The Mississippi Phosphate Corporation Site (MPC) includes wastewater ponds and ditches that contain approximately 750,000,000 gallons of low pH (at or approaching the pH 2). This water also contains elevated levels of phosphorus, flouride, ammonia, and other contaminants. Ammonia concentrations in water originating from the eastern gypsum stack range from 300-500 parts-per-million (ppm). Water treatment ponds associated with the east stack contain phosphorus concentrations ranging from 4000 to 8000 ppm and fluoride concentrations of approximately 300 ppm. These pollutants pose a continual threat to the surrounding surface water bodies and ecosystems due to the high nutrient loading and chemical oxygen demands when discharged during bypasses from the Site. During operation of the former phosphate facility, numerous bypasses have been documented from this Site which caused harm to surrounding Bayou Casotte and Grand Bay National Estuarine Research Reserve/Grand Bay Savannah Coastal Preserve. Additionally, one inch of rainfall generates approximately nine million gallons of wastewater that requires treatment. The facility is no longer in operation.
On February 21, 2017, EPA and EPA’s Emergency Response and Removal Services contractor (ERRS) began operation of the wastewater treatment and discharge systems at MPC to reduce the threat of an uncontrolled release.
