3M chemicals have been detected at high levels in at least three more landfills in the Twin Cities metro area and in one case are leaking into the Mississippi River, according to a new study. Now, state pollution control officials will study whether the chemicals—potentially hazardous to humans—also occur in groundwater near those and other area landfills.
The former Pig’s Eye dump in St. Paul, the Pine Bend landfill in Inver Grove Heights and the SKB industrial landfill in Rosemount contain chemicals at levels ranging from three to 150 times higher than state guidelines for drinking water, according to data from the study. There are no drinking-water wells near the sites, and all of the landfills received the wastes legally from 3M’s Chemolite plant in Cottage Grove.
The study comes on the heels of Minnesota Health Department tests in January that detected one of the chemicals in drinking-water supplies of Woodbury, Cottage Grove, St. Paul Park, Newport, Hastings and South St. Paul.
3M officials said they haven’t seen the study results but will continue to work with the state to identify any possible problems.
“We want to work with the MPCA on what these test results mean,” said company spokesman Bill Nelson.
Matt Simcik, associate professor of environmental health at the University of Minnesota, said he’s not surprised that the compounds, known as perfluorochemicals (PFCs), are showing up in many places. Minnesota is one of the few places in the country where the chemicals were produced, he said, and 3M manufactured them for half a century until 2002. “I expected this to be a growing problem,” Simcik said. “We’re forging new ground here to determine what the effects might be and what the dangers might be.”
PFCs do not break down in the environment and have been detected at low levels in the blood of polar bears and other wildlife and humans throughout much of the world. Maplewood-based 3M Co. made them primarily in Minnesota and Alabama.
PFCs also were detected in public wells in Oakdale and private wells in Lake Elmo beginning in 2004, the result of 3M wastes that spread into groundwater after being dumped into landfills in those communities in the late 1950s and early ‘70s.
Most of the latest findings pertain to disposal of 3M chemicals contained in wastewater sludge from its Cottage Grove plant. In response to a Pollution Control Agency request two years ago, 3M reported that it sent PFC wastes to the Pig’s Eye dump in 1971, to the Pine Bend landfill from the mid-1970s to the early 1990s, and to the industrial landfill in Rosemount from the 1990s to mid-2003. A 1993 letter from 3M indicates the company disposed of other “dry scrap” wastes at Pig’s Eye, near the Mississippi River, from 1961 through 1967.
At that former dump, Pollution Control Agency scientists found concentrations of one chemical, PFOA, at up to 79 parts per billion, said Kurt Schroeder, a hydrologist with the agency’s Superfund division. The Minnesota Health Department’s concentration limit for PFOA in drinking water is 0.5 parts per billion.
Schroeder also found two other chemicals, PFOS and PFBA, at levels up to 13 and 44 parts per billion. The Health Department’s well advisory guideline for PFOS is 0.3 ppb and for PFBA is 1.0 ppb.
The Pollution Control Agency also sampled surface water just downstream from the former dump at Pig’s Eye Lake, a backwater of the Mississippi, and found levels of PFOA about five times higher than the state drinking-water guideline.
Spokesman Ralph Pribble said the Pollution Control Agency will continue those tests, but that other landfills with PFCs are a higher priority for cleanup.
The agency expects to learn more about the effects of the chemicals on aquatic life in a few weeks, Pribble said. Agency scientists will receive data about PFCs in fish taken last year from the Mississippi near the 3M plant. The agency will use those and other data to establish what levels of PFCs in surface water that it considers to be safe, Pribble said.
In the two other landfills, the chemicals were found in these concentrations:
Pine Bend landfill in Inver Grove Heights: PFOA at up to 81 ppb and PFOS at up to 31 ppb. SKB industrial landfill in Rosemount: PFOA at 9 ppb, PFOS at 4.7 ppb and PFBA at 23 ppb.
In a separate study, the agency also has found low levels of PFCs in 11 landfills where 3M did not send wastes. The chemicals likely came from residential, commercial and industrial products; groundwater testing near those areas is also planned this year.
3M’s Nelson noted that PFCs have not been detected in other municipal wells that state health officials tested earlier this year, including those in Inver Grove Heights and Rosemount. 3M will continue to focus mainly on its former disposal sites in Oakdale, Woodbury and at the company’s Cottage Grove plant, Nelson said, which received the majority of the PFC wastes.
3M’s wastes buried at its plant in Cottage Grove have become a contested issue within the state agency, as its scientists have debated the best way for 3M to clean up. MPCA Commissioner Brad Moore has decided to seek outside advice about the most effective method, said Pribble, and it’s possible that the state may ask the federal Environmental Protection Agency to become involved