United Creosoting Co.

Overview

The United Creosoting Company ran a wood-treatment operation on a 100-acre property in Conroe, Texas, from 1946 to 1972. Workers used creosote and pentachlorophenol (PCP) to treat telephone poles and railroad ties. Wastewater from that process flowed into on-site ponds, pushing hazardous chemicals into the soil and groundwater. The EPA added the site to the National Priorities List (NPL) on September 21, 1984. About 15,000 people live within two miles of the site today.

Eight contaminants of concern have been identified, mostly in soil and groundwater in Operable Unit 1 (OU 1). They include 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), chlorinated dibenzodioxins, pentachlorophenol, polycyclic aromatic hydrocarbons (PAHs), and benzo[a]pyrene equivalents. The main health risk comes from people ingesting or touching contaminated soil. Groundwater migration has been stabilized in its original area, and the area is served by a municipal water supply with no expected private shallow groundwater use.

Cleanup work has gone through several stages. A Record of Decision in 1986 called for excavation, demolition, offsite disposal, onsite consolidation, and engineered caps. A second decision in 1989 added chemical treatment using solvent extraction. A 1998 amendment further modified the remedy to include excavation and offsite disposal. Physical construction was completed on September 30, 1999. Soils were cleaned to residential standards near homes, and the property now hosts a residential subdivision and light industrial structures. The Texas Commission on Environmental Quality (TCEQ) operates the groundwater monitoring system with annual sampling events.

The site has not yet been deleted from the NPL. EPA is reassessing dioxin risk in both industrial and residential soil areas, with that investigation expected to finish by the end of 2025. A remedial investigation for OU 1 is estimated to conclude between December 2026 and February 2027, and a feasibility study is scheduled to follow. Groundwater monitoring is planned for completion in 2026. Institutional controls restrict groundwater use on vacant lots and soil excavation across the entire site to prevent future exposure. The most recent five-year review was completed on September 18, 2025. EPA determined that additional information is still needed to confirm long-term protectiveness of the remedy.

Community members can read the 2025 Five-Year Review Report online at https://semspub.epa.gov/src/document/06/100034950 or at the Montgomery County Memorial Library, Central Branch, at 104 Interstate 45 N in Conroe, Texas (phone: 936-539-7814). Media inquiries go to R6Press@epa.gov.