Commercial Plumber in Belmont, CA

A Property Manager’s Guide to Plumbing in Belmont

Water from MPWD, sewer from the City

Belmont splits its utilities. Drinking water comes from the Mid-Peninsula Water District (MPWD), formerly the Belmont County Water District, which serves the City of Belmont and parts of San Carlos, Redwood City and unincorporated San Mateo County. Sewer collection is run by the City of Belmont: its Sewer Utility Division maintains more than 90 miles of sewer mains and 10 pump stations, and sends the wastewater to Silicon Valley Clean Water for treatment, along with Redwood City, San Carlos and the West Bay Sanitary District.

Keep both numbers with your building’s emergency contacts. For a sewer main backup, call Public Works at 650-595-7425 during business hours and 650-595-7400 (police dispatch) after hours and on weekends. For water service, call MPWD at 650-591-8941.

Sewer laterals: the owner’s responsibility, to the main

Belmont’s code (§21-210, from Ordinance 1070) makes the property owner responsible for the whole sewer lateral, including its connection to the public main and any cleanouts and backflow devices the code requires. If the City finds a lateral damaged or letting in groundwater, it can issue a notice to repair with a deadline. The City may help determine whether a stoppage is in its main or in your lateral, but only where a standard property-line cleanout exists, and only after the owner signs a release (§21-211). Where backflow has occurred or may occur, the City can also require a backflow device and gate valve on the lateral (§21-216).

Lateral repairs may need a building permit, a Public Works encroachment permit or both; Public Works confirms which at 650-595-7425. For older buildings, a property-line cleanout and periodic camera inspections are worth planning for. See commercial sewer repair.

Sewer lateral certificates: triggered by projects, not sales

Belmont does not require a lateral certificate when a property sells; the seller only gives buyers the City’s Notice to Buyers about lateral responsibility. A valid sewer lateral certificate is required before the final building permit for:

• improvements valued by the building official at $200,000 or more, or
• work that changes the water service, such as adding a second meter or changing meter size.

The certificate is issued either on proof that the whole lateral was lawfully built within the last 15 years, or on a CCTV video reviewed by Public Works (for a fee), which is normally valid for 4 years. The City’s video checklist is specific: clean the lateral first, record one continuous color video with a distance counter from the building cleanout to the City main, narrate defects and junctions, include a written inspection report, and submit within 6 months of the inspection. The video contractor needs a California contractor’s license and a Belmont business license.

Restaurants: Belmont’s FOG permit

Food service establishments apply to the City for a FOG Control Program permit, listing their fixtures, grease interceptors or traps and who services them. The City’s best-practice guide for permitted kitchens calls for:

• Cleaning traps and interceptors on the schedule set in the FOG permit, keeping grease below 25% of total liquid depth.
• Records of cleaning and maintenance in a FOG binder, kept for 3 years.
• Drain screens in all drains, with openings between 1/8” and 3/16”.
• Fryer oil recycled through a rendering company, and staff trained on these practices.

City Code also bans discharges above 300 mg/l of animal or vegetable grease or hotter than 150°F (§21-159). Interceptor pumping deals with the interceptor; scheduled hydro jetting keeps the kitchen lines leading to it open.

Backflow testing with MPWD

MPWD requires a reduced-pressure (RP) backflow assembly where a service connection is judged hazardous, and every assembly must be tested at least once a year by a tester authorized by San Mateo County; the County’s Environmental Health Services tracks the results. MPWD’s installation rules call for approved assemblies, installed by a C-36 licensed plumber, inspected by MPWD before backfill and tested before going into service. MPWD began contacting commercial, industrial, institutional and multi-family customers in spring 2026, so expect a survey if your building hasn’t had one. We install and repair backflow assemblies; see backflow preventers.

Permits, inspections and work hours

Plumbing permits come from the City’s Building Department (Permit Center, building inspector 650-595-7422). Inspections are scheduled and results posted through eTRAKiT, the City’s online permitting system, with morning (9 a.m. to noon) and afternoon (1 to 4 p.m.) windows. Construction is limited to 8 a.m. to 5 p.m. on weekdays and 10 a.m. to 5 p.m. on Saturdays, with no work on Sundays or holidays, which matters when planning shutdowns in occupied buildings. The Building Department also publishes standard details for water heater installation and seismic bracing.

Water heaters: soft water and electrification

MPWD buys all its water from the San Francisco Regional Water System, mostly Hetch Hetchy snowmelt. Its 2025 water quality report shows hardness of 8.1 to 112 ppm, averaging 62 ppm, so scale is a smaller factor than in the South Bay, though tanks still need regular flushing. Belmont’s electricity provider, WestLight Energy (formerly Peninsula Clean Energy), offers businesses no-cost access to design experts for switching equipment from gas; check WestLight for any current business rebates before budgeting. See commercial water heaters.

Sources

City of Belmont: Sewer System · Sewer Operations and private sewer laterals · All About Sewers · Maintenance policy for house sewer lateral service · Notice to Buyer · Sewer lateral certificate application · Sewer lateral video requirements · FOG Control Program guide · FOG permit application · Building Department · Inspections · Plumbing handouts · City Code ch. 21: Art. V, use regulations and Art. VII, sewer laterals. Mid-Peninsula Water District: Home · Cross-connection control · Backflow assembly requirements · 2025 Consumer Confidence Report. Silicon Valley Clean Water: About SVCW. WestLight Energy: Electric buildings for businesses. Checked October 2026.