MISSISSIPPI PHOSPHATES CORPORATION
Health & Environment
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What Are the Risks at the Site?
Without daily active wastewater management and additional surge capacity, there may be a release of acidic wastewater and nutrients (phosphorous, ammonia and nitrogen) to Bayou Casotte and the Grand Bay Estuary Reserve. The wastewater, if improperly discharged, may be toxic to fish and other forms of marine life, and can also cause algal blooms.
Large, catastrophic releases of acidic, nutrient-rich wastewater occurred in 2005 and 2013 (before EPA began overseeing wastewater treatment operations on-site). Previous releases have caused devastating fish kills in Bayou Casotte and the Grand Bay Estuary Reserve. The public uses Bayou Casotte and the Grand Bay Estuary Reserve for fishing and recreation.
EPA samples multiple locations throughout Bayou Casotte twice a day—and even after previous intentional bypass events—the concentrations have remained at levels that do not pose long-term risks to the environment.
EPA treats the wastewater with lime during normal operations, or sodium hydroxide during bypasses, to neutralize pH and prevent any acute toxicity impacts to aquatic wildlife. The other contaminants in the wastewater, including nitrogen, phosphorous and ammonia, are associated with nutrient loading which poses chronic risk to aquatic wildlife only after long-term exposure.
EPA uses performance measures to track environmental results at Superfund sites. If you have any questions or concerns about the measures at this site, please contact the site team members listed under Site Contacts.
Read more about Superfund Remedial Performance Measures.
|Status at this
|What does this mean?|
|Human Exposure Under Control||Insufficient Data||Yes means assessments indicate that across the entire site:
No means an unsafe level of contamination has been detected at the site and a reasonable expectation exists that people could be exposed.Insufficient data means that, due to uncertainty regarding exposures, one cannot draw conclusions as to whether human exposures are controlled, typically because:
|Groundwater Migration Under Control||Insufficient Data||
Yes means EPA reviewed all information on known and reasonably expected groundwater contamination. EPA concluded the migration of contaminated groundwater is stabilized and there is no unacceptable discharge to surface water. EPA will conduct monitoring to confirm that affected groundwater remains in the original area of contamination.
No means EPA has reviewed all information on known and reasonably expected groundwater contamination, and the migration of contaminated groundwater is not stabilized.
Insufficient data means that due to uncertainty regarding contaminated groundwater migration, EPA cannot draw conclusions as to whether the migration of contaminated groundwater is stabilized.
Yes means the physical construction of the cleanup is complete for the entire site.
No means either physical construction is not complete or actions are still needed to address contamination.
|Sitewide Ready for Anticipated Use||No||Yes means:
No means that one or more of these three criteria have not been met. However, a site listed as no may still have redevelopment occurring on portions of the site and may be eligible for additional redevelopment.