Biomass Incinerator Fined for Pollution

June 4, 2013. Source: Thomas Content, The Journal Sentinel

The operator of a biomass power plant on the Mississippi River in Cassville will pay $150,000 to settle air pollution violations at the plant in recent years.

The fine was announced by state Attorney General J.B. Van Hollen after a stipulation to settle air pollution violations by the Department of Natural Resources. The operator of the plant, DTE Stoneman LLC, and the Department of Justice signed the agreement in Grant County circuit court.

DTE Energy Services of Ann Arbor, Mich., bought the plant in 2008 and converted it from burning coal to burning renewable wood waste and other forms of biomass. The biomass sources for power generation include green wood residue from forestry and tree trimming operations, railroad ties and demolition waste.

According to the complaint, DTE Stoneman had operated the plant in violation of its air pollution control permit and failed to build the facility into accordance with the application that was approved by the state Department of Natural Resources.

The plant began operating as a biomass power plant in 2010, selling its power to Dairyland Power Cooperative of La Crosse. The complaint also said the power plant failed to operate an air pollution control device to control small particle emissions during plant startups between Aug. 30, 2010, and Jan. 5, 2011. The complaint says fires took place "on multiple occasions" at the power plant's biomass storage piles, in violation of the state's open burning laws.

A DNR warden saw dust from the plant at Cassville's high school and elementary school, as well as nearby homes and businesses, according to the complaint. Small particles are a public health concern because they can affect the heart and the lung and cause serious health effects, according to the DNR.

Randi Berris, a spokeswoman for DTE Energy, said the company disagreed with some of the DNR's initial violations but that it was pleased with the settlement. The Stoneman plant experienced mechanical and other problems during the startup and commissioning of the power plant, she said.

DTE has taken steps to improve the plant's performance, including not allowing large stockpiles of wood to build up, having vendors wet down wood that's being supplied, and replacing certain suppliers that were providing biomass that was too dusty, Berris said. "The concerns raised by the Wisconsin Department of Justice have all been addressed at this point, and we're operating in full compliance with the state's air pollution control laws," she said.