Contact: Sam Brungardt, 651-757-2249
St. Paul, Minn. - Excavation and removal of contaminated soil has begun prior to construction of an apartment building for students at 2500 S. Delaware St. in Minneapolis. This is the location of the Gopher Oil-Delaware Superfund Site.
Before 1980, a bulk petroleum storage facility was on the site. After that, the half-acre property was fenced, paved with asphalt and used for parking.
According to the Minnesota Pollution Control Agency (MPCA), investigations conducted at the site from 1982 to 2007 found the soil and groundwater to be contaminated with petroleum products. A small area of the property is contaminated with polychlorinated biphenyls (PCBs).
Before it can begin construction of the apartment building, the developer, Solhaus Associates LLC, is removing the contaminated soil from the site under a plan approved by the MPCA’s Petroleum Brownfield and Voluntary Investigation and Cleanup programs. Solhaus Associates received grants from the Minnesota Department of Employment and Economic Development and Hennepin County to remove the contaminated soil so the underutilized property could be redeveloped. The grants will also cover the cost of a vapor-control system for the six-story, 75-unit building, which will have parking on the first floor.
Solhaus Associates will excavate about 11,000 cubic yards of petroleum-contaminated soil and about 20 cubic yards of soil contaminated with PCBs from the site. Trucks will haul the contaminated soil to an approved landfill for disposal.
Noise and petroleum odors will be generated by the excavation work. The developer will be required to do environmental monitoring during the removal, and to control dust generated by the work. Petroleum vapors from the site may cause temporary headache, which should go away when the affected person moves away from the site or goes indoors. Workers at the site will be wearing respirators because they will be exposed to stronger vapors for longer periods. There should be no more noticeable odors once the site has been excavated and backfilled.
The groundwater contamination, which extends under Huron Boulevard, will be further investigated to see whether additional cleanup measures are needed. The area is served by the municipal water supply, and the contaminated groundwater has not impacted any drinking water supply wells.