Collection System Odor Control Ventilation: Treating the Disease, not the Symptoms

When trying to solve a collection system odor control problem oftentimes the natural inclination is to focus all attention on the locations of the odor complaints; the thought being that the source of the problem must lie near where the complaints occur. While complaint information is very important and valuable it does not necessarily tell the whole story on where to focus attention on determining the best possible solution to collection system odor problems. A full investigation of the affected sewer system network, with particular emphasis placed on those physical aspects which cause odorous air to be ejected to atmosphere, provides the best opportunity to developing an economically and technically viable permanent solution to such problems. This paper uses extensive differential air pressure data taken over the past two years on large scale sewer odor studies in Minnesota and Arizona to support this approach. A stepwise approach that starts with a sewer hydraulic and headspace airflow analysis, followed by baseline air pressure sampling and full-scale pilot testing of odorous air removal from the collection system, provides owners with definitive proof on the viability of such an approach and gives them confidence that related solutions for solving their collection system odor control problems are both technically and economically reliable.