CONROE CREOSOTING (MONTGOMERY COUNTY) CONROE, TEXAS EPA REGION 6 U.S. CONGRESSIONAL DISTRICT 08 Contact: Gary Baumgarten 214-665-6749 Updated: May 2015 EPA ID# TXD008091951 Site ID: 0601732 Current Status Ari independent review team is conducting an optimization review of the selected remedial action for the site. Recommendations from the optimization review are based on an evaluation and analysis of existing site information, represent the technical views of the optimization review team and are intended to help the site team identify opportunities for improvements in the current site remediation strategy. EPA and the Texas Commission on Environmental Quality (TCEQ) are reviewing the draft optimization report. EPA continues to implement the long-term ground water monitoring program which began in November 2005. Results from the ground water monitoring program are used to assess the natural attenuation of pentachlorophenol in the shallow aquifer. A landfill constructed at the Site is securely fenced, has locked gates, and is marked with signs. TCEQ completed repairs to the landfill cover over the RCRA vault containing the contaminated soils and sediments from the site. EPA completed the Second Five-Year Review for the Site on September 27, 2013. The Second Five- Year Review determined that the remedy for on-site soils and off-site sediment is protective of human health and the environment because the waste has been removed and contained. The remedy for ground water is protective of human health and the environment in the short term because there is no evidence that there is current exposure, and the remedy is being implemented as planned to reduce the volume of contamination and to control migration. Conroe Creosoting 1 EPA Publication Date: June 9, 2015 ------- Background The Conroe Site is a former wood-treating facility located at 1776 E. Davis Street, Conroe, Montgomery County, Texas, The former wood-treating facility occupies approximately 147 acres and operated from 1946 until March 1997. The Site is fenced and borders residential property to the east, State Highway 105 to the south, and forested land to the west and north. The facility consisted of two process areas, one tank area, two kilns, a re-work area, a vehicle maintenance shop, boiler, lumber shed, a pole machine, two fuel pumps, an office, a sales office, and a retail office along with several storage sheds and storage areas prior to a removal action conducted by the . Three wood preserving processes were used at the facility, including pentachlorophenol (PCP), creosote, and copper chromated arsenate (CCA). The PCP and creosote wood preserving processes used pressure to force a solution of PCP or creosote dissolved in diesel into the wood. The CCA treatment process is water based and occurs at ambient pressures. The treated wood was then allowed to dry on a drip pad. Treatment residues from these processes were scraped from the drying pad for shipment off- site. The facility was closed down by the Montgomery County Tax Assessor/Collector in March 1997, due to delinquent taxes. In September 2002, the EPA started a time-critical removal action of on-site structures and soils. All the contaminated material, soils, sediments, and solidified wastes were placed inside an on-site Resource Conservation Recovery Act (RCRA) vault. A total of 252,000 cubic yards of contaminated material was placed inside the vault. The Record of Decision (ROD), signed on September 29, 2003, set forth the selected remedy for the site, which includes monitored natural attenuation of the contaminants in the ground water, no further action for the on-site soils and offsite sediments, iong-term maintenance of the RCRA vault, and placement of institutional controls. Benefits The removal action addressed contamination above health-based levels at on-site and off-site locations, including Stewart's Creek and off-site drainage areas. The ground water investigation determined that contamination from the facility has only impacted the ground water beneath the facility and is not a threat to the surrounding private water supply wells. The long-term monitoring program will continue to monitor the contaminant levels in ground water. National Priorities Listing (NPL) History NPL Inclusion Proposal Date: April 30, 2003 NPL Inclusion Final Date: September 22, 2003 Conroe Creosoting 2 EPA Publication Date: June?, 2015 ------- Location: The Site is located in Conroe, Montgomery County, approximately 30 miles north of Houston, Texas. Population: Aproximately 15,000 people live within two miles of the site. Setting: The site consists of 147 acres and is a former wood treating facility. There is a residential community to the east, a wooded area to the north, and commercial activities to the west and south. The shallow water-bearing zone is 60 feet deep and is currently not being used. The first water-bearing zone used for domestic supply is 125 feet deep. The City of Conroe water supply is 400 to 1000 feet below the surface. Site Map The following map illustrates the site location on the east side of Conroe, Texas. Legend: ® Sand-1 Shallow Monitoring Well ^ Sand-1 Cluster Monitonng Wfell ® Sand-2 Monitoring Well ® On-site Water well V7A Business Park Residential Area j ) Approximate Boundary Conroe Creosoting 3 EPA Publication Date: June?, 2015 ------- Conroe Creosoting 4 EPA Publication Date: June 9,2015 ------- The following site map illustrates the PCP concentration levels in ground water based on the January 2013 ground water sampling data. PCP concentrations shown in red are above the PCP cleanup goal of 1 ppb (or 1 M9/L). Conroe Creosoting Company Superflind Site Conroe, Montgomery County, Texas PCP Concentrations Sand-1 Shallow Monitoring Wells January 2013 gend: > Sand-1 Shallow M onitoring Well 5 Sand-1 Cluster Monitoring Well > Sand-2 Monitoring Well > Onsite Water Well 2I Business Park Residential Area Approximate Boundary less than MCLfor PCP of 1pg/L eater than or equal to MCLfor PCP of Ipg'l- US EPA Maximum Contaminant Level Tetrachlorophenol Micrograms per liter indicates duplicate sample result Not detected at quantitation limit Wastes and Volumes Approximately 252,000 cubic yards of soils exceeded the EPA Region 6 Human Health Medium-Specific Screening Levels for either arsenic, chromium, PCP, total creosote compounds, or dioxin and furans and were placed in the site RCRA vault during the emergency response action. The cleanup goal for PCP in the ground water is 1 part per billion (ppb). Health Considerations The Second Five-Year Review determined that the remedy for the Site is protective of human health and the environment, and will remain so provided the follow action items are addressed: Establish a grass cover on the cap of the RCRA vault; Monitor and characterize leachate accumulation in the RCRA vault on a regular basis; Install temporary bollards around flush mounted wells and ensure that monitoring wells are locked; Continue monitoring ground water using the exiting monitoring well network; Evaluate existing data to determine if additional ground water characterization of the Shallow Sand-1 aquifer is necessary. Conroe Creosoting 5 EPA Publication Date: June?, 2015 ------- Record of Decision (ROD) A Final Record of Decision was signed on September 29, 2003. Community Involvement Proposed Plan: Public Meeting: Issued July 18, 2003 July 31, 2003 Information Repository: Montgomery County Memorial Library 104 I-45 North Conroe, TX 77301 (936) 442-7712 Site Contacts EPA Remedial Project Manager: EPA Regional Public Liaison: TCEQ Project Manager EPA Superfund Region 6 Toll Free Number: Gary Baumgarten 214-665-6749 Donn Walters 214-665-6483 SubhashPal 512-239-4513 1-800-533-3508 Conroe Creosoting 6 EPA Publication Date: June 9, 2015 ------- |