Need a septic inspection, pumping, a repair or a new system in San Mateo, CA? Describe your project once and up to three septic contractors who work in San Mateo and San Mateo County get back to you. Free, no obligation.
San Mateo has about 103,006 residents (2024 Census Bureau estimate) and 8,489 people per sq mi: a densely built-up area. Outside the reach of the public sewer, homes rely on an onsite septic system that needs regular pumping and, when it fails, a repair permitted by the local health department.
San Mateo at a glance
- Population (Census Bureau estimate, 2024)
- 103,006 (−2.5% since 2020)
- Rank in California
- 71st of 482 cities and towns
- Land area
- 12 sq mi
- Population density
- 8,489 people per sq mi (densely built-up)
- Type
- City (San Mateo city)
- Main county
- San Mateo County
What to check before hiring in San Mateo
- Permits: new systems and most repairs in California need a permit from the state or county health department, often with a soil or percolation test first. Your contractor should handle or explain the paperwork.
- License: septic installers and pumpers are licensed or registered in most states. Ask for the license or registration number.
- Maintenance: the U.S. EPA recommends having a household septic system inspected at least every three years and the tank pumped typically every three to five years.
- Buying a home: a septic inspection before closing tells you the condition of the tank and drain field; some counties require one at sale.
Useful official resources
-
U.S. EPA SepticSmart
How septic systems work and how to maintain them.
Services available in San Mateo
-
Septic inspection
Inspection of the tank and drain field, often requested when a home is sold or by the local health department.
-
Septic tank pumping
Pumping the solids out of the tank. EPA notes household tanks are typically pumped every three to five years.
-
New septic system design and installation
Soil and percolation testing, system design, permit and installation for a new home or a replacement system.
-
Septic repair
Diagnosis and repair of backups, odors, a failing drain field or damaged components.
Frequently asked questions in San Mateo
How often should a septic tank be pumped in San Mateo?
Typically every three to five years for a household system, according to the U.S. EPA, depending on tank size, household size and water use. An inspection tells you when yours is due.
Do I need a permit to repair or replace a septic system in California?
Usually yes: new systems and most repairs require a permit from the state or county health department, often after a soil evaluation. Your contractor can tell you what applies to your property in San Mateo.
What are the signs of a failing septic system?
Slow drains, gurgling pipes, sewage odors, wet or unusually green spots over the drain field and backups in the house. Have the system inspected quickly: early repairs cost less.
Who will contact me?
Up to three independent septic contractors who serve San Mateo, chosen for the service you need. Your details are shared only with your consent.
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2024) and Gazetteer Files (public domain), imported on 10/31/2026. Figures describe the incorporated place or county as published; they are shown for information only.