Development of Gis-Based Dispersion Modeling for Odor Impact Assessment from DCWASA Reuse Sites

Land application of wastewater biosolids can generate nuisance odor due to elevated biosolids emissions levels, unfavorable weather conditions, and topographic characteristics. These odors may upset communities neighboring the land application sites, often resulting in legislation to ban or minimize biosolids recycling.This paper describes an odor dispersion model to evaluate biosolids emission impacts on surrounding communities by measuring the level and dispersal of biosolids odorant emissions. The U.S. Environmental Protection Agency Regulatory Model, AERMOD, was used in this evaluation to address odor dispersion modeling of biosolids land application sites in Virginia. A Geographic Information System was employed to generate concentration maps that show predicted odorant sensation areas. The sensation area usually occurs during low wind speed and adverse meteorological conditions, especially in early morning and night. The sensation area, moreover, is sensitive to topographic features, particularly complex terrain. The methodology and results described in this paper will help biosolids managers to select appropriate land application sites prior distributing biosolids.