Municipal Department
Ontario Municipal Utilities Company – Domestic Water Division
Serving City of Ontario municipal water service area in San Bernardino County
Population served
185,010 people served by active CWS PWS CA3610034 in the California SDWIS registry, with approximately 35,167 residential, 4,493 commercial, and 336 industrial metered service records.
State system code
FIPS 06
Billing frequency
Monthly water and wastewater rate structure. Ontario’s July 1, 2026 rate sheet labels residential potable-water use, readiness-to-serve, and wastewater charges as monthly. The City’s unified utility bill can combine water, sewer, refuse, and storm-water-related services.
Provider briefing
How this utility’s billing works
Ontario Municipal Utilities Company – Domestic Water Division operates as a municipal department serving City of Ontario municipal water service area in San Bernardino County. Customers should use the provider’s current account-specific bill and official customer-service instructions as the final authority for deadlines, balances, and service requests.
The published water-rate framework is described as Metered increasing-block residential potable-water rates with a monthly readiness-to-serve charge by meter size. Effective July 1, 2026, residential potable water is $2.61/HCF for 1–10 HCF, $4.87/HCF for 11–18 HCF, and $5.76/HCF over 18 HCF; one HCF equals 748 gallons. The 5/8-inch monthly RTS charge is $12.80, with larger meter sizes charged more. Non-single-family, recycled-water, fire-service, and other categories use separate schedules.. Bills are generated monthly water and wastewater rate structure. ontario’s july 1, 2026 rate sheet labels residential potable-water use, readiness-to-serve, and wastewater charges as monthly. the city’s unified utility bill can combine water, sewer, refuse, and storm-water-related services., and a typical residential cost reference is A 5/8-inch single-family customer using 5,000–7,000 gallons per month consumes approximately 6.7–9.4 HCF, remaining in the first residential tier. At $2.61/HCF plus the $12.80 monthly 5/8-inch RTS charge, water alone is approximately $30.24–$37.23 per month. Ontario’s July 2026 wastewater sheet also lists a single-family monthly sewer structure with City and Inland Empire Utilities Agency components, so a combined water-and-sewer estimate is roughly $75–$85 per month before integrated waste, taxes, or other municipal charges; the exact sewer amount depends on the current EDU and IEUA factors.. These descriptions are useful planning benchmarks; actual charges can change with meter size, usage, sewer averaging, local taxes, drought stages, or account-specific fees.
Wastewater and sewer calculation
Ontario bills sewer on the unified utility account. The July 1, 2026 rate sheet describes residential wastewater as a monthly single-family-per-dwelling-unit base/City charge plus an Inland Empire Utilities Agency charge; non-residential wastewater uses an equivalent-dwelling-unit calculation, expressed as HCFs multiplied by a sewer factor, with the sheet showing an EDU-based charge and a $1.62/HCF component. The City does not publish a residential winter-average formula in the reviewed sheet; wastewater is a separate service-cost schedule rather than a fixed percentage of potable intake.
Meter and infrastructure notes
Ontario operates more than 630 miles of potable-water lines and serves more than 45,000 water connections. The City has a Customer Service & Meter Reading operational function and uses metered monthly potable-water rates. A 2025 City fiber plan identifies Automatic Meter Reading (AMR) for water services as a planned/possible municipal network application, but the reviewed 2026 customer pages do not identify a universal AMR/AMI vendor, deployment percentage, or transmission interval. The defensible description is routine municipal meter reading with monthly billing and customer-service investigation of leaks and meter issues.
Emergency water support
Report a leak or water emergency
909-395-2678 for water leaks, open or leaking fire hydrants, water-quality questions, and utility emergencies during OMUC hours. After hours, contact Ontario Police Department Dispatch at 909-986-6711 for water-related needs. OMUC’s posted regular hours are Monday–Thursday 7:30 a.m.–5:30 p.m. and Friday 7:30 a.m.–4:30 p.m.
Official starting point
Choose the right next step
Reading this profile
A practical reference for City of Ontario municipal water service area in San Bernardino County
Ontario Municipal Utilities Company – Domestic Water Division is listed here as a municipal department. The profile separates account actions—such as paying a bill or requesting service—from explanatory material about rates, meters, wastewater, leaks, and delinquency.
Because utility rules can vary by account class, meter size, service address, billing date, and local ordinance, treat the published bill and current provider website as the final authority. Use this profile to locate the correct channel and prepare better questions for customer service.
If your issue is urgent, start with the provider’s emergency number or official payment route rather than waiting for an email response. Keep a written record of calls, confirmation numbers, notice dates, and documents you submit.