What We've Found So Far

Frequency graph
Frequency graph: how often each chemical was found

This graph shows the chemicals that we found most often in our samples, color-coded by type of chemical. The bigger the bar for a chemical, the more often we found it.

  • Blue: recreational drugs. Caffeine (like from coffee and tea) was expected, but other drugs such as cocaine and nicotine were surprising.
  • Dark green: even more surprising was how often we found the psychotropic medication carbamazepine (Tegretol), which is used to treat seizure disorders, schizophrenia, and bipolar disorder.
  • Orange: the most commonly found antibiotic was sulfamethoxazole, an antibiotic commonly used for skin infections, among other things.


Concentration graph
Concentration graph: how much of each chemical was found

This graph shows the concentrations of the chemicals we found in our water samples on a logarithmic scale, color-coded by type of chemical. These concentrations are small, but for some chemicals even that is enough to cause changes in the environment.

The compounds with the highest concentrations were caffeine (from coffee and tea), triclosan (an antibacterial used in soaps), cocaine (a recreational drug), ciprofloxacin (an antibiotic), and sarafloxacin (another antibiotic)


 For more nitty-gritty details on the chemicals we've found, click here.


CLEAR volunteers collect samples all around Milwaukee. Click "Map" below to explore how much of each chemical volunteers have found at each site. Or stay put and download the data to discover your own correlations.

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