Pharmaceuticals Found in Chicago Waterways Originating From Treated Wastewater

While it was originally hypothesized that drugs and contaminants that were not fully removed from treated wastewater would degrade in the water over time and disperse throughout the larger bodies of water, it has been discovered that this is not accurate. While the concentration of drugs present in the treated wastewater likely greatly decrease due to the large volume of water they are being introduced into, it does not seem that they degrade over time. Conducted studies have shown that not only can these drugs remain for many years in the water and sediment, but can be found in the aquatic life. A study was conducted regarding a city that drains treated wastewater into Lake Michigan. This study found that the drugs could be found in detectable levels up to two miles away from the chosen effluent site. With the possibility that many cities are draining their contaminated wastewater into the lake in hopes of further cleaning and disposing of the water, there could be many drugs present. One of the largest cities in the country lies along the shore of Lake Michigan that has yet to be studied regarding their possible contribution to the solution of the lake with drugs. This is the city of Chicago in the state of Illinois. Chicago, in efforts to reduce pollution of the lake, reversed the flow of the Chicago River to direct the river water away from the lake. So while Chicago does not directly drain into Lake Michigan, contaminants from nearby cities could have dispersed all the way to the Chicago shores. To prevent possible contamination of the lake from the wastewater, Chicago drains effluent wastewater into nearby rivers. Samples from the Chicago River, DesPlaines River, and Lake Michigan were collected near wastewater treatment plants. Samples were collected every half of a mile up to two miles away from the treatment plant. Three samples were collected at each sampling location. Each sample was then analyzed using LC-QQQ for drugs. Both drug screenings and THC quantitation screenings were performed on the samples collected. While there was little THC found, which indicates that the treatment methods currently utilized effectively remove the cannabinoid metabolite, other drugs were confirmatively identified. Many of the drugs detected were commonly prescribed drugs including anti-depressants and mood stabilizers.bThis indicates that many people are taking these drugs within the area. This leads to a high quantity of the drug being present in the wastewater, which makes it more difficult to fully remove. Other drugs taken as illicit, recreational drugs were also found within the some of the samples. These results indicate that while some of the drugs are being removed, drugs can remain in large enough amounts to be detectable.