Biotrickling Filter - Evolution to City of Los Angeles’ Preferred Odor Treatment Technology

The City of Los Angeles maintains and operates one of the world’s largest wastewater collection network and reclamation plants. The City services a 550 square mile area with a network of 6,700 miles of sewer lines, 49 pumping plants, and four water reclamation plants with a combined capacity to treat 580 million gallons per day (MGD) of municipal wastewater.A natural phenomenon within any wastewater collection and treatment system is the production of odorous compounds. The City has been proactive in managing odors emanating from its collection system and treatment plants working on its goal of being a “Good Neighbor”. The City’s overall goal is to implement a cost effective and community-supported odor control program that will mitigate and control odors from its sewer and water reclamation plants. One of the objectives of the City’s odor control program is to investigate new technologies to identify material and/or processes to control odors. The City began pilot testing new biological systems in the 1990s and 2000s, including media testing to identify media that would meet the City’s level of odor treatment. Biotrickling Filtration (BTF) technology was chosen as the treatment of choice due to its lower footprint requirement, lower operational requirement, and excellent performance to remove high levels of hydrogen sulfide (H2S), a major odor constituent.The City installed its first Air Treatment Facility (ATF) utilizing BTF in 2010 at its East Central Interceptor Sewer (ECIS) - Jefferson Blvd and La Cienega Air Treatment Facility (ATF), and (North Central Outfall Sewer) NCOS- Jefferson Blvd ATF locations. Currently the city operates and maintains three BTF ATFs on its collection system. As a result of the success with the full-scale installations, the City began initiating new projects to replace its chemical odor control systems with sustainable, operation and maintenance friendly, and safer BTF odor control systems. Currently the City has three BTF projects in construction, two projects in the design phase, and one project in planning/preliminary design for a total budgeted construction value of 56,000,000.This paper will describe the progression of biotrickling filter technology as a primary treatment of choice for odor control for the City of Los Angeles. The paper will describe phases of development of technology selection including technology evaluation, pilot testing, media performance evaluation and life cycle cost evaluation. By implementing BTF odor treatment as a preferred odor treatment technology the City thrives on its overall strategy and goal to implement a community-supported and sustainable odor control program.