Originally my installer indicated he was going to use three wells at 200' deep for my new system. He even laid out the well locations with some surveying flags and had three locations marked. The well driller called me this afternoon to make sure he was at the correct house and he said he was told to drill 2 wells at 310' each.

I know I'm ending up with the same footage but I was wondering if the number of wells and their depth affects the performance or the operation cost of the system. Will the pump use more energy since it has to pump up 300' instead of 200'?



 

Hi,
My contractors told me I could have more shallower bores or fewer deeper bores for the same price, but the earth temp is more constant the deeper you bore so fewer deeper is better.  I dont know if this is true, because everything I read says the temp is constant once you go 5 or 6 feet deep until you get really deep, but I think they really just want the driller to cut fewer holes and leave sooner. 

Total footage of bore hole is what is needed.  3 shallow or 2 deep  will give you the same  performance.   Since the loop is closed,  it takes no more pumping energy to go 200 or 300' .    The pipe diameter comes into play.  3/4" is OK for a 200' well.  1" would be needed for a 300' well.

Hope this helps.

I checked the pipe they had laying in the yard and it was 1", so it appeared they were doing the right thing.

However, I talked to the driller this morning and they're switching back to three wells because they ran into a lot of water. They're down 190' in the first well and hit 60 gpm (which is more than my domestic well @ 35 gpm). I guess all the water is creating some problems for them as they drill and creating quite a mess in the yard.

To the drillers credit I was really worried about them driving the big rig on my rain soaked yard but they laid down some thick plastic mats to drive on. The lawn is squishy but there's no tracks! I guess this was as much for their benefit as mine since I'm sure those rigs aren't very good in mud. This morning they were installing a silt fence in the run off area to contain all the dirt and stone.

Tomorrow they'll be back to grout the holes completing the first part of the installation.