Sharpsville, Mercer and West Middlesex school districts have all discovered lead and copper levels exceeding the national standard limits at some places within their buildings. All three are served by the private water company Aqua Pennsylvania. None of the schools found lead in the drinking fountains used by students. There is no state mandate for schools to test for lead or copper in drinking water, so it is unclear which if any of the other nine public school districts in Mercer County have been tested. Calls to the Sharon City School District and Farrell Area School District went unreturned....