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 - 2022. The numbers displayed show the percentage of Door County wells indicating various levels of contaminants compared to Wisconsin averages.

Water Quality Standard 
(Level Detected)
Fall 2022
(196 wells)
Spring 2022 
(260 wells)
2021
(217 wells)
2020 
(295 wells)
2019 
(148 wells)
Wisconsin Average
Total Coliform (0 MPN/100 ml)92%90%
76%
86%
84%
17%
(>0 MPN/ 100 ml)
Total Coliform (1-10 MPN/100 ml)6%6%
14%
9%10%
Total Coliform (10-100 MPN/100 ml)2%3%
6%
3%4%
Total Coliform (>100 MPN/100 ml)1%1%
3%
1%1%
E.coli (0 MPN/100 ml)100%99%
98%
99%100%5%
(>0 MPN/ 100 ml)
E.coli (1-10 MPN/100 ml)0%<1%
1%
1%0%
E.coli (10-100 MPN/100 ml)0%0%
<1%
0%0%
E.coli (>100 MPN/100ml)0%0%
0%
0%0%
Nitrate (0 mg/L)74%80%
75%
72%71%10%
(>10 mg/L)
Nitrate (2-5 mg/L)18%16%
11%
16%
16%
Nitrate (5-10 mg/L)(>10 mg/L)7%4%
12%
12%
11%
Nitrate (>10 mg/L)1%0%
2%
<1%
2%
Arsenic (<2 µg/L)92%88%
89%
90%
99%
4%
(>10 µg/L)
Arsenic (2-5 µg/L)7%11%
9%
6%
1%
Arsenic (5-10 µg/L)1%1%
1%
3%
0%
Arsenic (>10 µg/L)0%0%
1%
<1%
0%


2022 Fall UW-Oshkosh Presentation of the Door County Well Monitoring Program (pdf)

2022 Fall UW-Oshkosh Recorded Presentation of the Door County Well Monitoring Program

2022 Spring UW-Oshkosh Presentation of the Door County Well Monitoring Program (pdf)


2021 UW-Oshkosh Presentation of the Door County Well Monitoring Program (pdf)
2021 UW-Oshkosh Recorded Presentation of the Door County Well Monitoring Program


2020 UW-Oshkosh Presentation of the Door County Well Monitoring Program (pdf)

2020 UW-Oshkosh Door County Well Monitoring Final Report (pdf)
2020 UW-Oshkosh Recorded Presentation of the Door County Well Monitoring Program


2019 UW-Oshkosh Presentation of the Door County Well Monitoring Program (pdf)


2023 Private Well Monitoring Program

Spring 2023 Door County Private Well Monitoring Program Results Form (pdf)

Curious about this year's results?

Please join us in person or virtually for the spring 2023 Door County Well Program Results Forum!  We will discuss findings of the ongoing well program.  No registration is required.

Join us on June 13th at 6:00 pm

This meeting will be located at Crossroads at Big Creek located at 2041 Michigan St. Sturgeon Bay, WI  54235.  For those unable to attend in person below is a link to join:

Spring 2023 Door County Well Monitoring Forum Zoom Webinar

Or open your camera on your smartphone to scan QR Code.  Note if joining via smartphone, you may need to have the Zoom app installed.

Spring Results Forum QR Code