Nutrient Criteria for Water Quality
Development of Nutrient Criteria for Water Quality
In 2001, the U.S. Environmental Protection Agency published water quality criteria for nutrients (nitrogen and phosphorus) as called for in section 304(a) of the Clean Water Act. These criteria were developed as a starting point for states, authorized tribes, interstate commissions, et al., to develop criteria that would be appropriate for their own jurisdictions. This approach was due to the recognition that the determination of suitable limits for nutrients for water bodies is a highly complicated issue. It is governed by wide variation in local ecological conditions, as well as the uses placed upon the waters. Too much nutrient loading to a water body can cause rapid growth of algal blooms, organic enrichment and depletion of dissolved oxygen. Too little may result in insufficient enrichment of the aquatic food chain, which would be detrimental to a healthy aquatic biological community.
Developing the nutrient criteria that will protect the waters of the state requires significant analysis of water quality data. It also requires input from citizens concerned with the impact of implementation of nutrient criteria. With this in mind, a plan for developing nutrient criteria in Missouri was developed in 2005 and is presented here. There is also an update of the proposed schedule for development.
Nutrient criteria for lakes and reservoirs were adopted as part of the water quality standards rule in October 2009. The part of the rule applicable to nutrients is at 10CSR 20-7.031(4)(N), on page 16. The department has drafted a policy for implementation of the rule. In August, 2011, EPA denied approval of a substantial part of this rule, expressing some technical issues with the criteria that were introduced. The department is in the process of addressing these concerns, with the goal of including them as part of ongoing revisions to the water quality standards. A reply has been drafted that includes a proposed revised rule. Data and information for numeric nutrient criteria for lakes can be requested by submitting an open records request.
Rivers and Streams
Stakeholders began meeting in 2009 for briefings on how criteria development for streams will proceed. These meetings were suspended so a technical workgroup could take the time necessary to make recommendations for criteria that will be scientifically defendable and sufficiently protective of the state's streams and rivers. Criteria will be based on a compilation of several lines of evidence, including a statistical review of available data, a USGS study of algae response to nutrients in the Ozarks, and analyses of macro-invertebrates and chlorophyll-a as response variables. When all analyses are complete, stakeholder meetings will be reconvened for consideration of the recommendations.
Nutrient Criteria Technical Subcommittee
July 30, 2014
Draft Reply to EPA Regarding Missouri's Numeric Nutrient Criteria
Nutrient Criteria Stakeholders Group
Aug. 13, 2012
Nutrient Criteria Technical Subcommittee
July 23, 2012
Revised Lake Nutrient Rule
Presentation: Lake Rule Rationale
UMC-MDC Chl-a and Secchi Depth Recommendations
Influence of Environmental Variables in Small Lake Impoundments (Michaletz et al, 2012)
Missouri Reservoirs: An Analysis of regional limnology (Jones et al, 2008)
Fish Catch and Water Quality in Agriculturally Eutrophic Lakes (Egertson and Downing, 2004)
Production of Fish Populations in Lakes (Downing and Plante, 1993)
Sportfish Harvest Predicted by Summer Chlorophyll-a (Jones and Hoyer, 1982)
Water Clarity and Quality Black Bass and Crappie Fisheries in Alabalma (Maceina et al, 1996)
Responses of Channel Catfish to Stocking Rate (Michaletz, 2009)
Oligotrophication and its Discontents: Effects of Reduced Nutrient Loading (Ney, 1996)
Nov. 16, 2010
Examination of Algal Community Data for Establishment of Nitrogen and Phosphorus Criteria
Nutrient Criteria Database Quality Assurance and Statistical Analysis
Draft Rule: Nutrients in Streams
Biological Response to Nutrients in Central Plains Regional Streams of Missouri
Table 5: Matrix of Summary Statistics
Nutrient Lines of Evidence
- Missouri Nutrient Criteria Plan.
- EPA - DNR Agreement on Missouri's Nutrient Criteria Development Plan.
- Missouri Water Quality Standards.
- EPA Nutrient Water Quality Criteria.
- EPA Region 7 Nutrient Benchmarks for Streams.
- Nutrient Data for Missouri Streams.
- Eutrophication of U.S. Freshwaters: Analysis of Potential Economic Damages.
- Natural Background Concentrations of Nutrients in Streams and Rivers of the Conterminous United States.
- Relationships among Nutrients, Chlorophyll-a, and Dissolved Oxygen in Agricultural Streams in Illinois.
- Comparison of algal, microinvertebrate and fish assemblage indices for assessing low-level nutrient enrichment in wadable Ozark streams.