Plumbers in Ontario, CA

A model colony that became an airport city

Ontario lies about 15 miles west-northwest of Riverside in a straight line, in San Bernardino County. George and William Chaffey founded it in 1881 as a planned, irrigated citrus colony, and it incorporated in 1891. Today it has 175,265 residents (2020 Census), Ontario International Airport, Ontario Mills and a large logistics base along I-10, SR-60 and I-15. Euclid Avenue runs through Downtown, and new building is concentrated in Ontario Ranch, also called New Haven, in the south.

City water, mostly from the Chino Basin

The Ontario Municipal Utilities Company (OMUC) supplies water citywide. Most of it is Chino Basin groundwater from City wells, supplemented by groundwater bought from the Chino Basin Desalter Authority and Jurupa Community Services District, and imported State Water Project water treated at the Water Facilities Authority plant. The system uses a chlorine residual made up of chloramines and free chlorine.

Hardness depends on which source reaches you. OMUC's report lists City groundwater at an average of 124 mg/L (range 82 to 150), imported water at 91 mg/L and purchased groundwater between 137 and 177 mg/L. That is moderate by Inland Empire standards, yet still enough to leave scale on fixtures and in tank heaters over time. OMUC also reports that its inventory found no lead service lines.

Older core, brand new south end

Census survey data put Ontario's median year built at about 1980, but that average hides a wide spread. Homes near Downtown and Euclid can still carry galvanized supply lines, cast iron drains and clay laterals, while Ontario Ranch houses are recent builds where water heaters, fixtures and warranty-age issues are the usual calls. OMUC manages the City's gravity sewer lines and the Inland Empire Utilities Agency treats the flow.

Backflow rules are strict here

OMUC's Water Quality Programs Division decides case by case whether a property needs a backflow assembly. Where one is required, the owner must have it tested at least once a year by a City-approved certified tester, and results are accepted only electronically through the City's tester portal. A failed assembly must be repaired or replaced within 30 days and retested. Questions go to backflow@ontarioca.gov or (909) 395-2678.

Permits, gas and utility contacts

The Building Department at 303 East B Street (909-395-2023) issues permits, and applications go in through the City's Citizen Portal Access website. Utilities Customer Service is (909) 395-2050. SoCalGas provides natural gas; if you smell gas, leave the building first, then call 911 and SoCalGas at 1-800-427-2200 from outside.

How Ontario differs from Riverside

Riverside's water is its own groundwater blend through Riverside Public Utilities, and backflow reports go to that utility. Ontario has its own utility, its own tester portal and a bigger share of brand new housing. Call the number on this page, explain what is going on, and you will be connected with an independent plumber who works in Ontario. The plumber quotes and schedules the job directly with you.