Mississippi Phosphates Corporation made fertilizer in Pascagoula from the late 1950s until it declared bankruptcy in December 2014. The company left behind over 700 million gallons of acidic contaminated wastewater and two large piles of waste called gypsum stacks. EPA added the site to the Superfund National Priorities List (NPL) in January 2018. The site is divided into three operable units covering the sitewide area, the plant property, and leachate treatment.
The main contaminants of concern are acidic wastewater containing phosphorus, ammonia, and nitrogen. Without active daily management, these pollutants can reach Bayou Casotte and the Grand Bay Estuary Reserve, harming fish and marine life and triggering algal blooms. Large releases in 2005 and 2013 caused devastating fish kills before EPA took over wastewater treatment. EPA now samples Bayou Casotte twice daily. Even after past discharge events, contaminant levels have remained at concentrations that do not pose long-term risks to the environment. The gypsum stacks also hold phosphorus, nitrogen, and residual acidity.
EPA assumed control of cleanup in February 2017 after the company's Environmental Trust became insolvent. The main cleanup action has been closing the East Gypsum Stack with a liner and geosynthetic turf cover system, which began in November 2018. As of late 2025, closure work on the stack itself is nearly complete. Water treatment is ongoing at roughly $400,000 per month, down from $1.2 million per month in 2018. A second phase of sitewide removal work is estimated to finish between September and November 2027. For the leachate treatment unit, remedy selection is estimated for late 2026 or early 2027, and remedial action is expected to begin between March and May 2028. The site has not yet reached construction completion.
Seven Seas Terminals purchased the 106-acre former plant property in September 2023 and signed a settlement agreement with EPA and the Mississippi Department of Environmental Quality to carry out cleanup as a Bona Fide Prospective Purchaser. BWC Terminals took over as successor in July 2025. Demolition began in February 2024, and soil sampling under demolished structures was completed in November 2025. The property is being redeveloped as a bulk tank terminal for petroleum storage. As of December 2024, three on-site businesses employed 104 people and generated about $5.2 million in annual sales revenue.
Community members can get involved by contacting EPA staff, who are available to attend meetings held by local groups and government organizations upon request. EPA representatives share site information and answer questions at these gatherings. To stay updated on EPA activities at the site, residents can request to be added to the mailing list. Site records are available at the Jackson County Public Library at 3214 Pascagoula Street in Pascagoula, Mississippi, and many documents are also accessible electronically through the site's web page.
