CARLSBAD - A company that has dreamed for six years of turning ocean water off the coast of Carlsbad into "drought-proof" drinking water has forwarded its plans to the California Coastal Commission, the regulatory commission that could be the project's biggest hurdle.

However, officials said it could still be months before the application is finally given to coastal commissioners themselves, and before any decision is made about whether the long-discussed project is approved or rejected.

Connecticut-based Poseidon Resources Inc. has been studying since 2000 the idea of building a $270 million project at the Encina power plant on Carlsbad's coastline. Poseidon's plant would turn 50 million gallons of seawater a day into drinking water.

During the last five years, the company has been in and out of the news as it tried unsuccessfully to negotiate a deal with the San Diego County Water Authority, the region's main water supplier, to buy the water for county residents.

Water Authority board members abandoned five years of negotiation with Poseidon a month ago.

But hedging its bets, Poseidon had already reached a deal to build the plant with the city of Carlsbad and a handful of other, small water companies.

On Monday, Poseidon Vice President Peter MacLaggan said the company mailed out its coastal commission application that afternoon.

The application contained the proposed project's voluminous environmental study, technical studies, permits granted by the city of Carlsbad and Regional Water Quality Control Board and other information.

However, MacLaggan said the company expects coastal commission staff members to review the application and request additional information -- perhaps several times -- before the application is ever forwarded to coastal commissioners for action.

"It's a minimum 30 days statutory requirement for (the commission) to review the application and get back to us," MacLaggan said.

Both MacLaggan and Tom Luster, the coastal commission's desalination expert, said it was common for the commission's staff to send applications back to request additional information.

The coastal commission is generally considered a coastal land-use and environmental watchdog.

It was created in 1972 by state voters, and is charged with protecting, conserving and restoring California's coast.

Commission staff members have already issued some criticism of the Carlsbad environmental study. In December, staff members sent Poseidon and the city an 18-page letter listing "numerous significant shortcomings." Among other things, the commission asked for more information on proposed fish-kill rates, impacts on marine ecology, and for clarifications on how much power Poseidon -- a private company -- would have over a drinking water supply, which some say should be considered a public utility.

The question of public-versus-private control is expected to be one of Poseidon's big hurdles with the commission.

Since 2004, the commission has suggested that it is uncomfortable with the idea that private companies, rather than public agencies, be in control the water supply that desalination plants would produce. The question of whether the ocean is a "public" utility or not is a complicated one. Historically, water -- on land, in streams, lakes and rivers -- is often "owned" by those who first staked claim to it. But that type of ownership does not currently extend to the oceans.

Meanwhile, other questions about Poseidon's proposed Encina plans surfaced in July.

The company that owns the Encina site, NRG Inc., said in July that it wants to build a new "air-cooled" plant at the Encina site in the next three years. That would lead to the eventual abandonment of the seawater cooling system the current plant uses -- a seawater system that would provide the water for Poseidon's desalination plant.

Poseidon says its 60-year lease contract at Encina would ensure that it be allowed to take over the seawater system.

But some have suggested that regulators want to crack down on those systems because they harm marine life.

Water Authority board members cited the NRG plans as part of their reason for terminating negotiations with Poseidon.

But the company says it is confident it can satisfy the coastal commission's questions and make the project work.

- Contact staff writer Gig Conaughton (760) 739-6696 or gconaughton@nctimes.com.