part_subject: "NATIONAL PRIMARY DRINKING WATER REGULATIONS IMPLEMENTATION"
subpart_code: "K"
subpart_subject: "Variances for Small System"
section_number: "142.304"
section_subject: "For which of the regulatory requirements is a small system variance available?"
cfr_reference: "40 CFR 142.304"
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"
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(a)A small system variance is not available under this subpart for a national primary drinking water regulation for a microbial contaminant (including a bacterium, virus, or other organism) or an indicator or treatment technique for a microbial contaminant.
(b)A small system variance under this subpart is otherwise only available for compliance with a requirement specifying a maximum contaminant level or treatment technique for a contaminant with respect to which;
(1)a national primary drinking water regulation was promulgated on or after January 1, 1986; and
(2)the Administrator has published a small system variance technology pursuant to Section 1412(b)(15) of the Act.
Small system variances are not available for public water systems above the pre-1986 maximum contaminant level even if subsequently revised. If the Agency revises a pre-1986 maximum contaminant level and makes it more stringent, then a variance would be available for that contaminant, but only up to the pre-1986 maximum contaminant level.