Second UCMR Seeks Data on 25 Chemicals

Abstract

This article details the U.S. Environmental Protection Agency's (USEPA's) second Unregulated Contaminant Monitoring Rule (UCMR2), which requires all water systems serving more than 10,000 people (roughly 4,000 systems) and 800 selected systems serving fewer people to conduct first‐tier assessment monitoring for 10 contaminants using approved methods and laboratories during a 12‐consecutive‐month period between the start of 2008 and the end of 2010. As detailed in a table included in the article, the chemicals include dimethoate, terbufos sulfone, five flame retardants, and three explosives. Although the approved methods for these chemicals are new, the analytical techniques are commonly used. The article discusses the exclusion of perchlorate from the UCMR2 monitoring requirement and two bills introduced by California Senator Barbara Boxer responding to this exclusion called The Perchlorate Monitoring and Right‐to‐Know Act and the Protecting Pregnant Women and Children from Perchlorate Act. Also discussed are UCMR2 requirements for a second‐tier screening survey of 15 additional chemicals; the shift from requiring a 12‐consecutive‐month monitoring period over a 3 year period from 2008 ‐ 2010 in the proposed rule to requiring a full 3 years of monitoring between 2008 to 2010 in the final rule; revision and clarification of several requirements regarding system applicability as well as certain aspects of monitoring, reporting, and quality control; and, guidance and training provided by USEPA for each monitoring component, frequently asked questions, and documents detailing laboratory approval procedures, use of approved methods, and reporting requirements (including for public notice and Consumer Confidence Reports). The article includes a summary of UCMR2 compliance essentials.