Sixth Five-Year Review for the National Zinc Site

Sixth Five-Year Review for the National Zinc Site The Oklahoma Department of Environmental Quality (DEQ) is conducting a Five-Year Review of the National Zinc Corporation Site (NZS) (EPA ID# OKD000829440) located in Bartlesville, OK. This review is intended to ensure the cleanup actions taken at the site remain protective of human health and the environment, as outlined in the Record of Decision (ROD) and/or remedial design. The review will assess the past five years of data and activities performed since the last review. Five-year reviews of remedies at Superfund sites are required when waste is left in place. This will be the sixth Five-Year Review for the site. This NZS Five-Year Review focuses on the residential, commercial, and industrial properties located adjacent to and outside of the current Zinc Corporation of America (ZCA) facility. The ZCA facility has a history of metal processing operations from the 1900s through 1977. Sampling by the U.S. Environmental Protection Agency (EPA) in 1991 and 1992 identified elevated metal concentrations in soils on properties surrounding the ZCA facility. After reviewing the data, EPA determined that soils impacted by arsenic, cadmium, and lead posed a potential health threat. An Expedited Removal Action was initiated by the EPA in spring 1993. In May 1993, a Memorandum of Understanding was signed between EPA and DEQ that allowed the State to conduct a Superfund Accelerated Cleanup Model to complete the removal action under a State authority pilot project program. A December 1994 Record of Decision report describes the cleanup remedy that DEQ selected for the site. The remedy was designed to prevent current or future exposure to metals-impacted materials by implementing treatment and/or containment. The selected NZS remedy included excavation to remove impacted materials up to a maximum 24-inch depth followed by covering excavated areas with clean soil backfill. The Potentially Responsible Parties (PRPs) began removal actions in March 1994. In March 1995, DEQ approved a remedial design developed by the PRPs, and the PRPs substantially completed the NZS site work in June 1999. The City of Bartlesville maintains an Institutional Control Plan, which it implemented in 2002, to control construction activities for any area where impacted materials were covered in place. A report documenting the completion of the Five-Year Review is anticipated to be completed and made available to the public in June 2026. More information, including current and previous Five-Year Review reports, is available at the Bartlesville Public Library and the following websites: DEQ Website: National Zinc Deferral Site EPA Website: NATIONAL ZINC CORP. | Superfund Site Profile | Superfund Site Information | US EPA DEQ will be conducting interviews as part of the Five-Year Review. If you wish to be interviewed, have any questions, or need further information concerning the site, please contact: OK DEQ: Michael Lea Land Protection Division 707 North Robinson, PO Box 1677 Oklahoma City, OK 73101 Work: (405) 702-5195 Email: michael.lea@deq.ok.gov EPA: Janetta Coats Community Involvement Coordinator, EPA Region 6 Work: (214) 665-7308 Email: coats.janetta@epa.gov Bill Longley Remedial Project Manager, EPA Region 6 Work: (214) 665-2293 Email: Longley.William@epa.gov All media inquiries should be directed to the EPA Region 6 Press Office at 214-665-2200. LPXLP December 26 2025 LOKL0429047