Excavation of a former 3M disposal site in southeastern Woodbury will begin next month, 3M officials informed the Woodbury City Council last week.

Last summer the Minnesota Pollution Control Agency revealed the Maplewood-based company’s plan to remediate the disposal site that 3M used primarily in the 1960s to dump products containing perfluorochemicals (PFCs).

Over the last year the public and several local governments were allowed to provide feedback on the plan, which the MPCA approved earlier this year.

Per an agreement 3M signed with the MPCA in 2007, the company is responsible for the costs of cleaning up the site, which is located between Woodbury Drive and Cottage Grove Drive and south of Dale Road in Woodbury.

Excavation activities will take place on two sections of the site with work on the more southern section to begin in August and finish before the end of construction season, said 3M spokesperson Katie Winogrodzki.

Excavation of the contaminated northeast section of the site is scheduled to begin early next year. All of the contaminated soils will be transported by a fleet of trucks to the SKB Environmental landfill in Rosemount, Winogrodzki said.

The trucks will generally operate between 9 a.m. and 3 p.m. and plan to take routes along County Road 19 to Highway 61 on the way to and from the landfill.

“(Excavation activities) won’t have much of an impact on local traffic, given the short distance on rural roads, I think that it will hardly be noticed,” Winogrodzki said.

3M already has a pump-out system set up at the site to keep any PFCs from entering into the municipal water system, and will plan to keep the system running even after all the contaminated soil is removed from the site.

The excavation of the contaminated soil will eliminate about 80 percent of the contamination from the site, while the pump-out system will eliminate the remaining 20 percent over time, Winogrodzki said.

Woodbury Mayor Bill Hargis said news that remediation of the site is just about to begin should be encouraging to residents.

“We feel good about our water system, but we think (the remediation plan) is a good strategy in the long run,” Hargis said.

Water remains safe to drink

Although different types of PFCs have been found in soil and water systems in other cities, the only measurable PFC found in Woodbury drinking water is perfluorobutanoic acid (PFBA), which was manufactured decades ago at the 3M chemolite plant in Cottage Grove.

In early 2007, 3M and the Minnesota Department of Health informed the public that the contaminants had leaked from several disposal sites in the east metro into the municipal drinking water systems of several nearby communities.

Levels of PFBA measured in Woodbury drinking water were far below the health-based value determined by the Minnesota Department of Health (MDH) and continue to remain at those trace levels, said Woodbury Public Works Director David Jessup at the Wednesday, July 22 city council meeting.

The latest concentrations of the chemical in local drinking water ranged from 0.2 to 0.4 parts per billion, Jessup said.

The MDH has established the health-based value (HBV) of PFBA at seven parts per billion, which, according to health department officials, means the levels measured in Woodbury and its neighboring communities are well below the maximum level allowed before it poses an immediate or long-term health risk.