The Montana Department of Environmental Quality is taking comment until Dec. 31 on a draft air permit change allowing Montana-Dakota Utilities to add new gas-fired generators at its Lewis & Clark coal plant.
“On November 7, 2014, the Department received an application to modify Montana Dakota’s air quality permit MAQP#0691-01 to construct, operate and maintain two 9.3 mega-watt (MW) Wärtsilä natural gas reciprocating internal combustion engine (RICE) generators, an indirect fired fuel heater (gas line heater) and associated building heating, ventilating and air condition (HVAC) units for the purpose of generating electricity at the Lewis & Clark Station,” said a DEQ permit notice.
Said one permit condition: “Montana-Dakota shall limit full load operation of the two Wärtsilä natural gas RICE to a maximum of 7,940 hours per year (hr/yr) combined.”
Said another condition: “Emissions from the RICE generator sets shall be controlled with a selective catalytic reduction (SCR) system using urea as the reaction agent, and an oxidation catalyst capable of maintaining the required emission limits.”
Lewis & Clark consists of a tangential coal-fired boiler (Unit 1) capable of burning coal or natural gas and associated equipment for generation of electricity. The facility is located in Richland County, Montana. Montana-Dakota is a subsidiary of MDU Resources Group (NYSE: MDU).
The DEQ noted: “The Montana-Dakota Lewis & Clark Station shall operate two Wärtsilä natural gas RICE generator sets as peaking units to provide Montana-Dakota with additional generating resources to help meet its customers peak load requirements as well as providing reliability support to the region as a result of the increased peak electric demand in the areas around the Bakken oilfields in Eastern Montana and Western North Dakota.”