The Orange County Sanitation District, one of our valued regional partners, is leading the Cypress Trunk Sewer Project—an important infrastructure effort that spans the cities of Cypress, La Palma, and Los Alamitos. The project will enhance approximately seven miles of sewer lines to improve system reliability and support future capacity needs.

Key improvements include replacing one mile of pipe with a larger diameter pipe to increase capacity, chemically grouting and cleaning roughly 5.5 miles of existing pipe to extend its service life, and rehabilitating or replacing approximately 100 manholes throughout the project area.

Construction is expected to begin in summer 2025 and last approximately 3 years.

Project Benefits

The Cypress Trunk Sewer Project will ensure the continued reliability of the regional sewer system.

The regional sewer line in the cities of Cypress, Los Alamitos, and La Palma is approximately 50 years old and in need of upgrades. These repairs will increase sewer capacity and allow for more efficient and reliable management while extending the life of the sewer pipes by another 50 years.

Stay Informed

Sign up for project alerts and view an interactive project map at ocsan.gov/cypress.

Have Questions?

Contact the Orange County Sanitation District Community Liaison:

Phone: (714) 378-2965

Email: constructionhotline@ocsan.gov

Construction Update: Orange Ave. at Alderbury St.

Starting Tuesday, February 17, access to the neighborhood at Alderbury St. and Orange Ave. will be closed as OC San crews begin replacing a section of sewer pipe. To maintain uninterrupted service during construction, crews will first install a temporary bypass system to reroute flow, then excavate the work area, and place the new section of pipe. Please note: Work is still occurring in this neighborhood prior to the Alderbury work.

When: Starting Tuesday, February 17–late March 2026*
Hours: Monday–Saturday, 7:00 a.m.–7:00 p.m.* (Crews will be working extended hours and days to shorten the overall duration of the work)

What to expect:
○ Reduced traffic lanes – left turns may be limited to and from Julie Beth St.
○ Crosswalks and bike lanes will be closed within the traffic control area until the work is completed.
○ Traffic control barriers will remain in place throughout the duration of work.
○ Increased activity, dust, and noise levels.