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. June 1-July 6, 2003: EPA and START conducted an on-site tour of the neighborhood to determine the accessibility for sampling equipment of individual residential properties. No additional on-site activities were conducted during this period. START continued preparation for field activities scheduled for late July 2003.
B. On June 24, 2003, OSC Aquino contacted contact person from TOSC - University of Maryland School of Nursing as per conversation with CIC Evans to request assistance with the residents of Lamont Riggs Park. TOSC will assist the community in the area under investigation with resources outside the federal government on understanding the science and health concerns associated to the site.
A. Implementation of the sampling plan is scheduled to begin in late July 2003. After obtaining property access approval from individual residents, EPA and START will initiate field activities. In the first phase of field activities, 16 permanent soil vapor implants and six pre-packed groundwater monitoring wells will be installed. Using power hand-tools or manual methods, one implant will be installed no more than 5 vertical feet beneath the concrete basement slab of each selected residential duplex. The six monitoring wells will be installed in two groups of three: one set will be located in the vicinity of the southern end of Oglethorpe Street block between Riggs Road and 8th Street, and the other set will be located near the intersection of Oglethorpe Street and Riggs Road. The wells will be installed using direct-push methods.
EPA and START will begin the second phase of field activities by conducting resident interviews and coordinating temporary removal of any potential household vapor sources (e.g., gasoline, rubbing alcohol, spray paint, etc.) from indoor areas of individual residences. The Emergency Response Team's (ERT) Trace Atmospheric Gas Analyzer (TAGA), a mobile laboratory, will subsequently be utilized to conduct real-time screening of specific individual homes to determine if any hidden or undiscovered vapor sources remain in the home. By removing all vapor sources from indoor areas, EPA can more accurately assess potential intrusion of soil vapor into the home. If ERT determines that all vapor sources have been removed from indoor areas, START will place Summa canisters in basement and first-floor areas of the home. The Summa canisters will use a continuous-flow regulator to collect air samples for a period of 24 hours. START will return the following day to retrieve the Summa canisters.
In addition, START will also collect active soil vapor samples from the permanent soil vapor implants, groundwater samples from the pre-packed monitoring wells, tap water samples from two residences, and up to six aqueous sump samples if water is observed in the sumps of any homes scheduled to be sampled as part of this phase of the project.
B. Attend public meetings and prepare presentations of completed, on-going, and planned activities in response to the PERC release.
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