There is nothing wrong with using copper pipes for drinking water.However, dissolved copper in drinking water can be harmful. The only way copper pipes could cause this is if they were so badly oxidized (rusted) that the copper piping was disintigrating into your water. It is likely that this will never happen and if it did you would notice leaks.It is a known fact that the largest source of copper in water is from natural sources. I would be more concerned about the natural sources (such as mineral deposits in wells) than I would copper piping.The US EPA drinking water guidelines suggest that no more than 1 ppm (part per million) of copper should exist in drinking water. If you are concerned you could have your water tested for copper by a government accredited lab facility. This is usually about $50-80.