding the United States government’s obligation to accept and store spent fuel are not favorably resolved, APS will evaluate alternative storage solutions that may obviate the need to expand the ISFSI to accommodate all of the fuel that will be irradiated during the period of extended operation. The Energy Transition Act On March 22, 2019, the Governor signed into New Mexico state law Senate Bill 489, known as the Energy Transition Act (“ETA”). The ETA became effective as of June 14, 2019 and sets a statewide standard that requires investor-owned electric utilities to have specified percentages of their electric-generating portfolios be provided from renewable and zero-carbon generating resources. Prior to the enactment of the ETA, the REA established a mandatory RPS requiring utilities to acquire a renewable energy portfolio equal to 10% of retail electric sales by 2011, 15% by 2015, and 20% by 2020. The ETA amends the REA and requires utilities operating in New Mexico to have renewable portfolios equal to 20% by 2020, 40% by 2025, 50% by 2030, 80% by 2040, and 100% zero-carbon energy by 2045. The ETA also amends sections of the REA to allow for the recovery of undepreciated investments and decommissioning costs related to qualifying EGUs that the NMPRC has required be removed from retail jurisdictional rates, provided replacement resources to be included in retail rates have lower or zero-carbon emissions. The ETA requires the NMPRC to review and approve utilities’ annual renewable portfolio plans to ensure compliance with the RPS. The ETA also directs the New Mexico Environmental Improvement Board to adopt standards of performance that limit CO 2 emissions to no more than 1,100 lbs. per MWh beginning January 1, 2023 for new or existing coal-fired EGUs with original installed capacities exceeding 300 MW. The ETA provides for a transition from fossil-fuel generation resources to renewable and other carbon-free resources through certain provisions relating to the abandonment of coal-fired generating facilities. These provisions include the use of “energy transition bonds,” which are designed to be highly rated bonds that can be issued to finance certain costs of abandoning coal-fired facilities that are retired prior to January 1, 2023 for facilities operated by a “qualifying utility,” or prior to January 1, 2032 for facilities that are not operated by the qualifying utility. The amount of energy transition bonds that can be issued to recover abandonment costs is limited to the lesser of $375.0 million or 150% of the undepreciated investment of the facility as of the abandonment date. Proceeds provided by energy transition bonds must be used only for purposes related to providing utility service to customers and to pay “financing costs” (as defined by the ETA). These costs may include plant decommissioning and coal mine reclamation costs provided those costs have not previously been recovered from customers or disallowed by the NMPRC or by a court order. See Note 12 for a discussion of the NM Supreme Court’s decision to affirm the NMPRC’s disallowance of certain costs, including the cost of BDT at SJGS, in PNM’s NM 2015 Rate Case. Proceeds from energy transition bonds may also be used to fund severances for employees of the retired facility and related coal mine and to promote economic development, education and job training in areas impacted by the retirement of the coal-fired facilities. Energy transition bonds must be issued under an NMPRC approved financing order, are secured by “energy transition property,” are non-recourse to the issuing utility, and must be repaid by a non-bypassable charge paid by all customers of the issuing utility. These customer charges are subject to an adjustment mechanism designed to provide for timely and complete payment of principal and interest due under the energy transition bonds. The ETA also provides that utilities must obtain NMPRC approval of competitively procured replacement resources. In determining whether to approve replacement resources, the NMPRC must give preference to resources with the least environmental impacts, those with higher ratios of capital costs to fuel costs, and those located in the school district of the abandoned facility able to reduce the cost of reclamation and use for lands previously mined within the county of the EGU to be abandoned. The ETA also provides for the procurement of energy storage facilities and gives utilities discretion to maintain and control these systems to ensure reliable and efficient service. PNM expects the ETA will have a significant impact on PNM’s future generation