E. J. Stoneman Generating Station

The E. J. Stoneman Generation Station is a coal powered electrical generation facility with a nominal output of 50MW. It was originally built by Dairyland Power Cooperative in 1951. It is located in Cassville, Wisconsin.  Various plans have been made over the years for the Stoneman Station, although none have been implemented. WPS Resources (Wisconsin Public Services, a subsidiary of Integrys Energy Group) purchased the plant in 1996 and planned a conversion to a gas fired facility as large as 300 to 500MW.

But at issue was the proximity of Cassville Municipal Airport; tall smokestacks couldn’t be built at the Stoneman Station. The conversion plan was abandoned, and in 2001 a proposal to upgrade to 200MW of coal-fired generation was substituted, with the idea that the airport could be closed to allow the upgrade to take place. This plan also fell by the wayside.

WPS later proposed an alternate plan to convert the station to 300MW of coal fired capacity but instead sold the plant to DTE Biomass Energy in 2008. While the plant is currently shut down, DTE has in mind conversion of the plant to fire it with wood waste. This would reduce the capacity to a nominal 40MW. The story of the plant came full circle with the agreement of Dairyland Power Cooperative to purchase the output of the wood waste fired facility when conversion was complete.

As an older facility, Stoneman Station has a number of issues. Stoneman burned coal to heat water and produce steam, which turned a steam turbine, driving an attached electrical generator. The steam generation cycle is associated with high temperature water and steam, and makes use of much piping. Steam turbines, piping, and related mechanical equipment in stations from that era were insulated with asbestos, and Stoneman Station was likely no exception. Asbestos is linked to pleural mesothelioma, a form of lung cancer. When the asbestos is cut or damaged in some way, asbestos fiber is released into the air, where it can be inhaled and lodge in the lungs. Older power stations such as Stoneman have suffered such damage over the course of the years. Abatement action, to encapsulate and contain the asbestos, is often a necessity for power plant worker protection.

In addition, the ash disposal pond for Stoneman Station has been found to contain hexavalent chromium, another potent carcinogen with the potential to contaminate drinking water.