I bought this house 2 years ago,toilet never did flush good,checked everything I could looked ok. Seen some small green corrosion on 3inch copper drain pipe did not think nothing. Then when bare-foot in basement and touch water pipe got very small shock? Hum? Finally talked to a plumber said the copper pipe is coroded from electric backfeeding call electric company,so I did, they came out checked wires and transformer on pole,ground was gone, and neutrual was off transformer, they said this would cause a backfeed to my house or others too,[new transformer on] Now here photos of how bad my pipes were filled up with this green stuff a 7 feet piece and one smaller were stuffed. Anyways took out all copper drains put pvc. in everything works good now and no more shock from pipe.