portfolio, including PNM’s planned retirement of SJGS in 2022. See additional discussion in Note 12 of PNM’s SJGS Abandonment Application. PNM cannot predict the full impact of the ETA or the outcome of its pending and potential future generating resource abandonment and replacement resource filings with the NMPRC. The Clean Air Act Regional Haze In 1999, EPA developed a regional haze program and regional haze rules under the CAA. The rule directs each of the 50 states to address regional haze. Pursuant to the CAA, states have the primary role to regulate visibility requirements by promulgating SIPs. States are required to establish goals for improving visibility in national parks and wilderness areas (also known as Class I areas) and to develop long-term strategies for reducing emissions of air pollutants that cause visibility impairment in their own states and for preventing degradation in other states. States must establish a series of interim goals to ensure continued progress by adopting a new SIP every ten years. In the first SIP planning period, states were required to conduct BART determinations for certain covered facilities, including utility boilers, built between 1962 and 1977 that have the potential to emit more than 250 tons per year of visibility impairing pollution. If it was demonstrated that the emissions from these sources caused or contributed to visibility impairment in any Class I area, then BART must have been installed by the beginning of 2018. For all future SIP planning periods, states must evaluate whether additional emissions reduction measures may be needed to continue making reasonable progress toward natural visibility conditions. On January 10, 2017, EPA published in the Federal Register revisions to the regional haze rule. EPA also provided a companion draft guidance document for public comment. The new rule delayed the due date for the next cycle of SIPs from 2019 to 2021, altered the planning process that states must employ in determining whether to impose “reasonable progress” emission reduction measures, and gave new authority to federal land managers to seek additional emission reduction measures outside of the states’ planning process. Finally, the rule made several procedural changes to the regional haze program, including changes to the schedule and process for states to file 5 -year progress reports. EPA’s new rule was challenged by numerous parties. On January 19, 2018, EPA filed a motion to hold the case in abeyance in light of several letters issued by EPA on January 17, 2018 to grant various petitions for reconsideration of the 2017 rule revisions. On December 20, 2018, EPA released a new guidance document on tracking visibility progress for the second planning period. EPA is allowing states discretion to develop SIPs that may differ from EPA’s guidance as long as they are consistent with the CAA and other applicable regulations. SIPs for the second compliance period are due in July 2021. EPA’s decision to revisit the 2017 rule is not a determination on the merits of the issues raised in the petitions. PNM is evaluating the potential impacts of these matters. SJGS December 2018 Compliance Filing – As discussed in Note 16 of the Notes to the Consolidated Financial Statements in the 2018 Annual Reports on Form 10-K, in December 2015 PNM received NMPRC approval for a plan to comply with the EPA regional haze rule at SJGS. Among other things, the NMPRC’s December 2015 order required that, no later than December 31, 2018, PNM make a filing with the NMRPC to determine the extent to which SJGS should continue serving PNM’s customers’ needs after June 30, 2022 (the “December 2018 Compliance Filing”). The December 2018 Compliance Filing was required to be made before PNM entered into a binding commitment for post-2022 coal supply but after PNM received firm pricing and other terms for the supply of coal at SJGS, unless PNM did not intend to pursue an agreement for post-2022 coal supply at SJGS. The NMPRC’s December 2015 order also indicated that, if SJGS Unit 4 is abandoned with undepreciated investment on PNM’s books, PNM is prohibited from recovering the undepreciated investment of its 132 MW interest and required that PNM’s 65 MW interest in SJGS Unit 4 be treated as excluded merchant plant. PNM is currently depreciating its investments in SJGS through 2053, which reflects the period of time over which the NMPRC has authorized PNM to recover its investment in SJGS from New Mexico retail customers. PNM submitted the December 2018 Compliance Filing to the NMPRC on December 31, 2018 indicating that, consistent with the conclusions