Odor Control System Upgrades: Experiences at San Diego’s Metropolitan Biosolids Center

The Metropolitan Biosolids Center is a regional biosolids treatment facility that is operated by the City of San Diego’s Public Utilities Department. Foul air collected from various process areas is treated in one of two odor control systems. The facility has experienced poor capture of foul air, primarily at the Biosolids Loading Facility. Brown and Caldwell is designing improvements to the foul air withdrawal system to improve foul air capture and improve the working environment. This will be accomplished by redirecting airflow capacity from one area to another. The overall airflow rate to the odor control system will remain unchanged. Field investigations conducted in September 2012 indicated that the concentration of odorous constituents was not significant enough to impact the operation of the odor control system following the redistribution of capacity between areas. The design of improvements to the facility has been completed and construction is anticipated to begin in 2015.