Piedmont Park drills for water, but not all is well

It’s not unusual to get it wrong when drilling for water in North Georgia’s Piedmont region — or in Piedmont Park for that matter.

The area’s various rock formations can fool even the smartest geologists.

The Piedmont Park Conservancy found that out recently when the second of two well-drilling attempts came up dry at the Midtown Atlanta park.

All the signs looked good. The spot, next to the lower meadow near the intersection of 10th and Monroe streets, was chosen by consultant Tom Crawford, a respected veteran well finder and professor emeritus of geology at the University of West Georgia.

But at best, finding a well in the bedrock of North Georgia is an educated guess, experts say.

“It’s not uncommon to identify a favorable location and have the yield not really be that high,” said Jim Kennedy, state geologist with the Georgia Environmental Protection Division. The only way to know for sure, he said, is to drill.

Unlike in South Georgia, where cavernous aquifers beneath the sandy soil hold abundant amounts of water that’s relatively easy to access, the water beneath the ground in North Georgia is trapped inside joints and fractures in the rock.

“The trick is to find where the cracks and fractures are more concentrated,” Kennedy said.

The water comes from rain that has either soaked through the soil or fallen directly on exposed rocks.

In South Georgia, a well that pumps 1,000 to 2,000 gallons of water per minute is not uncommon. In metro Atlanta, however, a well that pumps 100 to 300 gallons per minute is considered high yield, Kennedy said.

The difference explains why South Georgians get most of their water from underground aquifers while North Georgians depend on rivers and lakes.

Monica Thornton, the conservancy’s vice president and chief marketing development officer, said the first drilling attempt revealed a well site that is expected to yield 50 gallons of water per minute, enough to water the park’s 1,000 trees. A crew drilled about 500 feet, the equivalent of one and two-thirds football fields, to find the water.

Starting next week, the conservancy plans to run a 30-day test on the first site before building a permanent pipe and pump system next to Park Drive near Lake Clara Meer.

Here’s how it will work: The conservancy will draw water directly from the lake to irrigate the park. The well water will be pumped into the lake to replenish it.

The conservancy’s second and third priorities, which could be met by future wells, are to water the newly renovated $2.1 million athletic fields in the Active Oval and the rest of the park.

The goal is for the park to become less dependent on the city of Atlanta’s water and the attendant restrictions during the ongoing drought.

And the conservancy has explored other options. Consultant Daniel Benner, an irrigation specialist with Hydro Environmental Inc. of Marietta, said he briefly considered using discharge from a nearby sewage treatment facility that disinfects both storm water runoff and sewage, but decided it was too polluted.

Crawford found five other potential well locations. But most of the others are in the undeveloped, 53-acre north section of the park, and too far away to replenish the lake.

Still, those could be tapped in the future.

Of the $50,000 the conservancy set aside to investigate well locations and perform an irrigation study, about $37,000 has been spent, Thornton said.

More will need to be spent to develop the wells.