Emerging Contaminants in Your Drinking Water
By Chris Leaf, Project Chemist, Kelso, WA
Imagine turning on a faucet to get a glass of water and discovering that perfluorooctane sulfonic acid, methyl tert-butyl ether, or chloromethane has flowed into your glass. These chemical compounds represent real threats to the public and are present in many public water supplies today.
In September of 2009, the EPA finalized its Contaminant Candidate List 3 (CCL3), comprised of 116 drinking water contaminants. These contaminants have already been discovered in public water systems or pose the risk of existing in public water supplies. Under the Safe Drinking Water Act (SDWA), the EPA is required to evaluate and determine whether to regulate at least five contaminants from the CCL every five years. The EPA decides if regulations will be required based on the following criteria1:
- The contaminant may have an adverse effect on the health of persons.
- The contaminant is known to occur, or there is a great likelihood that the contaminant will occur in public water supplies with a frequency and at levels of public health concern.
- In the sole judgment of the EPA Administrator, regulation of the contaminant presents a meaningful opportunity for health risk reduction for persons served by public water systems.
How can health risks be determined for these contaminants? The September 2009 Journal AWWA (American Water Works Association) published risk indexes to the CCL32 in effort to assess the health risk and level of exposure. The risk indexes are likely to be used by the EPA in prioritizing the need for regulatory limits on any of the 104 chemical compounds or 12 microbes that comprise the CCL3. Historically, the data from the Unregulated Contaminant Monitoring Rule (UCMR) has been used in regulatory determinations as well. That means that as UCMR2 is coming to a close, the UCMR3 list will be derived from the CCL3.
This list of pharmaceuticals, pesticides, disinfection byproducts, chemicals from manufacturing, waterborne pathogens, and biological toxins will be closely scrutinized by the EPA. More data is needed at this time as to the overall health effects, occurrence in the environment, and the analytical methods to be reviewed or established.
Yet, the potential for exposure exists today. If you are interested in investigating your water supply, it can be done by a laboratory. There is no need to wait for regulations to pass to be assured your water supply is free of the contaminants in the CCL3.
Learn more about Drinking Water Testing…
1 Drinking Water Contaminant Candidate List and Regulatory Determinations, http://www.epa.gov/safewater/ccl/index.html (Updated: 2/22/2010)
2 Risk indexes for draft Contaminant Candidate List 3 chemicals, J. Alan Roberson, Matthew Lueders, Craig Adams, and Jeffrey Rosen, Journal AWWA, Volume 101, Issue 9, September 2009, ISSN 1551-8833
Tags: AWWA, CCL3, CDBM, chemicals, Contaminant Candidate List, disinfection byproducts, Drinking Water, Emerging Contaminants, MTBE, pesticides, PFOS, pharmaceuticals, public water, SDWA, waterborne pathogens