Enviro groups battle Minnesota Power plan for Boswell 4 retrofit

The Minnesota Center for Environmental Advocacy, on behalf of over 100 Minnesota citizens, on April 24 filed a request for an Environmental Assessment Worksheet for Minnesota Power’s proposal to spend $350m to retrofit emissions controls on the coal-fired Boswell Energy Center Unit 4.

Under Minnesota law, the environmental and human health impacts of major decisions such as this must be studied and the information must be provided to the public, the groups noted in an April 24 statement.

“Continuing to burn coal at Boswell 4 will mean more air and water pollution in Minnesota for decades to come” said Kevin Reuther, Legal Director at the advocacy center. “We are petitioning on behalf of Minnesota citizens today to ask for a study of the environmental and human health impacts of this $350 million investment before state agencies take action on the project. Minnesotans deserve to know the full environmental and public health impact of this project”

Without the proposed pollution controls, the 585-MW unit would need to be retired or replaced in 2016. With the extension, the unit will continue to operate until at least 2036, the groups noted. Besides Boswell Energy Center, the plant is also known as Clay Boswell.

“Minnesota spends billions of dollars every year importing coal from out-of-state,” said Jessica Tritsch, Organizer with the Sierra Club Beyond Coal to Clean Energy campaign in Minnesota. “Installing pollution controls at old coal plants keeps us tied to a fuel of the past. Instead of spending $350 million of customer dollars to extend the life of an old coal plant, Minnesota Power should be investing in more renewable energy and energy efficiency in northern Minnesota.”

The few alternatives described in Minnesota Power’s plan for this project were evaluated based on economic and system benefits. Neither Minnesota Power nor the state Public Utilities Commission has provided any analysis of the environmental and human health impacts of the project as compared to alternatives, the groups claimed.

Environmental organizations will also be submitting comments on the Minnesota Pollution Control Agency’s draft air permit for Minnesota Power’s Boswell 4 project, including a discussion on the need for “adequate” environmental review.

Minnesota agency still working on air permitting for this project

The Minnesota Pollution Control Agency recently added an extra public comment period, April 18-24, on a draft air permit amendment for the Boswell 4 project. MPCA originally set a Feb. 28-March 29 comment period on the draft, but it couldn’t honor a Freedom of Information Act request from a commenter in time for that party to file comments by the original deadline, thus the decision for an extra comment period.

“The Permittee proposes a multi-pollutant air pollution control retrofit project at Unit #4 to reduce mercury, particulate matter, SO2, and hazardous air pollutants,” said an agency support document. “The project includes a new semi-dry flue gas desulfurization system (semi-dry FGD or ‘FGD’) and fabric filter baghouse for SO2 and particulate matter removal. The desulfurization and fabric filter baghouse are integrated into one control device (CE 030). A powder activated carbon injection (ACI) system (CE 031) for mercury removal will also be installed. Lastly, new dry ash handling and transport infrastructure will be constructed to convey waste product generated from the CDS/fabric filter process to onsite storage and disposal. This permit action requires the Permittee to revise the fugitive emissions control plan because the project changes the characteristic of Unit #4 fly ash from a wet waste material to a dry waste material.”

Minnesota Power operates the Boswell Energy Center. The facility is a coal-fired steam generating plant. Emission units include four power boilers, emergency engine generators, and fuel, additive, and ash handling equipment. Boilers 1 and 2 emissions are controlled by fabric filter baghouses, over-fire air, and selective non-catalytic reduction. Boiler 3 emissions are controlled by low NOX burners (LNB), overfire air, selective catalytic reduction, a baghouse fabric filter, and a flue gas desulfurization system. Boiler 4 (also referred to as Unit #4, Power Boiler #4, and EU 004) emissions are controlled by a wet venturi scrubber/electrostatic precipitator, selective non-catalytic reduction, a sulfur dioxide spray tower, separated over-fire air, and LNB.

Minnesota Power said in a recent integrated resource plan that it plans to invest $350m in additional environmental controls at the Boswell Unit 4, the company’s newest, largest and most efficient unit, to retain reliability and reduce mercury emissions by 90%. The upgrades will comply with the Minnesota Mercury Emission Reduction Act and the EPA’s Mercury and Air Toxics Standards (MATS).

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.