Feds works out deal with Four Corners co-owners on new air emissions controls

The U.S. Environmental Protection Agency (EPA) and the U.S. Department of Justice on June 24 announced a federal Clean Air Act settlement with several Arizona- and New Mexico-based utility companies to install pollution control technology on the coal-fired Four Corners Power Plant, located on the Navajo Nation near Shiprock, New Mexico.

The settlement requires an estimated $160 million in upgrades to the plant’s SO2 and NOx controls. The settlement also requires $6.7 million to be spent on three health and environmental mitigation projects for tribal members and payment of a $1.5 million civil penalty. EPA expects that the actions required by the settlement will reduce harmful emissions by approximately 5,540 tons per year.

“All power plants should be using the latest air pollution control technology,” said Cynthia Giles, assistant administrator for EPA’s Office of Enforcement and Compliance Assurance. “The law requires companies to protect clean air, and those living nearby – like Navajo communities – expect it. In addition to installing pollution controls, Arizona Public Service will also take the responsible steps to protect the health of those living near the Four Corners plant, which is one of the largest sources of harmful pollution in the country.”

“This settlement is a significant achievement for air quality and the health of the people of the Navajo Nation and the surrounding region,” said Assistant Attorney General John C. Cruden for the Justice Department’s Environment and Natural Resources Division. “The agreement will require stringent pollution controls as well as public health and environmental projects that will have lasting benefits for the Navajo people.”

“This settlement will reduce pollution from the Four Corners Power Plant for years to come, and requires the Plant’s owners to fund significant health and environmental projects that will further benefit the Navajo Nation and other communities impacted by the Plant,” said New Mexico U.S. Attorney Damon P. Martinez. “We also applaud the efforts of the citizen groups and other co-plaintiffs who helped represent the interests of the Navajo people and the environment so well, and who contributed significantly to obtaining such a fine result for the Four Corners Region.”

Arizona Public Service (APS) is the operator and primary owner of the Four Corners Plant. El Paso Electric, Public Service Co. of New Mexico, Salt River Project Agricultural Improvement and Power District and Tucson Electric Power are current co-owners of the plant and Southern California Edison is a former co-owner of the plant. The settlement resolves claims that the companies violated the New Source Review provisions of the federal Clean Air Act by unlawfully modifying the Four Corners plant without obtaining required permits or installing and operating the best available air pollution control technology.

The pollution controls for NOx required by the settlement improve on the Selective Catalytic Reduction controls for the Four Corners plant finalized by EPA in 2012 under the Clean Air Act’s regional haze program. The current controls for SO2 will be upgraded to increase their efficiency. These additional upgrades will reduce SO2 emissions by approximately 4,653 tons per year and NOx emissions by approximately 887 tons per year.

This settlement is part of EPA’s national enforcement initiative to control harmful emissions from large sources of pollution, which includes coal-fired power plants, under the Clean Air Act’s Prevention of Significant Deterioration requirements. The total combined SO2 and NOx emission reductions secured from all these settlements will exceed 2 million tons each year, once all the required pollution controls are installed and implemented.

Citizen groups including Diń́é Citizens Against Ruining Our Environment, To’ Nizhoni Ani and National Parks Conservation Association are co-plaintiffs to the settlement and will simultaneously be resolving their own currently pending lawsuit against the companies. The settlement was lodged with the U.S. District Court for the District of New Mexico and is subject to a 30-day public comment period and final court approval.

Four Corners plant consisted of five coal-fired units (designated as Unit 1, Unit 2, Unit 3, Unit 4, and Unit 5) with a combined capacity of 2,070 MW. It is located near Farmington, New Mexico. Units 1, 2, and 3 are owned by APS, and were shut down effective Dec. 30, 2013, due to regional haze restrictions. Units 4 and 5 are getting SCRs and will stay in operation over the long term.

Decree sets new NOX and SO2 limits for remaining coal units

Said the consent decree: “Owner Defendants shall install and commence Continuous Operation of an SCR on either FCPP Unit 4 or FCPP Unit 5 by no later than March 31, 2018. Commencing no later than 30 Operating Days thereafter, Owner Defendants shall Continuously Operate the SCR installed on the Unit selected pursuant to this Paragraph 52 so as to achieve and maintain a 30­ Day Rolling Average NOx Emission Rate of no greater than 0.080 lb/mmBtu, subject to the petition process in Paragraph 54.

“Owner Defendants shall install and commence Continuous Operation of an SCR on the FCPP Unit not selected pursuant to Paragraph 52 by no later than July 31, 2018. Commencing no later than 30 Operating Days thereafter, Owner Defendants shall Continuously Operate the SCR installed on such Unit so as to achieve and maintain a 30-Day Rolling Average NOx Emission Rate of no greater than 0.080 lb/mmBtu, subject to the petition process in Paragraph 54.”

“Beginning on the Date of Entry of this Consent Decree, Owner Defendants shall Continuously Operate the existing FGDs at FCPP Unit 4 and Unit 5 so as to emit SO2 from FCPP at an amount no greater than 10.0% of the potential combustion concentration assuming all of the sulfur in the coal is converted to SO2. Compliance with this emissions standard shall be determined on a rolling 365-Operating Day basis using the applicable methodologies set forth in [federal regulations]. The first day for determining compliance with this emissions standard shall be 365 Days after the Date of Entry of this Consent Decree. The requirements of this Paragraph 60 shall remain in effect until Owner Defendants achieve compliance with the requirements set forth in Paragraphs 61 and 62.

“By no later than March 31, 2018, Owner Defendants shall convert the existing ductwork and stack at either FCPP Unit 4 or FCPP Unit 5 to a Wet Stack, so as to eliminate the need to bypass flue gas around the FGD absorbers for reheat purposes. Commencing no later than 30 Operating Days thereafter, Owner Defendants shall Continuously Operate the existing FGD at the FCPP Unit selected pursuant to this Paragraph 61 so as to achieve and maintain a 30­ Day Rolling Average SO2 Removal Efficiency of at least 95.0%.

“By no later than July 31, 2018, Owner Defendants shall convert the existing ductwork and stack at the FCPP Unit not selected pursuant to Paragraph 61 to a Wet Stack, so as to eliminate the need to bypass flue gas around the FGD absorbers for reheat purposes. Commencing no later than 30 Operating Days thereafter, Owner Defendants shall Continuously Operate the existing FGD at such Unit so as to achieve and maintain a 30-Day Rolling Average SO2 Removal Efficiency of at least 95.0%.”

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.