reached in PNM’s 2017 IRP, PNM’s customers would benefit from the retirement of PNM’s share of SJGS after the current SJGS CSA expires in mid-2022 (Note 12). The December 2018 Compliance Filing also indicated that, pursuant to the terms of the agreements governing SJGS, all of the SJGS owners except for Farmington provided written notice that they do not intend to extend the SJGS operating agreements beyond their June 30, 2022 expiration dates, and that PNM has provided written notice to SJCC that PNM does not intend to extend the SJGS CSA beyond June 30, 2022. On January 30, 2019, the NMPRC issued an order initiating a proceeding and requiring PNM to submit an application for the abandonment of PNM’s share of SJGS by March 1, 2019. PNM filed a motion requesting the NMPRC vacate the January 30, 2019 order, which was deemed denied. On February 27, 2019, PNM filed a petition with the NM Supreme Court stating that the requirements of the January 30, 2019 order exceed the NMPRC’s authority by, among other things, mandating PNM to make a filing that is legally voluntary, and that the order is contrary to NMPRC precedent which requires abandonment applications to also include identified replacement resources and other information that would not be available to PNM by March 1, 2019. On March 1, 2019, the NM Supreme Court granted a temporary stay of the NMPRC’s order. Various parties intervened in the petition. On June 26, 2019, the NM Supreme Court lifted the stay, denied PNM’s petition without discussion, and vacated oral arguments that had been scheduled for July 9, 2019. See additional discussion of PNM’s July 1, 2019 SJGS Abandonment Application in Note 12. GAAP requires that long-lived assets be tested for impairment when events or changes in circumstances indicate that their carrying value may not be recoverable. As of December 31, 2018, PNM evaluated the events surrounding its future participation in SJGS and determined that it is more likely than not that PNM’s share of SJGS will be retired in 2022. As a result, PNM performed an impairment analysis that assumed SJGS would not continue to operate through 2053, as previously approved by the NMPRC. PNM’s impairment analysis indicated that, pursuant to the NMPRC’s December 2015 order, PNM’s undepreciated 132 MW interest in SJGS Unit 4 at June 30, 2022 will not be recovered from customers; that the estimated future cash flows expected to result from the operation of SJGS Unit 4 through June 30, 2022 are not sufficient to provide for recovery of PNM’s 65 MW merchant interest in the facility; and that it is unlikely PNM will be able to sell or transfer its interests in SJGS to third parties at amounts sufficient to provide for their recovery. As a result, as of December 31, 2018, PNM recorded a pre-tax impairment of its investment in SJGS of approximately $35.0 million , which is reflected as regulatory disallowances and restructuring costs on the Consolidated Statements of Earnings in the 2018 Annual Reports on Form 10-K. This amount includes the entire $11.9 million carrying value of PNM’s 65 MW interest in SJGS Unit 4 as of December 31, 2018 and $23.1 million of estimated undepreciated investments in PNM’s 132 MW jurisdictional interest as of June 30, 2022 that will not be recovered from customers. As of June 30, 2019 and December 31, 2018, the net book value of PNM’s investments in SJGS are $364.6 million and $373.6 million . See additional discussion below regarding the increase in PNM’s estimated liability for coal mine reclamation. NEE Complaint – On March 31, 2016, NEE filed a complaint with the NMPRC alleging that PNM failed to comply with its discovery obligation in the case authorizing the shutdown of SJGS Units 2 and 3 and requesting the NMPRC investigate whether financing provided by NM Capital to the former owner of SJCC (the “Westmoreland Loan”) could adversely affect PNM’s ability to provide electric service to its retail customers. On January 31, 2018, NEE filed a motion asking the NMPRC to investigate whether PNM’s relationship with the former owner of SJCC could be harmful to PNM’s customers. On May 23, 2018, PNM filed its response to the NMPRC staff’s comments noting that the Westmoreland Loan was paid in full on May 22, 2018. On October 11, 2018, PNM notified the NMPRC that the former owner of SJCC, Westmoreland, had filed voluntary petitions for relief under Chapter 11 of the U.S. Bankruptcy Code. As discussed in Note 6, on March 15, 2019, Westmoreland announced that it had emerged from Chapter 11 bankruptcy as a privately held company owned and operated by a group of its former creditors. Under