Steve,
The pond is entirely excavated and although there is some shallow spring seepage at the bottom, all the water that goes in is via a well that has to be pumped. We hit a gravel layer when drilling at about 30 feet and the well is set at 88 feet. Aquifer is typically about 40 feet thick in this area.
Although I have to pump I am fortunate to have an excellent aquifer supply in my area, and in fact, one farmer pumps 2000 gpm when he irrigates. Hard to believe but true. 500 gpms in large diameter wells is not unusual in my area. We even have a double aquifer in some areas.
I don't know about New Hampshire but in my state of Indiana you can get well records on line. All you need to know is township range etc for your area and I was able to print out lots of records of wells of my neighbors which include well depths, composition of layers encountered etc.
You are giving good advice Steve. I would think a local well driller should be up to speed on all the details of his area too.
