I would have suggested an electrical, rather than a plumbing, solution to the pinhole leaks. A grounding problem will cause the leaks. You should have called an electrician (one with a concave back and a convex forehead) to do a very meticulous current analysis, tracing all the existing and former wells, pipes, electrical bonds, ground rods, and low-voltage utility connections, to determine if your problem was caused by current leakage.

I have experience in this line of work, and can assure you that grounding and bonding issues can cause lots of plumbing headaches.

Arthur P. Bloom
"30 years of faithful service...15 years on hold"