Drugged by your tap water?

There is a 3-part series in this week’s Wisconsin State Journal concerning an Associated Press (AP) story on pharmaceuticals and other chemicals that are being found in drinking water supplies across the nation, Europe and Asia. These chemicals can be natural compounds such has human and animal estrogens or synthetic compounds, such as birth control estrogens as well as the full array of hundreds of chemicals contaminants.

Madison Water Utility is aware of this issue and continues to follow the research being conducted by the Environmental Protection Agency, AWWA Research Foundation, the U.S. Geological Survey, the Water Environmental Research Foundation, and other investigators concerning the occurrence and potential health impacts of these compounds. We are not aware of any findings that these trace compounds in drinking water have any impact on human health.

This is not a new issue: there have been studies in Europe and by the U.S. EPA over the last decade regarding the presence of these compounds in surface waters. We do expect that the AP articles will generate further discussion at the federal level regarding the presence of these compounds.

The Water Utility is committed to protecting public health, is paying close attention to the health effects research, and is awaiting guidance from the research and regulatory communities on what compounds to test for and standardized tests for those compounds.

The Utility does not currently test for any pharmaceutical or personal care product, but it does tests for over 130 potential contaminants that may be present in Madison drinking water including,

· 28 inorganic chemicals (iron, manganese, arsenic, lead, antimony, chloride, etc.);
· 41 volatile organic compounds (trichloroethylene, tetrachloroethylene, etc.);
· 40+ other synthetic organic compounds (pesticides and herbicides);
· 35 other contaminants including additional pesticides and their metabolites, flame retardants, disinfection byproducts, and radioactive contaminants; and

· microbial contaminants including bacteria (E. coli) and viruses.
Although the Utility pumps its water from deep wells, given the length of time that these natural and synthetic compounds have been in the environment, we would not be surprised to find them in the groundwater.

It is also worth noting that the compounds being detected are often measured at a level of a part per trillion or less. One part per trillion is equivalent to a single sand grain in an Olympic size swimming pool. People regularly consume or expose themselves to products containing these compounds in much higher concentrations through medicines, food, and beverages. As testing methods become more sophisticated, contaminants will increasingly be detected at smaller and smaller concentrations. Ongoing research will need to assess the potential impacts of these trace amounts of contaminants in drinking water.

Our science has advanced to the point that we can detect and measure these compounds at these very low levels. But, we do not have the technology to remove all of them from the drinking water or from surface waters.

Finally, the revelation that these compounds are omnipresent in the environment highlights the importance of source water protection, which is a shared responsibility for all in the community. Strategies include the proper abandonment of unused wells, which can serve as conduits for chemicals to contaminate groundwater, and med-drop events such as the very successful one hosted last fall by Public Health Madison and Dane County that will keep unused medicines out of landfills and the wastewater stream.

Although research has not shown human health impacts arising from exposure to pharmaceutical compounds in drinking water, the ongoing conversation should remind us of how valuable our drinking water is and additional steps that need to be taken to protect it from harmful substances.

Larry D. Nelson, P.E.
City Engineer
608.267.4227