Northwest Winter Feeding Assessment Tool

Can Grazing Operations Be an AFO Based on Winter Feeding Practices?

Assessment of and protection for water quality resource concerns impacted by livestock winter feeding practices

Grazing lands management assistance with NRCS focuses on forage and range conditions for livestock producers and management practices during the growing season. Animal waste management system installations with NRCS have focused on water quality protection associated with confined animal feeding operations. The winter feeding management strategies of grazed livestock can also have a significant seasonal impact on the quality of nearby surface water resources.

In northern regions, winter is a dormant season for forage and a time when significant precipitation can occur. In recent years EPA has clarified the regulatory definition of an Animal Feeding Operation (AFO). The winter feeding management practices employed by grazing operations may risk water quality resource concerns and meet the EPA definition of an AFO.

A planning tool to identify sites where livestock density during the winter feeding period could create a resource concern can facilitate addressing this water quality issue. This assessment tool can review the applicability of NRCS practices for an animal waste management system and if appropriate move the planning process forward for a site design to protect surface water quality resources as needed for the seasonal feeding period.

What did we do? 

As the Environmental Engineer at the West National Technology Support Center I am developing the planning tool for livestock winter feeding sites. The landowner can participate in developing the concerns to be considered for their natural resources and operational practices. Animal manure and the nutrient balance with forage crops can be checked. A review is made if the winter feeding operation approaches the EPA definition of an AFO. The buffer quality conditions can be checked between the feeding site and the surface water sources. This tool can help engage the landowner in a conversations about adaptive management options for pasture or waste storage facility structures as might be recommended for higher animal density management over winter.

What have we learned?             

Resource planning must include the concerns and values of the landowner and the practice must fit with the characteristics of their operation. Animal production and natural resource management is ultimately effected by landowner decisions for the management of livestock and protection of natural resources.

Northwest winter feeding assessment tool

Northwest winter feeding assessment tool

Future Plans    

Continue to test the winter feeding assessment tool and make revisions for utilization.


Sally Bredeweg PE, Environmental Engineer, NRCS West National Technology Support Center

Additional information                

NRCS – Agricultural Waste Management Field Handbook

NRCS – Comprehensive Nutrient Management Planning Procedure

EPA – Animal Feeding Operation (AFO) as defined in the EPA Technical Manual for Concentrated Animal Feeding Operations, EPA 833-F12-001, February 2012


NRCS Range Management Consortia West Region

NRCS staff in WA, CO, UT, CA

EPA region 10

Growing Forward, British Columbia Init

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