As reported previously in Pumper, an ongoing study is being conducted in southwestern Wisconsin to test private wells for evidence of contamination. The Southwest Wisconsin Groundwater and Geology study began in 2018 with two objectives: (1) Evaluate private well contamination using indicator bacteria (total coliform and E. coli) and nitrate based on randomized synoptic sampling events, and (2) identify the source of contamination in a subset of total coliform- and nitrate-positive wells once per season using microbial tests that distinguish between human, bovine and swine fecal sources.Two phases of the study have been completed, and the results are concerning. During
