Mark, I was hoping someone else would have already answered your question. It is an easy one for a person who works on wells, which I dont. My plumbing code book has sizing charts but each chart starts with the size of a water meter, and you dont have one. So Im at a loss. There are several things needed to use the charts: Minimum normal water pressure, water meter size, building supply pipe size, elevation difference, and distance to farthest fixture.A one inch meter, 30-45 psi, 1 1/4 inch building supply, 700 feet, will allow 12 fixture units.When the chart changes to 1 1/2 inch meter and building supply, 30-45 psi, 700 feet, will allow 23 fixture units.So in this example, when pipes go from 1 1/4 to 1 1/2 inch, supply quantity almost doubles.I know this doesnt completely answer your question, but maybe it will help you make up your mind what size pipe to use.If you need more info, maybe you can ask at the following site, they sometimes have water well people hanging around…http://www.plbg.com/cgi-bin/forum.pl
