The Helena Chemical Company (HCC) facility located in Mission, Texas, was used for pesticide formulation from 1950 to 1972. The facility is located in a primarily residential neighborhood and currently incorporates five structures within the property boundary (Attachment 2). Soil samples collected in 1980 from the HCC site and surrounding areas indicated elevated concentrations of various pesticides. A lawsuit was filed on behalf of the EPA against the two former owners of the facility, HCC and the Tex-Ag Company. As a result of the lawsuit, the former owners entered into a Consent Decree to remediate the contaminated properties. In 1982 the most highly contaminated soils on the HCC facility site were excavated to a depth of six inches below ground surface (bgs) and buried on site within a soil repository. The repository was capped by a six-inch layer of caliche that was overlain by a one-inch layer of asphalt. In 1983 a Federal District Judge in Brownsville, Texas, ruled that all cleanup activities specified in the Consent Decree had been carried out (Shaw 2004). The Texas Commission on Environmental Quality (TCEQ) remediated residential areas adjacent to the Site in August, 2003.
During the TCEQ remediation of the residential areas, they observed the weakness and failures of the cap. They contacted EPA’s Site Assessment Team to request a new Preliminary Assessment / Site Investigation (PA/SI) to be conducted at the site for Hazard Ranking System (HRS) analysis. The HRS analysis resulted with the Site not qualifying for inclusion on the National Priorities List (NPL). The Site was referred for consideration for a potential Removal Action due to the deteriorating cap.
On Monday October 16, 2006 EPA began the excavation of contaminated soil underneath the asphalt cap on the southwest corner of the Site near the intersection of Holland Ave. and W. Sixth St. A series of small 25 foot square grids have been identified throughout the Site that will be used as markers for excavation. Excavation will be completed in small manageable grids to minimize offsite migration of odors and dust. To date, EPA has excavated and stockpiled approximately 280 cubic yards of soil. EPA has not begun the transportation and disposal of any soil off Site.
Excavated soils are being stockpiled on Site for further analysis and waste characterization. A plastic sheathing is being used to cover all stockpiles and excavated holes on Site to minimize offsite migration of odors, dust, and the potential for contaminated storm water runoff. A fractionation tank has been mobilized on Site and will be used for containment and water quality sampling of any potentially contaminated storm water.
A network of air monitoring and air sampling devices are being used at excavation and stockpile areas on Site and in the community during the clean up process to ensure air quality standards are met.
An EPA community office trailer is available on Site. This office will allow communities an opportunity to speak with and EPA representative in person about any questions or concerns they may have about ongoing Site activities. This office has up to date and current information available in both English and Spanish.
On Saturday October 20, 2006 EPA plans on continuing the excavation of contaminated soil underneath the asphalt cap on the southern half of the Site. Results from soil sampling for waste characterization and soil analysis is excepted early next week.
Based upon sampling results, contaminated soil will be properly disposed of in accordance with Federal and state guidelines.
EPA plans on conducting air sampling and monitoring during evening and night hours to ensure air quality standards are met. All data will be made available to the public immediately after a through laboratory analysis is completed.
Review soil sampling data for waste characterization and analysis.
Continue excavation of contaminated soil underneath asphalt cap.
Begin evening and nighttime air sampling and monitoring at the Site and in the community to ensure air quality standards are being met.
Health and safety concerns have been raised about dust that may be potential contaminated migrating offsite during the clean up process.
An extensive network of air monitoring and air sampling safe guards are being utilize on Site and within the neighboring community. All scientific data will be quickly analyzed and made public for city and community leaders to review and discuss with the EPA. Dust control techniques will be used during soil excavation to reduce and / or eliminate offsite migration of dust.
EPA is committed to the public health and safety of it's workers and the neighboring community.
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