Capitol Lakes is a federally listed Superfund site in Baton Rouge, Louisiana, added to the National Priorities List on September 7, 2023. The site is a lake system created in the early 20th century when Grassie Bayou was dammed. Because the lakes have no natural outlet, water must be pumped out through a station on the Mississippi River. That setup causes stagnation and allows sediment and contaminants to accumulate over time.
Contamination in the lake system dates back to at least 1972, when oil laced with pesticides and PCBs (polychlorinated biphenyls) was first detected. The Louisiana Department of Environmental Quality investigated a report of PCB-laden oil entering the lake in 1983, and a fish advisory was established that year due to PCBs and various metals. That advisory is still in effect. Fish tissue samples collected in April 2022 from North Lake confirmed PCBs at concentrations above the Human Food Chain Cancer Risk benchmark. Despite warning signs posted at the site, fishing and occasional fish consumption continue to occur there.
The lakes hold hazardous substances in their sediment, including arsenic, lead, mercury, cadmium, copper, zinc, manganese, antimony, pesticides, and two forms of PCBs called Aroclor-1016 and Aroclor-1260. These contaminants have spread to both North Lake and South Lake at significant concentrations. No cleanup work involving the contaminated sediments has taken place to date.
The site is in its early investigation phase. EPA is currently in settlement negotiations with potentially responsible parties (PRPs). On March 2, 2026, the PRPs submitted a good faith offer letter proposing terms for an Administrative Settlement Agreement and Order on Consent, under which they would jointly fund and perform the Remedial Investigation and Feasibility Study (RI/FS). That combined study, which will identify contamination and evaluate cleanup options, is estimated to begin between October and December 2026. No cleanup method has been selected yet, and construction of any remedy has not started.
Community members with questions can contact the EPA Community Involvement Coordinator or the Remedial Project Manager. For state-related questions, contact the Louisiana Department of Environmental Quality. Site records are available for public review at the River Center Branch Library in Baton Rouge.
