Why is the County Adopting New Erosion Prevention Standards?
Last year, the County adopted erosion prevention standards in the County-Administered MS4 Area around the Eugene and Springfield urban growth boundaries (the small, bright green areas on the map below).
This year, the County is tasked to adopt erosion prevention standards within the Willamette River Basin (the areas in white below).
These new erosion prevention requirements are a part of the County’s Willamette Basin Mercury Total Maximum Daily Load (TMDL). A TMDL specifies the maximum amount of a pollutant that a water body can receive and still safely meet water quality standards. The Willamette Basin Mercury TMDL was developed by the Oregon Department of Environmental Quality and approved by the federal Environmental Protection Agency, as authorized through the Federal Clean Water Act (CWA) of 1972. The Willamette Basin has high levels of mercury, a toxin that threatens not only habitat and fish health, but human health as well. The purpose of the Mercury TMDL is to reduce mercury levels within the Willamette Basin.
Mercury cycling pathways in aquatic environments are very complex. The various forms of mercury can be converted from one to the next. Most important is the conversion to methylmercury, the most toxic form. Ultimately, mercury ends up in the sediments, fish, and wildlife, or evades back to the atmosphere by volatilization. Reprinted with permission from Mercury Pollution: Integration and Synthesis. Copyright Lewis Publishers, an imprint of CRC Press.
County staff will present the proposed Mercury TMDL code to the Board of County Commissioners in August, 2025.
More information may be found on the Board of County Commissioners webpage.
Click on the Board packet link to the right to see the proposed code.
Staff have worked to adopt the minimal amount of new regulation needed to meet the minimum requirements of the Mercury TMDL.
Here is a synopsis of the County’s proposed Mercury TMDL code changes:
- The final code will have two different erosion prevention areas, each with its own set of requirements:
- The original County-Administered MS4 Area, and
- The Mercury TMDL Area
- The new requirements will apply to the Mercury TMDL Area, which covers the greater Willamette River Basin, outside of the MS4 Area.
- The code and permitting requirements in the MS4 Area will remain unchanged.
- All land-disturbing activities within the Mercury TMDL Area must use best management practices to meet the erosion prevention outcomes of Lane Code 9.090.030.
- Erosion prevention permits will not be required within the Mercury TMDL Area.
- Development permit applications will need to provide a signed self-certification declaration, stating that erosion prevention methods will be used throughout the course of construction.
- Amendments are proposed to the County right-of-way code (LC Chapter 15) to account for Mercury TMDL and Municipal Separate Storm Sewer System (MS4) Phase II permit requirements.
- Some sections of the existing MS4 Area code have been reorganized to accommodate the inclusion of the new language, but the existing code and permitting requirements for the MS4 Area have not changed.
The County is seeking your feedback!
- Please let us know how this new code language will affect your business or agency.
- Feedback for suggested changes is welcome.
- Please attend the Public Hearing on August 26, 2025, at 1:30PM, at Harris Hall, 125 E. 8th Avenue, Eugene.
- Feedback may also be sent to: [email protected]
(541) 682-7660
Please let us know what you think!