After 20 years of doing studies on potential ways to solve the city's water problem, the Water Department of Santa Cruz has decided that a desalination plant, filtering the salt out of seawater to make it drinkable, is the only answer.

"If we had a drought similar to the one in 1976-1977, we would be approximately 45 percent short right now," says Linette Almond, the city's deputy water director and project manager for the desalination project. "The consequences of that are that we couldn't meet health and safety needs, you know, basic cleaning and flushing and that sort of thing. So it's a dire situation,"

The effect of a coastal desalination plant on marine biology--along with the high volume of energy a plant requires to run--are common concerns associated with desalination. Even so, the City Council voted unanimously in November of 2005 for the Santa Cruz City Water Department to carry on its research and planning for a desalination plant here in Santa Cruz. If the city approves the proposal, such a plant could be built and functioning by 2011.

On Oct. 17, the Women's International League for Peace and Freedom will host a panel of three speakers to bring the pros and cons of desalination before the public.

Brent Haddad, who teaches fresh water policy at UCSC and is principal investigator on a statewide project assessing benefits and costs of desalination, will be providing general background information at the talk. Speakers Aldo Giacchino, chairman of the executive committee of the local chapter of the Sierra Club, and Mike Rotkin, lecturer in the community studies department at UCSC, activist and City Council member, will debate the pros and cons.

"The pressure that our water supplies are coming under will not slow down in our lifetimes or for the foreseeable future," says Haddad, "so the search for new water supplies will go on. And one possible option is desalination either of ocean water or other impaired waters.

"Desalination is already happening elsewhere in the world as well as in the United States and California on a smaller scale," he adds. "It occurs both along the coast and in California, more frequently inland where they draw water out of the salty aquifers. So we're at the beginning of a long discussion about desalination, and it's good that the community is getting informed about its strengths and drawbacks."

According to Haddad, even though desalination plants have been built all over the world, the environmental effects of the proposed Santa Cruz plant remain unclear. Seven desalination plants have been recently proposed along the Monterey Bay coast alone, and some of the planned plants, if built, will be 10 to 20 times the size of the proposed Santa Cruz plant. Yet there are no currently functioning plants in the United States of comparable size and nature to the proposed Santa Cruz plant.

"[Plants using ocean water] are common especially in Spain and in the Middle East. But since we don't share the environmental regulatory structure of these other regions of the world, we haven't really looked at their environmental performance as guidance for us. Instead what we're looking at are the environmental impacts of power plants' intake and outflow, and also waste-water treatment outflows," says Haddad.

The cooling systems of some power plants require ocean water to be taken in, used and returned to the ocean. The process is similar to that of the proposed desalination plant but on a far different scale.

"So we're looking at [power plants and waste water treatment outflows] because a lot of research has been done on those impacts. But both of these are imperfect comparisons," says Haddad. "In the case of the power plant it's imperfect because the environmental and the water quality profile of the water that leaves the power plant is different than what leaves the desal plant, and also the scale is different. The amount of water that is taken in and leaves a desal plant is only 2 to 7 percent of what comes into and leaves a power plant. So there is some data there but it's not a really good comparison. The power plant takes in about a billion gallons a day, and a desal plant takes in up to 50 or 75 million gallons per day, depending on its size. Santa Cruz is planning to take in 20 million gallons per day during droughts."

The qualities of water exuded from desalination plants and power plants are also considerably different, the water outtake from power plants being far warmer than the intake, and the desalination plant outtake having more concentrated brine, meaning higher salt content.

In addition to environmental concerns, Aldo Giacchino and other residents of Santa Cruz County and the Central Coast fear the expansion they suspect might result from an increased water supply.

But according to Almond, the scale of Santa Cruz's proposed plant is not large enough to legitimate these concerns: "Two and a half million gallons a day for drought use--it's not for everyday use," says Almond. "It could be expanded to 4 1/2 million gallons per day if growth required it. It's not getting out ahead of growth, but it's able to respond to growth should it happen. It's actually a really good plan in that respect."

The Santa Cruz City Water Department has also been exploring the possibility of assisting Soquel Creek Water district with their troubles.

"The city facility, the way it's planned, for city use, would be for drought time only," says Almond. "But because the plant will be sitting there, available, Soquel Creek Water district, who is our neighbor to the east, they have pumping depressions around some of their wells that would indicate that they need a supplemental supply all the time. So if we do this as a joint project, it could be that the plant would run at a very low rate, like 1 million gallons per day or less even during the winter for them. And then we'd just take it over during a drought."

According to Rotkin, the residents of the city of Santa Cruz use about half as much water as the average person in California, he thinks partially due to water conservation regulations implemented by the city, including required toilet retrofitting, and the use of water-saving clothes and dishwashers.

Additional water restrictions will come into effect during drought years, cutting people's water consumption by 15 percent.

Rotkin describes Santa Cruz's search for a supplemental water source as a long-term one, and though he's extremely wary of bringing desalination to Santa Cruz, he now feels it's the only logical course of action.

"We've exhausted every other alternative. And it's only the last step here. I would never have supported desal when the process started, it was my last choice."

The desalination meeting will be held Tuesday, Oct. 17, at 7pm at the Quaker Meeting House, 225 Rooney St., Santa Cruz (off the Morrissey exit). The meeting is free and open to the public. For more information call 831.457.6797.

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