Rule 3745-81-10. Maximum residual disinfectant levels

119.03 (A) Community and nontransient noncommunity public water systems that supply water treated with chlorine or chloramines shall comply with the total chlorine MRDL. (B) Public water systems that treat water with chlorine dioxide shall comply with the chlorine dioxide MRDL. (C) Maximum residual disinfectant levels (MRDLs) are as follows: Disinfectant residual MRDL (mg/l) Total chlorine ................................................. 4.0 (as Cl 2 ). Chlorine dioxide ............................................. 0.8 (as ClO 2 ). (D) The director identifies the following as the best available technology for achieving compliance with the MRDLs identified in paragraph (C) of this rule: control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to reduce disinfectant levels. Last updated June 25, 2025 at 5:54 PM Supplemental Information Authorized By: 6109.03 , 6109.04 Amplifies: 6109.04 10/31/2029 1/1/2002