Post by jamesp on Apr 29, 2013 9:33:46 GMT -5
Been around this business before.Drilling wells around Atlanta area is consistent average of 12 gallons per minute at 320 feet deep.Average top soil/clay layer is 10-100 foot deep,the rest is pure gray glass granite.
Studying the state publication certain topographical features create high yield.One such feature is water falling off a granite shelf(waterfall)such as the 30 footer i got at bottom of my property.In this case,often a large layer of clay and soil has washed off a large area(acres) removing the weight off the granite and causing it to bow up like paint bubbling up.This rising granite 'disc' is typically 3-900 feet in diameter and causes a 1-4 inch horizontal gap.If you hit such a gap you will get water 99 percent.If you hit such a gap you will get a few chunks of rock in the drilling debris where the vibratory diamond bit breaks chunks out of the ceiling of that gap.Otherwise it is all fine sand and bad news because you are surmounting huge costs drilling thru solid garanite that does not have a teaspoon of water in it.
Ok,the guys arrive and i got my $4000 in cash for 400 foot hole.We drill 27 feet and hit solid granite.Drill a bit into the granite and set casing into granite 3 more feet for seal.Change to smaller bit to fit pst casing and back at it.I go over to the shop so not to look over their shoulder.A little over a 20 foot bit later i heard the hammer go quiet-hanging by the chain and no rock to drill-a gap!I walk over and the driller is pissed.He tries to buffaloe me and say we got a long way to go.I see 50-70 gallons per minute going down the hill and his helper getting a pipe secured to keep it from washing the hill away.I leave it alone and play dumb.By the time they hit 140 five more gaps had been drilled past and the bit was barely cutting -called float-up,a lot of water messing with the down pressure.They barely got 30 more feet to a total of 170 and called it quites.So it was $1700 and i gave bigg tip.He said it was rare situation and predicted 300-500 or more gallons per minute.I popped a 40 gallon per minute pump in and it ran 11 days filling three ponds.We were about to run out of irrigation water and all 3 creeks had stopped flowing.The municipalities have been buying water out of wells over 200 GPM.I must look into that.Check out the machinery
We got granite(Stone Mountain Ga)
This video shows the first 50 gallon per minute gap hit at b70 feet deep
www.flickr.com/photos/67205364@N06/8690950530/in/photostream
Studying the state publication certain topographical features create high yield.One such feature is water falling off a granite shelf(waterfall)such as the 30 footer i got at bottom of my property.In this case,often a large layer of clay and soil has washed off a large area(acres) removing the weight off the granite and causing it to bow up like paint bubbling up.This rising granite 'disc' is typically 3-900 feet in diameter and causes a 1-4 inch horizontal gap.If you hit such a gap you will get water 99 percent.If you hit such a gap you will get a few chunks of rock in the drilling debris where the vibratory diamond bit breaks chunks out of the ceiling of that gap.Otherwise it is all fine sand and bad news because you are surmounting huge costs drilling thru solid garanite that does not have a teaspoon of water in it.
Ok,the guys arrive and i got my $4000 in cash for 400 foot hole.We drill 27 feet and hit solid granite.Drill a bit into the granite and set casing into granite 3 more feet for seal.Change to smaller bit to fit pst casing and back at it.I go over to the shop so not to look over their shoulder.A little over a 20 foot bit later i heard the hammer go quiet-hanging by the chain and no rock to drill-a gap!I walk over and the driller is pissed.He tries to buffaloe me and say we got a long way to go.I see 50-70 gallons per minute going down the hill and his helper getting a pipe secured to keep it from washing the hill away.I leave it alone and play dumb.By the time they hit 140 five more gaps had been drilled past and the bit was barely cutting -called float-up,a lot of water messing with the down pressure.They barely got 30 more feet to a total of 170 and called it quites.So it was $1700 and i gave bigg tip.He said it was rare situation and predicted 300-500 or more gallons per minute.I popped a 40 gallon per minute pump in and it ran 11 days filling three ponds.We were about to run out of irrigation water and all 3 creeks had stopped flowing.The municipalities have been buying water out of wells over 200 GPM.I must look into that.Check out the machinery
We got granite(Stone Mountain Ga)
This video shows the first 50 gallon per minute gap hit at b70 feet deep
www.flickr.com/photos/67205364@N06/8690950530/in/photostream
