Commerce City’s plan to develop a portion of the former Rocky Mountain Arsenal is not “a slam dunk”

It might be perfectly safe, but state environmental officials say it needs a thorough investigation.
5 min. read
A prairie dog outside the Rocky Mountain Arsenal Wildlife Refuge. (Kevin J. Beaty/Denverite) nature; animals; kevinjbeaty; denver; colorado; denverite;

The former Rocky Mountain Arsenal site is good enough for this prairie dog. (Kevin J. Beaty/Denverite)

Commerce City is hopeful that a provision in a recently passed defense spending bill will clear the way for houses, stores and offices on the former Rocky Mountain Arsenal site. Since the 1980s, restrictive covenants have barred any residential construction at the former chemical weapons manufacturing facility, most of which is now, post-remedition, a national wildlife refuge.

Will it be safe? Quite possibly, but right now, no one knows.

What the legislation allows is for the restrictions to be lifted if environmental assessments show its safe for human habitation. Now Commerce City needs to come up with a plan for testing and sampling that will pass muster with the Colorado Department of Public Health and Environment and the Environmental Protection Agency.

A preliminary study in 2002 did not find contamination, but state public health officials said a much more thorough examination needs to be done.

"The state and the EPA would work with Commerce City to develop the methodology and the criteria," said Warren Smith, community involvement manager for the Hazardous Materials and Waste Management Division of CDPHE. "It would be quite rigorous. It would not be a slam dunk."

The land bought by Commerce City in 2004 for the Victory Crossing project sits at the southwest corner of the former chemical weapons manufacturing site and includes the area north of 56th Avenue between Quebec Street and Central Park Boulevard. Dick's Sporting Goods Park is part of this project, but the development of housing, stores and offices has been delayed by the covenants whose purpose was to prevent just such habitation.

Susan Newton, Rocky Mountain Arsenal project manager for CDPHE, said the site is a bit unusual for a Superfund site in that the covenants were put in place before any detailed assessment of the dangers. In later projects, covenants were put in place after assessment and remediation to restrict access to areas that could not be cleaned enough to ever be safe, but Rocky Mountain Arsenal was one of the first projects to go through the Superfund process.

"It was just known that there was a big, ugly mess out there," Newton said.

The clean-up effort focused on the interior of the site, where weapons manufacturing occurred and where there was known to be extensive contamination with volatile organic compounds, heavy metals, pesticides and diisopropyl methylphosphonate, a chemical associated with the production of nerve gas. The area identified for the Victory Crossing project was a buffer area on the exterior of the site. It's never really been studied.

The contamination was remediated mostly by removing enormous amounts of soil and burying it in specially constructed landfills. Groundwater contamination continues to be a problem, and there are several spots where water is pumped and treated before being returned to the earth.

The good news for Commerce City is that groundwater in the area flows to the north and northwest, away from the area the city wants to develop.

That said, when Rocky Mountain Arsenal was removed from the Superfund program's National Priorities List, that delisting was contingent on the covenants staying in place.

"It's known that the buffer areas were not subject to the same intensive use, but they haven't been characterized and there hasn't been the sampling that would be necessary to determine if it's safe for the kind of residential uses that Commerce City envisions," Newton said.

"I don't know that there is any expectation that they would find something that would be of concern, but that investigation absolutely has to be done."

I knew this was probably an apples and oranges comparison, but I had to ask about Rocky Flats, Denver's other infamous Superfund site that's now a wildlife refuge with new housing development on its edges. Rocky Flats was used to manufacture plutonium triggers for warheads. On two occasions plutonium fires sent contamination across the metro area, and there were also storage leaks that contaminated the soil.

This year, a group called Rocky Flats Downwinders conducted a health survey in cooperation with Metro State University of people who lived in the area while the plant was in operation and found a possible elevated incidence of certain rare cancers. CDPHE's Colorado Cancer Registry is using that data to update a previous study that found cancer risks were similar to people living in other parts of the region. The Downwinders study required people to self-report, so people who got sick may have been over-represented, but it also includes people who moved away from the area before they got sick who may not have shown up in previous studies.

Newton said one difference is that we know a lot more about the off-site areas around Rocky Flats than we do about the buffer areas around Rocky Mountain Arsenal. Though some people have a lingering unease about living near Rocky Flats, the areas around the refuge have been cleared by the EPA and CDPHE, Smith said.

"The similarities are that they were federal weapons facilities that have been cleaned up to the point they can be wildlife refuges," Smith said. "The similarities kind of end there."

"Some of the chemicals that were present at Rocky Mountain Arsenal are much scarier to me personally than anything at Rocky Flats," he added. "There were things at Rocky Mountain Arsenal that could kill you immediately."

Newton said the environmental assessment could take about a year.

"We want people to understand that it is not going to be a quick or haphazard process, and we are extremely committed as an institution to making sure that whatever happens out there is safe," Smith said.

Clarification: This story has been updated to include that there was a preliminary study on the site in 2002.

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