This paper discusses the development of a unique sewer tunnel ventilation strategy for a future City of Los Angeles wastewater project in the northern part of the City’s service area. Air accumulation in sewer tunnels can be a major issue due to high air volumes generated both in the sewer pipe and in drop structures feeding it. High air flows have many negative impacts including limiting the liquid flow, accumulating odorous air that requires exhaust and treatment using air treatment facilities (ATFs) at various locations, and in extreme cases causing high pressure air pockets that can cause structural damage due to pressure alone. The design team developed strategies to reduce those negative impacts by limiting the volume of air entering and conveyed in the tunnel. This project is believed to be the first to use these strategies for a sewer tunnel of this size. The paper also discusses alternative treatment technologies for exhaust air.
Optimization of Air Flow in a Deep Tunnel System for the City of Los Angeles
Authors: Philip Wolstenholme, Carlos Amaya, Roy Cook and Chris Hunniford
2010 WEFTEC