WIN000509948, Superfund Alternative Approach Agreements Sites | Region 5 Superfund

U.S. EPA REGION 5
BROWN COUNTY
GREEN BAY

Congressional District # 08

WPSC GREEN BAY MGP

EPA ID# WIN000509948
Last Updated: May, 2008

Site Description

The WPSC Green Bay MGP site is located in Green Bay, Wisconsin on the south bank of the East River, near the confluence of the Fox River. Wisconsin Public Service Corporation (WPSC), an operating utility company now known as Integrys, is responsible for several former manufactured gas plants (MGPs) throughout Wisconsin. The Green Bay site is about 13 acres in size, with approximately one additional acre of contaminated adjacent sediment. The Green Bay site is located in an historically industrial area. The gas plant operated from 1871 to 1947. The site is currently used as WPSC corporate offices and as a parking lot for employees. There is a hotel located to the southwest and a river walk located along the shoreline.

MGPs were industrial facilities that produced gas from coal, oil, and other feedstocks. MGPs started operating in the U.S. in the early 1800s, typically in urban areas where gas was needed for lighting, cooking, and heating. Two gas production methods were used at the WPSC 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.

Site Responsibility

This site is being addressed through federal and potentially responsible party actions. This is one of six former MGPs in Wisconsin to be addressed by WPSC under the Superfund Alternative Sites approach.

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 or tar associated with MGP waste.

Cleanup Progress

WPSC and EPA entered a settlement agreement in May 2006. Under this unique agreement, WPSC has agreed to conduct remedial investigations and feasibility studies at six former MGP sites located throughout Wisconsin. Because the six sites have similar conditions and contaminants, and WPSC is responsible 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 allow progress on 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 will occur under the enforcement agreement with EPA.

Contacts