Congressional District # 08
WPSC GREEN BAY MGPEPA ID# WIN000509948
Last Updated: May, 2012
The WPSC Green Bay former MGP site is located on the south bank of the East River, near the confluence of the Fox River in Green Bay, Wisconsin. Manufactured Gas Plants (MGPs) were industrial facilities that produced gas from coal, oil, and other feedstocks. The Green Bay site totals about 14 acres in size, with about 13 acres on land and about 1 acre of potentially contaminated sediment found in an adjacent stretch of the river.
The Green Bay site is located in an historically industrial area. The site is currently houses corporate offices and an employee parking lot. A nearby hotel is located to the southwest of the site and a river walk is located along the shoreline.
MGPs started operating in the U.S. in the early 1800s, typically in urban areas where gas was needed for lighting, cooking, and heating. The Green Bay gas plant operated from 1871 to 1947. Two gas production methods were used at the MGP facilities: coal carbonization and carbureted water gas. Both processes produced waste and by-products such as tars, purifier waste, oils, sludges, and acidic waste. Disposal of waste and spills and leaks often resulted in contaminated soil and groundwater. MGPs were often located near waterbodies and sediment contamination is also common.
Wisconsin Public Service Corporation (WPSC), an operating utility company, is a potentially responsible party for several former MGPs located throughout Wisconsin, including the Green Bay site. WPSC is addressing six of its former MGP sites under the Superfund alternative site approach.
The WPSC Green Bay former MGP site is being addressed through potentially responsible party (PRP) actions under state and federal oversight.
Threats and Contaminants
Soil, groundwater and sediment at former MGPs are often contaminated. At the Green Bay site, soil cleanup was conducted on the most contaminated areas; however, soil at the site still contains residuals of polynuclear aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs) and cyanide. Groundwater at the site flows radially from the center towards the East and Fox Rivers. Groundwater contamination includes PAHs; cyanide; napthalene; and a group of VOCs called benzene, toluene, ethylbenzene, and xylene (BTEX). Sediment is the nearby East River contain PAHs and BTEX, and shows evidence of odor, sheen and tar associated with MGP waste.
People could be exposed to MGP wastes at the Green Bay site by dermal contact with contaminated soil or river sediment or by drinking contaminated groundwater. Benthic (bottom-dwelling) organisms could be exposed to sediment contaminants in the rivers. Exposure to the MGP contaminants could cause toxic health effects. However, because there is a building and a parking lot covering the site soil, and nearby building occupants and residents use city water for drinking, there is no one currently being exposed to the MGP wastes from the site.
WPSC and EPA entered a settlement agreement in May 2006 to address site conditions at six former MGP sites in Wisconsin, including the Green Bay site. Under the agreement, WPSC has agreed to conduct remedial investigations and feasibility studies at the former MGP sites. Because the six sites have similar conditions and contaminants, and WPSC is a potentially responsible party (PRP) for each, the agreement allows a streamlined approach to site investigation and remedy development. Some benefits of the agreement include the use of multi-site documents, a mechanism to review the adequacy of past work, and scheduling flexibility to address the worst problems first.
Under the state program various investigations of the Green Bay site have occurred since 1984. In 2003, about 26,000 tons of highly contaminated soil were excavated, thermally treated, and removed from the site. Routine groundwater monitoring occurs semi-annually.
Additional investigation of remaining contamination is planned to occur in 2015 under the enforcement agreement with EPA.
ContactsRemedial Project Manager, U.S. EPA
margaret gielniewski (email@example.com)