03/09/2026
Interns, Adama and Kathryn, conducted water samples in Mill River in Hamden, by testing for indicator bacteria like E. coli. While E. coli does occur naturally in our rivers, high levels show there is a likely pollution source. Potential sources of E. coli include non-working septic systems, leaking sewage pipes, areas with large amounts of geese, or illegal dumping.
They also measured water temperature, dissolved oxygen, and conductivity using a YSI meter. Temperature and dissolved oxygen demonstrate the overall health of a river because fish and other organisms need certain temperatures and levels of oxygen dissolved in the water in order to survive. Conductivity shows the amount of dissolved ions in the water, such as salt, minerals and impurities.
While the meter doesn’t identify what ions are present, it monitors fluctuations of conductivity in the river over the long term and seasonal changes. For example, if conductivity only spikes in spring during snowmelt, you can reasonably assume that the ion might be salt from the roads.
This meter can be used quickly to detect potential pollution sources. For example, if you’re in a river and see several pipes feeding water into the river, you can measure the water from each pipe to see if the conductivity is high. If so, there may be some form of pollution coming from the pipe.
We teach students from various high schools how to process water samples in our lab. Sharing this science with our youth and our community is how we empower each other to stay informed about our environment! 🌊🐟
