
07/15/11, 10:56 AM
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The first wells were hand dug. Then someone figured out how to hammer in a sandpoint to get a well. Both tap into the ground water. The driven well is less likely to have junk fall in to it and contaminate it. Ground water is only filtered through feet of earth. It can be effected by livestock wastes or farm chemicals much quicker than a deep well. That said, people have been drinking ground water for a very long time. As long as it tests good you should be OK.
You can drive a sand point if the ground does not have rocks in it, the watertable is high enough, and the type of dirt will allow the water to flow into the well fast enough. If you are driving a sand point and you hit a rock, it won't go down any further. If you are not deep enough you have to pull it up and try a different place. Sandpoint wells are shallow wells. You drive a 1 1/4 or 1 1/2 inch point and caseing. This is too small a diameter to use a submersible pump, you have to use a shallow well pump. The maximum a shallow well pump can lift water from is 25 feet so you have to hit water before that. It is better to sink the well beyond the watertable so the water you pump is filtered through the dirt. The watertable here is 4 feet and the well is 19 feet. If the dirt is clay, the water won't flow through it very fast and the well won't produce water very fast. Sand is best. Water flows through it like it is not even there. Flow rates over 4 gallons per minute are not unusual. Other types of dirt have flow rates in between. Check with the neighbors, They know what's down there at their place. Some states have a record of what a well driller found when he drilled a well. Don't ask a well driller what they think. They will only make money if they drill a deep well and so will recommend that.
Hammering in a sand point is easy. You start with a sand point which is a piece of well caseing with a point on it and holes in the side of it with screen inside the holes. You screw on a coupling and another piece of well caseing useing teflon tape or thread joint compound just like putting galvanised pipe together for plumbing. Be sure to use the couplings and caseing for wells, not plumbing. It's stronger. Once you have screwed the first piece of caseing to the sandpoint you screw a drive cap on the top, position it where you want the well, make sure it is going in straight, and hammer it into the ground. Some states require you to make an indentation arround the caseing and fill it with Bentonite clay as a seal. I use a driver designed for T post fence posts to hammer the well down but a sledge hammer works too. When the top of the caseing is within a couple of feet of the ground, take the drive cap off, screw on another piece of caseing with sealant, and hammer some more. It's not unusual to only have the caseing go down a quarter inch with each smack. When it is down far enough you want to leave enough caseing sticking out of the ground to connect the pump.
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