The Chatham County Health Department has lifted the advisory for Polk Street Beach on Tybee Island. The advisory was issued on March 30 after routine water quality tests showed a high level of enterococci bacteria which increase the risk of gastrointestinal illness in swimmers. Subsequent samples on this northern most part of Tybee Island, at the mouth of the Savannah River from the end of the beach to the jetty, show that bacteria levels are now within acceptable limits.