Many chemicals in drinking water can be removed with small activated-carbon filters.

What are they? Units that drip into a pitcher, mount on the tap or install under the sink. These point-of-use filters remove many organic compounds, a wide class of carbon-containing chemicals that include pesticides and solvents.

Do they work on PFCs? Preliminary testing by the Minnesota Health Department suggest small filters remove low levels of PFBA, a 3M film-coating chemical found in groundwater in the southeastern metro area. Further testing of filters is planned.

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Sept. 16, 2007: The Longest Cleanup: Battling tainted water

  • Article by: David Shaffer
  • Star Tribune
  • September 17, 2007 - 7:05 AM

Groundwater contaminated with industrial chemicals lurks under vast portions of the Twin Cities metropolitan area even though more than $200 million has been spent over two decades to combat the problem. The contamination, a legacy of once-prevalent industrial dumping, persists beneath communities from Edina to New Brighton to Woodbury. In Washington County, the spread of underground pollution is turning out to be worse than anyone thought.

A Star Tribune examination of groundwater monitoring reports, maps and other records has identified 20 significant plumes of contaminated groundwater underlying parts of 35 metro communities. If added together, the polluted zones would equal an area 2½ times the size of Minneapolis.

No illnesses have been directly linked to the pollutants, but the contamination can pose long-term risks to health. And parts of the metro area will be stuck trying to clean up the chemicals for decades, often at taxpayers' expense.

Already 150,000 people served by six suburban utilities drink water that must be specially treated to remove chemicals that leached underground. Two more suburbs with 37,000 people are likely to get such filtration soon.

The discovery of something unwelcome in the water is crashing into the lives of more families like Kim Lindholm's of Lake Elmo.

In May, her telephone answering machine blurted out a warning from the state Health Department: "Do not drink your water. Do not cook with your water. ..."

The family's well had tested positive for a substance that likely escaped from a nearby landfill. "That freaked me out," recalled Lindholm, who has two young boys. More than 1,000 private wells in Washington County contain pollutants from old dumps and industries. Many residents, including the Lindholms, have turned to whole-house filtration units for protection.

Maps issued by the state Health Department in July show low levels of the 3M chemical PFBA in groundwater beneath 99 square miles of Washington County, a quarter of its land mass. In a third of that area, levels of the chemical once used for coating photographic film exceed what the state advises for drinking water.

Other industries have left a taint elsewhere in the region, creating plumes of contaminated groundwater up to 9 square miles, some containing cancer-causing chemicals.

Often the cleanups seem endless. At 15 locations in the metro area, special wells have been extracting and filtering out pollutants from groundwater for up to 39 years.

In other places, regulators hope soil bacteria will render chemicals harmless in the future. One plume of pollution beneath St. Louis Park probably won't be flushed clean for a century or longer.

"It is almost like when you throw dye into a jar of water," said Michael Convery, a supervisor in the Health Department's well management section. "It is hard to get it back again. It just spreads out."

Suburbs bear the brunt

When Jim Altier built a house outside Bayport, Minn., more than three decades ago, he and his family could look across farm fields and see the IDS Tower in Minneapolis.

Trees have matured to block the view, surrounding his house with a canopy of green. He not only escaped the city, he no longer can see it from the back porch.

But there's a crack in this idyllic picture: Altier's well is polluted with an industrial solvent. So are about 260 other nearby wells. He now has an activated-carbon filter, like many other Baytown Township residents, though for at least 14 years he and his family drank tainted water.

"I had mixed feelings about it," said Altier, a retired Air National Guard mechanic who worked around solvents in his job. "... I feel better that the filter system is in there."

He still wonders if the chemical, known as TCE, affected his first wife, Teddie, who died of leukemia in 1997. State health officials have reported no cancer clusters in Washington County, but Altier said he is not sure he believes it.

More than 1.8 million metro residents get tap water from the ground. Suburbs have a disproportionate share of the metro area's major groundwater chemical plumes, most of them created when the land was an open space.

"They were places that people thought were good places to bury stuff or dump stuff," said Michael Kanner, who heads the state Superfund program for the Minnesota Pollution Control Agency. "Some of the industries needed more land. ... It was easier to move outside the city."

To be sure, many places have groundwater pollution. Cities struggle to clean up so-called brownfields for redevelopment. In rural and some suburban areas, nitrates from fertilizer and other sources often contaminate wells, putting infants at risk.