the reorganization, all the assets of SJCC were sold to WSJ LLC. As successor entity to SJCC, WSJ LLC assumed all rights and obligations of Westmoreland including obligations to PNM under the SJGS CSA. The NMPRC has taken no further action on NEE’s complaints. PNM cannot predict if the NMPRC will take any further action on these matters or the potential outcome. Four Corners Four Corners Federal Agency Lawsuit – On April 20, 2016, several environmental groups filed a lawsuit against OSM and other federal agencies in the United States District Court for the District of Arizona in connection with their issuance of the approvals that extended the life of Four Corners and the adjacent mine. The lawsuit alleges that these federal agencies violated both the ESA and NEPA in providing the federal approvals necessary to extend operations at Four Corners and the adjacent mine past July 6, 2016. The court granted an APS motion to intervene in the litigation. On September 15, 2016, NTEC, the current owner of the mine providing coal to Four Corners, filed a motion to intervene for the limited purpose of seeking dismissal of the lawsuit based on NTEC’s tribal sovereign immunity. On September 11, 2017, the court granted NTEC’s motion and dismissed the case with prejudice, terminating the proceedings. The environmental group plaintiffs filed a Notice of Appeal of the dismissal in the United States Court of Appeals for the Ninth Circuit on November 9, 2017, and the court granted their subsequent motion to expedite the appeal. Oral arguments for the appeal were held on March 7, 2019. On July 29, 2019, the Ninth Circuit issued a decision affirming the District Court’s dismissal of the case. PNM cannot predict if parties to the lawsuit will appeal this decision. Carbon Dioxide Emissions On August 3, 2015, EPA established standards to limit CO 2 emissions from power plants. EPA took three separate but related actions in which it: (1) established the carbon pollution standards for new, modified, and reconstructed power plants; (2) established the Clean Power Plan to set standards for carbon emission reductions from existing power plants; and (3) released a proposed federal plan associated with the final Clean Power Plan. The Clean Power Plan was published on October 23, 2015. Multiple states, utilities, and trade groups filed petitions for review in the DC Circuit to challenge both the Carbon Pollution Standards for new sources and the Clean Power Plan for existing sources. Numerous parties also simultaneously filed motions to stay the Clean Power Plan during the litigation. On January 21, 2016, the DC Circuit denied petitions to stay the Clean Power Plan, but 29 states and state agencies successfully petitioned the US Supreme Court for a stay, which was granted on February 9, 2016. The decision means the Clean Power Plan is not in effect and neither states nor sources are obliged to comply with its requirements. With the US Supreme Court stay in place, the DC Circuit heard oral arguments on the merits of the Clean Power Plan on September 27, 2016 in front of a ten judge en banc panel. However, before the DC Circuit could issue an opinion, the Trump Administration asked that the case be held in abeyance while the rule was being re-evaluated, which was granted. On March 28, 2017, President Trump issued an Executive Order on Energy Independence. The order put forth two general policies: promote clean and safe development of energy resources, while avoiding regulatory burdens, and ensure electricity is affordable, reliable, safe, secure, and clean. The order directed the EPA Administrator to review and, if appropriate and consistent with law, suspend, revise, or rescind (1) the Clean Power Plan, (2) the New Source Performance Standards (“NSPS”) for GHG from new, reconstructed, or modified electric generating units, (3) the Proposed Clean Power Plan Model Trading Rules, and (4) the Legal Memorandum supporting the Clean Power Plan. It also directed the EPA Administrator to notify the US Attorney General of his intent to review rules subject to pending litigation so that the US Attorney General may notify the court and, in his discretion, request that the court delay further litigation pending completion of the reviews. In response to the Executive Order, EPA filed a petition with the DC Circuit requesting the cases challenging the Clean Power Plan be held in abeyance until after the conclusion of EPA’s review and any subsequent rulemaking, which was granted. In addition, the DC Circuit issued a similar order in connection with a motion filed by EPA to hold cases challenging the NSPS