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About the Water Utility

About the Water Utility


The Utilities Department’s responsibilities include master planning and capital improvement projects, water production, distribution, backflow protection, water quality monitoring, water conservation, customer service, meter installation and replacement, meter reading, wastewater collection system maintenance and repair, and environmental compliance. These activities play a vital role in ensuring that our residents’ and businesses’ water needs are met. Working together, the department is able to provide affordable, high-quality drinking water that meets all Federal, State and local requirements. 

Delivering Water 

The City of Ontario serves 13 billion gallons of water annually to the City’s 170,000-plus residents and 6,000-plus businesses through the operation and maintenance of 24 active groundwater wells, 572 miles of potable and recycled water pipelines, and 12 water reservoirs that store 75 million gallons of water. Approximately 80% of Ontario’s drinking water comes from local groundwater sources, including 17% of the total supply from two water treatment plants operated by the Chino Basin Desalter Authority (CDA). The remaining 20% of Ontario’s water is imported surface water supplied through the State Water Project and treated at the Agua de Lejos Treatment Plant, before it is delivered to the City for use.

Recycled water is provided for non-potable uses, such as outdoor irrigation and some industrial applications. During the past five years, more than 200 recycled water service connections have been completed, supplying nearly 10% of Ontario's total water demand.

The City of Ontario has remained in compliance with all State and Federal drinking water laws and is committed to delivering high quality drinking water. To ensure the delivery of high quality water, the Utilities Department collected thousands of water samples and monitored for more than 144 possible substances during 2009.

  • View information on the history of the Water Utility

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