On Tuesday the Santa Cruz City Council approved final plans and contracts to rebuild most of the Graham Hill Water Treatment Plant at 715 Graham Hill Road. The project has a total budget of $232 million, including $151 million for construction, the Santa Cruz Sentinel reported.

Why now

The plant was built in 1960 and has not had significant improvements since the 1980s, Water Director Heidi Luckenbach told the council. It runs on 50-year-old equipment. When the work is done, the plant will be able to treat 18.2 million gallons a day. It will also handle muddier, higher-turbidity water, which the Sentinel notes matters during heavy winter flows, severe storms and after wildfires.

What gets built

The city has not released full plans because they contain sensitive details about drinking water infrastructure. The State Water Resources Control Board, which is helping fund the project, filed a CEQA notice that gives the outline. It says most existing treatment processes would be replaced or substantially upgraded, including:

  • solids dewatering
  • upgraded chemical feed systems
  • a replacement wash water tank
  • a new ozone contactor
  • pre-treatment processes
  • granular activated carbon contactors
  • recycled water clarifiers

The operations and filter building and older facilities such as sedimentation basins would be demolished. New administration or operations and maintenance buildings would be built, along with new ozone, solids dewatering and chemical storage facilities.

Who pays

  • $113.7 million through the EPA's Water Infrastructure Finance and Innovation Act program
  • $75 million in grants and loans from the Drinking Water State Revolving Fund
  • $43.3 million from future financing and customer rates

Luckenbach called it one of the most expensive projects in the water department's history.

Timeline

Construction is scheduled to start in January 2027 and finish by November 2031. Luckenbach told the council the effort dates to 1997. The council authorized a progressive design-build agreement in 2021 and approved the first version of the plan in 2024. With Phase 1 design work finished, Tuesday's vote moves the project into Phase 2, construction.