Door County Private Well Monitoring Program

Past Testing Results

The common contaminants that are tested for in the study have been bacteria in the form of Total Coliform and E. coli and Nitrate. The following table summarizes the results from 2019 and 2020. The numbers displayed show the percentage of Door County wells indicating various levels of contaminants compared to Wisconsin averages.

Water Quality Standard (Level Detected)
2020 (295 wells)
2019 (148 wells)
Wisconsin Average
Total Coliform (>0 MPN/100 ml)14%
E.coli (>0 MPN/100 ml)<1%0%5%
Nitrate (>10 mg/L)<1%2%10%
Nitrate (5-10 mg/L)
Nitrate (2-5 mg/L)
Arsenic (>10 mg/L)

Join the 2021 Study

If you are a private well owner, please consider participating to learn more about the drinking water that you rely on, as well as to help contribute to our knowledge of the resource. This great opportunity is open to all Door County well owners, so please share the details with friends and family.

 Funding provided by Door and a donation from the Door County Medical Center will allow for a discounted rate for the first 250 registrants. Base tests will include analysis for bacteria and nitrate. Optional arsenic and cumulative testing that includes pH, hardness, alkalinity and iron will be available for those that would like to add it.

Participants can follow the easy steps laid out below:

1.  RSVP using the link or QR code by September 10th, 2021:

  • Total Coliform/E.coli/Nitrate for $30*
  • Optional: Arsenic & cumulative tests for an additional $25

*A discounted cost of $30 is available to the first 250 registrants.  Cost will be $45 for those registering after the first 250 registrants.

2.  Attend a virtual forum to learn how to sample, receive sampling kit in mail

3.  Collect well water sample on October 8th or 9th and submit it to a designated drop-off location:

  • North Highway Department Shop, 10363 Highway 57, Sister Bay
  • ADRC of Door County, 916 N 14th Avenue, Sturgeon Bay
  • South Highway Department Shop, 1729 County RD DK, Brussels
  • Washington Island - Please contact WICHP at 920-847-2108 or to make drop off arrangements

 4.  Receive results & countywide summary of the study