- Provided initial investigation, design, and construction phase services for this residential redevelopment project of a former Superfund site
- Obtained over $1 million in State and County investigation and cleanup grants
- Remediation included excavation and disposal of over 19,000 tons of soil, groundwater treatment, and a vapor mitigation system
- Managed extensive cleanup resulting in delisting on the Superfund registry
- Awarded a 2012 Minnesota Brownfields ReScape Finalist award and was voted “Best in Real Estate” by the Minneapolis-St. Paul Business Journal
On behalf of Solhaus Associates, Vieau/GZA obtained funding through State and County cleanup grant programs to facilitate redevelopment of the Gopher Oil Superfund Site, a former bulk petroleum storage facility. Vieau/GZA worked cooperatively with project stakeholders to develop a cleanup strategy to address petroleum- and PCB-contaminated soil and groundwater. This award-winning development broke ground in October 2010 and was completed on time and on budget for occupancy in September 2011, prior to the start of the school year.
Challenge
The property had heavily contaminated soil and groundwater across the entire 0.48-acre site. The property was a small, triangular parcel that needed to be excavated two-feet below groundwater and backfilled with clean soil to facilitate residential redevelopment. Due to the depth of excavation and concerns regarding structural integrity of surrounding buildings and roadways, additional precautions had to be in place to facilitate the redevelopment.
Solution
In order to protect the adjoining roadways and apartment building, piles and shoring were driven along the property boundaries so the entire parcel could be excavated to a depth of 20-feet below ground surface. Trucks had to be decontaminated onsite before they were allowed to leave the site. Vieau/GZA staff managed the excavation and handling of contaminated soils and directed the disposal of over 19,000 tons of petroleum-contaminated soil, and 17 tons of PCB hazardous waste to permitted industrial landfills, alleviating a continuing source of contamination to groundwater. In addition, Vieau/GZA directed and oversaw the installation of a dewatering treatment system for thousands of gallons of contaminated groundwater for permitted discharge into the sanitary sewer system.
Benefit
Vieau/GZA worked with three separate Minnesota Pollution Control Agency (MPCA) programs, Superfund, Petroleum Remediation, and Voluntary Investigation and Cleanup, through the course of the redevelopment. Due to the extensive cleanup, the property owner was issued available environmental liability letters and closure letters, and site was delisted from the State Superfund registry. The property was redeveloped with a six-story residential apartment building with underground parking. The redevelopment increased the property value by about 300% and provided much needed housing for the University of Minnesota and helping to revitalize the area for the nearby businesses and the University.