1. Rick Stowell Extension Specialist – Animal Environment
Odor & Other Air Quality Issues for Poultry Operations Poultry Interest Team Webinar
Rick Stowell
Extension Specialist – Animal Environment

2. Discussion Items Poultry manure [litter] Odor Other considerations
Nebraska Odor Footprint Tool
Other considerations
Indoor air quality
Dust and feathers
Flies

3. Poultry Manure Characteristic Broilers Layers
Less moisture as excreted
~75% MC
Modern facilities promote drying
20-40% MC
45-50% MC
Comparatively nutrient dense, esp. if kept in raw consistency
60-65 lbs. of total N per 1,000 gallons
55-60 lbs. of total N per 1,000 gallons
Modern handling approaches result in added potential N loss
50-75% of N retained
40-75% of N retained
Why important for air quality?
Dry  Aerobic and handled as a solid
Aerobic  Less odorous
Handle as solid  Easier containment, less exposed surface
Dry  Potential dust
Dry, concentrated  Rewetting issues
N loss  Ammonia emissions

4. Odor’s Path to Detection
Transport and Mixing
Emissions
Detection
Generation
Air dispersion models predict how pollutants are dispersed in the atmosphere from different pollution sources taking into account
Topography
Meteorology
Downwind distances and other factors
A critical part of Air Dispersion Modeling is verification of the modeling tool.
Measured or detected pollutant concentration at a receptor location are used to verify the performance of the model.

5. Odor Sources
Anaerobic decomposition of manure
Common offensive odors

6. Odor Emitting Potential
Facility information: odor source input data for use with the Nebraska Odor Footprint Tool
The ‘odor emission number’ represents the relative amount of odor emitted per unit of area (sq. ft.), based on facility dimensions.

7. Separation Distance
Recommendation: Provide reasonable separation between proposed AFO and local residences to minimize dust and odor risk

8. Nebraska Odor Footprint Tool (NOFT)
A planning tool
Used to determine minimum separation distances at various levels of odor risk
A ‘simple tool’
Excel® spreadsheet
Worksheet, tables, and set of curves
Based upon dispersion modeling
Not a tool to bypass county setbacks
While county setbacks often establish required minimum separation distances, specific consideration of odor risk may be helpful for improved siting of AFO. Recognize that county setbacks are generally designed for ease of use and consider impacts of noise, light, traffic, etc. which don’t depend on direction per se, thus the preferred use of circles.

9. Risk-Based Odor Assessment
Odor risk may be expressed as the projected percentage of hours over an extended period of time during which odor:
Exists at annoying levels
‘Odor annoyance frequency’
e.g. values from 1 to 10% OR
Is not present at annoying levels
‘Odor annoyance-free frequency’
e.g. values of 90 to 99%
90% full
10% empty
wording utilized within the NOFT

10. Four-House Broiler Site
Four-house broiler facility being constructed in eastern Nebraska (photo: R. Stowell)

11. NOFT Input: Spreadsheet View

12. NOFT Results: Spreadsheet View

13. Siting of Broiler Facilities
No residences within 94% or 98% annoyance-free distances for site X
Seems site Y may have advantage. X Y 13

14. Cautions in Interpretation
‘Low odor risk’ does not mean ‘No odor’
Siting for minimum NOFT separation negates the ‘low-odor poultry effect’ from the neighbor’s perspective
Same odor risk for chickens vs. cattle vs. hogs

15. Search for “NOFT” under manure. unl. edu http://water. unl

16. Other Air Quality Considerations
Elevated in-house concentrations when handling litter between flocks
Ammonia
Particulate matter

17. Dust and Feathers
Wind-blown particulate matter may be an issue during transfer and spreading
Very dry litter (20-30% mc)
Birds went through molt
Windy conditions
Open-top vehicles
Downwind neighbors?

18. Stored Manure/Litter
Concern: Damp stored litter is a breeding ground for flies and increases odor generation
Inside housing
Control water leaks
Maintain airflow
Stockpiled litter
Well-drained site
Preferably covered

19. Manure.unl.edu and extension.org/animal_manure_management
Thank You!
For more air quality information:
Manure.unl.edu
and
extension.org/animal_manure_management