Sewer Odor Investigation

If you notice a foul or unusual odor coming from a public street, sidewalk, or maintenance hole, please let us know immediately. LA Sanitation and Environment (LASAN) provides 24/7 rapid response teams to investigate neighborhood odor concerns.

You can submit an official investigation request in two easy ways:

• By Phone: Call our 24-hour Customer Care Center at 1-800-773-2489 to speak with a representative right away.
• Online: Fill out our quick, mobile-friendly Sewer Odor Form on the city website to log the exact location of the issue.

Note: If the odor is coming from inside your home or private drains, it may be an issue with your private plumbing or sewer lateral line. For indoor issues, we recommend contacting a licensed plumber to inspect your property.

Once you submit a report, our specialized maintenance crews are dispatched to look into the issue. Here is what our team does on-site:

• Locate the Source: Crews check public maintenance holes, sewer vents, and connection pipelines to find exactly where the odor is escaping.
• Inspect for Blockages: We often check the line using specialized equipment to make sure a hidden blockage from tree roots or fats, oils, and grease isn't slowing down the wastewater flow.
• Take Quick Action: If a build-up is found, our crews clear the pipeline immediately to restore proper flow and trap the odor back underground where it belongs.

Thanks to our proactive maintenance efforts, public sewer odor complaints across the City of Los Angeles have dropped by 52% since the 2009 fiscal year.

Under normal conditions, wastewater flows smoothly and odors stay trapped completely inside our massive underground pipe system. However, smells can occasionally escape into the outside air through tiny ventilation pick holes in maintenance hole covers or pipe connection points.

This usually happens due to two natural system changes:

• Heavy Pipe Flow: When sewer lines run completely full, the air inside the pipe gets pushed out through surface vents.
• Elevation Changes: When wastewater moves through steep underground drops or turns, the movement stirs up the liquid, releasing natural sewer gases into the upper parts of the pipe network.

LASAN is fully committed to stopping objectionable sewer odors before they ever reach your home or business. To do this naturally and safely, we install permanent Air Treatment Facilities (ATFs) directly in highly impacted areas.

These facilities are custom-engineered to blend right into your neighborhood’s environment and function without the use of harsh chemical sprays. Instead, they rely on a highly effective, natural two-step process:

• Step 1: Microorganisms at Work: The facility utilizes completely safe, natural microorganisms that thrive by eating sewer gases. These tiny organisms consume hydrogen sulfide (the gas responsible for the "rotten egg" smell) and convert it into a harmless, non-odorous liquid that drains safely back into the sewer.
• Step 2: Carbon Scrubbing: After the biological treatment, the air passes through an advanced carbon scrubber—which acts just like a giant aquarium filter—to clean away any remaining traces of odor before releasing pure air back into the neighborhood.