40 CFR § 141.542 - What must my system do if we are considering a significant change to disinfection practices?
If your system is considering a significant change to its disinfection practice, your system must calculate a disinfection benchmark(s) as described in §§ 141.543 and 141.544 and provide the benchmark(s) to your State. Your system may only make a significant disinfection practice change after consulting with the State for approval. Your system must submit the following information to the State as part of the consultation and approval process:
(a) A description of the proposed change;
(b) The disinfection profile for Giardia lamblia (and, if necessary, viruses) and disinfection benchmark;
(c) An analysis of how the proposed change will affect the current levels of disinfection; and
(d) Any additional information requested by the State.