part_subject: "NATIONAL PRIMARY DRINKING WATER REGULATIONS"
subpart_code: "T"
subpart_subject: "Enhanced Filtration and Disinfection—Systems Serving Fewer Than 10,000 People"
section_number: "141.544"
section_subject: "What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?"
cfr_reference: "40 CFR 141.544"
title_name: "Title 40"
title_subject: "Protection of Environment"
parts_covered: "Parts 136 to 149"
revised_date: "Revised as of July 1, 2019"
publication_date: "As of July 1, 2019"
contains_description: "Containing a codification of documents of general applicability and future effect"
publication_info: "Published by the Office of the Federal Register National Archives and Records Administration as a Special Edition of the Federal Register"
---
If your system uses chloramines, ozone or chlorine dioxide for primary disinfection your system must calculate the disinfection benchmark from the data your system collected for viruses to develop the disinfection profile in addition to the Giardia lamblia disinfection benchmark calculated under § 141.543. This viral benchmark must be calculated in the same manner used to calculate the Giardia lamblia disinfection benchmark in § 141.543.