Muscatine seeks approval for new SO2 limits at coal-fired power plant

The Iowa Department of Natural Resources (IDNR) will be taking comment until Oct. 26 on a draft air quality construction permit that would allow Muscatine Power and Water to get into attainment at its coal-fired power plant.

The proposed permitting actions are the modifications to the existing air construction permits for Unit 6, Unit 7, Unit 8 and Unit 9 boilers to establish SO2 emission limitations in response to the nonattainment designation for a portion of Muscatine County published in the Federal Register in August 2013. The nonattainment designation is for the 1-hour SO2 primary national ambient air quality standard promulgated in 2010. The DNR intends to submit the proposed actions to the U.S. Environmental Protetion Agency for inclusion in the State Implementation Plan to address Clean Air Act requirements for nonattainment areas.

The public comment period for these proposed permitting actions will be from Sept. 24 to Oct. 26.

The proposed permitting actions are the modification of Unit 6 Boiler (EU60), Unit 7 Boiler (EU70), Unit 8 Boiler (EU80) and Unit 9 Boiler (EU90) existing air construction permits to establish SO2 emission limitations. The June 3 application shows that the allowed fuels by unit are: EU60 (gas/oil); EU70 (gas/coal); EU80 (gas/coal); and EU90 (oil/coal).

Under the draft air permitting, the SO2 emission limit for Unit 60 is established as a pound per hour limit and compliance with the 1-hr SO2 limit is determined by fuel sampling or fuel certification. The SO2 emission limit for Unit 70, Unit 80 and Unit 90 is established as a pound per hour limit, with compliance to be determined on a 21-day rolling average basis. The boilers are not being physically modified as part of these proposed permitting actions. Only a potential SO2 emission limit is being established across Unit 60, Unit 70, Unit 80 and Unit 90.

Muscatine Power and Water (MP&W) indicated in its June 3 application that would like these new limits to go into effect in 2017, giving it time to line up an unspecified new coal supply for the plant that would help it with compliance with these new SO2 limits.

U.S. Energy Information Administration data shows that the primary coal supplier to Muscatine in the first five months of this year was Kiewit Mining‘s Buckskin mine in the Wyoming Powder River Basin, with some coal also coming from the Belle Ayr mine of Alpha Natural Resources, which is also located in the Wyoming end of the PRB.

Municipal also moving forward on MATS compliance

During a special meeting on July 17, MP&W’s Board of Water, Electric, and Communications Trustees met to review staff’s analysis regarding proceeding with a project to install previously purchased mercury control systems and equipment necessary for compliance with the Mercury and Air Toxics Standards (MATS) for MP&W’s power generating Units 8 and 9.

Updates were provided by Gage Huston, Director of Power Production and Supply, and Brandy Olson, Director of Legal and Regulatory Affairs. “Due to an original compliance date of April 2015 (MP&W has compliance date extension until April 2016), many companies have already implemented MATS compliance investments; further most legal and industry experts expect both the EPA and Court will favor leaving existing compliance dates in place while the EPA reconsiders the MATS rule versus vacating the rule entirely,” Olson advised the Board.

“The risks of delaying the decision are far more burdensome than the benefits of potentially saving capital dollars on the installation of the systems. Staff recommends that the powdered activated carbon (PAC) system for Units 8 and 9 be installed and commissioned as originally scheduled so that the Utility will meet the April 16, 2016 compliance deadline,” said Huston.

According to Huston: “Utilizing a combination of Refined Coal (currently in place and operating) and Powdered Activated Carbon (PAC) injection, MP&W can achieve the mercury emission targets set forth in the MATS rule. Through the combination of these control technologies, MP&W expects to reduce mercury emissions from its Units 8 and 9 boilers by 75-85% from baseline levels.”

The board approved a revised budget for the Unit 8 project and the award of a contract to TEI Construction Services Inc. in the amount of $1,073,888 for the installation of the previously purchased systems on Units 8 and 9. Installation should be completed in December 2015, which provides MP&W several months to ensure the equipment operates and produces the reductions expected in time for the April 2016 compliance date.

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.