Every evening when Donnie Graham arrives home from work, he hops on his golf cart and makes his way to his horse pasture.

However, last Wednesday, Graham stopped dead in his tracks.

"I looked over there and wondered 'what IS that?' " said the Turkey Creek Circle resident. "I could tell it was a hole, but I didn't realize until I got right up on it just how big it was."

There, only a few yards from the fence containing his horses, was a hole in the ground. Yet, the word "hole" doesn't adequately describe what Graham saw.

"It is maybe 10 to 12 feet wide," said Graham, "and easily 40 to 45 feet deep. All I know is it wasn't here yesterday!"

Graham said he stood in amazement looking down the cavernous hole. He not only wondered what had caused the sinkhole, but wondered what it must have been like when the earth simply began to disappear. The only witnesses were his horses, who looked at him as they nonchalantly munched their hay.

Upon closer inspection, Graham realized there was no loose dirt at the bottom of the hole. The mystery of the sinkhole grew deeper.

"If you'll notice, there is no loose dirt down there ... no grass or clumps lying on the bottom," Graham pointed out. "On one side it appears there is the opening to a tunnel. It looks like something literally sucked all that dirt out of sight and into that tunnel!"

Graham's curiosity tempted him to check out the bottom of the hole and inspect the tunnel, but he said common sense and caution won out. He wondered if the bottom was soft or hard, so he tossed an old 2x6 board in the hole.

"It is solid down there, but it could cave in more," Graham said. "There is only about eight inches of top soil, then it turns into that red clay." Shining a flashlight into the hole, Graham pointed out the layers of harden sediment visible all the way to the bottom.

"Then I began to wonder who do you call to fix this?" Graham said. "It's not as simple as just filling it with dirt, because whatever sucked out all that dirt would most likely suck out whatever is put back in there."

Graham first called his homeowner's insurance agent, but the agent had no idea what to advise him other than to call a county extension agent.

"He didn't know what I should do either," said Graham. Before the day was over, he also spoke to the county public works department, but they can only perform work on county property - not private property. County Sheriff Bill Harrell personally came to look at the hole, and while he had no recommendations he did suggest roping off around the massive crater to help prevent anyone from accidentally falling in.

Rural Fire and EMS Director Don Bryant also went to inspect Graham's sinkhole. "I didn't quite know what to tell him either. Sinkholes aren't all that common around here, although I do know of one other one near Dexter. So I called UGA, the Environmental Protection Division (EPD) and GEMA, but so far no one has called back with an answer."

Dr. Jim Kennedy, the state geologist with the EPD, not only clarified what the hole is, but had a suggestion for Graham.

"From what you've described, it's not actually a sinkhole, but what geologists call a conduit," said Kennedy, adding most likely there was an underground void capped off by a "veneer" of soil. He explained that while it would take approximately 1,413 cubic feet of dirt to refill the hole, there likely was not that much in there to begin with.

"There is limestone mixed with clay in that part of the state. Ground water can run through that conduit and the limestone dissolves while clay fills in. A good analogy is if you ran water over ice cubes and sand. The ice cubes would melt and the sand would fill in," Kennedy explained. He added that erosion may occur due to a drought or too much rainfall - or it can occur slowly over thousands of years. However, when it does reach a critical level, the earth can literally disappear overnight.

"The thing that needs to be done is something a smart engineer could design," advised Kennedy. "You have to bridge off the bottom of the conduit ... something to choke off the throat so nothing else gets out. Then a platform could be built and other material put on top of it to refill the conduit."

Kennedy had two warnings, "First you don't just want to start filling it back up because whatever is put in there could also disappear, and secondly without the conduit being sealed off, whatever is put in there could contaminate the underground water supply. That would be classified as an underground injection well and that is not permitted in Georgia. The best plan would be to plug it above the ground water level and back fill the hole above the plug."

Graham appreciated Kennedy's advice but still wondered where to find someone who knows how to do what Kennedy described.

Graham said Kennedy plans to come see the hole for himself or send another state geologist next week to further investigate.