Abstract |
The 17,000-acre Rocky Mountain Arsenal (RMA) (Operable Unit 23) site is a former U.S. Army chemical warfare and incendiary munitions manufacturing and assembly plant in Adams County, Colorado. Operable Unit 23 (OU23), the Shell Section 36 Trenches, is one of several areas being addressed as part of the Other Contaminated Sources Interim Remedial Action. Approximately 31 trenches occupy an 8-acre area of Section 36 in the central portion of the RMA. From 1952 to 1965, liquid and solid waste including bulk or drummed process intermediates, off-specification product, laboratory sample filters, and other debris from the manufacture of pesticides was disposed of and buried in the trenches. Investigations by the Army from 1987 through 1989 have identified ground water contamination in a surficial unconsolidated sand aquifer underlying the site. A plume of dense non-aqueous phase liquids (DNAPLs) was also detected, and is believed to have originated from the Shell Section 36 trenches. The primary contaminants of concern affecting the soil and ground water are VOCs and other organics including pesticides. |