By John Macpherson, Steven Porter, Thomas Alford, and Greg Tomlinson
Henrico County, Virginia (The County) utilizes multiple chemical technologies in the sewage collection system in order to control hydrogen sulfide concentrations at key points within the system. The county has strict compliance limits for hydrogen sulfide and was facing growing costs, spending in excess of $1.8 million dollars in 2010. The county decided to utilize programmable chemical dosing controllers and real-time hydrogen sulfide reporting to manage its odor control program costs. Evoqua Water Technologies installed programmable advanced dosing controllers at 14 dosing sites, and deployed cellular-modem enabled hydrogen sulfide data loggers at 11 compliance points. The primary objective of the hydrogen sulfide control program was to control hydrogen sulfide to compliance limits while reducing program costs. This paper reviews the effectiveness of the program against these primary and other secondary objectives.