EPA offers two options for regional haze compliance at two Utah coal plants

Air quality in Utah’s five national parks and others in neighboring states could improve significantly in the coming years if the U.S. Environmental Protection Agency ultimately chooses to require installation of industry-standard pollution controls on the two oldest and dirtiest coal-burning power plants in the state, said the Sierra Club in a Dec. 17 statement.

Late on Dec. 16, EPA released a draft plan with two separate options for dealing with NOx emissions from two coal-burning power plants. By far, the most effective of the two options proposed by the EPA to cut down on haze would require selective catalytic reduction (SCR) for PacifiCorp d/b/a Rocky Mountain Power’s Hunter and Huntington coal plants, the club said. The second option is a plan previously adopted by the state of Utah for a less costly alternative.

A coalition of health, clean air and national park advocates who have pushed for strong clean air protections in Utah said there is no comparison between the alternatives. The only option that offers a path to meaningful improvements to haze problems in Utah’s national parks, according to the groups, is the one requiring SCR on Hunter and Huntington.

“While EPA has presented two proposals for public comment, there is only one choice for clearing the air in eight of our most prized national parks, including Canyonlands, Arches and Bryce Canyon” said Cory MacNulty, a senior program manager for National Parks Conservation Association. “Only one option would cut roughly 80 percent of the nitrogen oxide pollution coming from four units at the Hunter and Huntington coal plants. The state’s alternative would cut none.”

Notable is that the word “none” is an overstatement, since the state plan does call for a lesser level of NOX reductions from these four units.

This draft plan will soon be out for public comment

The 165-page draft rule issued Dec. 16 will soon be published in the Federal Register, with 60 days of comment to then be taken on it. EPA’s choice is whether to entirely accept a State Implementation Plan (SIP) filed by Utah, or partially accept and partially reject the SIP. The rejection would be of the status quo NOx approach for Hunter and Huntington.

EPA is proposing to approve, under one of the options, these aspects of the state’s June 4, 2015 SIP submittal:

  • NOX best available retrofit technology (BART) alternative, including NOX emission reductions from Hunter Units 1, 2, and 3, Huntington Units 1 and 2, and Carbon Units 1 and 2, and SO2 and PM10 emission reductions from Carbon Units 1 and 2. Notable is that PacifiCorp earlier this year retired the small Carbon coal plant to meet EPA’s Mercury and Air Toxics Standards.
  • BART determinations and emission limits for PM10 at Hunter Units 1 and 2 and Huntington Units 1 and 2.
  • Monitoring, recordkeeping, and reporting requirements for units subject to the BART alternative and the PM10 emission limits.

EPA is proposing to approve these elements of the state’s Oct. 20, 2015 SIP submittal:

  • Enforceable commitments to revise applicable rules by March 2018 to clarify emission inventory requirements for tracking compliance with the SO2 milestone and properly accounting for the SO2 emission reductions due to the closure of the Carbon plant.

As part of the option to partially accept and partially reject the SIP, with the replacement parts covered by a proposed Federal Implementation Plan (FIP), EPA is proposing to approve these elements of the state’s SIP submittals:

  • BART determinations and emission limits for PM10 at Hunter Units 1 and 2, and Huntington Units 1 and 2.
  • Monitoring, recordkeeping, and reporting requirements for units subject to the PM10 emission limits.

EPA is proposing to disapprove these aspects of the state’s June 4, 2015 SIP:

  • NOX BART alternative, including NOX emission reductions from Hunter Units 1, 2, and 3, Huntington Units 1 and 2, and Carbon Units 1 and 2, and SO2 and PM10 emission reductions from Carbon Units 1 and 2.

EPA is proposing to disapprove the state’s Oct. 20, 2015 SIP submittal.

The federal agency is proposing promulgation of a FIP to address the deficiencies in the Utah regional haze SIPs that are identified in this notice. The proposed FIP includes the following elements:

  • NOX BART determinations and emission limits for Hunter Units 1 and 2 and Huntington Units 1 and 2.
  • Monitoring, recordkeeping, and reporting requirements for NOX at Hunter Units 1 and 2, and Huntington Units 1 and 2.

The state may submit a SIP revision to supersede the FIP, EPA noted.

State plan counts on Carbon plant shutdown, lesser level of NOx controls

PacifiCorp’s Hunter plant is located in Castle Dale, Utah, and consists of three electric utility steam generating units. Of the three units, only Units 1 and 2 are subject to BART. Hunter Units 1 and 2 have a nameplate generating capacity of 488.3 MW each. The boilers are tangentially fired pulverized coal boilers burning bituminous coal from Utah.

PacifiCorp’s Huntington plant is located in Huntington City, Utah, and consists of two electric utility steam generating units. Huntington Units 1 and 2 have a nameplate generating capacity of 498 MW each. The boilers are tangentially fired pulverized coal boilers burning bituminous coal from Utah.

Utah’s BART alternative consists of the shutdown of Carbon Units 1 and 2 and the installation of upgraded NOX combustion controls, which are new low-NOX burners (LNB) and overfire air (OFA), on Hunter Unit 3 (the non-BART unit). The Utah BART alternative also includes the NOX reductions from installation of upgraded combustion controls (new LNB and separated overfire air (SOFA)) at Hunter Units 1 and 2 and Huntington Units 1 and 2 (the BART units).

The BART Benchmark includes the four BART units with combustion controls and SCR, Carbon’s baseline emissions, and Hunter Unit 3’s emissions with original combustion controls.

EPA noted: “Utah cited PacifiCorp’s comments on the State’s proposed SIP revision that the BART Alternative not only produces greater reasonable progress, including lower emissions and improved visibility, but that it does so at a significant capital cost savings to PacifiCorp and its customers as compared to the BART Benchmark. Utah acknowledged that it did not officially determine the cost of installing SCR on the four BART units, but that it believed the cost of installing SCR would be significant. On the other hand, Utah noted that the Carbon Plant has already been closed due to the high cost of complying with the MATS rule. Utah explained that the costs to Utah rate payers (and those in other states served by PacifiCorp) to replace the power generated by the Carbon Plant have already occurred; there will be no additional cost to achieve the co-benefit of visibility improvement. As a result, Utah asserted that the BART Alternative not only achieves better visibility improvements than would be achieved by requiring SCR as BART at the four EGUs, but at a significantly lower cost.”

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.