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.
EPA resources that will be used for clean up of the contaminated property have begun arriving on site. Office trailers, heavy equipment, and personnel are being mobilized.
The overgrowth of weeds and grass will make it cumbersome to conduct site activities. EPA contractors have begun cutting weeds and grass throughout the site.
EPA has identified two buildings on site that will require demolition to address contaminated soil underneath a deteriorating asphalt cap. The first building to be removed is a small warehouse located at the center of the site parallel to the North and South Mixing Plant. The second building will be a tool storage shed that is located near 6th street on the southern half of the site. EPA is working closely with the current land owner on the removal of building contents to an alternate location to allow for building demolition.
EPA is disseminating information about current site activities to near by residents, city officials, the local media, and the general public. All information is made available in both English and Spanish. An EPA office trailer will be available on site to allow the communities an opportunity speak with and EPA representative in person about any questions or concerns they may have about site activities. This office will contain and have available up to date and current information on all site activities throughout the entire clean up process.
Once all building contents from the identified buildings have been relocated and secured, building demolition will begin. The process for building demolition is as follows. Demolition contractors will begin first by removing the exterior metal siding of the small building, identified as the warehouse, by using an excavator with a hydraulic thumb attachment. The removal of the exterior metal will be done slowly and carefully to ensure a minimum impact with the surrounding area. After all the exteriors walls have been taken down, the building's roof along with the metal bracing will be removed.
EPA is working closely with the City of Mission School district on ensuring the health and safety of it's school children. On 09/26/2006 the EPA met with the City of Mission school superintendent and board members on answering questions and concerns about current and future site activities. EPA and the school district will identify safe traffic routes for use by the EPA that will be utilized during the clean up.
The first phase of the clean up will consist of site preparation and the mobilization of EPA equipment and resources.
The second phase will involve the removal of the above ground storage tanks (ASTs), and building shed and warehouse demolition.
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 will be 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. Wet demolition techniques will be used during building demolition to reduce and / or eliminate offsite migration of dust.
EPA will take every precaution in minimizing the level of dust accumulation during all site activities throughout the entire clean up process. EPA is committed to the public health and safety of it's workers and the neighboring community.
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