Rocky Mountain Arsenal continues to leak contaminants into groundwater, Colorado health department suit says

The Colorado Department of Public Health and Environment has sued the U.S. Army claiming that dangerous chemicals including pesticides continue to leach into groundwater at Rocky Mountain Arsenal .

The Colorado department’s risky Materials and Waste Management Division filed the suit Monday in U.S. District Court in Denver to force the Army to follow with standards set by the federal Comprehensive Environmental Response, Compensation and Liability Act (CERCLA).

CDPHE is asking the federal court to compel the Army to install or modify the existing treatment system to effectively prevent pollutants from contaminating groundwater, the suit says.

Organochlorine pesticides, heavy metals, agent degradation products and manufacturing by-products, and chlorinated and aromatic solvents are getting into groundwater in unsafe levels, it says.

“All of these constituents constitute threats to human health and the environment,” the suit says.

Beginning in 1942, the Army used the 27-square-mile arsenal at 5650 entrance Road in Commerce City for the manufacture and disposal of chemical warfare agents, and chemical and incendiary munitions. Between 1946 and 1987, the Army besides hired portions of the arsenal to Shell Oil Company to manufacture pesticides.

The Army and Shell operated Basin F, a risky waste surface impoundment for the storage and treatment of liquid and solid risky wastes, but the facility leaked wastes into the environment after waste disposal complete in 1981, the suit says. Recent tests have confirmed that the contamination continues “to this day,” it says.

The CDPHE issued the Army a notice of non-compliance, claiming its containment and treatment measures were not working. It cited seven violations.

The Army replied by indicating federal government should regulate the arsenal Superfund program program site through the CERCLA, and not state environmental government.

But CERCLA empowers Colorado to enforce federal standards, the suit claims.

Colorado health officials contend that Shell’s trenches and suspension walls have not prevented pesticides and other dangerous chemicals from leach into the groundwater.

Beginning in October 2012, testing has discovered that pollutants have at large the Shell trenches and groundwater is likely coming into contact with the waste and migrating out of the trenches, the suit says. Further testing discovered that the containment issue is an ongoing problem, the suit says.

State health officials are asking the federal courts to intervene to stop the contamination on the north and northwest boundaries of the trenches. The defendants must build a system to “actively dewater” Shell’s trenches to prevent the mix of effluent with groundwater, the suit says.