A Basin (North Basin) Sewer Project CCTV Investigations Continue
The A Basin Sewer CCTV & Cleaning project began in late Summer 2025 and is scheduled to be completed in mid-2026. Notifications will continue to be mailed to residents and businesses prior to the start of work, and the contractor will provide additional notices two to three days prior to starting work in the area if access to public maintenance easements is necessary.
The scope of work at this phase of the Basin A project includes cleaning and CCTV inspection of:
- Approximately 190,050 linear feet of pipe in the public right-of-way
- Approximately 44, 450 linear feet in easements on private property
- Approximately 900 maintenance holes in the public right-of-way and 110 maintenance holes in easements on private property
Cracked sewer pipes and laterals, as well as faulty maintenance hole covers, allow rainwater and groundwater to flow into the sewer system. Regular checks are needed to maintain the proper operation of the system, to meet regulatory requirements, and to prevent sewer overflows.
Basin A covers the northern portion of San Mateo, including the North Central, North Shoreview, San Mateo Park, San Mateo Heights, and a portion of Baywood neighborhoods (see map). The purpose of the Basin A Sewer Rehabilitation Project is to repair and rehabilitate existing sanitary sewer pipelines and maintenance holes.
A Basin (North Basin) Sewer Rehabilitation
Project Type:
CCTV & Cleaning
Approximate Construction Start & End Dates:
Summer 2025 to Summer 2026
Project Location:
San Mateo’s stormwater and wastewater collection system includes a network of 240 miles of pipe divided into five major sewer basins. A Basin covers the northern portion of San Mateo, including the North Central, North Shoreview, San Mateo Park, San Mateo Heights, and a portion of Baywood neighborhoods (see map).
Project Description:
Notifications will continue to be mailed to residents and businesses prior to the start of work, and the contractor will provide additional notices two to three days prior to starting work in the area if access to public maintenance easements is necessary.
A condition assessment is the first step toward finding cost-effective and technically-feasible fixes to minimize inflow and infiltration (I/I). CCTV studies are conducted using a remote-controlled camera. The information will be analyzed to identify problem areas in the collection system and to design spot repairs without the expensive guesswork associated with digging blind.
The two types of repairs this project will address are:
- Gravity Sewer System – Spot and Segment repairs
- Maintenance holes – Repairs and replacements
Gravity Sewer Spot Repairs and Replacement
Gravity mains offer reliable movement of sewage and surface runoff through a sewer system. However, over time the ground can shift, roots can penetrate, and traffic can impact sewers causing them to settle and crack. After the design phase is complete for this project, the construction phase would commence which would potentially include spot repairs on damaged or displaced existing 6-inch, 8-inch, 10-inch and 12-inch gravity sanitary sewer pipes with new polyvinyl chloride (PVC) sewer pipe throughout the A Basin.
Maintenance Hole Repair and Replacement
Maintenance holes need to be easily accessible for sewer maintenance and related emergencies. Over time, maintenance holes can become covered with grass or can sink below the grade level of lawns, roads, or sidewalks. There are several methods of rehabilitating maintenance holes, and the method selected for a job depends on the condition of the maintenance hole. Common rehabilitation methods used for projects such as this include:
- Replacing the frame and cover;
- Applying cement mortar as a binding agent to the inside; and
- Applying epoxy liner to the inside for resurfacing.
Engineer Firm Name and Key Project Contact:
Engineer Consultant: CSG Consultants, Ed Slintak, 650-522-2533, ed@csgengr.com
CWP Office: 650-727-6870, info@CleanWaterProgramSanMateo.org
City/CWP Project Manager: Zachary Silverman, 650-522-7308, zsilverman@cityofsanmateo.org