LEHDER’s phased approach involves the following:
Phase 1:
Assessment of Odour Issues – qualitiative evaluation at facility
Phase 2:
Quantification of Odour Sources – quantitative evaluation of odours
Phase 3:
Odour Impact Analysis – how is the surrounding area affected
Phase 4:
Solution Development – prevention, taller stacks, control devices, etc.

Reasons for completing an odour evaluation may include:
	Conditions of a Certificate of Approval (C of A)
	Complaints from neighbors
	Changes in processes affecting odourous emissions
	Being proactive

LEHDER follows the testing methodology outlined in the Ontario Ministry of Environment Odour Sampling Code. Samples are taken using a diluter, a NEAT sampler (undiluted) or by use of a flux chamber (pond sampling). Diluted samples are cut with ultra high purity nitrogen. The LEHDER olfactometer is a ternary port system operated in a forced choice mode. Screened panelists are used to evaluate the odour samples which are collected in Tedlar bags. The panel is used to determine the odour threshold value (OTV) which is the point where 50% of the panelists detect an odour. Upon quantifying the odour, the impact is determined by use of EPA recognized models such as ISCST3.

For more detailed information please contact the individuals below:
	Sid Lethbridge, Eastern Division
	slethbridge@lehder.com Tel: 519.336.4101 ext. 222
	Peter Pakalnis, Eastern Division
	pakalnis@lehder.com Tel: 519.336.4101 ext. 227