Use of Sulfide Generation Model and Sewer Headspace Air Pressure to Evaluate and Solve Sewer Interceptor Odor Problems

An odor control study was performed for the Albuquerque / Bernalillo County Water Utility Authority (WUA) to identify locations of potential odor issues, determine the likely causes of the odors and recommend odor control methods that can be implemented in the collection system to prevent these odor issues and associated corrosion problems. Dissolved sulfide, hydrogen sulfide and air pressure were monitored at several locations in the collection system.The Tijeras Interceptor and major tributaries encounter extreme reductions in slopes and diameters along its alignment, which can cause significant changes in wastewater velocity and increased turbulence. The turbulence can cause an increase in sulfide stripping from the solution to atmosphere. It is theorized that in addition to sulfide stripping, ventilation characteristics of the gravity interceptor may play a role in releasing the odors from the sewer.This paper provides a summary of the results obtained through the field sampling and testing program, sulfide model analysis, and provides conclusions as to the cause of odor within the Tijeras Interceptor. Recommendations for mitigating the associated odors and corrosion are also discussed.