…in 1952 Shell Chemical took over. Among the substances produced were aldrin and dieldrin, both thought to cause cancer.
Robert C. Unruh, Associated Press 25 May 1986
For generations, a devil’s brew of waste nerve agents and chemicals has been percolating at the Rocky Mountain Arsenal, where rolling plains in the shadow of downtown Denver’s skyscrapers belie the trouble underground.
The arsenal’s grasslands, dotted with old farm buildings, once were an isolated production site for government nerve gas and commercial pesticides and herbicides.
But as the Denver metropolitan area grew to the northeast, houses sprouted just yards from the arsenal’s barbed boundary fence. People began feeling uneasy about their neighbor, which at 17,000 acres is about one-fourth as big as the city.
A few years ago, a chemical that can cause sterility, dibromochloropropane, or DBCP, was found migrating in groundwater to nearby water wells. A filtration system was installed to catch it.
It was a warning.
In recent months, 30,000 users of the South Adams County Water and Sanitation District have learned there are traces of trichloroethylene, or TCE, in their drinking water. They now are boiling their water or buying it bottled, and their children drink bottled water at school.
The Army, which runs the arsenal, says it knows roughly where some of the TCE is coming from. But spokesman Tom Donnelly says there is evidence of other contamination, to which none of the arsenal’s 140 known hazardous waste dumps could be contributing.
That would mean there are unknown sources of trichloroethylene at or near the arsenal.
TCE causes liver and nervous-system damage in laboratory animals and is considered a carcinogen. For years it was commonly used in degreasing compounds. There is no EPA-approved maximum standard level for TCE content in water yet, although one in the range of 5 ppb has been proposed.
The current readings of TCE have reached as high as 200 parts per billion in a test well on the arsenal grounds, and as high as 98 ppb in a private well 200 yards from the arsenal.
Water district wells tested in the 40-50 ppb range and were shut down. The district plans to tap temporarily into Denver’s water supply.
But the private well that had the highest TCE readings is not in line with the underground water flow from the arsenal wells with the highest readings. And the Army concedes it does not know what other chemicals are at the arsenal.
For many of the chemicals suspected of being present, there are no long- term studies for effects. It is known that massive doses to test animals over short periods cause problems, but that allows scientists only to guess about effects on humans.
The seriousness of the TCE concentrations for residents near the arsenal remains a subject of debate.
“The short-term risk is so close to zero that I myself would continue to drink the water,” said Dr. Thomas Vernon, of the state Department of Health.
Marc Alston, of the public water supply section of Denver’s office of the Environmental Protection Agency, added that “for the short term, (this) presents a very, very low risk as best we know.”
But for years people also lived with asbestos, unaware of the dangers of asbestosis, and many people who live near the arsenal are unwilling to talk about “allowable risks.”
“We are operating on approximations and estimates,” Alston said. “What we do not know overwhelms what we do know.”
The arsenal’s history helps explain that. The 27-square-mile area was opened in 1942 to make chemical and incendiary weapons, and during the Korean War a nerve gas plant was built there.
At the same time it was used for storing and disposing of obsolete chemical weapons, including mustard and nerve gases.
In 1947, Julius Hyman and Co. leased a portion to make pesticides and herbicides, and in 1952 Shell Chemical took over. Among the substances produced were aldrin and dieldrin, both thought to cause cancer.
Dibromochloropropane was found in nearby water wells in the 1970s. The Army and Shell built filtration systems to suck the water out of the water table about 60 feet in the ground, filter it and reinject it.
“Experts have called Rocky Mountain Arsenal the most contaminated piece of real estate in the nation,” said Rep. Ken Kramer (R., Colo.).
The Army is continuing to inventory known chemical hot spots, going back through records and fetching old-timers to test their memories.
Col. Wallace Quintrell, the deputy program manager of the arsenal’s cleanup effort, said studies show the arsenal’s TCE problem could stem from a single spill of 17 or 18 gallons.
The Army also has signed a preliminary agreement to provide $1 million for a new water treatment system, so that residents of Commerce City, Irondale, Adams City and Dupont no longer will have to boil their water or use bottled supplies.
Meanwhile, some of those living near the arsenal are impatient and are urging an EPA Superfund cleanup.
Says Beth Gallegos, a member of Citizens Against Contamination in Adams County: “The bottom line is that we are entitled to safe drinking water, and we should not have to go through a fight to get it.”
Associated Press syndicated article. This example published on page 6 of The Philadelphia Inquirer May 25, 1986
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Dow links chemical to low fertility: 21 October 1977
Pesticide exposure limitations sought: 02 November 1977
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