The Engine Test Area (ETA) was part of the U.S. Air Force Plant Number 65 used to test fire liquid-propelled rocket engines during the 1950s and 1960s. Since the 1970s, the ETA has been used for various training activities by the Missouri Army National Guard. Because the ETA remains under the control of the United States Army as a part of Camp Crowder, the Army Environmental Center (AEC) is the lead agency for selecting and implementing the cleanup action for the ETA.
Camp Crowder comprises approximately 4,300 acres with a portion lying within the Neosho, Missouri city limits. The ETA site is located just southeast of Neosho, Missouri in Newton County, Missouri and is outside of the Neosho city limits.
The ETA includes the following areas of concern (AOCs): North Engine Test Stand (NETS), South Engine Test Stand (SETS), Test Shop Number 1 (TS1), Hazardous Waste Pit (HWP), Hazardous Waste Pit Surrounding Area (HWPSA), and the liquid oxygen (LOX) storage area.
This removal action addresses only cleanup of soils at the ETA. Groundwater issues will be addressed in a future site-wide remedial investigation/ feasibility study of the entire Pools Prairie Superfund Site (including the ETA). Based on findings reported from subsurface investigations, the soil is contaminated with the volatile organic compound (VOC) constituents trichloroethylene (TCE) and vinyl chloride (VC). TCE and VC were commonly used as degreasers.
Overall, the majority of the contamination at the ETA site is at the HWP. This area is located centrally between the NETS and SETS. The HWP is a concrete pit which collected runoff from the liquids used in the flushing of fuel and lubricants at the test stands.
AEC conducted an engineering evaluation/cost analysis (EE/CA) to identify and evaluate potential removal actions that would appropriately address the contaminated areas. Information for the EE/CA was developed based on data collected during the subsurface investigations and a pilot study conducted at the ETA. The EE/CA was completed in March 2006.
RECOMMENDED CLEANUP ACTION
Based on information in the EE/CA, the recommended cleanup action for the contaminated soils at the HWP is excavation and treatment by landfarming.
Landfarming consists of removing the contaminated soil and spreading the soil in layers approximately one foot thick over a lined and bermed area. The berm contains the soil, and the liner prevents contaminants in the soil from moving to underlying soil. The soil is turned over frequently using a tractor and large disks. Turning the soil over exposes the contaminants to air and sunlight, causing them to degrade and evaporate. Rainwater collected in the bermed area is also treated before it is discharged. Sampling of soil and water will be performed to confirm effective treatment of the landfarmed materials. The cleanup for the HWP is estimated to cost between $1.25 and $1.4 million.
