On June 30, 2006, the Ohio EPA requested U.S. EPA assistance in conducting a time-critical removal action at the East Troy Contaminated Aquifer Site (aka Troy VOC Plume Site), located in Troy, Ohio. Ohio EPA investigations show that groundwater is contaminated with tetrachloroethene (PCE) from two or more sources. Wells within the Troy east well field have been impacted with volatile organic compounds (VOCs) at concentrations below maximum contaminant levels MCLs). PCE and other VOCs have been detected in indoor air samples collected by the city of Troy from several occupied structures including the Troy police station, a church, and a school.
Ohio EPA noted that residences and other occupied structures above and adjacent to the ground water plumes are at risk for exposure to VOCs through vapor intrusion from soil gas to indoor air. Ohio EPA requested U.S. EPA to conduct a removal action assessment to determine the extent of vapor intrusion contamination and to mitigate levels of VOCs in indoor air that exceed screening levels established by the Agency for Toxic Substances and Disease Registry (ATSDR) and Ohio Department of Health (ODH).
In July-August, 2006, U.S. EPA conducted sub-slab and indoor air sampling at residences, church, schools to evaluate threat to human health. ATSDR and ODH will review air data in August and provide recommendations.
In a letter dated September 11, 2006 to U.S. EPA, ATSDR and ODH recommended a health-based screening level for residential indoor air for PCE is 1.2 ppb.
A U.S. EPA public meeting was conducted on October 25, 2006 (6 pm) at Van Cleve School. See documents and links below for further information.
The extent of contamination sub-slab and indoor air sampling (Phase 2) continues in November-December, 2006 at residences identified since the October 25, 2006 public meeting. More than 40 residences and buildings have been sampled as of December 11, 2006.
January 3, 2007 Update: For Troy residents interested in EPA sub-slab sampling in the area of concern, please contact Weston Solutions at 937-602-3089 prior to January 14, 2007. See documents below (Resident Letter) for letter sent by EPA extending the sampling to January 14, 2007.
April 17, 2007 Update: From July 2006 through April 2007, the U.S. EPA collected sub-slab and indoor air samples from a total of 85 locations, which included 78 residences, 2 churches, 4 schools and the Troy Police Station during Phase 1 and Phase 2 air sampling activities.
May 31, 2007 Update: The EPA removal action was initiated on May 31, 2007. EPA, ODH, and OEPA met with 17 property owners at Troy City Hall to discuss installation of vapor abatement mitigation systems. Installation of vapor abatement mitigation systems is scheduled for June-July, 2007 at 16 residences and 1 elementary school. Following installation, EPA will conduct performance sampling to confirm that indoor air PCE and TCE levels are below ODH screening levels.
July 6, 2007 Update: The EPA removal action continues. To date, 4 (of 16) residential vapor abatement systems have been installed. On July 5, 2007, installation of the vapor abatement system at St Patrick Elementary School was initiated.
July 18, 2007 Update: The EPA removal action continues. The vapor abatement system installation at St. Patrick Elementary School was completed on July 17, 2007. Post installation indoor air sampling is scheduled for the week of July 23, 2007. To date, 4 (of 16) residential vapor abatement systems have been installed.
July 27, 2007 Update: The EPA removal action continues. Post installation vapor abatement system air monitoring was completed at St Patrick Elementary School on July 26, 2007. To date, 9 (of 16) residential vapor abatement systems have been installed (see images below).
August 8, 2007 Update: To date, 16 (of 16) residential vapor abatement systems have been installed. Post installation vapor abatement system monitoring is scheduled for August 2007 - March 2008.
The EPA removal action was completed on April 17, 2008. See POLREP #2 for more information.
