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Nancy Mesner Utah State University

TMDLs: a western focus. Nancy Mesner Utah State University. Clean Water Act of 1972 Point Sources: targeted through NPDES program and best available or best practicable technology. After 25 years of CWA: Many point sources have been identified and controlled But….

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Nancy Mesner Utah State University

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  1. TMDLs: a western focus Nancy Mesner Utah State University

  2. Clean Water Act of 1972 Point Sources: targeted through NPDES program and best available or best practicable technology

  3. After 25 years of CWA: • Many point sources have been identified and controlled • But…. • 40% of assessed water bodies listed impaired •   (20,000 water bodies) • Impacting an estimated 300,000 miles of river • and 5 million acres of lakes.

  4. Main pollutants: excess sediments, nutrients and pathogens In CWA, nonpoint sources targeted through voluntary implementation of best management practices

  5. Section 303 Requirements: States / tribes / territories to set ambient water quality standards (receptor based). Designated beneficial uses (eg. aquatic life, recreation, irrigation) Water quality standards . Numeric standards (eg. 5.0 mg/L DO) Narrative standards (eg. “free from toxics”) Antidegradation provisions

  6. Section 303 (d) requirements: • States and territories must: • Identify waters not meeting standards • Identify specific pollutants • Develop a TMDL for each pollutant for each listed water • EPA must approve or act in lieu of state

  7. Total Maximum Daily Load the maximum amount of a given pollutant that a water body can assimilate without violating its ambient water quality standard. = Point sources + Nonpoint sources + Background sources + Some margin of safety 

  8. TMDL regulations revised in 1992 State lists every 2 years TMDLs prioritized Did not provide for implementation

  9. Since 1992, courts got involved ~ 45 lawsuits have been filed in 37 states and DC… Issues: 303(d) listing process timetables for meeting goals.

  10. In West: EPA under court order (or has signed consent decree): Alaska, California, Hawaii, Montana, New Mexico, Oregon, Washington. Suits have been filed in: California, Idaho, Nevada, Wyoming Intent to sue has been filed in: Arizona.

  11. 1999: Proposed TMDL revisions • Federal advisory committee convened to develop revised rules to address issues concerning lawsuits: clarifying listing procedures, clarifying decision rules, etc. • Intent: to achieve more consistency in EPA’s approach to TMDLs • To make the process more flexible and cost effective • To streamline and improve the listing process • To provide for implementation of the TMDL

  12. 1999 Proposed Rule withdrawn on Dec 20, 2002 • EPA will take recommendations by National Academy of Science’s National Research Council • + 1000s of public comments • Expect a new rule by spring 2004 (at earliest) • Anticipate utilizing Section 303(e) of CWA, which provides for a continuing planning process for watersheds by states.

  13. TMDLs approved since January 1996: Nationally: 7,327 approved (17% of listed waters)

  14. In West (13 states): 2,382 approved (0.2 - 32% of listed waters)

  15. Some trends: • Early TMDLs focused on pollutants with good data or good predictive models • (often associated with point sources)

  16. Approaches have varied between states and between regions. • Eg… • Region 8: Many TMDLs developed within context of an existing or developing watershed plan. • Region 10: Relied more heavily on modeling outcomes to predict target concentrations or loads.

  17. Phosphorus TMDLs in the west : • 650 water bodies listed as nutrient impaired • 159 phosphorus TMDLs approved • > 50% in just 3 states. • 4 states with no approved TMDLs for nutrients

  18. Ongoing issues and needs:

  19. East Canyon Reservoir TMDL Pollutants of Concern (TP, DO)  Impaired beneficial uses (CW fishery)  TMDL Target load (5,647 lbs)  Defined endpoints (water column DO, algae, TP) Reservoir TMDL based on load

  20. East Canyon Creek TMDL Pollutants of Concern (TP, DO)  Impaired beneficial uses (CW fishery)  TMDL Target Concentration .05 mg/l  Defined endpoints (in stream DO, algae, TP) Stream Phosphorus TMDL based on concentration

  21. A need for flexibility in approaches • and for improved science: • Target loads (standing water) • vs concentrations (running water) • Phosphorus assumed to be limiting • Total P vs bioavailable P

  22. The Twenty Needs Report: • How Research Can Improve the TMDL Program • EPA 841-B-02-002, July 2002 • Improve understanding of effectiveness of BMPs • Improve watershed and water quality modeling • Improve monitoring protocols • Bring better science to ID of impaired waters.

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