A sample of the water leaving the Berwick Sewer District.
The last step before the water exits the treatment plant is to disinfect. This is to kill any microorganisms, such as E. coli, that could be a potential health hazard after the water is discharged into the environment. Adding chlorine is the most common method of disinfection. Chlorine is added when the water enters the chlorine contact chamber, pictured below. As the water makes it way through the chamber, the chlorine kills the microorganisms. At the end of the chamber, another chemical is added to dechlorinate the water before discharging it to the Salmon Falls River.