The Site was formerly a manufactered gas plant (MGP) and produced gas using a carbureted water gas method from 1925 to 1946.
After 1946, the facility was used for propane storage and distribution prior to the availability of natural gas in the area. Wisconsin Public Service Corp. (WPSC) maintains ownership of the Site.
Current Site features includ historic concrete building foundations. A chain link fence secures the Site perimeter. A wetland exists in the center and western portion of the property. Large portions of the Site east of the wetland are covered in crushed stone and asphalt. The vegetation in the wetland consists of a fringe scrub/shrub on the eastern edge of the wetland dominated by aspen and dogwood. Emergent and wet meadow species such as green bulrush and horsetail, are located closer to the bank of the West Twin River.
Analytical results from historical samples in the proposed removal areas indicate the presence of elevated concentrations of polynuclear aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) in the DNAPL present in both the surface and subsurface. In particular, this past data indicates the presence of TCLP benzene concentrations exceeding 0.5 mg/l in addition to concentrations exceeding the 340 mg/kg RML. Depth to groundwater in the area varies from 2-5 feet below ground surface. Groundwater flows west towards the West Twin River in which the river flows east toward Lake Michigan and organics contained in the DNAPL, may leach into the groundwater and migrate to the West Twin River and Lake Michigan. The total volume of impacted materials in areas is estimated to be 71,000 cubic yards.
