@article {Wolstenholme:2011:1938-6478:5481, author = "Wolstenholme, Philip and Fickas, Justin", title = "Air Dispersion Modeling at Wastewater Plants: A Significant Shift in Odor Objectives", journal = "Proceedings of the Water Environment Federation", volume = "2011", number = "10", year = "2011", abstract = "Engineers have used air dispersion modeling for many years to determine offsite odor impacts from wastewater facilities. The recent use of the European standard to measure odor concentration has resulted in significantly higher emission rates being measured and, because they are directly proportional to emission rates, higher offsite impacts being projected.

Goals and regulations established based on the previous American standards are no longer valid. Plants with uncontrolled area sources comprising open tanks, channels, and basins should have great difficulty achieving the single-digit odor unit (OU) impact goals that have been historically set unless there is a significant perimeter buffer.

Offsite impacts predicted by the three most commonly used models are in general, highest for CALPUFF, second highest for Industrial Source Complex Short-Term Version 3 (ISCST3), and lowest for AERMOD. AERMOD has become the most frequently used model in recent years and became the U.S. Environmental Protection Agency (EPA) preferred model in 2006.

Measures that can be implemented to reduce offsite impacts from area sources include construction of barrier walls, use of wind machines to break up stagnant air, and good operational practices.", pages = "5481-5493", url = "http://www.ingentaconnect.com/content/wef/wefproc/2011/00002011/00000010/art00011", doi = "doi:10.2175/193864711802766227", keyword = "Dispersion modeling, odor, dilutions-to-threshold, odor units, CALPUFF, AERMOD" }