12VAC5-590-1000: Disinfection

A. The objective of disinfection is to prevent the occurrence of waterborne diseases from the consumption of drinking water.

B. Primary disinfection shall be provided for all surface water sources, all spring sources, all GUDI sources, and all well sources determined to be of questionable bacteriological quality as required by the department. Consideration shall be given to minimizing the formation of DBPs when designing a disinfection process. Waterworks with groundwater sources requiring disinfection under this section shall meet the requirement of 12VAC5-590-421 A 1 d.

C. All pipes, tanks, and equipment that convey, store, or treat potable water shall be disinfected with chlorine before being placed in service in accordance with the following AWWA standards where applicable: C651-14, C652-19, and C653-20.

D. All residual disinfectant determinations shall be made using methods identified in 12VAC5-590-440.

1. The project documents shall outline the procedures and include the disinfectant dosage, contact time, and method of testing the results of the procedure.

2. Methods of disinfection other than chlorination may be considered by the department on an individual basis.