Germantown water comes from a ground water source aquafer distributed and pumped by wells though miles of buried underground pipes. Please see the link for a description of Aquifer water sources.
https://wgnhs.wisc.edu/water-environment/wisconsin-aquifers/
https://wi.water.usgs.gov/glpf/images/hydrogeologic_framework_2.jpg
The water quality is largely affected by the contact the water has with its surroundings from the underground aquifers through the pumping and distribution process and your interior plumbing. Please see the link for a list of our testing requirements in the annual Consumer report.
https://www.village.germantown.wi.us/271/Water-Quality-Reports