Among other things, the scientific group that I worked in developed safety standards for chemicals in drinking water. We reviewed, assessed and discussed the toxicological information for a chemical in the scientific literature and then put that information into a mathematical model to determine how much of a chemical would be allowable in the water. For example, for a carcinogen (a cancer-causing chemical), we would use the model to determine how much of it a person could consume over the course of drinking two liters of water for 70 years and not get cancer. There is a lot of “art” in this science and lots of uncertainties…..but the predominant convention at the time when I was in the group was precautionary. When in doubt, err on the side of caution.
And once you know how much is “safe,” you need to know how much is there. For new chemicals (those for which we were just developing safety limits and were not regulated), we had to sample public drinking water systems ourselves, because water systems are not required to test for chemicals that are not regulated. For example, arsenic is regulated but perchlorate is not. So, my colleague (I’ll call him Tox) and I would travel around the state collecting water samples to analyze for both regulated and unregulated chemicals.
Most of the time, water systems were cooperative when we made a surprise visit to sample the water. Other times, they preferred that we go away. In fact, one time, in a northern New Jersey township that will remain unnamed, we were greeted by an attack dog. Thing is, we didn’t know about the dog until AFTER we had entered the facility and the gates were locked behind us. There we were, with our sampling equipment and coolers filled with glass bottles to fill. At the gate, someone from inside the building buzzed us into the facility, but that someone was no where to be seen. Instead, we were greeted by sharp teeth and growls.
Want to hear more? Check it out in my novel, Diamond on a Lizard’s Tail.