Manure Application Setback

Manure application setback guidelines for Whatcom are based on scientific studies which recommend specific distances for sediment and nutrient removal based on seasonal precipitation and soil saturation conditions.

Manure Application Setback Distances (in feet)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
804 804 40 40 40/101,2 102 102 102 40 80 803,4 803,4

   1This is a floating date and should be evaluated based on current weather and forecast information.
   2A big gun applicator should NEVER be closer than 40 feet at any time of the year due to drift.
   3Application during November and December is typically not necessary and must be shown to be agronomic before manure is applied.
   4Any manure application made from November-February must have a winter spreading plan in place. Contact your CD planner to add this  to your DNMP.

Click here for the current seasonal recommend setback distance.

These guidelines apply equally to both liquid and solid manures.


A distance of 40 feet has been shown to be most effectual under our spring and fall rain events at preventing runoff of surface nutrients and sediment, while we allow that distance to be reduced to 10 feet in the dry summer months when the chance of runoff is slight. The setback distance is increased to 80 feet in the late fall through the winter to be protective against periods of heavy, prolonged rain events, and/or saturated soils which require greater distances for nutrients and pathogens to be treated prior to reaching a waterway. Application during this risky time can readily move surface applied manure from your field if you’re not careful.

If you have any discharge due to poor management, you may be put under the penalty of an EPA CAFO permit with a mandatory setback of 100 feet year-round.

When applying manure, remember to follow the manure application setback guidance posted on the Manure Spreading Advisory. These setbacks will help you avoid applying too close to a waterbody or sensitive area when the risk of runoff is high. Your Nutrient Management Plan requires the implementation of these setbacks.




This page was last modified on 05/19/14 - 11:11