USEPA aims to open door for small system variances

摘要

Small system variances allow systems serving fewer than 10,000 people to install treatment technologies that are affordable but incapable of meeting a chemical contaminant's maximum contaminant level (MCL). They are not available for regulations covering microbial contaminants. Unlike relatively shortlived exemptions, which require eventual compliance with an MCL, SSVs allow utilities to avoid meeting an MCL for the lifespan of the variance technology, subject to state review every five years. They must, however, "achieve the maximum reduction or inactivation efficiency that is affordable" considering system size and source water quality and also be "protective of public health" as determined by USEPA.