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MPCA Phosphorus Strategy

Controlling phosphorus is an important part of protecting Minnesota's water resources. Phosphorus is the primary pollutant associated with the eutrophication of our surface waters. Excess phosphorus causes nuisance algae blooms and reduced water transparency, making waters unsuitable for swimming or other activities. Phosphorus comes from both point and nonpoint sources. Point Sources consist mainly of municipal and industrial wastewater discharges. Nonpoint sources include runoff from agricultural fields, feedlots, urban areas, and on-site sewage treatement systems.

Comprehensive Phosphorus Strategy

Because of the importance of Minnesota's water resources to the state's environment and economy, the MPCA has been working to control phosphorus for many years. In 1996, MPCA developed a comprehensive phosphorus strategy with seven action steps for phosphorus reduction and control. These action steps apply to both point and nonpoint sources of phosphorus and are in various stages of implementation.

1. Develop education/outreach information on environmental impacts of phosphorus.
2. Cosponsor basin-wide phosphorus forums.
3. Use basin management as the main policy context for implementing the phosphorus strategy.
4. Broadly implement Minnesota's point-source phosphorus controls.
5. Broadly promote lake protection activities.
6. Address phosphorus impacts on rivers.
7. Modify water-quality standards if necessary.

Statewide Phosphorus Report

In February 2004, the MPCA submitted a report to the legislature entitled a “Detailed Assessment of Phosphorus Sources to Minnesota Watersheds.” The report evaluates sources of phosphorus to Minnesota’s surface waters and to municipal wastewater treatment systems. The report is available at:

• MPCA Legislative Report: Detailed Assessment of Phosphorus Sources to Minnesota Watersheds

Addressing Phosphorus in Wastewater Permits

One part of the MPCA's comprehensive phosphorus strategy is a Strategy for Addressing Phosphorus in National Pollutant Discharge Elimination System (NPDES) Permitting. MPCA staff held several consultation sessions with stakeholders on this issue, considered the comments and input received, and adjusted the draft strategy to reflect comments, as appropriate. The MPCA Board adopted the strategy on March 28, 2000 as the guiding framework for applying phosphorus controls in NPDES (wastewater) permits and requested that staff return in six months to report on how the strategy was being applied and to review the strategy for any necessary modifications.

• Strategy for Addressing Phosphorus in NPDES Permitting

The purpose of the NPDES strategy is to develop a consistent framework for applying phosphorus controls in permits. The decision tree, included with the strategy, outlines the variables to be considered by MPCA staff in making decisions on whether to apply a phosphorus limit or a management plan in individual permits. The decision tree does not identify what a particular phosphorus limit will be, nor was it intended to. Rather the decision tree provides a guiding framework under which those decisions can be made.

• MPCA Phosphorus Strategy: NPDES Permits Decision Tree

The strategy and decision tree lay out the primary considerations that will determine whether a permit limit or a phosphorus management plan (PMP) should apply to a given situation. In general, facilities considered for the de minimus category would generally receive monitoring requirements only (with management plans required if average effluent concentrations exceed 4 mg/L). Phosphorus limits may be required for new facilities, expanded discharges or significant upgrades, or where the facilities are discharging to or upstream of resources of concern as defined in the decision tree. Other facilities would receive requirements for phosphorus management plans. The decision tree provides greater detail on these considerations.

• Phosphorus Management Planning Guidance (including permit language and monitoring frequency)

PMPs will be recommended or required in many new or reissued NPDES permits. PMPs are a tool being used to determine if publicly owned treatment works (POTW) and industrial wastewater dischargers contribute substantial loads of total phosphorus (TP) that could be reduced through pollution prevention or improved wastewater treatment methods. It is important to note that phosphorus limits may become future permit requirements regardless of management plan efforts taken. Therefore, it is recommended that phosphorus reduction strategies be considered with industrial users and/or treatment options.

• MPCA Phosphorus Strategy NPDES Permits (24 pages)
• MPCA Summary of Comments and Responses: Strategy for Addressing Phosphorus in NPDES Permits

Links to Related Sites

• Pre-TMDL Phosphorus Trading: A draft guidance for issuing water quality permits for discharge to impaired waters.
• Minnesota River Basin General Phosphorus Permit — Phase 1
• Phosphorus Management Plan Development Resources. Use a template to help prepare Phosphorus Management Plans for wastewater treatment facilities. A checklist, tip sheet and fact sheets are also included to help identify sources of phosphorus and evaluate strategies for phosphorus reduction. Read about how industrial businesses have successfully reduced phosphorus effluent to wastewater treatment facilities.
• Citizens Lake Monitoring Program
• Toxic Algae can Spell Danger for Pets and Livestock
• EPA Office of Water: Water Quality Criteria and Standards Program, Nutrient Criteria
• Minnesota Technical Assistance Program (MnTAP). MnTAP is a nonregulatory program at the University of Minnesota working with businesses to prevent and manage waste. MnTAP can help industries identify and implement ways to reduce phosphorus and other pollutants. Contact Cindy McComas at 612-624-4678 or 800-247-0015 for assistance.

For More Information

For more information about the MPCA Phosphorus Strategy contact Steve Heiskary at the MPCA (telephone 651-757-2419 or 800-657-3864).