The San Ysidro School District continues to distribute bottled water at its three oldest campuses following findings of elevated levels of lead, copper and bacteria in plumbing at one of the schools. Last October, an employee at La Mirada Elementary noticed discolored water in faucets during pressure tests for plumbing leaks. Water to all drinking fountains, sinks and faucets was shut off immediately. “For the safety of the kids it was a very easy decision,” said district Superintendent Julio Fonseca. Water quality reports from the Otay Water District indicated that the water itself was not contaminated, but rather that the water was contaminated by aging plumbing. The district has…