sand-point well - questions

has anyone made a sand-point well? If so how did you determine the water-table depth?
anyother advice would be appreciated.

thnx,
dennis

When driving a point you can add threaded pipe extensions as you progress. Our nurseries use these for water in the sandy soil that is no more than 25' thick before hitting hard un-drivable point destroying shale.
I suppose they are mostly useful in this context when there has been a lot of rain in spring and fall. The water runs on top of the non absorbent shale within the sand, enabling the point to access water.
Our county Soil and Water office has well logs online. Easy enough to see where water begins appearing in your vicinity. Logs that would be useful for sand points would be the wells that display 15-40' water levels as opposed to 100-200', which would be drilled wells.   

I had to look it up.  Wasn't sure what it was.
http://www.dnr.state.wi.us/org/water/dwg/pubs/DrivenPointWells.pdf

gary wrote:
I had to look it up.   Wasn't sure what it was.
http://www.dnr.state.wi.us/org/water/dwg/pubs/DrivenPointWells.pdf

Outstanding link/article!

It occurs to me that a mechanical vibrator might be an easier way to drive one than impact.

Thanks for the responses.....Really nice article from the DNR. I looked on the Missouri DNR site and they didn't have the water-table diagram i was looking for. I think i will call them Monday.....

dennis

I've driven a couple sand points.

If you have nice well-sorted sand they drive o.k.  If you have clay lenses or cobble layers you have to go through, it can really stink.  If you have to go more than 30 feet - I would forget a sand point.

You may find a some well log data near you in the database link below that will help estimate water table depth.

http://www.dnr.mo.gov/env/wrc/logmain/

Otherwise, if you have a lake, opnd or stream close by the water table is most likely a little higher in elevation than the surface of the water.  If you have springs that come out of slopes above these water features, you can assume the elevation of the spring is pretty much the elevation of the water table.  You then have to figure out how much the land rises from the point you want the well to the water surface.