(Portland, OR) -- Grant High School will need to find another field than Portland Parks & Rec's Grant Bowl for athletic events. Portland Parks says the field is no longer safe and it's being closed. The artificial turf was installed in 2013 with an eight to ten year lifespan. Several maintenance projects have been performed, but the field still doesn't pass safety tests. Portland Parks will work with Portland Public Schools to find alternate sights. Portland Parks has a 600-million-dollar maintenance backlog.