EPA eyes monitoring 26 water contaminants

The U.S. Environmental Protection Agency has proposed a new rule that would monitor 26 unregulated contaminants by many drinking water suppliers in the United States.

EPA said that under the second cycle of the Unregulated Contaminant Monitoring Rule 2, it also proposes the use of nine analytical methods to detect the contaminants.

“The data collected will help EPA determine whether to regulate the contaminants, their occurrence in drinking water, the potential population exposed to each, and the levels of exposure,” said the EPA in a statement.

The rule encompasses some contaminants that are not regulated under existing law.

EPA said the agency currently has regulations for more than 90 contaminants. The Safe Drinking Water Act requires EPA to identify up to 30 contaminants for monitoring every five years. The first cycle of UCMR 1 was published in 1999 that covered 25 chemicals and one microorganism.

The contaminants are divided into two lists: assessment monitoring and screening surveys. EPA has information from some public water systems on 11 contaminants chosen for assessment monitoring but lacks a national estimate of how widely they occur. EPA needs to collect more data on the 15 selected for screening surveys because analytical methods recently have only been developed.

The EPA said all public water systems serving more than 10,000 people and a sample of 800 systems serving 10,000 people or fewer will monitor those contaminants on the assessment list for 12 months from July 2007 to June 2010.

Another 322 systems serving more than 100,000 people and 800 serving 100,000 or fewer will conduct the screening surveys during a 12-month period from July 2007 to June 2009.

The costs for the five-year UCMR 2 will reach approximately $42.1 million. EPA said the agency would conduct and pay for the monitoring for those water systems serving 10,000 people or fewer at a cost of $8.05 million.

The substances were chosen through a process that included a review of an existing list of “reserved” contaminants for which no analytical methods were yet available; the EPA’s Contaminant Candidate List, which contains priority contaminants that are researched to make decisions about whether regulations are needed; and, additional contaminants of concern based on current research of occurrence and various health-risk factors.

EPA said the contaminants on the list are known or anticipated to occur in public water systems, but they are currently still unregulated by existing national drinking water regulations. (PR)