Water: Drinking Water Standards
Variances and Exemptions for Small Drinking Water Systems
Variances under SDWA allow a public water system to deviate from the maximum contaminant level (MCL) of a national primary drinking water regulation (NPDWR) under certain conditions when exceptionally poor source water conditions prevent compliance with that NPDWR. Exemptions under SDWA allow a public water system extra time to comply with a new NPDWR. When operating under variances or exemptions, water systems must still provide drinking water that protects public health.
The revised regulations create a new affordability-based small systems variance which may be granted by a State to a public water system serving fewer than 3,300 persons, or, with the approval of EPA's Administrator, to a system serving 3,301-10,000 persons.
The rule highlights the conditions for granting small system variances under SDWA section 1415(e)(3). This section states that no variance may be granted unless certain conditions are met according to affordability criteria developed by the State. First, according to that affordability criteria, the State must find that the small public water system is unable to afford to comply with a NPDWR through treatment. Further, no variance may be granted unless the State finds that the system is unable to afford to comply by developing an alternative source of water.
Also, the State must find that the system is unable to afford to implement necessary restructuring changes or consolidation (unless the State makes a written determination that restructuring or consolidation is not practicable in that situation). Finally, after these options for the system have been exhausted, the State may grant a small systems variance on the condition that the system install, operate, and maintain a nationally listed variance technology, and the terms set by the State in the variance ensure "adequate protection of human health."For more information see the Variances & Exemptions rule: This rule provides options that states can use to help small drinking water systems meet EPA's drinking water standards. Read the Federal Register Notice online or download in PDF format.