LACSD sewer line collapse worksite on Friday, December 31, 2021 at 6:33 a.m. (LACSD)

Communicating During an Emergency: LACSD Responds to January’s Sewer Spill

By Wendy Wert, LACSD, Members in the News, Wastewater News

The Los Angeles County Sanitation Districts (Sanitation Districts) protect public health and the environment by providing wastewater management for 5.5 million people. The agency operates and maintains a regional wastewater collection system, which includes approximately 1,400 miles of sewers, 48 pumping plants and 11 wastewater treatment plants that convey and treat about half the wastewater in Los Angeles County.

The Spill

Just as 2021 was coming to a close, the Sanitation Districts found itself dealing with a major emergency. After two days of heavy rainstorms, a 60-year old, 4-foot diameter sewer collapsed creating a major spill in a residential area. It took a little over 24 hours to completely stop the spill.

By then, over 8.5 million gallons of raw sewage had flowed down a residential street into a storm drain, the Dominguez Channel and eventually into the LA Harbor, creating the largest recorded spill in Sanitation Districts’ history.

Working around the clock, Sanitation Districts staff and contractors were able to repair the collapsed sewer by January 8 and completely restore the site of the collapse by January 13, 2022. In addition to field crews, employees throughout the agency contributed to our response.

Initial External Communications

At approximately 2 p.m. on December 30, 2021, the Sanitation Districts were notified of a sewage spill at the intersection of 212th Street and Moneta Street, a residential street in Carson, California. The agency immediately responded. By 5:15 p.m., the spill had been verified, the cause of the spill had been determined, and staff and contractors were mobilized to stop the spill and repair the collapse. At that time, the manager of our Public Information Office (PIO) was briefed on what was happening.

PIO staff then mobilized using its incident communications plan as a guide. This plan helped us quickly provide accurate, relevant information to interested parties including those impacted by the spill, elected officials and the Carson community. Early that evening, PIO staff established a Microsoft Teams channel to facilitate communication between responding managers and another for the PIO staff involved in the incident. We provided updates as more information became available, including three the first evening.

These were posted to a dedicated webpage (Carson Sewage Spill) on our website and on our social media platforms (Facebook, Twitter, Instagram and NextDoor). These updates were emailed to a growing contact list of interested parties. Initially, this list involved key staff at the City of Carson but grew to include a variety of local and state elected officials and all members of the media that expressed interest in this incident.

The evening of December 30, our General Manager contacted the Mayor of Carson and the County Supervisors with districts nearby. Our staff notified regulatory agencies like the Los Angeles County Department of Public Health and the Los Angeles Regional Water Quality Control Board so that they could take any necessary action. PIO staff handled numerous media requests.

By 6:45 p.m. on December 30, the first of two PIO staff members arrived at the spill location to inform residents of what was going on and answer any questions. On December 31 and succeeding days, staff handed out and posted numerous advisories in multiple languages describing the situation to affected residents and what the Sanitation Districts would do to restore the area where the spill occurred.

As crews worked around the clock to repair the damaged sewer, PIO staff kept all impacted residents informed. Staff went door to door, listening to residents’ concerns. For the first week of the incident, staff met with residents in the area of the spill almost every day.

The sinkhole created by the sewer collapse was next to Carson Stree offramp from the Northbound 110 freeway in Los Angeles. (LACSD)


An important aspect of our response was taking responsibility for the sewage spill, as summarized by the statement from our Chief Engineer and General Manager that was issued on Wednesday, January 5, 2022, on our website and emailed to Sanitation Districts Directors and Public Works Directors for the cities we serve in the Los Angeles Basin.

Part of taking responsibility is fixing a situation. Along with repairing the collapsed sewer, our other main priority was restoring the area where the spill occurred in close coordination with the affected residents.

On Friday, December 31, 2021, our field crew began cleaning 212th Street. On Saturday, January 1, 2022, our crews did another round of cleaning. Additional cleaning was completed on January 3 and 5 by a third-party cleaning service.

On January 1, our staff began working with residents to arrange for washing of affected cars and we provided a flyer describing how residents could file a claim for any damages. On January 2, our staff distributed a flyer describing the restoration work we would do on the north side of the street and offering to replace material in residents’ parkways (e.g., grass between the curb and sidewalk) that was affected by the spill.

We quickly set up a streamlined claims process and provided residents with multiple and easy ways to file a claim. These included a simple claim form, a dedicated email address and a telephone number to staff who would be processing their claims.

On Monday, January 3, 2022, the Mayor of Carson, Lula Davis-Holmes, and our Chief Engineer, Robert Ferrante walked the impacted street and listened to residents. The residents expressed their appreciation for the Sanitation Districts’ prompt efforts to restore their neighborhood.

On Tuesday, January 4, 2022, our Chief Engineer briefed the Carson City Council. At that meeting the City Council commended the Districts for their responsiveness and communication. At the January 25, 2022, meeting of the Los Angeles County Board of Supervisors, Chairperson Holly J. Mitchell expressed similar appreciation:

Again, Mr. Ferrante thank you very much. Please extend our thanks to your entire team on behalf of the Board and on behalf of the residents of Carson that you all showed up and showed out to provide them with relief as quickly as possible. We deeply appreciate that.

The Districts efforts were helped by having a well-defined incident communications plan and having gone through a practice incident earlier in 2021.

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About the author: Wendy is an Environmental Engineer with Los Angeles County Sanitation Districts, Past President of CWEA, and a Board Certified Environment Engineer (BCEE). For the past 22 years she has been working on programs that rely on public participation to integrate water supply, water reuse with wastewater facilities planning. She received a bachelor’s degree in Environmental Engineering and a master’s degree in water resources engineering both from the University of Central Florida (UCF).