Colorado agency’s lawsuit: Rocky Mountain Arsenal still leaks contaminants into groundwater
By KIRK MITCHELL | The Denver Post | Published: April 16, 2019
DENVER (Tribune News Service) — 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 Hazardous Materials and Waste Management Division filed the lawsuit Monday in U.S. District Court in Denver to force the Army to comply 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 lawsuit 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 lawsuit says.
Beginning in 1942, the Army used the 27-square-mile arsenal in Commerce City for the manufacture and disposal of chemical warfare agents, and chemical and incendiary munitions. Between 1946 and 1987, the Army also leased portions of the arsenal to Shell Oil Company to manufacture pesticides.
The Army and Shell operated Basin F, a hazardous waste surface impoundment for the storage and treatment of liquid and solid hazardous wastes, but the facility leaked wastes into the environment after waste disposal ended in 1981, the lawsuit says. Recent tests have confirmed that the contamination continues “to this day,” it says.
The CDPHE issued the Army a notice of noncompliance, claiming its containment and treatment measures were not working. It cited seven violations.
The Army replied by indicating federal authorities should regulate the arsenal Superfund site through the CERCLA, and not state environmental authorities.
But CERCLA empowers Colorado to enforce federal standards, the lawsuit claims.
Colorado health officials contend that Shell’s trenches and slurry walls have not prevented pesticides and other dangerous chemicals from leaching into the groundwater.
Beginning in October 2012, testing has revealed that pollutants have escaped the Shell trenches and groundwater likely is coming into contact with the waste and migrating out of the trenches, the lawsuit says. Further testing revealed that the containment issue is an ongoing problem, the lawsuit 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 mixing of effluent with groundwater, the lawsuit says.