Chlorine leak detectors consist of a control unit and a sensor. Sensors are available in two different types such as single and double sensor leak detectors. A chlorine leak detector sounds an alarm when elevated chlorine concentrations are found. It sounds continuously for the duration of the abnormal concentrations. The employees, contractors and visitors exit from the leak area while observing the wind direction and report to the designated area. Two chlorine leak detector are installed in the chlorination room to alert the plant staff quickly in the event of a chlorine leak. One chlorine leak detector is located next to the chlorinators and the other chlorine leak detector is located next to the active containers. An audible alarm automatically sounds inside and outside of the building.