My sister has a dug well (close to 100 years old) and water has always been very good for all uses. She recently had a new pump and pressure tank installed (bladder type) and shortly after began having rust problems. It stains the plumbing fixtures as well as discolors white clothing. A neighbor draws water from the same well without any problems. All piping is copper and is quite old. Could this be the problem? Anyone have a solution?