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Congressional District # 08


EPA ID# WIN000509948
Last Updated: March, 2015

Site Description

The WPSC Green Bay former MGP ("Green Bay") site is located on the south bank of the East River, near the confluence of the Fox River in Green Bay, Wisconsin.   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 site is located in a historically industrial area of Green Bay.  The site currently houses corporate offices and employee parking lots.  A hotel is located nearby to the southwest of the site and a river walk is located along the shoreline.

Manufactured Gas Plants (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.  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) 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 EPA's Superfund Alternative site approach.

Site Responsibility

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 with tarry polynuclear aromatic hydrocarbons (PAHs), a group of volatile organic compounds (VOCs) called benzene, toluene, ethylbenzene, and xylene (BTEX), the heavy metal lead, and with cyanide.  At the Green Bay site, a soil cleanup was conducted on the most contaminated areas; however, residual contaminants remain including PAHs and BTEX.  Site groundwater flow is radially from the center towards the East and Fox Rivers.  Groundwater contamination includes PAHs, BTEX, cyanide and napthalene.  Sediment is the nearby East River contain PAHs and BTEX, and shows evidence of odor, sheen, and tarry material 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, no one is currently being exposed to the MGP wastes from the site.

Cleanup Progress

WPSC and EPA entered into an administrative 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 a remedial investigation and feasibility study at each of 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 allow EPA and WPSC to address the "worst problems first."

Under the state voluntary cleanup 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. 

WPSC began the sediment portion of the remedial investigation at the Green Bay site in October 2014.  WPSC will begin the upland soil and groundwater sampling portions of the RI in April 2015 in accordance with the 2006 agreement. EPA will oversee the work.


Remedial Project Manager, U.S. EPA
margaret gielniewski (gielniewski.margaret@epa.gov)
(312) 886-6244



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