Bass Lake Dump site

Bass-Lake-Dump-site-530

The Minnesota Pollution Control Agency (MPCA) provided cleanup oversight of a dump for the construction of a state-of-the-art medical treatment facility along Bass Lake in St. Louis Park.

History

United Properties, LLC entered the Bass Lake Dump site in the Voluntary Investigation and Cleanup (VIC) Program in September 2006. The purpose was to conduct an environmental cleanup of the property under MPCA oversight during construction of Park Nicollet Health Services’ Melrose Institute, an eating disorder treatment facility. The property is 5.5 acres located at the northeast corner of Monterey Drive and Beltline Boulevard in St. Louis Park, adjacent to a wetland and Bass Lake. The property was used for disposal of burned household, commercial and industrial wastes in the 1960’s and 1970’s. The ash had been covered by a thin layer of soil and vegetated, and was used for sports fields prior to 2006.

Environmental issues

In 2002 and 2003 the MPCA Brownfields Program conducted an environmental investigation of the ash dump. The mixed soil and ash was found to contain metals, polychlorinated biphenyls (PCBs), pesticides, polynuclear aromatic hydrocarbons and diesel range organic compounds. These contaminants were also detected in the groundwater and wetland water and sediment. It is believed that while past dumping of ash probably impacted the wetlands, the dump is currently not a major contributor to the wetland and open water contamination.

Cleanup process

The cleanup goal was to increase the soil cover over the ash in order to reduce the risk of human contact with the ash and to reduce the potential for further erosion or runoff from the ash into the wetlands. During construction of the Melrose facility, the ash and contaminated soil was reused at a deeper depth and clean soil was reused at the surface. The ash was completely removed in the areas developed as stormwater ponds. Approximately 400 cubic yards of excess contaminated soil was disposed of at an industrial solid waste landfill. As a precaution against vapor intrusion, a vapor barrier and passive venting system were installed on the building.

Redevelopment of the site

The Melrose Institute facility was completed in 2009 with main building, parking ramp, stormwater collection ponds and landscaped green spaces. Currently a sculpture garden is in progress in the vacant southwest portion of the property.

Environmental and economic benefits

Environmental benefits include:

  • About 5.5 acres were returned to productive use.
  • Lake and wetland protection was improved through erosion prevention and stormwater management.
  • Health risks from the dump materials were completely mitigated.

The Melrose Institute facility is:

  • The only facility in the Midwest of its kind.
  • Provides innovative medical and life-style counseling services for people with eating disorders.
  • Contributes long-term professional and service jobs to the community.
  • The construction project won the Minneapolis St. Paul Business Journal’s Award for Best in Real Estate Development for healthcare facilities.

Assurances received

June 12, 2007 – No Association Determination issued to United Properties LLC and Park Nicollet Health Services.
November 26, 2007 – No Association Determination issued to Park Nicollet Methodist Hospital.
October 21, 2009 – No Further Action Determination issued to Park Nicollet Methodist Hospital, United Properties, LLC and the City of St. Louis Park.

Institutional controls

An environmental covenant, documenting the location and depth of the former dump materials and requiring the maintenance of the clean soil cover and vegetation, was registered on the property deed on May 8, 2008. Annual cover maintenance reports are required by the MPCA.

Project partners

  • MPCA VIC Program staff included Shanna Schmitt, Lynne Grigor and Jerry Stahnke.
  • The City of St. Louis Park and Park Nicollet Health Services were the project owners and managers.
  • The developer was United Properties.
  • The environmental consultant was AECOM Environment.