To replenish the area’s seawater-intruded aquifers, the Pure Water Soquel project will pump treated water from the Santa Cruz Wastewater Treatment Facility to a new facility in Live Oak for more treatment, then inject the water into two seawater-intrusion prevention wells in Aptos and a separate well in Capitola.

The Live Oak water purification center at Chanticleer and Soquel avenues started operations in the fall, and system testing continues there and at the wells. The project was slated to finish in mid-2024, but is now projected to be online by late spring.

Melanie Mow Schumacher, general manager of the Soquel Creek Water District, attributed the delay to coordination with treatment system manufacturers and state regulatory staff.

“The multi-decade water crisis of the Soquel region will be over,” said Brent Haddad, a professor of environmental studies at UC Santa Cruz. “The serious problems are going to be finally solved.”

Haddad, who conducted an economic assessment of the Pure Water Soquel project, said that without the project, the Soquel Creek Water District’s customers eventually would be forced to ration as if they were in a perennial drought. There are about 20,900 homes in the water district.

“No one will notice a difference in their water,” Haddad said. “It will just be business as usual with water. Better than usual, frankly, because there will be a more reliable supply from a healthy aquifer.”

The three seawater intrusion prevention wells have been drilled, along with nine monitoring wells, and 8 miles of underground pipeline installed between the two water treatment facilities. 

Some paving work continued this week on Laurel and Blackburn streets near the Santa Cruz High School football field. Crews in the past few years ripped up Broadway, Soquel Avenue, Kennedy Drive and many other roads to install new water pipes underground.

The Pure Water Soquel pipeline runs recycled water from Santa Cruz to a Live Oak treatment center, then to wells in Aptos and Capitola. (Pure Water Soquel)

Soquel Creek Water District, in yellow, spans from 41st Avenue in Capitola and Soquel to La Selva Beach. (Soquel Creek Water District)

How it works

Soquel Creek Water District serves about 40,600 people in Aptos, Soquel, Seascape, La Selva Beach, Rio Del Mar, parts of Capitola and other areas. 

Water from the Santa Cruz Mid-County Groundwater Basin has supplied all of its water, but more water is being pumped out of the aquifers than is being replenished by rain. The problem prompted state authorities to designate the basin “critically overdrafted” in 2014.

“It’s the sole source of water for most of the mid-county area,” said Schumacher, the water district manager. “We’ve been in a groundwater emergency because of that ‘critical overdraft’ declaration.”

As a result of the overdrafting, saltwater from the ocean has penetrated inland and affected the aquifers’ water quality — a common occurrence in coastal areas. State law requires that the basin become sustainable by 2040. “That means our groundwater supplies must be able to meet current and future needs without causing unacceptable environmental or socioeconomic consequences,” according to the Soquel Creek Water District.

“We’re trying to be in the mindset of recycling. Water shouldn’t be used just once and then discharged into the ocean.”

—Melanie Mow Schumacher, general manager of the Soquel Creek Water District

The Soquel Creek Water District has looked at various ways to solve the problem, including a desalination plant, increased conservation measures and additional capture of winter stormwater runoff, said UC Santa Cruz coastal scientist Gary Griggs. Ultimately, the district opted for a recycled wastewater project that became known as Pure Water Soquel.   

The City of Santa Cruz Water Department gets about 95% of its water from the San Lorenzo River and other surface water sources, and only about 5% from aquifers. Its wastewater is treated at the Santa Cruz Wastewater Treatment Facility on Bay Street. 

Pumping some of that water to the newly built Live Oak facility then injecting it into the basin with three seawater-intrusion prevention wells is supposed to save the basin from further saltwater intrusion. The wells are near Monterey Avenue in Capitola, Willowbrook Lane in Aptos and Twin Lakes Church in Aptos.

Griggs said the injections would build up a pressure ridge to keep the seawater out. “By pumping in that treated wastewater, you’re raising the groundwater table closer to the surface, to where it would have been under natural conditions,” Griggs said.

Once in the aquifer, the heavily treated wastewater will mix with the water already there and become part of the drinking water supply.

Glass beads are used in well construction to allow purified water to flow into the groundwater basin. (Soquel Creek Water District)

An aerial geophysical instrument measures seawater contamination in the Pure Water Soquel project. (Soquel Creek Water District)

“We’re trying to be in the mindset of recycling,” said Schumacher. “Water shouldn’t be used just once and then discharged into the ocean.”

Some people have balked at drinking treated wastewater. But a 2022 study found it to be no worse quality than conventional tap water. Griggs said it was a “social acceptance issue,” rather than a technical or safety issue.    

An added benefit is that less treated wastewater will be expelled into Monterey Bay, Schumacher said. 

Rising costs

The $140 million in construction costs was a significant increase from original estimates of $90 million. Including planning, design, environmental review, financing and other non-construction fees, the project cost about $195 million overall, Schumacher said.

Of those costs, $30 million was funded by a U.S. Bureau of Reclamation grant and over $60 million was funded by state grants, Schumacher said. The rest, she said, will be covered by low-interest state and federal loans. Soquel Creek Water District rates have increased in recent years.

Haddad’s economic assessment found that the project would provide more than $900 million in benefits. “The jobs that are associated with any kind of economic growth are threatened if you can’t fix the groundwater basin,” Haddad said.

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