Swimming areas being monitored for safety Bacteria tests have yet to clear the swimming and recreation area in Greenfield, which has been closed to swimming since June 24. STAFF PHOTO/PAUL FRANZ Laurel Lake in Erving State Forest was open for swimming Tuesday, with a lifeguard on duty. Laurel Lake in Erving State Forest was open for swimming Tuesday, with a lifeguard on duty. STAFF PHOTO/PAUL FRANZ The Green River Swimming and Recreation Area in Greenfield continues to be closed due to high bacteria levels. STAFF PHOTO/PAUL FRANZ Silver Lake in Athol is open for swimming. STAFF PHOTO/PAUL FRANZ