1,2,3 TCP Removal Treatment Plant

The City of Chino Hills has broken ground on the City’s new 1,2,3-Trichloropropane (TCP) water treatment facility, a project that will allow the City to reactivate six City-owned wells and reduce dependence on costly purchased water deliveries. Once completed in late 2024, the water treatment facility will allow the City to provide an additional local source of high-quality drinking water that is clean, safe, drought-proof, and cost-effective.

What is TCP?

TCP is a contaminant substance found in pesticides, paint, varnish remover, and degreasing agents, and used as a cleaning and maintenance solvent.

Why is this treatment facility needed?

  1. In 2017, the California State Water Resources Control Board changed the acceptable levels of TCP allowed in drinking water. As a result, many cities and water agencies across California, including Chino Hills, were required to inactivate wells until they could construct water treatment facilities to remove TCP from the water and meet the new, more stringent, State and Federal drinking water standards.
  2. Currently, all of Chino Hills’ surface water is imported from the State Water Project and is purchased from the Metropolitan

    Water District and treated at the Water Facilities Authority in Upland. Treated ground water is provided by the Monte Vista Water District and the Chino Basin Desalter Authority. These purchased water deliveries are subject to rising costs that the City has no control over.

  3. The City needs to develop its own resources to supplement its reliance on purchased water deliveries. The 1,2,3-TCP facility will allow the City to use local and cost-effective ground water as an alternative.

How does the treatment process work?

The water treatment process uses state-of-the-art water purification steps that will create nearly 3 million gallons per day of local, high-quality drinking water. The treatment process filters source water through granular activated carbon (GAC) to remove 1,2,3-TCP; much like a Brita filter you may have on a faucet in your home.

  1. City wells pump groundwater from the Chino Basin Aquifer to the TCP treatment plant.
  2. When groundwater arrives at the treatment plant, it is treated through a series of filters to remove TCP from the groundwater. The treated water is then tested to ensure the removal of TCP. If treated water does not meet the standard, the plant automatically shuts off.
  3. Once treated and tested, the water is distributed to customers!

Download Fact Sheet (PDF)

Construction Description:

The work comprises the following: mobilization, demolition, tree removal, grading and earthwork, piping, instrumentation, Booster 9 improvements (such as replacing pumps and motors, upgrading electrical units and telemetry system), landscaping, block wall, installing GAC treatment vessels, surge tank, connections to existing utility mainlines, start-up and commissioning, and other appurtenances to complete the project.


3982 Eucalyptus Avenue, Chino Hills 
Site Plan

Current Construction Activities:

Below are the general construction key milestones/ schedule:

  • November 2022: Begin Demolition
  • November 2023: Delivery and Installation of GAC Vessels
  • Summer 2024: Complete Construction
  • Summer 2024: Testing, start-up, and commissioning

Construction Update/ Notices:

On-Site Work (Ongoing)
Various on-site work continues such as excavation/trenching, installation of pipes, stubouts, valves, electrical conduits, and appurtenances.  Prepping and fine grading base/foundation for GAC pad; forming concrete pad.

  • Delivery of GAC vessels on-site (November 2023)
Street Work (TBD - November/December 2023) 
(Adjacent to the site on Eucalyptus Avenue between Bluebell Drive and Pipeline Ave)
  • Traffic Control Devices set up on public ROW (Message Boards, cones, signage, flaggers, etc.) to match the approved Traffic Control Plan within Eucalyptus Avenue.
  • Intermittent lane closures and shifting of traffic involving flagmen as needed.
  • Excavate/expose the water main line. 
  • Install recessed steel traffic plates.
  • Install/drop in new water valves.

Construction Timeframe:
375 calendar days
(Working hours are from 7:00 am - 7:00 pm, M-F, except City holidays)

Point of Contact:

Fe Rama, P.E., Senior Engineer 
Phone: (909) 364-2776
Email: frama@chinohills.org