The Star Tribune found that of the 20 significant pollution plumes in the metro area, 17 are in suburbs. The list is based on interviews with regulators and public health officials and a review of state cleanup and monitoring records and data. The list includes large areas of pollution -- 10 are greater than 1 square mile -- and smaller plumes with notable risks.

Chemicals with abbreviations BTEX, PAHs, TCE and PCP seeped into the ground at rural dumps, industrial plants, refineries, wood-treatment operations and arms plants. Some sites had extensive cleanups, but groundwater still is contaminated.

State Pollution Control Commissioner Brad Moore said cleaning up groundwater is a long-term commitment, "and we have to be vigilant to ensure the resources are there in 10, 20, 30 years from now."

The plumes includes a narrow, mile-long slug of dry-cleaning chemicals beneath Farmington that is drifting toward the Vermillion River, one of the last surviving trout streams in the metro area. Recently drilled monitoring wells show that no pollution has reached the river yet.

In Edina, officials discovered in 2002 that one city well contained low levels of vinyl chloride, a cancer-causing chemical formed by the breakdown of other compounds. The city shut down the well, and plans to drill a new one elsewhere. The estimated replacement cost is $800,000.

Groundwater-dependent cities St. Louis Park, Blaine and Bayport require special treatment of their drinking water to remove chemicals dumped long ago. Cottage Grove and St. Paul Park could be the next cities needing such water purification plants; the 3M coating compound PFBA has been detected in those cities' wells.

At a U.S. Navy munitions plant in Fridley, groundwater containing a degreasing compound called TCE has been pumped out of wells on the bank of the Mississippi River for nearly two decades. Otherwise, TCE likely would enter the river -- just above the Minneapolis water supply intake.

Old dumping, back to haunt

One of the largest groundwater problems is the 7-mile-long blob containing solvents from the former Twin Cities Army Ammunition Plant in Arden Hills that has spread to northeast Minneapolis and the Mississippi River. At its widest point, the plume is 1½ miles across.

The U.S. Army and civilian contractors dumped chemical wastes at the plant from the 1940s on. The pollution seeped into a drinking-water aquifer, and years later reached municipal wells in New Brighton, where it was discovered in 1981.

For 17 years, giant carbon filters have purified the contaminated water for New Brighton's water system, removing enough solvents to fill an estimated 2955-gallon barrels, according to the Army. Ten times that amount has been extracted from groundwater and treated on the site.

"What is being drawn out of the wells now probably was dumped in the 1950s and later," said Mike Fix, director of the Army installation. The plant last produced ammunition in 1975.

The filtered water is considered safe to drink, and all the pumping helps shrink the underground plume. Levels of TCE have dropped. Even so, TCE levels last year in one well were 600 times higher than the federal standard.

So far, the Army has spent $186 million cleaning up pollution from the plant, more than half of that to deal with chemicals in groundwater, Fix said.

The work probably won't be finished for another 20 to 40 years.

In Woodbury, 3M has mounted a continuous battle since 1968 against groundwater pollution at one of its old dumps.

The company operates four wells that act like giant wet-vacs at the dump. For almost 40 years, they've sucked out enough groundwater to fill six Olympic-sized swimming pools -- every day. The system is supposed to halt the chemicals' underground movement. The extracted water is piped to 3M's plant in Cottage Grove, where some is used in production. It eventually ends up in the Mississippi River.

Regulators long believed such systems were slowly remedying the groundwater problem near the Woodbury site and two other disposal areas used by 3M in Washington County in the late 1950s and early 1970s.

That optimism has faded since 2004, when state officials began testing residential wells for 3M's perfluorochemicals, once used for nonstick cookware, stain-resistant fabrics, fire-suppression foams and film coatings. PFCs have been found in drinking water wells near the disposal sites, raising the question: Did the chemicals slip past the pump-out wells?

"It's soluble, it gets into the water and it goes," said Douglas Wetzstein, Superfund unit supervisor for the state Pollution Control Agency, which is still investigating how PFCs spread. "... We don't have all the answers, and the thing about PFCs is that every week or month that comes along, there seems to be some other angle that needs to be investigated."

One possibility is that PFCs escaped into Washington County's groundwater before any cleanup efforts began.

3M, the Maplewood-based manufacturer of Scotchgard, Post-It notes and thousands of other products, says it phased out PFCs by 2002 because the chemicals don't break down and had been detected in people and animals around the world. High concentrations of some PFCs have caused liver, thyroid and developmental damage in animals. One compound, PFOA, likely causes cancer, a federal scientific panel said last year.

