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Impaired Waters Program

The Department's Impaired Waters Program contains five key components:
  • Assessment of Waterbodies (Use Designation)
  • The 303(d) Impaired Waters List
  • Total Maximum Daily Load (TMDL) Monitoring, Modeling, and Development
  • TMDL Implementation
  • Post-TMDL Monitoring (Re-assessment of Waterbodies)
    Use Designation
    The Use Designation portion of the Impaired Waters Program focuses on the Department's efforts to classify surface waters that display varied physical and chemical characteristics. Surface waters have the capacity to support a number of important uses including, but not limited to:
    • The ability to supply water for commercial interests and human consumption
    • The ability to sustain viable communities of fish and other aquatic life
    • The ability to sustain viable communities of water-dependent wildlife
    • The ability to provide for human recreational activities
    Federal water quality standard regulations define existing uses as those currently being attained in a water body, and designated uses are those uses specified in water quality standards for each water body whether or not the designated use is being attained. The Department interprets the regulations to mean that use designations must be based on attainable uses, not necessarily existing uses.

    Guidelines for designating fish and aquatic life uses in Wisconsin's surface waters were first developed in 1982 as a point source management tool to qualitatively assess uses for surface waters that received discharges from treatment plants under the Wisconsin Pollutant Discharge Elimination System permits. These guidelines focused on potential uses at that time because many streams were not fully attaining their uses due to point source pollution.

    "Guidelines for Designating Fish and Aquatic Life Uses for Wisconsin Surface Waters" was published in December of 2004 (Publ-WT-807-04) by the Department to update and revise the original guidelines. This document addresses a wider range of environmental issues that face our surface waters such as agricultural runoff, stormwater runoff, and point source discharges. These guidelines apply only to fish and aquatic life communities and not to other used designations identified in Ch. NR 102, Wis.Adm.Code.
    The 303(d) Impaired Waters List
    Section 303(d) of the Clean Water Act requires states to list water bodies as impaired if they are not meeting water quality standards or use designations after application of technology-based standards. This list is due every two years. The Department is in the process of developing an Assessment Methodology to recommend new guidelines for listing and de-listing waters. The Department hopes to validate water bodies currently on the list by monitoring and restoring water quality on those on the list. In 2008, the 305(b) report and the 303(d) list will be integrated.

    Wisconsin's 2004 approved 303(d) list of impaired waters contains 613 lakes and streams. The breakout by category is shown in the pie chart below
    The 2006 303(d) list and current methodology is now available.
    TMDL Monitoring, Modeling and Development
    The development of a TMDL is required for 303(d) impaired waters. Technical guidance for developing a TMDL was developed as a three-tiered approach: simple, intermediate, and complex. Monitoring methods have been identified to provide a basic framework to assist staff in developing an integrated approach for TMDL development and work planning. The WDNR's TMDL Monitoring and Modeling Technical Guidance Document (2001) identifies pollutants to be monitored and the duration and frequency that samples are collected. The document creates a link between monitoring and modeling based on whether the simple, intermediate, or complex approach has been taken. This guidance will continue to be used in the future for TMDL development. Monitoring options were developed based on staff experience working on these types of projects and the DNR's monitoring strategy. However, each stream is unique, and an independent evaluation of each water body is required. Specific issues to be considered when determining the appropriate resource level of monitoring and modeling on a TMDL include:
    • Accuracy needs
    • Size of the waterbody/watershed
    • Stakeholder interest and input
    • Availability of funding
    • Knowledge and types of pollutant sources
    • Regulatory implications for dischargers
    Monitoring is occurring statewide for development of TMDLs starting in summer of 2006 (insert TABLEs)? Since 1996, 132 TMDLs have been approved for Wisconsin. Of those, 117 have addressed sediment as the pollutant (see approval TMDL table). Because many of the waters on the list are impaired by complex, multi-source problems, restoration will occur over an extended period of time.
    TMDL Implementation
    The Department is currently developing a statewide TMDL Implementation Program. The program framework will outline the process for stakeholder involvement and the development of TMDL implementation plans, and it will identify the financial and regulatory tools necessary to effectively implement the plans. The framework will also establish the roles and responsibilities for WDNR staff and stakeholders and include a process for tracking implementation activities and evaluating program progress.

    At this time, implementation activities to address impairments due to nonpoint source pollution are being administered largely through the WDNR's Runoff Management Program. The program is described in further detail elsewhere (Can we specify where?) in this report.
    Post-TMDL Monitoring
    Post-monitoring of the TMDL should occur on streams that have had best management practices installed, to assess the responsiveness of the stream to the practices.
    Last Revised: August 2006