Site Overview

Atlas D Missile Site 4 located in Laramie County, Wyoming is a Formerly Used Defense Site (FUDS), previously under the command of F.E. Warren Air Force Base (AFB). The U.S. Army Corps of Engineers (USACE), Omaha District, is managing the environmental cleanup resulting from former activities at the site that have contaminated the groundwater with trichloroethene (TCE), a cleaning solvent. The site is located approximately 18 miles west of Cheyenne and one mile south of the town of Granite, Wyoming. The site vicinity is illustrated in Figure1.

The property was one of four Atlas D missile sites and nine Atlas E missile sites operated in Colorado, Nebraska, and Wyoming by F.E. Warren AFB. The Atlas D model was the first fully operational strategic missile developed by the U.S. and, with a range of 8,700 miles, was designed for deployment of high-yield nuclear warheads against the Soviet Union. The Atlas D missile used liquid rocket propellant-1 (RP-1, similar to kerosene) for fuel and liquid oxygen as the oxidizer.

Site 4 was used for the housing, readiness, and potential launch of nuclear missiles. During readiness exercises conducted at each of the three launch areas, the RP-1 was pumped from an underground tank into the missiles and then pumped back into the tank. TCE was used as a solvent to clean the rocket fuel tanks, engines, and liquid oxygen lines to prevent accidental explosions. Spent TCE and other wastes formed during the readiness exercises were removed with water, which drained into a series of unlined pits and channels 20 to 30 feet deep (referred to as Burnout Pits). A site map, showing key site features and their respective orientation to one another, is provided as Site 4 features . If all three launch areas were tested each of the three years of operation, the estimated amount of TCE that may have been released would range from 450 to 16,200 gallons. 

Site 4 originally consisted of approximately 703 acres acquired by purchase and condemnation between 1959 and 1962 and was developed during that time. By 1964, the liquid-fuel Atlas D missiles were being phased out in favor of new solid-fuel Minuteman Intercontinental Ballistic Missiles and the property was excessed to the General Services Administration (GSA) for disposal in 1965. In early 1967, 338 acres of fee and easements were conveyed by quitclaim deed to Southern Scrap Iron and Metal Company of St. Louis, Missouri. That property was subsequently sold to the Belvoir Grazing Association of Ault, Colorado. The GSA sold the remaining property to Belvoir Grazing and Timnath Farms in January 1976. The Belvoir Ranch was acquired by the City of Cheyenne and the Cheyenne Board of Public Utilities in 2003. The property is leased to private parties for cattle grazing and stock watering.

TCE has been detected on-site at a maximum level of 200,000 micrograms per liter (ug/L) in one well.  Downgradient of the source area, TCE detections in groundwater are generally less than 40 ppb.  EPA’s maximum contaminant level (MCL) for TCE in drinking water is 5 parts per billion (ppb). Site 4 and the downgradient Belvoir Ranch and adjoining properties have been segregated into three general areas based on site characteristics, topography, and contaminated media. The three general areas are defined as Area A, Area B, and the Transition Area.

The launch and service building area of Site 4 (Section 20, Township 13 North, Range 69 West [6th Principle Meridian]) is the contaminant source area and is referred to as Area A. Numerous monitoring wells have been installed in this area by the USACE. The western portion of the Borie Well Field (a drinking-water source for the City of Cheyenne located in Sections 7 through 36 in Township 13 North, Range 68 West) is referred to as Area B. Numerous residential, industrial, municipal, and irrigation wells are located in Area B. Several deep oil wells are also located in the northeastern part of Area B. The west edge of Area B is located four miles east of Area A; the area between Area A and Area B is referred to as the Transition Zone. The Transition Zone contains a four-mile long segment of Lone Tree Creek and adjacent upland areas (three miles wide, including Sections 13-17 and 21-27). Several monitoring wells have also been installed in this area by the USACE. Two stock wells are located in the northwest corner of this area (1/2 mile northeast of Area A) and a few residential wells are located in the northeast part the Transition Area.