Driven Point Well Question

[well94]

First the background. About two years ago I put in a 1-1/4â€, three foot driven point well at my house for a water supply to water grass. After driving the well point to a depth of 18’, I measured that the water level in the pipe was only eight feet below ground, or 10’ above the well point.

I next flushed the well point by running a water hose down into the well point, which brought up a sandy, gritty looking mixture. I then attached a hand pump, which yielded very little water. The pump handle had a lot of back pressure. So I repeated the process of trying to flush and pump, with the same result. This went on for several weeks, until I ran out of patience.

This past weekend, I decided to give it another try.

After talking with several of my neighbors who have working wells driven to the same depth, I attached a water hose and forced water down the well. I attached a gauge and when I first started the water flow, I had 25 psi of back pressure, which slowly decreased to 10 psi. I repeated the flush and pump cycle, which gave me a little more water, but I still have a lot of backpressure on the pump handle.

So, as a last resort, I jacked the well point up to 12’ and tried again, with no luck. I then jacked the well all the way out to inspect the well point, which is still in good shape. I measured the water level in the hole that was left at 8’ below ground level.

My question is could I have a well point that has an incorrect mesh size for the type of ground that I have? And if so, is it possible to modify the screen without ruining the well point?

Thanks in advance for any information you could pass on.

 

[NHmaster3015]

Yes, you very well could have too fine a screen. As for changing the screen, I doubt it. change the poing

 

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[well94]

Thanks for the reply,

I think replacing the head is what I will try next. I checked with the plumbing supplier where I bought the well head, and he said that he only keeps 80 gauze mesh well points in stock. I was thinking about trying a 60 gauze or a slotted point this time. Does this sound reasonable? Could anyone post a link where I could find one online?

 

[Krusty the Klown]

There's a big difference between 80 and 60, though the substrate needs to be fairly coarse to use a 60 else you'll pump sand continuously. In my area a 60 will do 14-15 gallons per minute with a 3/4 HP jet pump, while an 80 will do 8-9 and be subject to slowing down over time. The local Home Depots and Lowes all sell just 80's. I prefer slots to screens (a 10 slot is equal to a 60 gauze) and given the work involved recommend you get something high quality like a Johnson 10 slot 3' screen (42" overall). I buy at a local well supply store, but noticed this place has them on-line - a little pricey.

http://www.us*********.com/inet/shop/item/80220/icn/20-761254/johnson_water_well/836ss6010.htm

Edit. Not sure why this web site name is getting "censored", but the site is u s a h a r d w a r e.com (don't use the extra spaces). My apologies to Terry if I shouldn't be posting web site names.