Soquel Creek turns to water reuse to replenish groundwater supplies

Construction has begun on a new water purification centre in California as part of the Soquel Creek Water District’s project to replenish depleted groundwater sources.

Decades of overuse

California continues to be a water progressive North American state with development moving ahead to inject treated wastewater back into ground sources.

Construction has started on the Chanticleer Water Purification plant as part of the Soquel Creek Water District’s Pure Water Soquel Groundwater Replenishment and Seawater Contamination Prevention Project.

“It’s our obligation and responsibility to develop a resilient water source.”

Proven water purification technologies will be used to produce safe, high-quality drinking water to replenish the groundwater basin. This new plant will operate as a buffer against seawater contamination as well as bolstering drinking water supplies.

“It’s our obligation and responsibility to develop a resilient water source — and that’s where the wastewater comes in — because conservation just isn’t enough,” said Rachél Lather, board president at Soquel Creek.

The project follows in the footsteps of the Orange County Water District’s well known Groundwater Replenishment System, which has been expanded over the years. The three-stage advanced process cleans up wastewater before putting it back into the Orange County aquifer to create a sustainable water supply.

Climate crisis anxiety

Recently, the Environmental Protection Agency (EPA) delivered a $388 million loan to help drive projects that focus on water reuse in San Diego County, California.

“We just experienced the driest two-year period on record here in the state,” said E. Joaquin Esquivel, state water resources control board chair.

The Soquel Creek Water District serves 40,400 residents and sources its drinking water exclusively from the Santa Cruz Mid-County groundwater basin, which is currently suffering from years of intensive pumping.

It is estimated that the total costs of the Pure Water project will cost $90 million. A total of $50 million has been received to date from the state water bond that was passed in 2014, $9 million from the Bureau of Reclamation and a further $6 million from the EPA.

"The climate crisis is incredibly real, and it creates a lot of anxiety … but this project is an example of taking that anxiety and transforming it into action,” added Esquivel.

Turning the tide on water resilience

It is hoped that the new Chanticleer Water Purification plant will help change the tide against years of freshwater withdrawals that have left the Santa Cruz Mid-County groundwater basin in a state of critical depletion.

As a result of years of high pumping, more water has been withdrawn from the aquifer than has been replenished. This has caused seawater to seep into and contaminate the underground freshwater source.

Soquel Creek, along with other agencies in the US, has been mandated by the state to bring the Mid-County basin back to a sustainable level. The project also includes the construction of eight miles of new water pipelines to transport water to the plant.

Once the water has been treated, it will be injected into three seawater intrusions prevention wells that have recently been completed construction.

Looking through a 21st-century lens

The project is expected to be completed by the end of 2023, according to the Soquel Creek Water District.

However, there is still more that needs to be done to address the pressing concerns of the state that have recently been exacerbated by climate change and wildfires.

“Water recycling should be the first line of defence.”

This particular region of the US is not currently connected to any state or federal imported water system and relies solely on rainfall to naturally replenish groundwater sources.

John Laird, the state senator who represents Santa Cruz County, recently said that they need to look for further water storage opportunities and that water recycling should be the first line of defence.

Commenting on the state approach to water storage, Esquivel said: "We really need to look at our systems with a 21st-century lens … which means following the drops through the watershed and figuring out where there are opportunities for investments that create water quantity and water quality improvement."