The Conroe Creosoting Company site covers 147 acres in Conroe, Texas, about 30 miles north of Houston. It operated as a wood-treating facility from 1946 to 1997, using pentachlorophenol (PCP), creosote, and copper chromated arsenate (CCA) as preserving chemicals. Those operations left soil, sediment, and groundwater contaminated with hazardous substances. The site was added to the National Priorities List (NPL) on September 29, 2003. The NPL is the EPA's list of the most serious uncontrolled or abandoned hazardous waste sites in the country.
The two contaminants of concern targeted for cleanup are naphthalene and pentachlorophenol, both found in groundwater across the entire site. Earlier cleanup work also addressed arsenic, chromium, total creosote compounds, and dioxins and furans in soil. Starting in 2002, about 252,000 cubic yards of contaminated soil were moved into an on-site Resource Conservation and Recovery Act (RCRA) vault, a lined containment structure built to hold hazardous waste safely. A Record of Decision issued in September 2003 set the long-term plan: monitored natural attenuation for groundwater, no further action for on-site soils and off-site sediments, ongoing vault maintenance, and institutional controls. An environmental easement placed in 2010 blocks new water well installation and limits the property to non-residential uses.
Human exposure is under control across the entire site. Contaminated groundwater has stabilized in its original area and is not migrating toward surface water. Physical construction of the cleanup is complete, and all cleanup goals for current and reasonably anticipated future land uses have been met. The Texas Commission on Environmental Quality (TCEQ) oversees ongoing groundwater monitoring and vault maintenance. As of December 2024, one business operates on the site, employing 20 people and generating about $8.2 million in annual sales.
The most recent five-year review was completed on September 20, 2023, and found the site protective of human health and the environment. The next five-year review is estimated between September and November 2028. Community members can read the 2023 Five-Year Review Report online at https://semspub.epa.gov/work/06/100029497.pdf or in person at the Montgomery County Memorial Library at 104 I-45 North in Conroe, Texas. The library can be reached at (936) 539-7814. For media inquiries, contact the EPA Press Office at (214) 665-2200.
