TCMA Chloride TMDL - Reasonable Assurance
Reasonable Assurance
The MPCA has worked with stakeholders in the TCMA to develop a plan to restore and protect waters impacted by chloride. The TCMA CMP incorporates water quality assessment, source identification, implementation strategies, monitoring recommendations and measurement and tracking of results into a performance-based adaptive approach for the 7-County TCMA. The goal of the CMP is to develop the framework to assist local partners in minimizing chloride use and provide safe and desirable conditions for the public. The CMP will guide and assist agencies, local governments and other TCMA stakeholders in determining how best to restore and protect water resources impacted by elevated chloride levels while balancing the need for public safety, level of service considerations, as well as water softening needs. The CMP is not intended to resolve all issues. Rather, it provides understanding and guidance for management activities over the next 10 years.
Significant progress has already been made by many entities, including MnDOT, a number of cities including Prior Lake, Shoreview, Richfield, and Waconia, as well as the UMN (see section 3.5 of the TCMA Chloride Management Plan for examples). Their efforts have demonstrated that salt use can be reduced without detrimentally impacting the level of service, as well as showing the economic benefits of improved winter maintenance practices. Funding mechanisms are available to entities interested in investing in better equipment and enhanced education efforts. This is includes the Clean Water, Land, and Legacy Fund which has several grant and loan programs that could be used for implementation of BMPs, education and outreach, and WWTP modifications. Additional discussion of implementation strategies is included in Section 8 of this TMDL as well as in the TCMA CMP.
Tracking Implementation Efforts
Measuring water quality in the TCMA and monitoring chloride loads in the lakes, wetlands, and streams is critical to understanding progress toward the ultimate goal of restored and protected lakes, wetlands, and streams. However, these types of measurements alone will not be sufficient to demonstrate the progress made in implementing individual salt reduction efforts and accomplishments taking place throughout the TCMA to reduce chloride. Tracking of implementation activities is needed to assess the related benefits to water quality, take credit for making progress, and identify areas where additional effort is needed.
The approach to tracking implementation efforts will vary by the source type. The Winter Maintenance Assessment tool (WMAt) will be an option available to any winter maintenance group and will support a consistent approach to tracking and reporting winter maintenance activities.
Permitted
Permits issued under the NPDES program are required to have effluent limits consistent with the assumptions and requirements of the WLAs in this TMDL. Compliance with the WLAs, as developed and presented in this TMDL, is assumed to ensure meeting the water quality standards for all of the chloride 303(d) listings. Sections 8.1 and 8.2 of this TMDL report present a brief summary of the permit programs that exist to put into place requirements consistent with the WLAs. For the MS4 Permits, conditions will be included to document winter maintenance practices, establish goals for improving winter maintenance practices, and track improvements as part of the MS4 Storm Water Pollution Prevention Plan (SWPPP). While existing loads and the necessary percent reductions have not been estimated for this TMDL, the expectation for the MS4s is to track progress from the year that implementation of salt reducing BMPs began for each individual winter maintenance organization and reporting that progress to the MPCA as part of their annual reporting. The two previously completed chloride TMDLs in the TCMA, Nine Mile, and Shingle Creek estimated reductions of 60%-70% in existing chloride loads and may be used as an example target to work towards. However, the progress made already will vary greatly as well as the local chloride loadings and target reduction/BMP implementation goals should be