The Oklahoma Refining Co. site covers 160 acres in Cyril, Oklahoma. It operated as an oil refinery until 1984 and was added to the EPA's National Priorities List in February 1990. Contamination from refinery operations spread into soil, sediment, surface water, and groundwater. The site is being addressed through multiple operable units, and physical construction of the cleanup is not yet complete.
Contaminants of concern include polycyclic aromatic hydrocarbons (PAHs) such as benzo[a]pyrene and anthracene, volatile organic compounds (VOCs) including benzene, toluene, xylene, and ethylbenzene, and metals such as arsenic, lead, mercury, and cadmium. The south portion of the site also contains sludge and liquid waste. The north source area adds methylnaphthalenes and cresols to the mix. All of these affect soil and sediment, and some affect groundwater.
Cleanup has moved in stages. Demolition work in 2003 removed process towers, vessels, storage tanks, and asbestos-containing materials. A second removal action in 2006 took down the refinery superstructure and fenced the site. The south source remedial action ran from 1997 through 2006 using bioremediation, stabilization, neutralization, and containment, including two landfills and two temporary biotreatment areas. That work is now in operation and maintenance. The north source area has a Record of Decision from June 2013, and remedial action work ran from 2016 through September 2024, with operation and maintenance now underway. A groundwater investigation that began in January 2015 is studying how contamination interacts with Gladys Creek and will inform a future cleanup decision for that area. Funding through the Bipartisan Infrastructure Law is supporting excavation and off-site disposal of contaminated soil.
The most recent five-year review, completed in May 2022, found the remedy is protective of human health and the environment in the short term. Human exposure is currently under control, and contaminated groundwater migration is stabilized with no unacceptable discharge to surface water. Ongoing fence repair and maintenance remain necessary. The site is estimated to be ready for anticipated reuse between January and March 2027, though it has not yet been deleted from the National Priorities List.
Community members with questions can contact the EPA Community Involvement Coordinator or the Remedial Project Manager. For state-related questions, contact the Oklahoma Department of Environmental Quality.
