Disinfection facilities shall be designed to provide the dosage rate and contact time prior to the first customer sufficient to provide a quality of water that complies with the microbiological MCL and the appropriate MRDL, specified in § 109.202 (relating to State MCLs, MRDLs and treatment technique requirements) and the treatment technique requirements in § 109.1302 (relating to treatment technique requirements).
25 Pa. Code § 109.611