City protests pump decisionChange could increase water contamination, officials say
The Minnesota Pollution Control Agency has OK’d a change in 3M Co.’s water cleanup plan that will slash the amount of water pumped to contain contaminated groundwater at the company’s old Woodbury dumpsite.
It’s a move opposed by city officials in Cottage Grove, who say the reduction could directly impact the level of perfluorochemicals in the city’s water system.
The MPCA in June approved the changes that will allow 3M to turn off two of four pumps that create a containment zone around the Woodbury site, preventing PFC-contaminated water from migrating elsewhere. That change would reduce by roughly 25 percent the amount of water pumped out of the ground, piped to 3M Cottage Grove, treated and then dumped into the Mississippi River.
The remaining pumps will still pump an average of 2,800 to 3,300 gallons per minute, according to the MPCA.
“(I)t is evident that this reduction will still result in capture of perfluorochemical (PFC)–contaminated groundwater over the required area,” wrote MPCA Remediation Division director Kathryn Sather in a letter to 3M and Minnesota Department of Health officials, local legislators and city officials.
The pumps are part of a multi-million dollar cleanup effort aimed at stopping the spread of the 3M-manufactured chemicals in area groundwater. In a letter to state pollution control officials, 3M requested to scale back the volume of water pumped at the Woodbury site, which sits just north of the Cottage Grove border.
The city lodged its displeasure with the decision in a letter to MPCA Commissioner Paul Eger, saying the agency should follow Minnesota Department of Health recommendations that more testing is needed before cutting off any wells.
“I don’t want to have us reduce pumping by 25 percent and then a year, two years later find out the levels of chemicals have gone up in the city’s water system,” said mayor Myron Bailey.
The plan is an effort, the company said in the letter, to “preserve groundwater resources within Woodbury … and at the same time, balance water supply and treatment issue needs at 3M’s Cottage Grove site.”
Reduced pumping is of concern to Cottage Grove because groundwater flows south from the Woodbury landfill site toward the Mississippi River and “has a direct impact on the city’s municipal water supply,” city engineer Jennifer Levitt told the city’s Environmental Commission last week.
As part of the MPCA’s approval of reduced pumping, the agency will require 3M to conduct monthly water level monitoring and continuous data logging in the wells in addition to water quality sampling.
Pumping on all four wells will resume immediately should testing show the curtailed system isn’t maintaining its level of PFC capture, according to the MPCA.