An Overview of LACSD's I&I Reduction Efforts

Presentation Description: In 2024 LACSD initiated a new inflow and infiltration (I&I) reduction program. This presentation will describe the I&I reduction program, including the various methods utilized, accomplishments and lessons learned.

The presentation will begin with an overview of I&I and the adverse impacts on the sanitary sewer system, including reduced capacity, sewer surcharging, spills, and overburdened treatment plants. The introduction will touch on the specific events that lead to the initiation of the I&I reduction program.

Next, the presentation will describe how different sections within LACSD work together to prioritize areas of concern, investigate these areas, identify specific sources of I&I, and address these sources.

The presentation will then continue to list the various methods and tools to identify and reduce stormwater intrusion, including the following:
1. LACSD’s Industrial Waste Section updated the agency’s stormwater policy to reduce stormwater inflows from industrial and commercial facilities.
2. Inspections are conducted at both permitted and nonpermitted industrial facilities to identify sources of I&I and notify companies of compliance requirements.
3. Flow meters are used to identify areas of the collection system that experience high peaking factors during storm events. This data is used to initiate investigations for the I&I team.
4. Trail-cameras are placed inside numerous manholes within an investigation area to narrow down where I&I is entering said area during storm events.
5. Clear-sphere sewer inspection cameras are used to capture video footage of sewer segments during storm events to identify where heavy inflow is entering the sewer.
6. Smoke testing is used to identify I&I sources in residential areas during dry weather.
7. Manhole covers located in drainage pathways or in streets subject to flooding are identified and sealed to prevent stormwater inflow.

The presentation will conclude with next steps that LACSD has planned to further reduce I&I within our service area.