Plumber in Menlo Park, CA

A Homeowner’s Guide to Plumbing in Menlo Park

Water: check which provider serves your street

The City says four water providers serve Menlo Park. Most homes get water from one of two:

• Menlo Park Municipal Water, run by the City, serves about 4,400 connections in Sharon Heights and the areas east of El Camino Real. For a main break or a leak on the City’s service line, call 650-330-6750, or the police non-emergency line, 650-330-6300, after hours and on weekends.
• California Water Service (Bear Gulch District) serves about 8,800 addresses in Downtown and West Menlo. Its district number is (650) 561-9709.

O’Connor Tract Co-Operative Water Company serves a small part of the Willows from two deep wells, and Palo Alto Park Mutual serves fewer than ten addresses on Menalto Avenue. The City’s water provider lookup map settles it for any address.

Where your pipe begins: Cal Water says owners are responsible for plumbing on their side of the meter, and the City’s 2025 water quality report describes the privately owned service line as running from the meter to the house. Leaks on that line, and the pipes inside, are yours to fix. See leak detection and water line replacement.

Sewer laterals: West Bay Sanitary District’s rules

West Bay Sanitary District, not the City, runs Menlo Park’s sewers. Report backups and overflows at (650) 321-0384, 24/7. The District checks its main first; if the main is clear, the problem is in your lateral.

• Ownership: every side sewer, from the connection at the District’s public sewer to the house, belongs to the property owner, along with blockages, roots and repairs.
• Cleanout: each lateral must have a cleanout within 5 feet of the property line, in a box kept accessible and visible.
• Courtesy cleaning: with a conforming property line cleanout, the District will attempt to clear the lateral from that cleanout to the main. It doesn’t do this for laterals rebuilt with trenchless methods, because its tools could damage the new pipe.
• Permits and methods: lateral repairs need a West Bay permit and inspection. The District’s preferred method is open trench; lining is allowed with camera inspections before and after, and pipe bursting only where the lateral is at least 36 inches deep (code revised October 14, 2026). Replacement laterals get a root control barrier.

If a camera inspection finds roots or cracks, see trenchless sewer repair and sewer line replacement.

Backwater valves and tree roots

West Bay reminds owners of Plumbing Code section 710.1: drains serving fixtures whose rims sit below the next upstream manhole cover must have a backwater valve, kept accessible for inspection. The District also requires an overflow relief valve at the property line cleanout, with the backwater valve behind it.

Roots are a common cause of backups. West Bay advises keeping new trees at least 10 feet from the lateral. Menlo Park’s heritage tree ordinance protects large trees, such as oaks 10 inches or more in diameter: removing or pruning over one-fourth of one needs a permit, and digging within the tree protection zone needs a City-approved protection plan first. A lateral running near a big tree should be planned around it.

1950s homes and older

The City’s 2014 Housing Element found that almost 30 percent of Menlo Park homes were built in the 1950s, and 56 percent in the 1950s or earlier, with about one in ten at least 80 years old. Homes of that age often still have galvanized steel supply pipe, which rusts inside and loses pressure, and cast iron or clay sewer lines that roots can enter. See repiping.

Permits, water heaters and WestLight programs

The City takes building permit applications online only, through its Accela Citizen Access portal (Building Division: 650-330-6704). Single-trade jobs such as a water heater replacement, sewer or water line replacement, or a repipe use the Limited Plan Check record type; work that combines trades goes in as a Building Pre-Application.

A gas water heater may be replaced with a gas model or a heat pump water heater. For a heat pump, the City wants a lot plan showing the electric panel, receptacle and circuit amperage. Larger remodels of pre-2011 homes valued over the City’s threshold must add two energy measures from a list, and replacing a gas water heater with a heat pump is one option.

WestLight Energy, Peninsula Clean Energy’s name since July 2026, offers active customers who own their homes heat pump water heater rebates (with a copy of the City permit), a full-service installation option, 0% loans and emergency replacement of a broken gas water heater. See WestLight Energy rebates and heat pump water heaters.

Menlo Park Municipal Water customers can get free water-saving fixtures and self-audit kits; Cal Water runs its own conservation programs.

Sources

City of Menlo Park: Water providers · Menlo Park Municipal Water · 2025 water quality report · Water conservation · New building permit applications · Water heater replacement submittal requirements · Single-family building energy efficiency requirements · Heritage tree definition and ordinance · Peninsula Clean Energy is now WestLight Energy · Housing Element, adopted April 1, 2014. West Bay Sanitary District: Call us first · Frequently asked questions · Courtesy cleaning service · Types of acceptable repairs · Protect your new pipe · Backwater valve letter (2024) · Class 1F/2F trenchless permit procedures. California Water Service: Bear Gulch 2025 water quality report · Who is responsible for making repairs? · District phone numbers. WestLight Energy: Water heating upgrades · Appliance rebate application · Emergency water heater replacement. West Bay Sanitary District: Code of General Regulations (rev. October 14, 2026). Checked October 2026.