Because aquifers supply drinking water, every well must be constructed, maintained, and tested to ensure that it is safe and will not contaminate the aquifer. The water from each well must also meet certain drinking water standards contained in NR 809 and enforcement standards contained in NR 140. Every well connected to an aquifer has the potential to contaminate the water within the aquifer.
Visit the DNR website below for more information on Drinking Water:
http://dnr.wi.gov/topic/DrinkingWater/