Congressional District # 08
WPSC MARINETTE MGPEPA ID# WIN000509952
Last Updated: March, 2015
The WPSC Marinette former MGP ("Marinette") site is located about 750 feet south of the Menominee River in Marinette, Wisconsin, and about 1.5 miles upstream from the mouth of the river at Green Bay. The Marinette site totals about 5 acres in size, with about 4 acres on land and about 1.3 acres of contaminated sediment found in an adjacent stretch of the river.
The Marinette site is currently owned by the city of Marinette and the property is now occupied by the city's wastewater treatment plant. Other area features include Boom Landing Park, which has a public boat launch and is located between the site and the river, and a former slough that was filled in and which ran from the site to the river across what is now Boom Landing Park. The site is located in a historically industrial area of the city, which counted lumber operations, asphalt manufacturing, and the MGP facilty as major establishments.
Manufactured Gas Plants (MGPs) were industrial facilities that produced gas from coal, oil, and other feedstocks. MGPs started operating in the United States in the early 1800s, typically in urban areas where gas was needed for lighting, cooking, and heating. The Marinette MGP was operated from 1910 to 1960. Two gas production methods were used at the Marinette MGP facility: coal carbonization and carbureted water gas. Both processes produced waste and by-products such as tars, oils, sludges, and acidic waste. Disposal of waste and spills and leaks often resulted in contaminated soil and groundwater at MGP sites. MGPs were often located near waterbodies and thus sediment contamination is also commonly found.
Wisconsin Public Service Corporation (WPSC) is a potentially responsible party for several former MGPs located throughout Wisconsin, including the Marinette site. WPSC is addressing six of its former MGP sites under EPA's Superfund Alternative site program.
The WPSC Marinette 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 the Marinette site are contaminated with typical MGP-generated compounds that include polynuclear aromatic hydrocarbons (PAHs) and a group of volatile organic compounds (VOCs) called benzene, toluene, ethylbenzene, and xylene (BTEX). Site soil contains PAHs and BTEX and groundwater contaminants include PAHs, cyanide, naphthalene, and BTEX. Contaminated groundwater is believed to have discharged from the site into the Menominee River via the former slough. River sediment shows evidence of odor, sheen and/or tar associated with MGP wastes.
People could be exposed to MGP wastes at the Marinette site by dermal contact with contaminated soil and/or river sediment or by drinking contaminated groundwater. Benthic (bottom-dwelling) organisms could be exposed to sediment contaminants in the river. Exposure to the MGP contaminants could cause toxic health effects. However, because the city-owned wastewater treatment plant is located on the former MGP property, exposure to contaminated soil is limited. Residents use the city water supply for drinking; therefore, no one is currently drinking contaminated groundwater 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 Marinette site. Prior to reaching this agreement, WPSC conducted various investigations of the Marinette site from 1994 through 2002 under the Wisconsin Voluntary Cleanup Program. In 2004, a limited amount of contaminated soil was removed to accommodate the city's modifications to its sewer line. Investigative results showed that site groundwater flowed generally north toward the Menominee River beneath the wastewater treatment plant property and easterly under Boom Landing Park. Routine groundwater monitoring occurred annually.
Under the 2006 settlement agreement with EPA, WPSC has agreed to conduct a remedial investigation and feasibility study at the Marinette former MGP site as well as at five other former MGP sites in Wisconsin. Because the six sites have similar conditions and contaminants, and WPSC is a potentially responsible party 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 WPSC to address the "worst problems first."
WPSC initiated bathymetric and ambient transects for Menominee River and sediment characterization in fall 2011, suspended the work during the winter, and then completed it in spring 2012. The data collected was used to evaluate potential river sediment cleanup plans in an Engineering Evaluation/Alternatives Analysis report that was published in summer 2012. EPA then issued a proposed plan to conduct a non-time critical removal action to clean up contaminated sediment in the Menominee River in late August 2012, taking public comments on the proposal until late September. EPA issued an Action Memorandum to select the proposed sediment cleanup action in early October.
WPSC mobilized contractors to the Marinette site to begin the river sediment removal action in late Octber 2012 and completed it in February 2013. Contaminated sediment was excavated from the river by an excavator on a barge, transported to shore, mixed with stabilizers, and then trucked to a landfill for disposal. Unrecoverable sediment with PAH levels exceeding the cleanup criteria were then covered with a 10-inch clean sand layer with the goal of having the residual sediment mix with the clean sand to decrease average concentration levels. Sediment samples will be taken to ensure that mixing is occurring. Upland restoration work was completed in June 2013.
From June 2013 to March 2014, WPSC worked to complete the necessary sampling and analysis tasks that will result in completion of the Remedial Investigation (RI) Report for the Marinette site. Based on the results of the RI and the subsequent feasibility study (FS), EPA plans to propose a final site cleanup remedy in January 2016 for public comment and then select the final cleanup remedy for the site later that year.
In February 2012, EPA performed community interviews. In June 2012, EPA issued a Community Involvement Plan, which is available online and at the Stephenson Public Library in Marinette.
In September 2012, EPA presented information regarding the Non-time Critical Removal Action of MGP-contaminated sediment from the Menominee River at the local Community Advisory Group meeting. The agenda and meeting minutes from that meeting are available on EPA's website.
In December 2012, EPA took part in a Lower Menominee River Technical Work Group meeting called to discuss restoration of the river after all cleanup activities have been completed.
ContactsRemedial Project Manager, U.S. EPA
margaret gielniewski (firstname.lastname@example.org)