Hexavalent Chromium and the Unregulated Contaminant Rule

Posted on Sep 27, 2016 in News

The LCWSC water system, along with other water systems across the nation, was sampled during 2014 as part of the Unregulated Contaminant Monitoring Rule 3 (UCMR3). The EPA uses the Unregulated Contaminant Monitoring (UCM) program to collect data for contaminants suspected to be present in drinking water, but that do not have health-based standards set under the Safe Drinking Water Act (SDWA). Every five years EPA reviews the list of contaminants, largely based on the Contaminant Candidate List.

The EPA will evaluate the information gathered, as well as potential health effects studies, to determine if regulatory limits are needed. Collecting information about the occurrence of these compounds in water supplies is the first step in the EPA’s efforts to determine whether they should be regulated.

As a result of the above sampling there was a recent article publish by EWG (Environmental Working Group) regarding the presence of hexavalent chromium in US drinking water systems, including Laurens County. This article was posted to local media outlets and shared by some Laurens County residents via Facebook. Hexavalent chromium is both naturally occurring and/or a result of industrial discharge activities. It can be found at various levels in public water systems, and possibly private wells and bottle water. The following is an American Water Works Association link which provides further information about hexavalent chromium.


Levels of hexavalent chromium in the LCWSC drinking water are far below the current EPA limit for total chromium of 100 ppb. Furthermore, in the future if the EPA decides to implement maximum contaminate limits (MCL) specific to hexavalent chromium it will more than likely follow the 2014 standard set by the state of California, which is 10 ppb. The levels in the LCWSC water system are 50 times lower than even this more stringent limit.

Our UCMR results, which were included in our 2014 Consumer Confidence Water Quality Report, is below. For results from this and other annual Water Quality Reports, please visit our web-site at http://lcwsc.com/consumer-confidence-report/ .


  • The presence of a compound does not necessarily mean there is a health risk. The concentration of a compound is a far more important factor in determining potential health implications. Results for the UCMR3 testing are measured in “part per billion” (ppb) increments.  An easier way to understand the concept of a “part per billion” is to consider it in the context of a few examples.  A part per billion is also:
    • 1 penny in 10 million dollars
    • 1 second in 32 years
    • 1 foot of a trip to the moon
    • 1 blade of grass on a football field
    • 1 drop of water in an Olympic-size swimming pool

The LCWSC is fully committed to protecting public health and ensuring your water meets or surpasses all state and federal health standards for tap water.  If at any time our water fails to meet federal or state drinking water standards, we will notify our customers and take all necessary actions to correct the problem immediately. If you have further concerns or questions do not hesitate to call our office 864-682-3250.