Proceedings

Wastewater biosolids applied to land application sites may generate nuisance odour due to uncertainty in
odour emission levels, variation of atmospheric conditions, and sensitivity of human perception. These
factors are challenging management of biosolids since these odours may upset communities neighboring
the land application sites, often resulting in legislation to ban or minimize biosolids recycling.
This paper describes probabilistic dispersion model to evaluate biosolids emission impacts on surrounding
communities. The U.S. Environmental Protection Agency (EPA) Regulatory Model, AERMOD, and a
probabilistic odour emission model are used to address biosolids odour dispersion from District of
Columbia Water and Sewer Authority (DCWASA) land application sites. The model accounts for uncertain
emission levels and variation of local flow condition. The results improve the accuracy of odour impact
assessment to local communities.

Keywords
Dispersion model, Odour impact, Probabilistic model