Farms and NPS Water Pollution

Manure can be considered a very useful agricultural by-product when used responsibly.  However when agricultural by-products are poorly managed, water pollution can result. When it rains or snows, runoff that comes in contact with uncovered manure piles, fecal waste from livestock areas or poorly designed compost/manure storage facilities may carry pollutants to local streams and groundwater. Manures improperly used as soil conditioners can cause the same results. As well, animals with access to a watercourse can cause pollution through defecation in or near the water.

Manure and agricultural by-products contain substances that may be considered harmful when not handled properly:

• excess fertilizers (phosphorus and nitrogen)

• disease causing pathogens (such as certain kinds of bacteria)

• and large amounts of organic matter. 

What can Result from Poorly Managed Manure and Agricultural By-products

• Excess fertilizers in a watercourse can result in algal blooms. As this excess algae is broken down by bacteria large amounts of oxygen is consumed, and can drop to dangerously low levels causing fish to suffocate and die. The same is true for runoff containing large amounts of organic matter which must also be broken down.

• High levels of nitrates in drinking water can increase the risk of "blue-baby syndrome," which can kill infants and has been linked to other health effects.

Animal by-products can contain disease-causing pathogens. If these pathogens enter drinking water or irrigation water used on fruits and vegetables they can cause human illness. Furthermore, potentially polluted water used for livestock watering may result in animal illness.

What You Can Do on Your Farm to Protect Water Quality through Responsible Manure By-products Management 

• Keep field-stored manure piles at least 30 m from any watercourse and keep them covered to prevent runoff to surface water, especially from October 1st to April 1st.  For more information click here:

Photo courtesy of BC Ministry of Agriculture and Lands

• Facilities used to store or compost/manure should be located at least 15 m from any watercourse and should be covered and lined to prevent overflow or leakage.

• Keep confined livestock areas such as paddocks or holdings at least 30 m from any watercourse.

• If animals are defecating in or near a watercourse it is recommended that alternate watering options be provided and that livestock be guided away by installing protective fencing around watercourses on your property.

	Cow patty in the stream
		Stream fenced out to prevent livestock access.

• Manure should not be spread as a soil conditioner during the fall and winter since the risk of runoff is very high. Furthermore, manure should not be spread on grass fields during “No-Spread” periods specified in Manure Spreading Advisories.  Click here for the advisory.

 Manure should not be applied:

• at rates of application that exceed the amount required for crop growth,

• on areas having standing water,

• on saturated soils,

• on frozen land, or

• in diverting winds.

Farm animal mortalities should be managed in a manner that does not cause pollution. For more information click here: