Beginning Tuesday, the tests will be done in the 10-mile radius around the plant Mondays through Thursdays, between 7:30 a.m. and 4:30 p.m.
Progress said since the sirens will be tested individually, there is no specific time when residents of Chatham, Harnett, Lee and Wake counties can expect to hear one.
The testing is part of annual maintenance on the Harris warning system. Each siren may be tested multiple times. Residents may not hear anything unless they are close to one when it is being tested.