Crystal Chemical Company operated a herbicide manufacturing facility on a 12.5-acre property in Houston, Texas from 1968 to 1981. The company abandoned the site in 1981, and EPA added it to the National Priorities List in 1983. Arsenic is the sole contaminant of concern, found in both soil and groundwater. Groundwater arsenic levels exceed the Maximum Contaminant Level of 50 micrograms per liter. The site is divided into operable units, with the primary unit (OU 01) addressing soil and groundwater contamination.
Cleanup has unfolded in several stages. Arsenic-contaminated soils were excavated and placed in an on-site monofill, which was sealed with an engineered cap completed in September 1995. A slurry wall and pressure relief system were installed to contain groundwater, finishing in 2003. A groundwater extraction and treatment system ran until January 2010, when it was shut down after a pilot test using eucalyptus trees. Physical construction is now complete. The City of Houston supplies drinking water to the area, so residents are not drinking contaminated groundwater. A deed restriction filed in March 2006 prevents groundwater use within the restricted area, and an environmental covenant to restrict activities on the monofill cap was expected to be filed in 2024.
EPA's most recent Five-Year Review, completed August 4, 2025, found the site protective of human health and the environment in the short term. However, several steps are still needed for long-term protection. These include completing a groundwater feasibility study, selecting a new groundwater remedy, updating the arsenic cleanup level for groundwater based on EPA's revised 2024 toxicity standards, and determining whether the current soil cleanup level of 30 mg/kg is protective for residential use. A remedial investigation and feasibility study for OU 01 are ongoing, with completion estimated between April and June 2026. A Record of Decision Amendment and new remedial design and action are expected to follow in 2026 and 2027. The property is currently undeveloped, and several parties have inquired about purchasing it.
Community members can get involved by reviewing site documents at the Robinson-Westchase Neighborhood Library at 3223 Wilcrest Drive in Houston, reachable at 832-393-2011. EPA held a public meeting on September 15, 2025, to present its preferred cleanup strategy for arsenic-contaminated groundwater. The public comment period ran through October 15, 2025. Comments could be emailed or mailed to EPA Region 6 in Dallas. For ongoing questions, contact the EPA Community Involvement Coordinator or the Remedial Project Manager. The Texas Commission on Environmental Quality also has staff assigned to the site.
