The North Plant MGP Site was formerly a manufactured gas plant (MGP) and produced gas using a coal carbonization process from 1912 to 1927. The MGP was converted into a carbureted water gas facility in 1927 and continued producing gas in this manner until it switched to oil gas manufacturing. Oil gas manufacturing began in 1951 and continued until 1953.
Analytical results from historical samples in the proposed removal areas indicate the presence of elevated concentrations of PAH and VOC 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/kg. Depth to groundwater in the area varies from 2-5 ft below ground surface. Groundwater flows east towards Lake Michigan and organics contained in the DNAPL may leach into the groundwater and migrate to Lake Michigan. The total volume of impacted material is estimated to be 260,100 cubic yards.
