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Palouse agriculture slice

Nonpoint Pollution from Agriculture

Landowner Practices Can Protect Clean Water

Many Partners Help Landowners Get to Clean Water

Many partners help provide financial and technical assistance to agricultural landowners. Key resources include the Washington Department of Ecology, the Washington Conservation Commission, the Natural Resources Conservation Service, and the state Department of Agriculture.

Best Management Practices = Pollution Control

When it comes to protecting clean water, water quality Best Management Practices (BMPs) are a landowner’s key resource for pollution-control advice.

What are BMPs? The term is used in many different contexts, but in the context of water pollution, BMP is a legal term that refers only to those combinations of pollution controls used to prevent and control water pollution in order to comply with water quality law. Regulations in Washington specifically define water quality BMPs as those approved by the Department of Ecology (WAC 173-201A-020), and those that are applied to attain compliance with the water quality regulations (WAC 173-201A-510).

Other agricultural resources may provide BMPs for the land. However, the Department of Ecology has the distinct responsibility under the Clean Water Act to help landowners achieve compliance with legal definitions of BMPs. Ecology has the obligation under its Clean Water Act authorities to be clear about practices that protect water quality.

Management Practice Examples

When it’s inevitable that pollution and precipitation will mix, water quality BMPs should be developed and implemented to prevent the pollution from entering water (source control) and remove pollutants (treatment) from water running off the property. However, to successfully address these sources, management practices for water quality should be implemented to stop all pollutants from entering surface waters.

Below are examples of agricultural activities that generate pollution and practices that can be implemented to reduce or eliminate pollution from these activities.

Tilling fields, crop residue and erosion

Tilling up to the edge of the stream.   Natural vegetation along streamside.

Bad Example: Tilling up to the edge of the stream (above) causes erosion and can also contribute fertilizers and pesticides to the stream. Erosion can also lead to the loss of riparian areas and productive land.


Good Example: On this property, the landowner has left an area of natural vegetation along the stream, protecting it from erosion, deposition of pesticides and fertilizers, and providing habitat for fish and other aquatic life.

Crop residue and erosion


Bad Example: Fields without sufficient crop residue can experience significant erosion that can discharge sediment, nutrients and pesticides to surface waters. Soil loss can also reduce the productivity of the land and once the soil is gone it can’t be replaced.


Good Example: Dense crop residue and the use of a no-till planting equipment (above) reduces soil disturbance and can significantly reduce erosion. Many farmers in Eastern Washington are beginning to adopt this technique.


Livestock access to streams

Bad Example: When cattle are allowed unrestricted access to streams, they can trample stream banks, manure gets into the water, and they can overgraze native plants. Mud and sediments harm fish and other aquatic life. Fecal coliform from the manure makes streams unhealthy for people to swim or boat in. A loss of plant cover reduces or destroys the riparian (streamside) area’s ability to filter and absorb pollutants.


Good Example: Exclusion fence keeps cattle out of the riparian (streamside) area. When cattle are restricted from a stream , the riparian (streamside) area can recover and provide the environmental benefits necessary to maintain stream health.


Landowner success stories

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Last updated July 2012