No local well drillers around can give any info on what to expect on depths for these types of wells. ARCGIS has some interesting online maps, and their maps for "Water Table Depth - Annual - Minimum" suggest that my water table is approx 100cm below earth's surface. I dont see how this is possible. In fact I think their maps are completely flawed - lots of central alabama is listed as water table from 0 - 25cm deep. Are there any other sources I can go to in order to see if a sandpoint is appropriate for my area? I have nice prairie soil, shouldnt be too hard to dig at all. Should I just go down to 25ft and if it produces nothing just write it off? Im in central Alabama, in a town particularly proud of its wells, (but not sure if they are aquifiers or shallows) at that.

House is 7 yo with at grade mound system. Problem, puddle in low spot on field. Septic guy dug into it and water poured out, (this was 4 hours after a very large storm) he said field has failed as rocks were black. We had another septic company out, they dug at top of field, rocks were white and they said we just needed more dirt as the "toe"as it was not covered with enough soil and set at edge of mound. While they had uncovered the white rocks, they also set the pump off and the area was receiving effluent. After investigating I realized this problem didn't start until they replaced our pump with one that is twice as strong as recommended for our field. They also didn't set float right, it was pumping out 200 gallons rather than the 100 per cycle. My question is, did my field fail or was it all just pooling to the low spot ? We had them replace the pump with the correct size and have just added clay soil to area and 2 trucks of top soil to extend the mound. The season is changing and I don't want to be surprised in the winter with 2 feet of snow! Any professional advise is greatly appreciated.