Santa Ana Trunk Sewer Rehabilitation Project

Progress continues on the Santa Ana Trunk Sewer Rehabilitation Project to improve the regional sewer system by rehabilitating sewers originally installed in the 1950s. Crews are currently in the City of Santa Ana. 

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Construction Update

Location: Alton Avenue between Bristol Street and Bear Street

A construction method called cured-in-place-pipe (CIPP) was recently used to rehabilitate the sewers between Bristol Street and Greenville Street. With CIPP, a new liner is installed inside the existing pipe through manhole openings, creating a new pipe within the old one. This method requires less excavation than traditional pipe replacement, helping reduce impacts to the surrounding community.

As part of OC San’s quality control process, the newly installed liner is inspected to confirm the work meets the project requirements. During the inspection of the pipeline between Bristol Street and Bear Street, crews identified an area that requires additional work. As a result, construction in this area will remain in the area longer than originally anticipated. 

Work is finished in other sections, allowing crews to remove portions of the temporary sewer bypass system. The bypass pipes and pumps between Bristol Street and Bear Street will remain in place while crews peform the additional work. Once that work is finished, crews will remove the remaining bypass equipment, complete work on individual manholes, remove traffic control, and restore streets and parking. 

• When: Ongoing – late October 2026*
• Hours: Monday – Friday, 7 a.m. – 3:30 p.m.*
• What to Expect:
  • Temporary bypass pipes and equipment will remain in the area.
  • Construction activity will continue near the work area.
  • Temporary traffic control and lane closures on westbound Alton Avenue.
  • Temporary no street parking on Bristol Street by Villa Marseilles Apartments. 
  • One marked parking space within the Bradford Place West neighborhood remains unavailable.

Current Work

Location: Alton Avenue between Fairview Street and Susan Street

Westbound Alton Avenue between Susan Street and Fairview Street is temporarily closed. Before actual sewer rehabilitation can take place, a temporary bypass system of above ground and buried pipes, pumps, and equipment will be installed to safely reroute sewer flow to maintain uninterrupted service during construction.

Crews will rehabilitate the regional sewer pipeline in segments requiring continuous work hours. Advanced notice about continuous work will be provided when dates are confirmed, tentatively in early November. After sewer rehabilitation is completed, individual manholes will be worked on, the bypass system removed, followed by street restoration and opening up westbound Alton Avenue. 

• When: Ongoing – February 2027*
• Hours: Monday – Friday, 7 a.m. – 3:30 p.m.
• What to Expect: 
  • Westbound Alton Avenue is closed; please follow all posted signs
  • Construction activity, dust, and noise near work areas.
    

*All dates and times are subject to change due to operational factors or inclement weather.

Project Description:

The Santa Ana Trunk Sewer Rehabilitation Project will rehabilitate portions of the Santa Ana Trunk sewer in the cities of Santa Ana and Costa Mesa. The project is relining almost 3 miles of existing sewer line to extend its service life. As part of this effort, over a dozen manholes will also be rehabilitated or replaced, and bypass pumps will be needed to reroute sewer flow and maintain service to the community.

The work will take place along Alton Avenue starting at Bristol Street and traverse across MacArthur Boulevard, Harbor Boulevard, Hyland Avenue, and Sunflower Avenue as shown in the map.

Map showing the Santa Ana Trunk Sewer Project area in the cities of Santa Ana and Costa Mesa.

Project Website: ocsan.gov/santaana

Schedule:  Spring 2026 through 2028