EPA has been asked to investigate tetrachloroethylene (PERC) contamination in Hyattsville (Chillum), Maryland and Washington, District of Columbia. PERC contamination was discovered during an on-going investigation of a gasoline-products release from a service station located in Hyattsville near the Chillum Perc property. The site under investigation includes a dry cleaning facility and a residential community. The dry cleaning facility is located in Maryland and is immediately adjacent to the Washington, DC border. Groundwater flow flows from Maryland into Washington, DC, and one or more plumes of groundwater containing PERC may be present beneath the local residential community.
A. May 1, 2003: EPA and START attended an Executive Committee meeting at Faith Moravian Church at 405 Riggs Road NE, Washington, DC, to summarize sampling activities and analytical results available to date. Individual resident personal privacy was maintained at all times.
A. The expanded scope of work includes but is not limited to the installation of "nested" permanent soil vapor implants and pre-packed one-inch microwells, sampling of soil vapor using active techniques, and sampling and laboratory analyses of groundwater, sump water (where present), tap water, and indoor air (using SUMMA™ canisters). In addition, the Emergency Response Team's (ERT) Trace Atmospheric Gas Analyzer (TAGA) will be utilized to conduct real-time screening of specific individual homes and analyze active soil vapor samples. Sampling locations will be selected based on a risk-based assessment of previously collected data. The expedited sampling event conducted on April 14-15, 2003, during which SUMMA™ canisters were placed in the homes of two residences is also part of this most recent scope of work. The two residences were selected based on an exeedances of the short-term soil screening level for PERC in soil vapor samples collected from beneath the basement slabs. Though no analytical data were collected from the adjoining residences of each duplex at which a short-term exceedence was encountered, EPA and START will collect samples from these residences since the each side of the duplex shares the same basement slab. Field exercises are planned for July/August, 2003.
B. Attend public meetings and prepare presentations of completed, on-going, and planned activities in response to the PERC release.
C. Prepare sampling and analysis plan for expanded work.
D. Forward analytical results of PERC data collected by Chevron to residents. During any correspondence between EPA and individual residents, resident personal privacy will be maintained at all times
|
