Southern Shipbuilding operated as a barge cleaning, docking, and repair facility on a 54-acre property in Slidell, Louisiana from 1919 to 1993. Operations left soil, sediments, and sludges contaminated with hazardous chemicals. A 1992 levee failure released 325,000 gallons of materials into nearby Bayou Bonfouca. EPA added the site to the National Priorities List in May 1995 and deleted it in June 1998 after cleanup goals were met.
Twenty-six chemical substances were identified at the site. These include polycyclic aromatic hydrocarbons (PAHs) such as benzo[a]pyrene, chrysene, and anthracene in soil, metals including arsenic and lead, polychlorinated biphenyls (PCBs) in soil and sediment, dioxins in the form of 2,3,7,8-tetrachlorodibenzo-p-DIOXIN (TCDD), and tributylstannyl benzoate in sediment.
Cleanup was organized into two operable units. Operable Unit 1 (OU 01) addressed contaminated soils through off-site incineration beginning in 1995, followed by on-site consolidation and capping of soils and incinerator ash. Tributyltin-contaminated sediments were also removed and incinerated. Construction finished in September 1997, and confirmation sampling confirmed remedial goals were met at all excavated locations. Operable Unit 2 (OU 02) received a no further action determination in September 1997, meaning no additional cleanup steps were needed there. The Louisiana Department of Environmental Quality and the site owner now maintain the site, conducting annual cap inspections and five-year remedy evaluations. Human exposure is under control, and groundwater migration is stabilized with no unacceptable discharge to surface water. An explanation of significant differences for OU 01 was issued in September 2025, and a second remedial investigation for OU 01 is scheduled to begin in April 2026.
One business currently operates on the site, employing one person and generating roughly $547,000 in annual sales. The city of Slidell and the current property owner are discussing potential reuse of the property. 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. Public records are available through EPA's records system, and a public comment period is scheduled during the next five-year review.
