The Mississippi Department of Environmental Quality (MDEQ) plans to release proposed numeric nutrient criteria (NNC) for lakes and reservoirs, wadeable and nonwadeable streams, and coastal and estuarine waters by June 2013; followed by delta waters by November 2014. MDEQ is taking a systemwide approach to coordinate and ensure consistency in developing NNC across all water body types and to address concerns related to downstream use protection. This is the reason for releasing NNC for the various water body types at the same time, with the exception of delta waters that will require more complex analyses.
MDEQ is prioritizing NNC development of subgroups within each water body type. Large lakes (more than 500 acres) are the first priority of the lakes and reservoir group because they comprise over 90 percent of the total surface area of lakes in the state. After those criteria are developed, MDEQ plans to assess their applicability to intermediate-sized lakes (between 100 and 500 acres). If the criteria are determined not to be applicable to the intermediate subtype, MDEQ will develop new NNC for that subtype. Narrative criteria will likely be applied to smaller water bodies because they comprise less than 10 percent of the state’s lake surface area.
NNC will be developed for wadeable and nonwadeable streams concurrently.
The first priority for NNC development in coastal and estuarine waters will be the large estuarine water bodies because they comprise most of the surface area of that resource group. The next priority will be to determine if NNC are needed for all coastal and estuarine water bodies or if there is a size category below which narrative criteria should be retained. If an intermediate size category is determined, MDEQ will assess the applicability of the NNC developed for the large estuaries for that category of estuarine water bodies. Additional NNC will be developed if those for large estuarine water bodies are not considered adequate to protect and support the highest attainable use for the intermediate-sized water bodies (MDEQ 2010).
Reference:
MDEQ. 2010. Mississippi’s Plan for Nutrient Criteria Development. Mississippi Department of Environmental Quality. Accessed October 2016.
https://www.mdeq.ms.gov/wp-content/uploads/2017/05/MS-Nutrient-Criteria-Development-Plan_Final_May-26-2016.pdf Exit .