Basin 2 & 3 Pipe Capacity Improvements – Delaware Street Relief Sewer Project Completed
Project Type:
Conveyance
Approximate Construction Start & End Dates:
June 2022 – July 2024
Project Status:
Construction was completed in July 2024.
Project Location:
In the Caltrain right-of-way between the north end of the Hillsdale Caltrain Station parking lot near 28th Avenue to the junction of Pacific Blvd and Delaware Street.
Project Description:
The purpose of the Basin 2 & 3 Collection System Upgrade is improvement of the ability of the overall wastewater collection system to manage heavy seasonal rainfall. These improvements will help prevent sewer overflows, as well as help the City comply with regulatory requirements. During heavy rains, the wastewater collection system capacity was overwhelmed by the amount of rainwater that enters the system through infiltration and inflow. This caused sewer overflows at locations throughout San Mateo, such as manholes and at the wastewater treatment plant. These overflows contaminated city streets, creeks, lagoons, beaches, and the San Francisco Bay.
The Basin 2 & 3 package of conveyance improvements included four independent pipe upgrades that total approximately 16,000 feet of pipe, including new relief sewers and extensions and size increases to existing lines. The upgrades reinforce the system, helping to reduce sewer overflows.
This Delaware Street Relief Sewer Project constructed approximately 3,100 feet of new high-flow relief gravity sewer line that generally parallels the existing gravity sewer along Delaware Avenue. The project used several construction methods, such as open-cut trenching and open cut and trenchless (micro tunneling) technologies.
Most of the new pipelines were installed in City streets, including some in high-traffic areas. Other pipelines were installed in existing utility easements on private property. Key aspects of the project were constructed in the Joint Powers Board right-of-way.
For more information, please contact CWP Project Manager Makarand Pendse at 1-925-392-3726 or Makarand.pendse@jacobs.com or (650) 727-6870, or email info@CleanWaterProgramSanMateo.org.