South DakotaOdor Footprint Tool

Dick Nicolai, Ph.D., Erin Cortus, Ph.D., P.E. and Bob Thaler, Ph.D.South Dakota State University

Airborne Emission Sources StorageHousing

Land Application

Factors Affecting Release and Dispersion

3. Source concentration

2. Area

1. Wind speed

1. Temperature2. Wind speed3. Topography

History of Odor Setback Tools• Desire for a science-based model to establish

setback distances from animal production sites• OFFSET – developed for Minnesota

• Odor emissions gathered from 85 farms in Minnesota (1998 to 2001)

• Odor plumes measured by trained field assessors and trained resident observers

• Measured data checked against dispersion model• Historical frequency of favorable weather conditions for

odor transport identified• Odor mitigation strategies

History of SDOFT• Uses similar principle to

OFFSET• Same odor emission

values• Different dispersion model

• Historical weather data by region, April through October

• Recent work has considered impact of shelterbelts

A rea 1

A rea 2

A rea 3

Wind Rosettes for Brookings County

What is a Footprint?• Shown through annoyance-free frequency curves during warm

weather

• Annoyance-free does not mean odor free. Annoyance-free means the odor intensity is a 2, on a scale of 0-5, for which the majority of the population would not find annoying

• SDOFT does not take into account all of the impacts topography and site-specific features (like animal diet and management) can have on the odor footprint for a particulate site

• Provides a starting point for investigating the odor impact

Limitations• Barn design and feeding programs change over

time• Odor emission data is costly and time-consuming to

collect• Science-based estimate• Management is key after the farm is constructed

and populated

Starting Point for Discussion!

% Annoyance-Free verses Distance

Radial Data

0.0 0.5 1.0 1.5 2.0 2.50.0

0.5

1.0

1.5

2.0

2.5

0.00.51.01.52.02.50.0

0.5

1.0

1.5

2.0

2.5

98% No Odor Control94% No Odor Control98% with Biofilter and Deep Pit94% with Biofilter and Deep Pit

North

West East

South

-97.190 E 43.157 S

-97.190 E 43.157 S

-97.190 E 43.157 S

Clark County ColonyGestation Barn 80 X 430

Farrowing Barn 100 X 175Nursery Barn 80 X 243

Finishing Barn (2) 101 X 412