A project that would employ wintry-cool ocean waters to help air-condition Downtown Honolulu buildings is delaying its start by six months as it completes its design work and permit applications.

Honolulu Seawater Air Conditioning LLC now plans to start the $152 million project in July, having identified areas where it wants to lay pipelines that will draw 45-degree ocean water, and having found a site in Kaka'ako for a cooling station where fresh water will be chilled and piped to buildings.

"We're very happy where we are," said Bill Mahlum, Honolulu Seawater president and chief executive officer. He said the company plans to announce a major customer for the system next week.

The project has had to put off its start date several times, but in the past year has found increasing support given the state's desire to wean itself from imported oil and rising energy prices that have boosted electricity and cooling costs.

An environmental impact statement was completed last month with one of its conclusions being the system is feasible and that any adverse impacts should be adequately mitigated.

As currently envisioned, the system will consist of pipes to draw seawater and return it to the ocean, connected to a 30,000-square-foot cooling station behind the former Gold Bond building in Kaka'ako. There, the chilly ocean water will be used to cool fresh water, which will be piped under roadways to buildings Downtown, where it will be used for air conditioning.

The EIS said the system will eliminate the need for 178,000 barrels of crude oil annually, reduce air pollution and avoid the need for 14 megawatts of new electrical generating capacity. It also will reduce the need for 292 million gallons of potable water used for current air conditioning systems.

"The proposed project would have positive effects on the local economy, reduce O'ahu's dependence on imported oil for electrical generation, reduce potable water consumption, reduce sewage generation and reduce use of ozone depleting substances and chemicals used in maintaining existing air conditioning systems," the EIS said.

Still to be decided are the routes of the pipes, which would run under Kaka'ako Waterfront Park and nearshore reef. The water intake pipe will be four miles long and draw seawater about 1,800 feet deep. The water return pipe would terminate in about an area about 150 feet deep.

Honolulu Seawater envisions using an area at Sand Island and Ke'ehi Lagoon to assemble the pipes.

Another 2.5 to 3.5 miles of pipes carrying the chilled freshwater to area buildings would be installed under roadways. About $100 million of the project cost would be financed using special purpose revenue bonds.

The report said potential environmental problems include possible disruption of archaeological and historic sites during construction, along with disturbing the ocean bottom and water while the offshore pipes are installed. Traffic would also be disrupted as roads are dug up to install pipes.