Oliver P. Roemer Expansion and Upgrade Project

West Valley Water District (District) proudly serves the Southern California communities of Rialto, Fontana, Colton, Bloomington, Jurupa Valley and unincorporated areas San Bernardino County. Over our agency’s many decades, our mission has always remained the same: to provide customers with safe, high quality, and reliable water service at a reasonable rate and in a sustainable manner.

To that end, the District is expanding the treatment capacity at the Oliver P. Roemer Water Filtration Facility to 21.6 million gallons per day (MGD) through an ambitious capital improvement project. The Project is being implemented to replace aging infrastructure, meet rising peak summer demands, provide existing users with a reliable water supply, meet projected demands due to infill and growth and to responsibly manage regional groundwater basins. With the implementation of the Project, the District is seeking to implement a conjunctive use strategy which is critical for the long-term, sustainable water management for the region.

The Oliver P. Roemer Water Filtration Facility is a surface water treatment plant that treats local surface flows from Lytle Creek and imported water delivered through the State Water Project pipeline. This Project will expand treatment capacity at the facility by 7.2 MGD and allow the District to maximize the use of surface water supplies when available and supplement this supply with local groundwater to meet water demands.




Enhances the existing water filtration facility to help ensure long-term dependability; Replaces aging infrastructure, bring the existing facilities and equipment up to today’s standards; Expands treatment capacity from 14.4 Million Gallons per Day (MGD) to 21.6 MGD which provides operational flexibility; Balances the use of groundwater, local surface water and imported water supply.


In 1995, West Valley Water District and the City of Rialto jointly constructed the original 7.2 Million Gallons Per Day (MGD) Oliver P. Roemer Water Filtration Facility to treat their Lytle Creek surface water rights for potable water use. 

In 1998, the District expanded the treatment capacity at the facility from 7.2 MGD to 9.6 MGD to allow the District to treat both Lytle Creek surface water and purchased State Water Project water.

In 2006 treatment capacity at the facility was expanded again from 9.6 MGD to 14.4 MGD by installing two new contact adsorption clarification package treatment units.  This upgrade expanded the treatment process capability of the plant to achieve both turbidity removal and total organic carbon reduction by installing pretreatment facilities consisting of chemical feed, flocculation and sedimentation facilities; installation of new ultraviolet light (UV) disinfection equipment; six (6) Granular Activated Carbon (GAC) removal vessels, construction of a raw water pumping station; influent blending pond; and sludge ponds.

In the summer of 2009, a new 36-inch raw water pipeline, which replaced an aging 12-inch pipeline was constructed which increased the District’s ability to take up to 20 MGD of SWP water.  In 2016 four (4) GAC vessels were added to the system to aid in the removal of total organic carbon.

With this new expansion project, treatment capacity at the facility will be increased from it’s current 14.4 MGD to 21.6 MGD by installing three (3) Trident packaged Contact Adsorption Clarifier (CAC) and Filter units.  A new influent pump station will supply water to the new Filter units and a new effluent pump station will pump this additional capacity to an existing off site storage reservoir through a 30-inch treated water pipeline in W. Via Bello Ave.  Three (3) inline UV Reactors and GAC pumps will replace existing units to meet the increased needs from the added facility capacity.  New recovery pond pumps and new piping will provide operators the flexibility to pump backwash and filter to waste water to either the existing pretreatment facilities or the existing sludge ponds.  A pre-engineered metal Filter Building will be constructed directly adjacent to the existing Filter Building to house the three new CAC/Filters and includes room for future CAC/Filters.  A new Programable Logic Controller (PLC) room, laboratory and SCADA room will be constructed to operate the entire facility.  This system integrates existing equipment and facility operations with new equipment and is a single source of communication and control of the facility.

May 2024 Project Update

In May 2024, PCL Construction Inc. (contractor) continued to make construction progress throughout the entire Oliver P. Roemer WFF Upgrades and Expansion Project site. Brief monthly updates are listed below:      


Filter Building No. 2: Contractor made significant construction progress erecting Filter Building No. 2 (FB-2), including:

  • Steel panels (siding) installation.
  • Installation of the main fire sprinkler system.

Siding being installed on the north westerly side of the building

Fire sprinkler system being installed


Relocated UV-Recovery Pipeline: The Contractor relocated the 24-inch UV-Recovery pipeline with a new cement mortar lined and cement coated (CMLC) steel pipeline. This relocation facilitates a new pipeline to be routed below the new retaining wall foundations, the retaining wall is to be erected in the upcoming months between the existing filter building and the blending ponds.