US Army Corps of Engineers, Kansas City District
Overview:Under our HTRW contract with the Kansas City District of USACE, Avatar conducted a Remedial Investigation of the Former Forbes Atlas E Missile Facility S-5, a FUDS located in Lyon County, Kansas. Project included:
- Geological investigation
- Soil and groundwater investigation
- Contaminant fate and transport
- Environmental chemistry data collection, management, and interpretation
- Human health risk assessment
The S-5 site is one of nine Atlas E missile launch facilities operational between 1959 and 1965 as part of the Forbes AFB operations at Topeka, Kansas. The site was a “coffin-type” installation having one missile erection and launch facility and supporting facilities, including an underground launch control center, tunnel, foundation for a missile operations building, water supply well, water supply buildings, water treatment plant, septic system, cooling tower pad and other support facilities. The site was declared excess in 1965 and was sold in 1967. The property has had several owners over a period of years. A substantial portion of the supporting facilities, hardware, and other equipment at the site was dismantled and removed prior to sale. The site has been under private ownership for approximately 47 years.
Based on historical sample results and experience at similar sites, the primary contaminant of concern was believed to be TCE contamination in groundwater and corresponding breakdown products. All required project planning documents including a UFP-QAPP (with a risk assessment work plan), an Accident Prevention Plan including a Site Safety and Health Plan, a Data Management Plan and a Community Relations Plan were developed prior to fieldwork. Plans were reviewed and approved by the USACE Kansas City District Project Development Team and the Kansas Department of Health and Environment (KDHE) with few revisions.
- RI field work consisted of:
- Collection of 50 soil samples from 10 soil borings
- Installation of 11 monitor wells including 4 shallow/deep well pairs
- Water level measurements and slug testing of all newly installed wells
- Collection of 10 surface water and 10 sediment samples from sumps and ponds
- 8 rounds of groundwater sampling
Soil borings and wells were advanced using sonic drilling equipment. To date, 3 of the 8 rounds of groundwater sampling have been completed. In addition to VOC analysis, natural attenuation parameter analysis is included for all groundwater samples. Groundwater flow maps and natural attenuation screening (Wiedemier scoring method) is performed for each round of groundwater samples. Based on the first 3 rounds of sampling minimal natural attenuation appears to be taking place within the aquifer.
Once the 8 rounds are completed a CERCLA compliant human health risk assessment will be completed and an RI Report prepared.