Bio-Ecology Systems, Inc. is an 11-acre former industrial waste management facility in Grand Prairie, Texas, in Dallas County. The state of Texas licensed it as a Class I facility in 1972, but the owners went bankrupt in 1978. EPA added it to the Superfund National Priorities List on September 8, 1983, and deleted it on August 5, 1996, after cleanup goals were met.
The site contaminated soil, groundwater, and leachate with nine contaminants of concern. Those contaminants are arsenic, benzene, cyanide, dichloromethane (also called methylene chloride), lead, naphthalene, toluene, and trichloroethene. All were found across the site's groundwater and soil operable unit.
Cleanup happened in stages. A removal action in 1983 pulled out hazardous liquids, sludge, contaminated soil, and 15 storage tanks. The state performed another removal action in August 1985, again removing 15 storage tanks and surface contamination and posting warning signs. The Texas Department of Water Resources completed the remedial investigation and feasibility study from 1982 to 1984. The long-term remedy, finished in 1988, raised the site above the 100-year floodplain, stabilized and disposed of waste on-site, installed a slurry wall, and set up groundwater monitoring. Remedial construction was completed on April 12, 1993. Operation and maintenance continued until 2007.
Human exposure is now under control. Physical construction is complete across the entire site. Contaminated groundwater is stabilized within its original area and shows no unacceptable discharge to surface water. Institutional controls limit land use to non-residential purposes. The Texas Commission on Environmental Quality (TCEQ) performs semi-annual leachate monitoring and groundwater sampling every two years. EPA's most recent five-year review, completed June 25, 2025, found the remedy protective of human health and the environment in the short term. For long-term protectiveness, EPA must issue an Explanation of Significant Differences to document institutional controls as part of the formal remedy.
Community members can read the 2025 Five-Year Review Report online at https://semspub.epa.gov/work/06/100033987.pdf or in person at the Grand Prairie Texas Library, 901 Conover Drive, Grand Prairie, Texas 75201, phone (972) 237-5700. For questions, contact the EPA's Community Involvement Coordinator, the Remedial Project Manager, or TCEQ.
