The agency broke off negotiations a year ago, but has endorsed the project.

In Tampa Bay, Fla., where Poseidon helped build a desalination plant that endured problems from 2003 to 2005, officials still say Poseidon used confidentiality claims to "conceal" information that would have made the plant operate better.

Despite that, local water officials who desperately want the Carlsbad seawater desalting plant to succeed because of drought worries, refused to criticize Poseidon after the California Coastal Commission's staff complained July 3 that Poseidon was not turning over requested information.

Some even suggested, as Poseidon did, that the commission may be asking for more information than it needs to decide whether to build the plant that would churn out 50 million gallons of drinking water a day at Carlsbad's Encina Power Plant.

"Most people know that there's actually staff on the Coastal Commission who are adamantly against desalination," said Bud Pocklington, who is board member for both the Water Authority and the South Bay Irrigation District that has agreed to buy some of the Carlsbad water Poseidon's plant would produce.

Poseidon itself, which eventually allowed the Water Authority to conduct its own environmental testing and has denied the Tampa Bay complaints, said last week that it was close to reaching a resolution with the Coastal Commission on its information requests.

However, company officials also said that they've asked to meet with the Coastal Commission's board in August to appeal to circumvent those requests if they can't reach a resolution.

Key permit

The Coastal Commission, which must approve the project for it to be built, has long been considered the Poseidon project's biggest regulatory hurdle. Created by state voters in 1972, the commission is charged with protecting, conserving and restoring California's coast.

Poseidon has been trying for 10 months to get the commission's staff to judge its application "complete" and pass it forward to the commission board for a ruling in November. The company hopes the plant could start churning out water by 2010.

However, the staff has returned Poseidon's application four times, most recently July 3, asking for more information.

The proposed plant would use a portion of the seawater the Encina plant sucks in from the ocean to cool its electricity-generating turbines and then spits back into the sea. Poseidon's plant would force some of that water through high-tech membranes to extract the salt and create drinking water.

The brine would be poured back into the ocean. If approved, the plant would be the largest in the United States. Poseidon has reached agreements with the city of Carlsbad and several other local water agencies to buy the plant's water.

More questions

Tom Luster, the commission's desalination expert, said recently that the agency still had substantial financial and environmental questions.

He said the agency wanted to know more about the estimated cost of the water the plant would produce, and asked to see Poseidon's contract with Encina's operators.

He said the commission wanted more information about whether the plant could or should be smaller, whether the plant would increase greenhouse gas emissions, and if the plant could use subsurface wells to get its water instead of pulling it directly from the ocean.

Luster also said that, when he and commission staffers issued their rejection letter, they had asked Poseidon for much of that information "over and over again," in the last 10 months, but Poseidon had not complied.

Poseidon Vice President Peter MacLaggan has repeatedly said the company has given the commission all the information needed to complete their application and rule on the project.

He said that every time Poseidon had given the commission staff more information, they used it to bring up new questions.

"We believe the application and subsequent submittals to the staff include all the information required to deem the application complete," MacLaggan said.

Both Luster and MacLaggan said late last week that they had talked, and they hoped they could come to an amicable compromise.

The two men said a key unresolved problem was the commission's request to review Poseidon's deal with the power plant's operators. The report, they said, would help show how much the electricity would cost over the plant's 30-year lifetime.

"It's a proprietary arrangement, and we don't care to make that information public at this time," MacLaggan said. However, MacLaggan said the two sides were trying to work out a deal to let the commission see the contracts on the condition they remained confidential.

Trouble brewing?

MacLaggan dismissed the suggestion that Poseidon could be headed into another dispute over information ---- and the characterization that Poseidon had such disputes with the Water Authority and Tampa Bay Water.

"I take exception to what you said about the Water Authority," he said. "I urge you to talk to our partners in Carlsbad and others. We've been very forthright in making information available."

Water Authority managers declined to comment last week.

One board member, Mark Watton, would only say the Poseidon negotiations were "exceedingly difficult." South Bay's Pocklington said Poseidon "holds their information close to their vests."

However, Watton, Pocklington, and other water officials suggested that the commission's staff could be predisposed against seawater desalination projects.

Since 2004, the commission has been on record as warning that it would look at issues outside traditional environmental harm when judging desalination projects, such as whether they could increase population growth and development.

The commission has also suggested that it doesn't like the idea that profit-driven companies, rather than public agencies, should be in charge of managing and pricing water supplies.

Luster, meanwhile, said the commission was not anti-desalination. He said the agency's staff was simply trying to get all the information coastal commissioners would need to make a decision. Luster said there was no animosity.

"I'm just doing what we need to do," Luster said. "It's not personal."

MacLaggan, meanwhile, said the company would appeal to the commission's board if Poseidon and Luster couldn't reach an agreement and rule the application complete.

He said with Southern California's drought, and droughts affecting Southern California's Colorado River and Northern California water supplies, the Carlsbad desalination plant was sorely needed.

"There is a sense of urgency at play here," MacLaggan said. "The water supply situation in Southern California has deteriorated significantly in the 10 months since we submitted this application."

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