Guidance for completing the TMDL reporting form

Warning: This guidance is for Phase II MS4 permittees (i.e., those covered under the 2020 MS4 General Permit). Phase I MS4 permittees should refer to Phase I MS4 Guidance for completing the TMDL Annual report form.

Warning: The MPCA is in the process of developing a new e-service for both the Phase II MS4 annual report and the TMDL annual report. There will be no TMDL Annual Report submission in calendar year 2023 for Phase II MS4 permittees (i.e., those covered under the 2020 MS4 General Permit).

Purpose of the TMDL Annual Report

If you (an MS4 Permittee covered under the 2020 MS4 General Permit) are assigned one or more Wasteload Allocation (WLA) in a Total Maximum Daily Load (TMDL) that was approved by the United States Environmental Protection Agency (USEPA) prior to November 16, 2020, and were not meeting the WLA(s) when you applied for permit coverage, you must complete the TMDL Annual Report to demonstrate progress toward meeting the WLA(s).

E-service TMDL Annual Reporting for Phase II MS4 permittees

The MPCA is in the process of developing a new e-service for both the MS4 annual report and the TMDL annual report. There will be no TMDL Annual Report submission in calendar year 2023. Permittees will be expected to report on 2022 activities once the e-service is operational.

Permit Requirements related to TMDLs

• Summary of TMDL requirements in stormwater permits
• NEW The list of best management practices (BMPs) or activities that will be considered as progress toward meeting wasteload allocations (WLAs) for Total Maximum Daily Loads can be found in this spreadsheet: File:2020 MS4 General Permit BMP List for Manual April2023.xlsx

Until the e-service is operational, permittees should keep track of the following:

For Total Phosphorus, Total Suspended Solids, and Oxygen Demand WLAs not being met or requiring further analysis at time of the 2020 MS4 general permit application submittal

• Updates on BMPs included in the compliance schedule submitted by the permittee as part of the application for the 2020 MS4 general permit
• Implemented BMPs for each applicable WLA since the Total Maximum Daily Load (TMDL) baseline year, including:
  • BMP type, BMP subtype (see list here), year when BMP was implemented and associated TMDL.
• Additionally, for constructed basins, filtration, infiltration, stormwater reuse BMPs:
  • Any MS4 permittee partners for that practice
  • Location (i.e., geographic coordinates)
  • Quantitative pollutant reductions per BMP
• For street sweeping and chemical treatment of stormwater practices:
  • Quantifying reductions is optional

For chloride TMDLs

• Amount of deicing salt used each winter maintenance season
• Certify completion of an annual winter maintenance assessment
  • Guidance for meeting chloride TMDL MS4 permit requirements

For temperature TMDLs

• Status of temperature management plan
  • Guidance for meeting temperature TMDL MS4 permit requirements

For bacteria TMDLs

• Status of inventory and prioritization plan
  • Guidance for meeting bacteria TMDL MS4 permit requirements

Anticipated changes

If you submitted TMDL Annual Reports under the 2013 MS4 General Permit, there will be some changes to the BMP categories and types (herein referred to as the BMP list). The draft BMP list can be found here. The BMP list is the naming convention for different BMPs and is important for consistency in annual reporting. Using the BMP list will help you be prepared to easily enter and label BMPs to demonstrate progress towards achieving applicable WLAs in the new annual report e-service.

Questions?

Refer to your submitted Custom TMDL Application if you are unsure of which TMDL WLAs need to be reported on, or reference this list. Contact Anna Bosch with questions.

For more information about the non-TMDL portion of the MS4 annual report, visit the MS4 annual report webpage.