In the News

WATER DISTRICTS BREAK GROUND ON EXPERIMENTAL DESALINATION PLANT

By Michael Thomas

Mid-County Post, 7/24/2007

Following a spring with relatively little rainfall, local water officials are getting the ball rolling on a pilot desalination plant that will extract drinkable water from the Monterey Bay.

On Friday, July 20, officials from the Soquel Creek Water District and the City of Santa Cruz gathered at UCSC's Long Marine Lab to break ground on a small plant that will process about 50 gallons of water per day, forcing it through a series of fine membranes to remove sediment, marine minerals and salt.

The plant, housed in a temporary building, will run for 12 months so that technicians can see how well the system handles seasonal changes and the bay's unique water conditions. Since the ocean is different everywhere, the system must be tailored to suit local currents, temperatures, and the suspended matter that's fed to the ocean by local rivers.

"We're looking at a few different membranes and seeing what works best," explained Heidi Luckenbach, desalination program coordinator for the City of Santa Cruz Water Department.

No one will be drinking the water produced by the pilot plant, though everyone involved jokes about trying it. After testing, it will be reconstituted with the salt and minerals that were removed and passed on to the tanks that house the Marine Lab's captive wildlife.

Two Very Different Uses for Desalinated Water

The two agencies teamed up to develop a shared desalination plant as a way to solve disparate problems. Fortunately, their challenges are complementary. The City of Santa Cruz relies mostly on surface water and needs the additional supply to survive drought years. In normal years, Soquel Creek could use the desalinated water to help recharge threatened aquifers that form the backbone of their system.

The cost of the pilot plant is estimated at $3.4 million and the City of Santa Cruz secured a $2 million grant from Proposition 50 to aid in construction.

The trial plant is part of environmental studies for a desalination plant capable of producing 2.5 million gallons per day. If it's successful, the plant could be expanded to a maximum of 4.5 million gallons.

If it isn't built, Santa Cruz Water Department Director Bill Kocher estimated that a drought in the year 2020 would require curtailing consumer consumption by 60 percent. In the Soquel Creek District, failing to address strained aquifers leaves the system's underground water reservoirs vulnerable to seawater intrusion that can permanently pollute water supplies.

Desal Space on Loan

UCSC is loaning the agencies space at Long Marine Lab for the 18-month project, which will be open to visitors next to the whale skeleton at Seymour Marine Discovery Center. The groundbreaking comes as the city and UCSC remain locked in a court battle over mitigations for campus growth impacts, including water use.

During the same week, UCSC also appealed the city Planning Commission's recommendation of approval for expansion of the Mission Street Safeway, in part due to concerns over increased water usage.

Amid those disputes, Long Marine Lab Manager Steve Davenport saw the pilot desal plant as a positive step.

"This is an example where the university and the city are really cooperating," he said.

A location for the larger plant has yet to be found. It would require about two acres of space relatively close to the coast. Officials are looking at vacant lands on the city's Westside and evaluating existing sewer outfall structures as collection and discharge points.