JEA looks into water alternative

JEA ponders pumping into aquifer; Utility wants to clean used water and put it back into its source.

By STEVE PATTERSON

Troubled by forecasts it could harm the Floridan aquifer by pumping too much water, JEA is asking whether it can put some water back after using it.

The utility and the St. Johns River Water Management District are looking into the costs and effectiveness of two plans to return sewer wastewater to the ground after carefully cleaning it to a high standard.

One idea involves laying pipelines to carry wastewater to places southwest of Jacksonville where water quickly percolates through the ground and into the aquifer.

The other involves drilling a shaft maybe 2,000 feet deep and injecting the cleaned wastewater into a different aquifer layer below the Floridan. The goal there is to create upward pressure that would maintain Floridan levels, somewhat like slipping a coaster under a wobbly table leg.

The cleaned water would eventually find its way into an aquifer anyway but not as fast, said Karl Hankin, JEA's manager of water and wastewater planning.

"The amount of water we've got on this planet is finite. ... We've probably recycled the water we drink a number of times already," Hankin said.

JEA has lagged behind many communities in using recycled wastewater to irrigate lawns and golf courses, partly because of the cost of laying new pipes through well-established neighborhoods.

As a result, great amounts of cleaned wastewater end up being released into the St. Johns River instead of being reused.

"There is still a lot of reclaimed water that is not presently spoken for," said Kirby Green, management district's executive director.

That wastewater is being viewed as a potential asset now, as the water management district pressures utilities to show how they will meet water demands through 2030 without overburdening the aquifer, their source of drinking water.

Gainesville's utility has returned wastewater to quick-recharge areas for years, Hankin said. He said water is still naturally filtered as it passes through yard after yard of earth, entering the Floridan with no risk of any environmental harm.

But Jacksonville's geology would make that process more complicated.

Most of Northeast Florida's ground contains a barrier, called the Hawthorn layer, that would slow the water's descent, defeating the goal of recharging the aquifer.

To get around that, JEA could run pipes somewhere out near Keystone Heights or other inland points where the Hawthorn layer disappears.

Doing that would cost many millions of dollars, but the exact price isn't known yet. It's likely to be clearer by the time the management district completes a 20-year water supply plan in December.

Hankin said JEA might be able to pour 30 million to 80 million gallons daily into a recharge system. If it injected water directly into a lower aquifer, the utility might handle 1 million to 40 million gallons daily that way, he said.steve.patterson@jacksonville.com, (904) 359-4263

(c) 2010 Florida Times Union. Provided by ProQuest LLC. All rights Reserved.

http://www.waterworld.com/index/display/news_display/142618362.html