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Animal Feeding Operations

Air Program Update

Presented By: William Schrock

Farm, Ranch, and Rural Communities Federal Advisory 

Committee

March 13, 2008

Washington, DC
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Background Information

• EPA & USDA asked National Academy of 

Science (NAS) to conduct the AFO air emissions 

study

• NAS study conclusions:

– No reliable emission factors for AFO exist

– Additional data needed to develop estimating 

methodologies

– Current methods for estimating emissions not 

appropriate

– Use process-based approach
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Goals for Next 2-3 Years

• Address issues of CAA requirements

– Emission estimation (e.g., emission factors, 

potential to emit)

– Source definition

– Applicability cutoff (i.e., size cutoff)

– Fugitive/non-fugitive

– Control technology effectiveness

– Monitoring, reporting and recordkeeping
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• Consent agreement developed in response to:

– Public concerns

– NAS report

• Consent agreement developed by:

– EPA

– Industry representatives

• Proposed agreement coordinated with:

– Agricultural industry representatives

– State & local government officials

– Environmental organizations

– Citizen groups

Agreement Overview
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Monitoring Study - Signups

• EPA received approximately 2,700 agreements representing over 13,000 

farms.

Number of Farms Represented in AFO Consent Agreement

Dairies, 4% of all 

Farms

Swine, 42% of all 

Farms

Broilers, 35% of all 

Farms

Layers, 19% of all 

Farms
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Monitoring Study - Overview

• Purpose: gather data for developing emission estimating 

methodologies

• Funding provided by participating AFOs - $14.8M

• Monitor for:

– Particulate matter

– Hydrogen sulfide

– Volatile organic compounds

– Ammonia

• Data made available to the public
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Monitoring Study – Site Selection
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Monitoring Study – The Challenges

Changing Climatic Conditions

Partially Enclosed and Naturally Ventilated 

Changing Feed Rations

Animal Movements

Large Open Sources
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What’s Next?

• Continue Data collection – Spring/Summer/Fall 

07 + 2 years

• Complete data analysis and publish Emission 

Estimating Methodologies – 18 months after 

completion of data collection

• Participants must comply with any applicable 

requirements – 120 days after publication of 

Emission Estimating Methodology
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Add-on Studies

Principal Investigator Topic/Sponsor Site(s)

Jacobson Odor Emissions/USDA NRI IA4A, OK4A, IN5B, & 

WI5B

Mitloehner VOCs & GHGs/CA Dept Food & Ag, Dairy CA5B

Lim Downwind Dairy Odor Survey/Purdue IN5B

Ni Air Emissions/USDA NRI IN2B

Koziel GHG/ISU IA4B

Jacobson GHG emissions (University of Minnesota) WI5B

Zhang GHG emissions (CARB) CA1B, CA2B

Wang PM size distribution (USDA-NRI) NC2B

Ndegwa Bioaerosols (PNASH) WA5B
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Future Outlook for AFO Strategy

• National Academy of Sciences developed 

recommendations to characterize all AFO processes.

• Consent Agreement/Monitoring Study is just one piece of 

overall strategy.

• Modifications to one area of an AFO can have impacts 

on another area and another media.

• Air Office still needs to consider the following:

– Regulations and/or guidance

– Conservation practices (conservation systems and activities, 

technologies)

– Emission estimating methodologies – short term

– Process based emission model – long term