Sep 12, 2007

State Sets Aside $1 Million to Study Underground Water Storage at Southridge

It may be one of Washington's hottest issues of the past several years, but for Kennewick, finding a new way to store water and reducing the impact on fish and farmers could be so simple that it's right under foot.

To find out, the state Department of Ecology has set aside $1 million to study how to store millions of gallons of treated Columbia River water in the natural basalt formations under Southridge.

"We've already done the initial studies that look at the geology in the area," said Peter Beaudry, Kennewick's public works director. "This would be the next step in the process -- to do a more in-depth study where we put water in the ground and later take it out."

The study will focus on operational questions such as how far below the surface the water would be stored. As described, the Southridge geology has the potential to store at least 319 acre-feet, or 100 million gallons of water, and that's considered a conservative estimate.

Because the plan calls for withdrawing water during winter months and using it in the dry summer, the aquifer would provide Kennewick a supplemental source during emergencies and times of peak demand.

"Right now, we're solely reliant on the Columbia River for our source," Beaudry said. "If something were to happen with the treatment plant -- a power outage that lasted an extended time -- or if something happened with the water in the Columbia, we would then have an alternative."

As alternatives go, the idea is as novel as they come. Ecology funded Kennewick's project because it represents a new way of thinking about water storage and could provide information for other communities considering ways to use their natural underground geology to their benefit.

The project has an added advantage -- much of the infrastructure needed to make the aquifer a reality already exists. Treatment plant: check. Delivery system: check.

All that's needed to put the Southridge aquifer to work are pumps to inject water underground and pumps to extract it. Kennewick also would need to build a substation to rechlorinate the extracted water, then find a way to connect to existing water lines. Beaudry estimated the total cost between $3 million and $4 million.