During the exercise, each siren will sound in test mode with a one-minute wail, followed by a prerecorded message and then a live announcement to conclude the test. BERKELEY COUNTY, S.C. – Santee Cooper will test 15 warning sirens serving the Santee Dam flood plain—including locations in Berkeley County—at 10 a.m. Thursday, Sept. 18. Santee Cooper employees will document the sirens’ wail time and evaluate the clarity, completeness and volume of both the recorded and live announcements. CREDIT: Santee CooperSantee Cooper conducts these siren tests twice a year to help ensure the emergency warning system is working properly for communities in Berkeley, Clarendon and Williamsburg counties. The eight-mile Santee Dam system is part of the Santee Cooper Hydroelectric and Navigation Project.