in abeyance. On October 10, 2017, EPA issued a NOPR proposing to repeal the Clean Power Plan and filed its status report with the court requesting the case be held in abeyance until the completion of the rulemaking on the proposed repeal. The NOPR proposed a legal interpretation concluding that the Clean Power Plan exceeded EPA’s statutory authority. On August 31, 2018, EPA published a proposed rule, informally known as the Affordable Clean Energy rule, to replace the Clean Power Plan. On June 19, 2019, EPA released the final version of the Affordable Clean Energy rule. EPA takes three actions in the final rule: (1) finalizes the repeal of the Clean Power Plan; (2) finalizes the Affordable Clean Energy rule; and (3) revises the implementing regulations for all emission guidelines issued under Clean Air Act Section 111(d), which among other things, extends the timing of state plans. The final rule is very similar to the August 2018 proposed rule. EPA set the Best System of Emissions Reduction (“BSER”) for existing coal-fired power plants as heat rate efficiency improvements based on a range of "candidate technologies" that can be applied inside the fence-line. Rather than setting a specific numerical standard of performance, EPA's rule directs states to determine which of the candidate technologies to apply to each coal-fired unit and establish standards of performance based on the degree of emission reduction achievable based on the application of BSER. States will have three years from when the rule is finalized to submit a plan to EPA and then the EPA has one year to approve the plan. If states do not submit a plan or their submitted plan is not acceptable, EPA will have two years to develop a federal plan. While corresponding NSR reform regulations were proposed as part of the EPA’s Affordable Clean Energy proposal, the final rule did not include such reform measures. EPA announced that it will be taking final action on the NSR reform proposal for EGUs in the near future. The Affordable Clean Energy rule is not expected to impact SJGS since EPA’s final approval of a state SIP would occur after the planned shutdown of SJGS in 2022 (subject to NMPRC approval). Since the Navajo Nation does not have primacy over its air quality program, EPA would be the regulatory authority responsible for implementing the Affordable Clean Energy rule on the Navajo Nation. PNM is currently reviewing the requirements of the Affordable Clean Energy rule and is unable to predict the potential financial or operational impacts on Four Corners. On December 20, 2018, EPA published in the Federal Register a proposed rule that would revise the carbon pollution standards rule published in October 2015 for fossil fueled power plants. The proposed rule would revise the standards for coal- fired units based on a revised BSER determination that would result in less stringent CO 2 emission performance standards for new, reconstructed, and modified fossil-fueled power plants. EPA is not proposing any changes nor reopening the standards of performance for newly constructed or reconstructed stationary combustion turbines. Comments on the proposal were due on March 18, 2019. PNM’s review of the GHG emission reductions standards under the Affordable Clean Energy rule and the revised proposed carbon pollution standards rule is ongoing. The Affordable Clean Energy rule has been challenged by several parties and may be impacted by further litigation. As discussed above, SJGS and Four Corners may also be required to comply with additional GHG restrictions issued by the New Mexico Environmental Improvement Board pursuant to the recently enacted ETA. PNM cannot predict the impact these standards may have on its operations or a range of the potential costs of compliance, if any. National Ambient Air Quality Standards (“NAAQS”) The CAA requires EPA to set NAAQS for pollutants reasonably anticipated to endanger public health or welfare. EPA has set NAAQS for certain pollutants, including NOx, SO 2 , ozone, and particulate matter. In 2010, EPA updated the primary NOx and SO 2 NAAQS to include a 1-hour standard while retaining the annual standards for NOx and SO 2 and the 24-hour SO 2 standard. EPA also updated the final particulate matter standard in 2012 and updated the ozone standard in 2015. NOx Standard – On April 18, 2018, EPA published the final rule to retain the current primary health-based NOx standards of which NO 2 is the constituent of greatest concern and is the indicator for the primary NAAQS. EPA concluded that the current 1-hour and annual primary NO 2 standards are requisite to protect public