The Hanlin-Allied-Olin site sits three miles south of Moundsville, West Virginia. It operated as a chemical production facility starting in 1953 under multiple owners, making chemicals such as aniline, nitrobenzene, and chloromethane compounds. EPA added it to the National Priorities List (NPL) on July 22, 1999. The site is divided into two operable units (OUs). Operable Unit 1 covers soils and the wastewater treatment plant. Operable Unit 2 covers the groundwater system, and no cleanup decision has been issued for it yet.
Contaminants found in soil and building structures at the site include arsenic, chromium, copper, hexachlorobenzene, lead, manganese, mercury, polychlorinated biphenyls (PCBs), thallium, and zinc. Mercury also appears in groundwater, along with chloroform and carbon tetrachloride. The Washington Lands public water supply well sits 3,000 feet south of the site, and the nearby Moundsville Country Club draws groundwater for irrigation. Extraction wells are running to keep contaminated groundwater from reaching those sources, and treated water is discharged to the Ohio River under a West Virginia permit. Human exposure status is listed as insufficient data, and groundwater migration is not under control.
Significant cleanup work has already taken place. Workers excavated roughly 100,000 cubic yards of contaminated soil in 2008 and completed a hazardous waste landfill in August 2009. A soil vapor extraction system installed in 2009 had removed about 336,000 pounds of volatile organic compounds (VOCs) as of May 2020. A wastewater treatment plant treats more than 300,000 gallons daily, achieving 99% contaminant removal. All former production buildings have been demolished. In June 2021, EPA issued a Record of Decision selecting the final remedy for soils and interim actions for South Plant alluvial groundwater. In April 2023, EPA and the West Virginia Department of Environmental Protection reached a settlement requiring Honeywell International and Olin Corporation to pay cleanup costs and carry out the remedial action.
Remedial design for Operable Unit 1 began in February 2023 and was finished in February 2026. Remedial action began in February 2026 and is scheduled to wrap up between August and October 2026. For Operable Unit 2 groundwater, the remedial investigation is ongoing, with a feasibility study estimated to begin between January and March 2027. A gas processing facility currently operates on the former Olin property, now owned by Williams Ohio Valley Midstream, LLC.
A public meeting was held on Tuesday, March 10, 2026 at the Marshall County Health Department in Moundsville. The Administrative Record is available for review at the Marshall County Public Library (700 5th St.
Moundsville, WV), or at the EPA Region 3 office (1600 John F. Kennedy Blvd
Philadelphia, PA). Appointments to visit the EPA Region 3 office should be scheduled in advance by calling (215) 814-2396.
