SAN DIEGO -- County water officials and a private company ended a six-month dispute Thursday -- temporarily, at least -- and said they would renew talks to build a futuristic plant in Carlsbad that would turn seawater into drinking water.

San Diego County Water Authority board members voted Thursday to restart negotiations with Poseidon Inc., and tried to reassure the company that the agency did not want to use its powers of eminent domain to force the company -- which has a 60-year lease on the site -- out of the project.

Poseidon officials, meanwhile, said they welcomed renewed talks with the agency, and that they would drop their objections and let Water Authority engineers come to the Encina Power Plant in Carlsbad to conduct tests for an environmental report.

However, Poseidon and city of Carlsbad officials also said Thursday that they had independently reached a deal to build a smaller, "local" desalination plant at Encina that could give the city 25 million gallons of drinking water a day. Carlsbad Mayor Claude "Bud" Lewis said Carlsbad City Council members would be asked to approve the deal in September.

Despite that, Poseidon, Carlsbad and water authority officials said the smaller deal would not preclude including the authority because together the company, city and the agency could build a bigger, "regional" plant that may someday produce 100 million gallons of drinking water a day.

After Thursday's meeting, Water Authority and Poseidon officials said they were glad to resume talks on the desalination plant. Water authority officials have identified the proposed plant as a "critical" source of San Diego County's future water supply.

But officials from both sides also seemed wary about the renewed talks.

Poseidon officials asked water board members to word their action Thursday that would basically have promised that the agency would never use its eminent domain powers to "take over" the proposed Encina plant site. Public agencies are allowed to "take" private property if it is deemed to be in for "the public's good."

But board members rejected that request after two hours behind closed doors, and instead approved a softer assurance -- pledging only that the agency was not interested in using eminent domain.

"We're taking them at their word that they're serious and interested in working in a cooperative fashion," Poseidon Vice President Peter MacLaggan said.

Ken Weinberg, the Water Authority's director of water resources, said, "we want to work together, we want to cooperate. And it's very encouraging that they're supporting giving us access to the site to complete our environmental impact report."

The Water Authority broke off negotiations with Poseidon in January after three years of talks because of a prolonged dispute over the environmental information it wants to collect by getting onto the Encina site.

Poseidon officials said the information was confidential. The company refused to let Water Authority officials on the property unless the agency promised it would only build the plant with Poseidon. The company said it felt the authority officials wanted to use the information to cut the Poseidon out of the deal and build the plant on its own or with another company.

Water Authority leaders have since said that the real problems between the agency and company were that agency officials felt that Poseidon wanted the agency -- and its ratepayers -- to pay too much for the plant. Under the terms of their proposed deal, the authority would have bought the Carlsbad plant at the end of its first five years.

Water Authority board Chairman Bernie Rhinerson said after Thursday's meeting that the authority would send Poseidon an official request to get on the site today, and hoped to gain access and start collecting information "within 10 days."

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