Verification of separation distance methods for meat chicken farms

OLD ABN-The State Of Queensland Acting Through The Department of Employment, Economic Development and Innovation

  • Project code: PRJ-002747

  • Project stage: Closed

  • Project start date: Monday, March 10, 2008

  • Project completion date: Wednesday, July 29, 2009

  • National Priority: CME-Priority 1-Improving environmental sustainability outcomes


Odour dispersion modelling (usually with Calpuff or Ausplume) is commonly used to estimate separation distance requirements between poultry farms and surrounding receptors in order to prevent odour nuisance. Modelling poultry plumes is challenging due to highly variable emission rates and horizontally emitted plumes. Plumes emitted from meat chicken sheds can be slightly buoyant at certain times depending on ambient and emission temperatures. The inclusion of thermal buoyancy into dispersion modelling activities is contentious because of a lack of knowledge regarding the effect and frequency of this buoyancy on dispersion of odours. Inclusion of thermal buoyancy in dispersion modelling will usually indicate enhanced dispersion resulting in shorter separation distances. Conversely, excluding thermal buoyancy from modelling altogether will usually produce more conservative (perhaps overly large) separation distances. The question of whether or not thermal buoyancy should be included in dispersion modelling needs to be resolved.


Chicken Meat

Research Organisation

OLD ABN-The State Of Queensland Acting Through The Department of Employment, Economic Development and Innovation

Objective Summary

This project has three (3) objectives:
1. Monitor the temperature of air exhausted from a poultry shed in order to assess temperature gradients with the outside air. This monitoring will also demonstrate how the air temperature changes when poultry exhaust mixes with ambient air.
Results from this monitoring program will be used to check the assumptions within CFD and Calpuff models.
2. Use computational fluid dynamics (CFD) modelling to demonstrate that Calpuff accurately simulates the emission of odour emissions from tunnel ventilated meat chicken sheds. This will include a sensitivity analysis of emission temperature on plume movement and dispersion due to thermal buoyancy
3. Verify the ‘S-factor’ formula for calculating separation distances and buffer zones, as specified in the Draft best practice technical guide for the meat chicken industry in Queensland, 21 October 2005, using Calpuff.