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The Honolulu Advertiser
Posted on: Monday, November 17, 2008

Kalaeloa desalination plant put on hold

By Gordon Y.K. Pang
Advertiser West O'ahu Writer

The city Board of Water Supply has no immediate plans to build a water desalination facility in Kalaeloa, despite the release this month of an environmental study, because anticipated increases in water demand have diminished.

Water officials have long talked about a plant that would use reverse osmosis desalination to turn seawater into potable water. Officials even held an August 2003 blessing for the plant, which was expected to cost $20 million in 2000 dollars and pump out 5 million gallons a day.

A final environmental impact statement for the project was released Nov. 6.

But Board of Water Supply spokeswoman Sue Shin said Friday that the EIS process was allowed to proceed only because it was near completion and the board decided in 2006 that it would put off building such a facility until "2020 or beyond."

Shin added: "We're not saying it's not going to happen. We're saying we don't need it now."

When water officials began talking about a desalination plant, demand for potable water was expected to grow to 212 million gallons a day by 2030. The need is now anticipated to be 185 million gallons a day in 2030.

According to the EIS: "In the 1980s, it was estimated that the sustainable yield of O'ahu's freshwater resources would be reached by the year 2000. However, because of the closure of the water-intensive sugar industry, combined with a modest economy, upcoming new groundwater resources, and successful conservation measures, the estimate has been pushed back to beyond the year 2020."

A chart provided by the board shows that demand grew at a rate of 1.6 MGD a year from 1970 to 1990, but only 1.0 MGD a year from 1970 to 2007.

"The numbers speak for themselves," Shin said. "We've been pumping essentially the same amount of water from 1990 until now. It would be pretty irresponsible for us to use our rate payers' money for something like desalination when we don't need it."

Shin noted that the board has a host of other priority projects on its capital improvements list, including major pipe replacement projects along Kapi'olani Boulevard and Farrington Highway.

"All of our projects cost money and we need to make sure that we are taking care of our system and can provide a safe and dependable water supply."

The board can only speculate on the reasons why demand has not increased as much as anticipated, Shin said.

Population figures on the island have not risen as had been predicted. But that's just part of the reason, Shin said.

The board has pushed water conservation efforts. Meanwhile, there have been changes in legislation requiring certain industries to use recycled water and that new homes include low-flow fixtures, as well as rebates for consumers who use high efficiency toilets, Shin said.

"Honestly, I think our customers are a lot more conscious of the environment nowadays," she said. "Sustainability is such a buzzword nowadays that I think people's attitudes and habits have changed over the years, so I think that's helped."

Environmental impact statements do not expire, and only need to be amended or redone if there are changes to a project proposal, Shin noted.

Additionally, the city conducted a pilot project in Kalaeloa that gave officials ample information for the future, she said.

"We have all this now in the back pocket so when the time comes for us to do this, we're a few steps ahead of the process."

The environmental impact statement calls for the project to be built on 20 acres that were once part of the Barbers Point Naval Air Station. While it would initially be able to provide 5 MGD, it would have the capability to go to 15 MGD.

The plan also calls for an electrical transformer substation to provide energy for the plant.

Up to 12 MGD of seawater would be used to produce the 5 MGD of potable water, coming from a network of three basalt aquifer wells located on the site. Pretreatment would consist of the addition of chemicals and filtration. The pretreated water would then undergo reverse osmosis desalination.

Seven MGD of waste cleaning solution and brine would be disposed of through injection wells in the lower caprock aquifer below sea level.

Reach Gordon Y.K. Pang at gpang@honoluluadvertiser.com.

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