40 CFR § 141.530
What is a disinfection profile and who must develop one?
June 9, 2020
A disinfection profile is a graphical representation of your system's level of Giardia lamblia or virus inactivation measured during the course of a year. If you are a subpart H community or non-transient non-community water system which serves fewer than 10,000 persons, your system must develop a disinfection profile unless your State determines that your system's profile is unnecessary. Your State may approve the use of a more representative data set for disinfection profiling than the data set required under §§141.532-141.536.
[67 FR 1839, Jan. 14, 2002, as amended at 69 FR 38856, June 29, 2004]