Plan to control nonpoint sources of pollution
Nonpoint Plan and Clean Water Guidance now finalized
We’ve completed updates to our Nonpoint Plan and finished the Voluntary Clean Water Guidance for Agriculture. We have sent both documents to the EPA for review.
Addressing nonpoint pollution remains a key issue across the state. While Ecology leads efforts to restore and protect water quality, it takes everyone working together to clean up our rivers, lakes, streams, and estuaries.
We describe the foundation of statewide strategies to address nonpoint sources of pollution in Washington’s Water Quality Management Plan to Control Nonpoint Sources of Pollution (Nonpoint Plan) and the Voluntary Clean Water Guidance for Agriculture (Clean Water Guidance).
It takes all of us
Nonpoint pollution refers to pollution that doesn't come from a single source. Instead, it comes from many sources and conditions. When rain or snowmelt flows across land, it can pick up pollutants and carry them into streams, rivers, lakes, and other waterways. Nonpoint pollution can also happen when streams don’t have enough shade‑providing trees, causing water temperatures to rise.
Because this pollution comes from many places, it’s harder to manage than pollution from one specific source. Together, the Nonpoint Plan and Voluntary Clean Water Guidance for Agriculture help shape the state's approach to address nonpoint pollution and support clean, cool water across Washington. While Washington’s Water Pollution Control Act gives Ecology authority to regulate active and potential sources of nonpoint pollution, achieving clean and cool water takes all of us working together.
Washington’s Nonpoint Plan
Washington’s Water Quality Management Plan to Control Nonpoint Sources of Pollution (Nonpoint Plan) explains how the state works to reduce water pollution that comes from many different sources. The Clean Water Act requires this plan, and it helps secure funding so we and our partners can put clean‑water projects into action.
How we updated Washington’s plan
Ecology is responsible for maintaining Washington's Nonpoint Plan, but it reflects work happening across the state. To keep the plan up to date, we worked closely with state and local partners who help carry out this work.
The plan reflects the work of Ecology, our partners, and many implementation groups across the state. To make sure it accurately represents our statewide strategies and partnerships, we worked with other Ecology programs, state agencies, local organizations, and Tribes to review the plan and update it.
Hearing from the public is an important part of our process. For this update, we held a 100‑day public comment period from May 22 to Aug. 29, 2025.
We also hosted an informational webinar (PDF) on June 11, 2025, to share details about the plan and the updates.
All comments we received are available online.
After the public comment period closed, we reviewed all comments and updated the plan. We also prepared a Response to Comments to explain how we considered the feedback.
We have submitted the final Nonpoint Plan and the Response to Comments to the EPA for their review and approval.
Voluntary Clean Water Guidance for Agriculture
Alongside the Nonpoint Plan, we have developed the Voluntary Clean Water Guidance for Agriculture (Clean Water Guidance). The guidance is a technical resource for agricultural producers. It recommends site-specific best management practices (BMPs) to protect water quality and is intended to support healthy farms while helping producers meet clean water standards.
The practices in the guidance apply across Washington’s diverse farms and landscapes. They focus on reducing runoff and erosion; preventing nutrients, pathogens, and pesticide from entering surface and groundwater; and helping keep streams cool and clean.
Clean Water Guidance now complete
The completed guidance includes two documents:
- Recommended Best Management Practices (BMPs): an introduction to the guidance, a practice‑selection tool, and all site‑specific practice recommendations. A focus sheet is available to explain these recommendations.
- Appendix: supplemental information on practice effectiveness and implementation considerations.
How we developed the guidance
We used the best available science and worked closely with partners to develop guidance that reflects the wide variety of farms in Washington. This helps us support both healthy farms and clean water.
The Clean Water Guidance advisory group helped shape our recommendations. The group included representatives from producer groups, WSU Extension, conservation districts, the State Conservation Commission, Washington State Department of Agriculture, Natural Resources Conservation Service, EPA, Northwest Indian Fisheries Commission, and other agricultural and conservation experts.
To give people as much time as possible to review the material, we released draft chapters on a rolling basis from June through October 2025. Comments on all chapters were due by Dec. 5, 2025.
We also held an informational webinar (pdf) on Nov. 5, 2025, to explain the guidance and answer questions.
All comments we received are available online.
After the public comment period closed, we reviewed all comments, updated the guidance, and prepared a Response to Comments. We submitted the final Clean Water Guidance, along with the 2025 Nonpoint Plan update, to EPA for review.
Reorganizing the guidance for usability
Feedback from the public and our advisory group showed the guidance needed to be easier to use. In response, we reorganized it into two documents, described above. All BMP recommendations are now in one place: the Recommended Best Management Practices.
Keeping it all up to date
We will update the Nonpoint Plan and the Clean Water Guidance again in 2030 to make sure they stay current and continue to support our progress toward clean water.
Related links
Contact information
Hannah Coe
Nonpoint Policy Lead
nonpoint@ecy.wa.gov
360-918-4958