Commercial Plumber in Fremont, CA

A Property Manager’s Guide to Plumbing in Fremont

Water from ACWD, sewer from Union Sanitary District

The City of Fremont doesn’t run its own water or sewer utility. Water comes from the Alameda County Water District (ACWD), which serves Fremont, Newark and Union City, and sewer service comes from Union Sanitary District (USD), which serves the same three cities. Save both numbers with your building’s emergency contacts: ACWD’s water emergency line, 510-668-6500, is staffed 24/7 for problems such as water leaking in the street or a damaged hydrant; USD answers (510) 477-7500 24 hours a day for sewer backups. ACWD customer service is 510-668-4200 on weekdays.

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

Under USD Ordinance No. 34, the property owner maintains and repairs the entire sewer lateral, from the building to the public main, including the section under the sidewalk and street. When a backup occurs, USD will inspect its main free of charge; if the main is clear, the blockage is presumed to be in the lateral and is the owner’s to fix.

Permits are split between agencies. USD requires a repair permit before any lateral work begins, even on private property, and repairs must meet USD specifications; USD asks for 48 hours’ notice before an inspection. The City permits sewer lines and cleanouts only up to two feet from the building’s footprint, and digging in a street or public right-of-way also needs a City encroachment permit. For older properties, camera inspections on a schedule find roots and cracks before a backup. See commercial sewer repair.

Restaurants: USD’s FOG program

Union Sanitary District regulates fats, oils and grease under FOG Ordinance No. 38. The key requirements:

• Pumping: grease interceptors must be pumped as needed, and at least every 90 calendar days, by a waste hauler licensed by the State. USD can require a shorter interval after a grease blockage; a longer one needs a written variance.
• Records: keep maintenance records and hauling manifests for at least 3 years and show them on request.
• Inspections: USD staff may inspect, sample and review records during normal business hours.
• New or remodeled kitchens: USD reviews food service plans. Grease-intensive kitchens need an outside interceptor of at least 1,500 gallons; some lower-grease businesses may use a 200 lb grease trap. Dishwashers may not drain to the interceptor, and garbage disposals are not allowed.

Interceptor pumping deals with the interceptor; scheduled hydro jetting keeps the kitchen lines leading to it open.

Backflow prevention

ACWD’s cross-connection specialists survey business properties and can require a backflow prevention device at the meter; certain commercial and industrial businesses must have one. Once a device is installed, it must be tested by a certified tester at least once a year. ACWD publishes a list of approved testers and a test report form, and its Backflow Prevention section answers questions at 510-668-6584. We install and repair the assemblies these rules require; see backflow preventers.

Permits for commercial plumbing work

The City of Fremont issues building permits through Citizen Access, its online permitting portal. Its automatically issued express plumbing permit, which covers same-location water heater replacements and water, waste and gas line work, is for residential projects only. Commercial plumbing work goes through a regular building permit, so allow more lead time for planned replacements. Every permit requires an inspection.

Water heaters: hardness and electrification

ACWD blends four sources. In its 2025 water quality report, blended water (San Francisco water mixed with local groundwater, delivered to north Fremont, Union City and parts of Newark) measured 120–160 ppm hardness, averaging 138 ppm; treated surface water from the South Bay Aqueduct, delivered to central and south Fremont, measured 77–120 ppm, averaging 96 ppm. ACWD disinfects with chloramine. Moderately hard water still builds scale in tanks, tankless heat exchangers and fixtures, so regular flushing matters. Fremont is served by Ava Community Energy, with Renewable 100 as the default for commercial accounts. Ava’s Building Efficiency Accelerator, which offered commercial heat pump water heater incentives, is closed to new enrollments; Ava points businesses to BayREN Business, PG&E rebates and GoGreen Financing, so check current offers before planning a replacement. See commercial water heaters.

Sources

Alameda County Water District: Water emergencies · Backflow prevention explained · Backflow prevention forms · 2025 water quality report. Union Sanitary District: Sewer repairs · FAQ · FOG FAQ · FOG Ordinance No. 38. City of Fremont: Permit types. Ava Community Energy: Communities we serve · Commercial buildings. Checked October 2026.