Minnesota Pollution Control Agency

Contact: Ralph Pribble, (651) 296-7792 St. Paul, Minn. -- The Minnesota Pollution Control Agency (MPCA) is seeking public comment on a proposed plan to clean up contamination related to perfluorochemicals (PFCs) at the 3M Woodbury Disposal site in Woodbury, Minn. The public comment period for the proposed plan will end Aug. 22, 2008. The site is located on a 656-acre parcel owned by St. Paul-based 3M Co., on the border of Cottage Grove and Woodbury, between Woodbury and Cottage Grove drives and south of Dale Drive. On the property are several former dump areas at which 3M had legally disposed of manufacturing wastes during the 1960s. Materials disposed there included wastes from the manufacture of perfluorochemicals (PFCs). 3M installed a ground-water pump-out system on the site in the 1970s to capture and control migration of volatile organic compounds (VOCs), which are primarily solvents, in ground water. The system continues to operate, pumping more than 3,000 gallons per minute. The water is conveyed by underground pipeline to 3M's Cottage Grove manufacturing facility, where it is used as process water and then discharged to the Mississippi River. Since 2005, 3M has been working under MPCA oversight to investigate the extent of PFCs in soils and ground water at and near the site. The site is one of the four suspected as a source of the PFC ground-water contamination in the east metro area that was discovered in 2004-2005. 3M completed a feasibility study of various options for cleaning up the PFCs at the site and submitted it to the MPCA in February 2008. After evaluating the options, the MPCA has selected its preferred alternatives. The MPCA recommends continuing the existing pump-out system, which has proven effective at removing PFCs from ground water at the site. Currently the water is not treated to remove PFCs, but under this proposal the water would be treated with carbon filtration before being discharged at the Cottage Grove facility. The discharge would be subject to PFC effluent limits contained in an MPCA-issued permit. In addition, 3M would excavate a large volume of PFC-containing soil from several areas of the site. Soils that meet standards for disposal of industrial wastes would be taken to the SKB Landfill, a permitted industrial landfill in Rosemount, Minn., where they would be placed in a secure long-term containment cell. Soils containing other constituents that may meet federal definitions of hazardous waste (for example, PCBs or VOCs, depending on concentration -- PFCs alone are not classified hazardous) would be segregated and shipped to other disposal facilities licensed for hazardous wastes. Excavated areas will then be backfilled and covered with clean fill and maintained long term by 3M. Ground-water monitoring will continue for at least 30 years to ensure reduction of PFCs in ground water. A public meeting on the proposed cleanup will be held at 7 p.m. on Thursday, July 24, at the Woodbury City Offices. A half-hour open house before the meeting will give interested parties the opportunity to ask questions in an informal setting.

The proposal is open for public comment through Aug. 22, 2008. Comments must be submitted in writing to Gerald Stahnke, MPCA, Remediation Division, 520 Lafayette Rd. N., Saint Paul, MN 55155-4194. After the comment period, the agency will determine the remedy with any applicable modifications. The MPCA commissioner will decide the remedy, which will be outlined in a final decision document. Copies of the feasibility study and other documents relating to the site and the proposed cleanup are available for review on the Web at /cleanup/pfc/pfcsites.html, as well as at the MPCA's St. Paul office.