AWWA JAW62288

This article discusses the second Unregulated Contaminant Monitoring Rule (UCMR2) that will require a national sampling of water utilities to monitor for 26 high-priority unregulated contaminants, including perchlorate. The UCMR2 features an assessment monitoring component that would have 3,910 public water systems look for 11 priority chemicals using six well-established analytical methods. The rule also includes a screening survey that would have 1,122 systems monitor for 15 other targeted chemicals using specialized and less commonly used methods. Scheduled for promulgation by August 2006, the rule would apply to community water systems (CWSs) and nontransient- noncommunity water systems (NTNCWSs). The article discusses the US Environmental Protection Agency's (USEPA) selection method for the 26 chemicals, the USEPA's request for a second monitoring for perchlorate, and possible additions to the final screening survey. Assessment monitoring process is described, along with the screening survey and state participation. Includes tables.