Cypress Trunk Sewer

Cypress Trunk Sewer

Crews continue working day and night to make essential upgrades to the regional sewer system in the cities of Cypress and Los Alamitos.

The next major phase of work is expected to begin in late April near La Palma Ave. and Denni St. in the City of La Palma, where crews will use pipe bursting, a trenchless method to replace the existing sewer pipe with a larger one.

Current Work

City of Cypress & Los Alamitos

Location: Bloomfield St. between Cerritos Ave. and Orange Ave.

Crews are performing manhole rehabilitation work along Bloomfield St. and occasional work on Chestnut St. Work at each manhole will take approximately 2-3 days.*

• When: Ongoing and lasting until the end of April*
• Hours: Monday – Friday, 8:30 a.m.– 5:00 p.m.*
• Work Impacts:
  • Reduced traffic lanes
    • Flaggers may be onsite in various locations to direct traffic; please drive with caution
  • Temporary traffic control while work is being performed 
  • Increased activity, dust, and noise levels

Location: Starting at Bloomfield St. and Cerritos Ave., moving west towards Oak St. and Catalina St. (see map below)

Crews are performing work at night during low-flow hours to inspect, clean, and grout the sewer pipes.

• When: Ongoing and lasting approx. one month*
• Hours: Sunday– Friday, 8:00 p.m.– 6:00 a.m.*
• Work Impacts:
  • Reduced traffic lanes
  • Temporary traffic control while work is being performed
  • Increased activity, dust, and noise levels

Upcoming Work 

City of La Palma 

Starting in late April, crews will begin work along Denni St. to upsize a portion of sewer pipe, increasing capacity and extending its service life. 

Location: Denni St. from La Palma Ave. to Robin Dr.

A full closure at Moorgate Dr. is needed to install a temporary bypass system to reroute sewer flow and maintain uninterrupted service during construction. Following bypass installation, crews will replace a portion of sewer pipe using a trenchless method called pipe bursting. Once pipe bursting is complete, crews will continue pipe replacement using an open-cut method for a section of pipe near Denni St. Park.

• When: Starting week of April 27, lasting until August*
• Work Hours: Weekdays, 8:00 a.m. – 5:00 p.m.*

Location: Intersection of La Palma Ave. & Denni St.

Pipe bursting will begin at the intersection, requiring an extended traffic control set-up. This will allow crews to safely carry out the work, including excavating pits to insert equipment, remove the existing pipe, and install the new one.

• When: Starting mid-May, lasting until July*
• Work Hours: Weekdays, 8:30 a.m. – 4:30 p.m.*

Work Impacts: 

• Permanent traffic control will remain in place throughout the duration of work.
• North/southbound travel on Denni St. will remain until intersection work begins.
• Closure at Moorgate Dr. (see map). Use Redford Ln. to access neighborhood & follow posted signs.
• Construction at Denni St. Park — the park will be closed during construction and restored once work is complete.
• Intersection Work Impacts:
  • One lane will remain open traveling east/westbound
  • No thru traffic moving north/southbound at intersection and no left turns in any direction.
  • One crosswalk, bike lanes, and bus stop closures until work is completed.

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

Project Description:

The regional sewer line in the cities of Cypress, Los Alamitos, and La Palma is approximately 50 years old and in need of upgrades. The Cypress Trunk Sewer Project will focus on enhancing about 7 miles of sewer, replacing portions of the pipe with larger diameter pipe to increase the capacity, or rehabilitating other segments of pipe to extend the life of the sewer system. Approximately 100 manholes will also be replaced and/or rehabilitated. These repairs will extend the life of the sewer pipes by another 50 years.

Schedule:
Construction began in Summer 2025 and is anticipated to last approximately 3 years.

Local Sewer Provider: 

• City of Cypress – Maintenance Division – (714) 229-6760
• City of La Palma – Public Works Division – (714) 690-3310
• City of Los Alamitos – Rossmoor / Los Alamitos Area Sewer District – (562) 431-2223