Illinois EPA Releases Final Report on Pharmaceuticals in Drinking Water Supplies

Aug. 13, 2008
Results found no immediate public health risk, only trace levels of prescription drugs and common chemicals

The Illinois Environmental Protection Agency (EPA) has completed its report summarizing the findings of unregulated pharmaceuticals and personal care products in Illinois drinking water supplies from samples taken in Chicago and four water supplies that rely on river water as their source. The report indicates that Illinois’ drinking water continues to be safe, and the Illinois EPA sees no cause for immediate concern; however, low levels of several pharmaceuticals were found in Illinois drinking water.

While there are no federal standards established for pharmaceuticals, the Illinois EPA tested drinking water as a proactive step to assess the scope of the presence of pharmaceuticals in waterways to ensure that drinking water supplies are adequately protected. Illinois EPA screened for 56 chemicals typically found in drugs and personal care products that may be released from water treatment plants into lake and river water. Illinois EPA detected low concentrations of 16 of these chemicals.

“I am pleased that the report found that concentrations of chemicals measured in drinking water supplies do not pose a threat to human health,” said Illinois EPA Director Doug Scott. “We believe that the consumers deserve as much information about their drinking water as we can provide to them. That’s why we’ll continue to monitor the safety of drinking water supplies and educate the public about how to keep pharmaceuticals and personal care products out of our water supplies.”

In March of this year, the Illinois EPA collected samples from both untreated “source” water and from the treated drinking water from public water supplies in Chicago, Aurora, Elgin, East St. Louis and Rock Island. In addition, the city of Springfield collected its own samples and provided the data to Illinois EPA; these data can be seen at

In order to assess the safety of the very low levels of the chemicals found in the treated drinking water, Illinois EPA toxicologists consulted with the Illinois Department of Public Health (IDPH) to determine what chemical concentrations will adequately protect public health. Illinois EPA and IDPH used the best available international risk assessment standards and then adjusted them to a level 3.5 times more stringent to ensure even greater public health protection. These protective thresholds were then compared to the chemical concentrations found in collected samples to determine if any of the chemicals pose a public health risk.

Cotinine, a byproduct of nicotine, was the chemical found closest to its threshold of concern, but still 333 times below the threshold of concern for human health.

While all samples revealed low chemical concentrations far below levels that could likely pose a public health risk, chemical concentration in samples of lake water were lower than samples of river water. Because river samples were collected during high-flow conditions, which could potentially dilute the concentrations, the report recommended additional sampling under low-flow conditions. The report suggested that additional chemicals may need to be tested beyond the 56 for which Illinois EPA screened in this study.

As a follow-up step, the Illinois EPA will continue to do additional sampling, to provide an even better understanding of potential risks from pharmaceuticals in water. The Agency will continue to assess the results, and do more sampling and testing as necessary. As with the initial sampling results, future analysis will add to the growing base of information currently available, and further reduce the uncertainty about the presence of pharmaceuticals in water.

Source: Illinois EPA