Innovative Odor Containment and Treatment at A Large Wastewater Pumping Station

The Woodbridge Avenue Pumping Station is a wastewater pumping station operated by The Township of Woodbridge, NJ. The facility has a capacity of 15 mgd, and includes aerated grit chambers and mechanically-cleaned bar screens. The existing station had two large activated carbon adsorbers to treat odorous air from the covered grit chambers and pumping station. However, due to the high H2S loading, the activated carbon media became quickly exhausted, and the odor control systems were abandoned. The lack of adequate ventilation and capture of the H2S created dangerous conditions for the operations and maintenance staff, especially in the lower level where the wastewater entered the station.An innovative enclosure system was designed to isolate the sources of odor and thus prevent the emissions of H2S into worker-occupied areas. Flat, corrosion-resistant aluminum covers were installed over the open influent channels. The grit chambers had already been covered, so the existing covers and ductwork remained. An enclosure consisting of stainless steel framework and clear polycarbonate panels was built surrounding the two screens from floor-to-ceiling on both levels of the pump station. The design team worked closely with operations staff so that the screens were easily accessible for maintenance using removable panels. The enclosure completely enclosed the two screens and part of the screenings conveyor. The total design air flow for the system was 4,600 cfm. After characterizing the air streams and evaluating various air treatment alternatives, a biotrickling filter was recommended as the most cost-effective technology for this application. A pilot system was operated for approximately nine months to verify performance.The odor control system began operation in September, 2008. Air quality in the pump station improved dramatically, with H2S levels