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Project ID: 2004MS24B

Title: Water Quality Standards: Establishing Nutrient Criteria for Mississippi's Coastal Waters

Project Type: Research

Focus Categories: Water Quality, Nutrients

Keywords: water quality, water quality standards, coastal zone, estuaries, nutrients, eutrophication, nitrogen, phosphorus, suspended sediments, algae

Start Date: 03/01/2004

End Date: 02/28/2005

Federal Funds: $28,682

Non-Federal Matching Funds: $57,364

Congressional District: Fourth

Principal Investigator:
Harriet MacGill Perry


Nutrient overenrichment of estuaries from human-based causes is now recognized as a national problem based on Clean Water Act 305b reports from coastal states that list waters whose use or uses are impaired. The Environmental Protection Agency (EPA) has published recommendations of water quality criteria for nutrients under section 304(a) of the Clean Water Act (66 FR 1671) and states must develop water quality standards for nutrients by 2006. The EPA has proposed criteria with the intention that they serve as starting points for states to develop more refined nutrient criteria, as appropriate. States, then, have the option to develop nutrient criteria that fully reflect localized conditions and protect specific designated uses with scientifically defensible approaches as supported by EPA technical guidance manuals. To that end, the MDEQ has incorporated an aggressive monitoring and data gathering initiative into existing programs in order to provide nutrient data to support nutrient criteria development. While much has been accomplished through leveraging resources and funding from existing monitoring programs, there are still many data gaps remaining. Mississippi’s estuaries are perhaps the most vulnerable and valuable of the state’s waters. Water quality and wetlands health are vital to the maintenance of fisheries production and to the other water-dependent activities that operate within the coastal zone. Development of clear numerical criteria that will allow discernment of natural nutrient concentrations from heightened anthropogenic concentrations in waters where increased nutrients may cause harm to the quality and usability are critical to the evaluation and management of Mississippi’s estuaries. The proposed research will provide for needed data on diel and tidal variations in nutrient concentrations and other important water quality parameters. Dissolved oxygen (DO) will be carefully monitored because adequate levels are a fundamental requirement for maintenance of estuarine biota. Levels of dissolved oxygen are affected by environmental stresses, such as point and nonpoint discharges of nutrients or oxygen-demanding materials. Dissolved oxygen levels are highly variable over time, fluctuating widely due to tides, winds, and biological activity. Random instantaneous measures of DO are likely to mis-classify a station with unacceptable DO conditions (DO <2 ppm for > 20% of time period) as acceptable at a rate of 60-70%. The proposed research will provide information on nutrients and associated water column parameters during spring high-flow/summer low-flow periods at two deep water and one shallow water site in each of the three coastal counties. Monitoring will include: total Kjeldahl nitrogen, ammonia nitrogen, nitrite + nitrate, total phosphate, chl a, total suspended solids, and field parameters such as dissolved oxygen, temperature, turbidity, transparency, salinity, pH, and depth. Activities will focus primarily on the water column using protocols established by MDEQ in sampling activities supporting USEPA’s National Coastal Assessment (NCA) Program. Samples will be analyzed according to an approved Quality Assurance Project Plan and defined QA/QC procedures. Following field work in Year 1, personnel will work closely with the State’s Estuarine Nutrient Taskforce and the MDEQ to evaluate historical data, integrate current data into the database, statistically analyze the data, and propose reference conditions for Mississippi’s coastal waters. Expanded sampling afforded by the proposed project will supplement existing guidance and broaden the base of available information. It will use a scientifically-based sampling approach to define current water quality conditions and will provide for evaluation of historic/legacy data to establish water quality in coastal waters prior to growth and development of the Coastal Zone. This approach will ensure that criteria developed for our estuarine waters are the result of a carefully designed program drawing upon available resources and expertise to benefit the people of the State of Mississippi.

Progress/Completion Report PDF

U.S. Department of the Interior, U.S. Geological Survey
Maintained by: John Schefter
Last Updated: Friday November 4, 2005 9:57 AM
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