Years after 3M Co. removed drums of toxic chemicals from an old dumping ground in Oakdale, the Environmental Protection Agency was about to give the place a clean bill of health.
Then in the nearby city of Lake Elmo, chemicals formerly used to make Scotchgard and nonstick cookware were detected in people's drinking-water wells. Now, an investigation into the source of that pollution has led to a familiar place: the old dump in Oakdale. State-ordered tests by 3M have found concentrations of the chemicals at thousands of times higher than state drinking-water standards allow.
The contamination, from a class of compounds called fluorochemicals, has flowed both underground and along at least part of a creek that empties into Lake Elmo. State health and pollution officials are studying the report to determine how to prevent the underground plume of contaminated water from spreading.
So far, more than 200 households in Lake Elmo have had to abandon their private wells and get hooked up to municipal water. The report also highlights the growing concern about fluorochemicals, whose past use and disposal may lead to costly cleanups for manufacturers from Alabama to Minnesota. Gary Krueger, project manager for the state Superfund program, said 3M removed a large number of barrels containing solvents and other organic compounds from the Oakdale dump in the mid-1980s. At the time, however, the cleanup did not require fluorochemicals to be removed because no one thought they were dangerous. It's like restarting the investigation all over again," he said.
Company spokesman Bill Nelson said that it's premature to say 3M will need to clean up the Oakdale dump, which it owns. "What these data mean will be determined jointly by the state of Minnesota with input from 3M," he said. The company has cooperated with state agencies and acted responsibly in assisting Lake Elmo, Nelson said, and will meet with state officials later this month to discuss the latest findings.
Chemicals in groundwater Fluorochemicals are a family of compounds that 3M manufactured at its plants in Cottage Grove and in Decatur, Ala., from the 1950s until 2002. One of the chemicals, perfluorooctanoic acid (PFOA), was used in the manufacturing processes that create nonstick coatings for cookware. Another, perfluorooctane sulfonate (PFOS), was used for stain- resistant treatments for carpets, fabrics and paper products. Nelson said that 3M disposed of the fluorochemical wastes in the Oakdale dump between 1956 and 1960, and in the former Washington County landfill in northern Lake Elmo from 1969 to 1974. Both dump sites are now suspected of leaching the chemicals into groundwater.
The latest findings at the Oakdale dump showed PFOA levels as high as 23,700 parts per billion in groundwater and PFOS levels up to 3,343 parts per billion. The Minnesota Department of Health's well-advisory guideline for PFOA is 1 part per billion and for PFOS is 0.6 parts per billion.
The guidelines, called health-based values, are the amount of a chemical in water considered safe for people to drink daily for a lifetime. State health officials have said that at high concentrations, fluorochemicals caused harmful changes in the liver and other organs in animal studies, as well as developmental problems in the offspring of rats.
In January, Environmental Protection Agency (EPA) officials asked companies to phase out the use of PFOA by 95 percent by 2010 and entirely by 2015. In February, a science advisory panel for the EPA recommended that PFOA be classified as a likely cause of cancer in humans.
3M officials have said that company employees who manufactured the chemicals in Minnesota and Alabama and who were exposed to much higher levels than the general public have shown no adverse health effects during 25 years of monitoring.
Flowing into Lake Elmo Part of the Oakdale study measured fluorochemicals just east of the dump in the sediment and water of Raleigh Creek, which flows into the city of Lake Elmo. John Linc Stine, division director for environmental health at the Minnesota Health Department, said those findings seem to confirm what hydrologists already suspected: that the dump is a potential source of contaminants for the city. However, Stine said health officials are still reviewing the study and have reached no final conclusions.
Stine said figuring out how the groundwater moves and potential sources of pollution are critical. "We need to know where it's coming from and where it's going so we can get ahead of it in terms of how we manage the drinking water," he said.
Martin Rafferty, Lake Elmo city administrator, said that the city is also planning ahead so that it will be able to hook up other neighborhoods to city water if the pollution spreads. During the past 18 months, he said, Lake Elmo has been preoccupied with the more immediate problem of ensuring that all households have clean water.
Affected homes have been given bottled water, carbon filtration systems or both, he said, and construction crews are rushing to hook up 216 households to the city's water system before winter. 3M volunteered to pay the full $4.3 million cost of extending the city's water system, Rafferty said, and the company donated 8 acres to provide Lake Elmo with a site to build a new water tower.
3M also spent about $1 million for a carbon-filtration system to remove fluorochemicals detected in one of Oakdale's city wells. City, company cooperating Rafferty expects that state officials and 3M will figure out a long-term solution, and said that he hopes the cooperation between the company, the city and state agencies will be a model for other communities around the country that may face similar problems. But not all citizens share that optimism.
Gary Carlson, a 32-year resident of the Tablyn Park neighborhood in Lake Elmo who is receiving bottled water, watched Friday as crews began drilling horizontally beneath his yard to hook up his home to city water. While not happy about the situation, Carlson said he's especially frustrated that the source of the contamination has not been removed. Without cleaning up the dump, he said, the pollution plume could spread to private wells in other neighborhoods. "This is 2006," he said. "We've got missions to Mars, and they can't dig a hole and remove some barrels."