An update on testing for contaminants in water at area schools is scheduled to be presented on Thursday to the City Council’s Environment Committee. The presence of contaminants has been a hot-button issue since elevated levels of lead, copper and bacteria were found in October in the water systems at three older campuses in the San Ysidro Unified School District. Earlier this year, lead was found in the water at Emerson-Bandini Elementary/San Diego Cooperative Charter, which share a campus in Southcrest, after a dog refused to drink from a bowl of water.