Cypress Trunk Sewer

Cypress Trunk Sewer

Construction on the Cypress Trunk Sewer Project is gearing up as crews prepare for pipe replacement work within Forest Lawn Cemetery. Replacement work is expected to begin as early as Monday, July 6, near Denni St. and Crescent Ave., moving south into Forest Lawn Cemetery.

Pipe replacement will use a trenchless construction method called pipe bursting, which uses access pits. From the access pits, a specialized machine will pull a new, larger pipe through the old one, breaking apart the existing pipe as it goes. 

For the latest project updates, continue to check this page and sign up for email and text alerts.

Current Work: City of Cypress

Location: Guardian Dr. within Forest Lawn Cemetery 

Crews have installed a bypass system to maintain sewer service during construction and are currently excavating an access pit needed for pipe bursting. To minimize impact on the community, construction work is taking place at night. 

• When: Ongoing – December 2026*
• Work Hours: Sunday – Friday, 8:00 p.m. – 6:00 a.m.*
• Work Impacts: Increased activity, dust, and noise levels

Location: Denni St. between Fontainbleau Way and Crescent Ave.

A bypass system is in place, including above-ground pumps and underground piping. Excavation for an access pit is currently taking place and once complete, pipe bursting will begin.

• When: Ongoing – late August 2026*
• Work Hours: Monday – Friday, 8:00 a.m. – 5:30 p.m.*
  • Please note: The bypass systems are operating continuously.
• Work Impacts: 
  
  • Reduced traffic lanes; flaggers will be present to direct traffic.
  • No parking on the eastside of Denni St. across from the bypass pumps. Additional parking restrictions may be needed—please follow all posted signs
  • Temporary closures on Denni St. Residential access will remain—follow detour signs.
  • Permanent traffic control around the bypass pumps.
  • Increased activity, dust, and noise levels, including humming from the bypass pumps. Noise barriers will be in place.

Location: Crescent Ave. between Acacia Dr. and Martinique Way

Additional bypass pumps have been installed on Crescent Ave. to ensure continuous sewer service. 

• When: Ongoing – late August*
• Work Hours: Monday – Friday, 8:00 a.m. – 5:30 p.m.*
  • For the week July 6, there will be one day where work will begin at 7:30 a.m.*
  • Please note: The bypass systems will be operating continuously.
• Work Impacts: 
  
  • Restricted left turns to and from Gay St., Denni St., and Beach Cir. Additional turns may be limited–please follow all posted signs.
  • Reduced lanes; thru traffic will remain on Crescent Ave.
  • Permanent traffic control around the bypass pumps.
  • Increased activity, dust, and noise, including humming from the bypass pumps. Noise-mitigating blankets will be in place.
  •  

Location: Along the Project Alignment

Crews are rehabilitating manholes, including installing new liners, frames, and covers, along the project alignment in the cities of Cypress and Los Alamitos, including on Denni St. and Orange Ave. Work at each manhole location will take approximately 2-3 days*

• When: Ongoing, lasting until mid-August *
• Work Hours: Monday – Friday, 8:30 a.m. – 4:30 p.m.*
• Work Impacts: 
  • Reduced traffic lanes
  • Temporary traffic control while work is being performed
  • Increased activity, dust, and noise levels.

 *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