In May, the company signed a new agreement with state regulators to investigate and to remedy the problems. It also has alerted 3M stockholders that another $121 million will be needed to deal with PFCs in Minnesota and at a plant in Alabama.

Paying the price, for years

At the Pine Bend oil refinery in Rosemount, pollution has trickled underground for years -- straight toward the Mississippi River 1½ miles a way.

After paying a record $6.9 million fine in 1998 for water and air pollution violations, the refinery owner Flint Hills Resources says it is working harder to prevent spills and leaks, and has spent $30 million cleaning up the old ones.

So far about 4.1 million gallons of product have been sucked out of the ground, using various methods. That's enough to fill nearly 500 tanker trucks. The waste is treated, incinerated or refined on site.

Workers periodically recover petroleum from a trench near the river, said John Hofland, a company spokesman. Some of the cleanup will go on another 10 years or more, he added.

Even low concentrations of pollution are worrisome -- and expensive.

In Oakdale, 3M last year paid $3 million to build a carbon-filtration plant that removes the chemical PFOA. The new plant is expected to cost $350,000 a year to operate.

The level of PFOA in the groundwater entering the plant is about 1 part per billion, slightly above the state drinking water limit. The chemical is undetectable after filtration. Each year, the city supplies 1 billion gallons of water to customers.

The net result: Filters will remove about a gallon of PFOA each year.

"That's the amount somebody threw in the ground years ago," said city public works director Brian Bachmeier.

At Jax Cafe in northeast Minneapolis, trout still swim in an artificial stream that runs through its back patio. For years, kids could net them for the cook to prepare and serve.

Not anymore.

The state Health Department says a private well feeding the stream contains low levels of PCP, a preservative once used to treat railroad ties at the Shoreham railroad yard, a mile to the north. Escaped chemicals left a 100-block plume of groundwater pollution.

No wells in the area are used for drinking water, including Jax Cafe's. Even if people ate trout from the artificial stream, the risk would be minimal, the Health Department says. Still, the 74-year-old bar and restaurant no longer serves them.

"It's costing us double," said owner Bill Kozlak Jr., who purchases other trout for eating. He is considering options including a new well or switching to city water, which already supplies the restaurant's faucets.

Jax Cafe's problem is emblematic of the burden of groundwater pollution. Low levels of chemicals in water rarely make people acutely sick. Yet across the metro area, the pollution carries a cost to cities, businesses and homeowners who have abandoned wells, drilled new ones, added expensive filters or switched to a municipal water source to avoid the long-term risks of chemical pollution.

In the ground, out of sight

Nobody sees or touches pollution at Louisiana Oaks Park in St. Louis Park. It has a pond, trails, playground equipment and soccer and football fields.

Almost forgotten is that from 1917 to 1972, Reilly Tar & Chemical Co. polluted the ground with chemicals used to treat railroad ties. The site eventually got cleaned up in the 1980s and 1990s under the federal Superfund program.

If you dig in the park, you'd soon hit creosote. It extends hundreds of feet below the surface. Engineers didn't try removing it all. The cost was estimated at more than $100 million in 1980, and the tar probably would have clung to the deepest crevices anyway.

"There wasn't anything you were going to do to make the site clean from top to bottom," said William Gregg, senior program manager for the environmental consulting and engineering firm ENSR in St. Louis Park. He has overseen the cleanup since 1980.

The groundwater is polluted for nearly 4 square miles with tar-related chemicals called PAHs, some of which are carcinogens and none of which easily degrade.

For two decades, high-capacity wells around the park have sucked out enough groundwater to halt the plume's progress into Edina's drinking water wells. Most of the pumped-out water is purified, using carbon filtration, and supplies St. Louis Park residents with drinking water.

Reilly spent about $20 million in legal fees, engineering work and cleanup in the 1980s, Gregg said. The company doesn't have to pay the $500,000 annual cost of monitoring and treating the groundwater pollution. The city accepted that responsibility under a 1972 agreement with Reilly.

"I think there was a miscalculation by the administration and the politicians at that time," said Scott Anderson, who became superintendent of utilities after the agreement. Pumping, treating and testing the groundwater likely will be necessary for decades.

"I do not believe I will live to see the end of it," Anderson said. "There is no projected time on it. ... I would say we don't see the light at the end of the tunnel."

Graphic artist Billy Steve Clayton contributed GIS mapping and analysis for this report. David Shaffer • 612-673-7090



David Shaffer •

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