(PORT HURON) -- The Port Huron Area School District was recently awarded a $99,365 grant through the Michigan Energy Office for installation of energy efficient lighting in seven elementary schools. The seven elementary schools were built between 1924 and 1965 and serve 2,787 students. The project will replace or retrofit obsolete lighting and ballasts containing PCB's with newer lighting technologies, helping the schools become more energy efficient and cutting costs. According to the U.S. Environmental Protection Agency, PCB ballasts can be a significant source of PCB emissions in schools. Exposure to PCB's can have toxic effects in children. Port Huron Area School District Superintendent H. Ronald Wollen says the lighting upgrades are estimated to reduce the school's energy bills by $15,000 a year.