health with an adequate margin of safety. The rule became effective on May 18, 2018. SO 2 Standard – On May 13, 2014, EPA released the draft data requirements rule for the 1-hour SO 2 NAAQS, which directs state and tribal air agencies to characterize current air quality in areas with large SO 2 sources to identify maximum 1-hour SO 2 concentrations. This characterization would result in these areas being designated as attainment, nonattainment, or unclassifiable for compliance with the 1-hour SO 2 NAAQS. On March 2, 2015, the United States District Court for the Northern District of California approved a settlement that imposed deadlines for EPA to identify areas that violate the NAAQS standards for 1-hour SO 2 emissions. The settlement resulted from a lawsuit brought by Earthjustice on behalf of the Sierra Club and the Natural Resources Defense Council under the CAA. The consent decree required, among other things, that EPA must issue designations for areas for which states have adopted a new monitoring network under the proposed data requirements rule by December 2020. EPA regions sent letters to state environmental agencies explaining how EPA plans to implement the consent decree. The letters outline the schedule that EPA expects states to follow in moving forward with new SO 2 non-attainment designations. NMED did not receive a letter. On August 11, 2015, EPA released the Data Requirements Rule for SO 2 , telling states how to model or monitor to determine attainment or nonattainment with the new 1-hour SO 2 NAAQS. On June 3, 2016, NMED notified PNM that air quality modeling results indicated that SJGS was in compliance with the standard. In January 2017, NMED submitted its formal modeling report regarding attainment status to EPA. The modeling indicated that no area in New Mexico exceeds the 1-hour SO 2 standard. On June 27, 2018, NMED submitted the first annual report for SJGS as required by the Data Requirements Rule. The report recommends that no further modeling is warranted at this time due to decreased SO 2 emissions. On February 25, 2019, EPA announced its final decision to retain without changes the primary health-based NAAQS for SOx. Specifically, EPA will retain the current 1-hour standard for SO 2 , which is 75 parts per billion (“ppb”), based on the 3 -year average of the 99th percentile of daily maximum 1-hour SO 2 concentrations. SO 2 is the most prevalent SOx compound and is used as the indicator for the primary SOx NAAQS. On May 14, 2015, PNM received an amendment to its NSR air permit for SJGS, which reflects the revised state implementation plan for regional haze BART and required the installation of SNCRs. The revised permit also required the reduction of SO 2 emissions to 0.10 pound per MMBTU on SJGS Units 1 and 4 and the installation of BDT equipment modifications for the purpose of reducing fugitive emissions, including NOx, SO 2, and particulate matter. These reductions help SJGS meet the NAAQS for these constituents. The BDT equipment modifications were installed at the same time as the SNCRs, in order to most efficiently and cost effectively conduct construction activities at SJGS. See a discussion of the regulatory treatment of BDT in Note 12. Ozone Standard – On October 1, 2015, EPA finalized the new ozone NAAQS and lowered both the primary and secondary 8-hour standard from 75 to 70 ppb. With ozone standards becoming more stringent, fossil-fueled generation units will come under increasing pressure to reduce emissions of NOx and volatile organic compounds since these are the pollutants that form ground-level ozone, and to generate emission offsets for new projects or facility expansions located in nonattainment areas. On November 10, 2015, EPA proposed a rule revising its Exceptional Events Rule, which outlines the requirements for excluding air quality data (including ozone data) from regulatory decisions if the data is affected by events outside an area’s control. The proposed rule is important in light of the more stringent ozone NAAQS final rule since western states like New Mexico and Arizona are subject to elevated background ozone transport from natural local sources, such as wildfires, and transported via winds from distant sources, such as the stratosphere or another region or country. On February 25, 2016, EPA released guidance on area designations for ozone, which states used to determine their initial designation recommendations by October 1, 2016. NMED published its 2015 Ozone NAAQS Designation Recommendation Report on September 2, 2016 and recommended designation of a small area in southern Dona Ana County as n |
