Agricultural pollution

How can agricultural practices impact water quality?

Agricultural landowners are important partners in ensuring clean and cool water for drinking, recreation, shellfish harvesting, and salmon recovery. Common pollutant sources associated with agricultural practices include the following: 

• Runoff from livestock confinement, manure storage areas and application fields.
• Over-application of nutrients.
• Irrigation runoff.
• Erosion from pasturelands and croplands.
• Modified or eroded stream bank channels by ditching, dredging, or animal access.
• Reductions in streamside vegetation by ditching, dredging, animal access, or agriculture production.

What is our role?

Provide recommendations to protect water quality

Our Voluntary Clean Water Guidance for Agriculture (Clean Water Guidance) provides Best Management Practices (BMPs) for producers that can both support productive land while also protecting water quality. When these practices are followed, it helps us and landowners know they are protecting water quality and meeting state clean water standards. Review the focus sheet to learn more about the guidance and how we use it. 

Provide funding to implement solutions

We provide financial assistance to local partners and landowners to help get water quality solutions on the ground. Our funding programs support our agricultural practices and can help landowners make changes necessary for their property to meet water quality needs. Connect with your local nonpoint staff to learn about resources that may be available to you!

Work with partners 

We work with agricultural landowners, interest groups, and programs across the state to improve water quality and support landowners. Our partnerships include the following: 

• Our Agriculture and Water Quality Advisory Committee brings together a broad array of agricultural interests to have an open dialogue about issues affecting the industry and how they intersect with our work to prevent water pollution.

• Our Voluntary Clean Water Guidance for Agriculture Advisory Group advises us on the identification and implementation of practices that support healthy farms and help farmers to meet clean water standards. The Clean Water Guidance resulting from this process is a technical resource to help the agricultural community implement practices in a way that ensures protection of water quality.

• Local conservation districts collaborate with us to assist landowners across the state in implementing solutions that support healthy farms and clean water.

What can landowners do to help?

Keeping Washington's water clean and cool requires all of us to do our part. Landowners have the responsibility under state law to prevent runoff from polluting waterways. We strive to work with landowners to find solutions that provide property-specific flexibility while protecting water quality. Some general practices landowners can do to protect water include the following:  

• Plant native trees and shrubs along streams, keep livestock away from any water edge, and leave streamside plants between fields and waterways.
• Leave crop residue on fields over the winter to reduce erosion and use direct seed and no-till practices.
• Store manure in facilities that prevent it from running off to waterways or impacting ground water.
• Apply fertilizer (including manure) in appropriate volumes and at times when plants can fully use the nutrients.

Questions about these practices or others? Our Clean Water Guidance provides recommendations for agricultural landowners. Contact your local nonpoint staff for more information about these practices or to find out if you are eligible for financial assistance to help implement clean water solutions!

Permitted agriculture runoff 

Although the majority of agricultural runoff is considered nonpoint, some agricultural operations are regulated as a point pollution sources and are issued permits. Under the Clean Water Act and the state Water Pollution Control Act, facilities defined as Concentrated Animal Feeding Operations (CAFOs) that have discharged pollutants to surface or groundwater must be covered under the CAFO permit.  

In Washington state, the most common facilities covered under the CAFO permit are large dairies, feedlot beef, and commercial poultry operations. See the CAFO permit webpage for more information on what defines a CAFO and the permitting process.

Landowner resources