On November 6, 2020, the Wisconsin Department of Health Services (DHS) recommended groundwater standards to the DNR for a number of different substances, including 16 additional types of PFAS compounds. (The agency had previously recommended standards for two types called PFOA and PFOS.)

All wells in Madison more than meet all of the DHS recommended groundwater standards for PFAS.

Below is a list of PFAS compounds, along with the recommended standard for each and the highest level of each substance found in Madison’s wells during 2020 testing. A list of levels found at Well 15 during 2019 testing is also included. Well 15 is not currently in service.

(Click here to view a map of Madison’s municipal well facilities.)

PFAS

WI DHS recommendation (ng/L or parts per trillion)

Maximum Level (2020)

Well with Max Level (2020)

Well 15 (2019)

PFOA

20*

1.8

Well 14

6.1

PFOS

20*

1.8

Well 16

5.9

FOSA

20*

4.4^

Well 31

ND

NEtFOSE

20*

1.5

Well 12

ND

NEtFOSA

20*

ND

--

ND

NEtFOSAA

20*

ND

--

ND

PFBA

10,000

37

Well 09

3.0

PFBS

450,000

1.7

Well 14

3.4

PFHxA

150,000

2.2

Well 14

6.2

PFHXS

40

5.0

Well 14

21

PFNA

30

ND

--

ND

PFDA

300

ND

--

ND

PFUnA

3000

ND

--

ND

PFDoA

500

0.56

Well 06

ND

PFTeA

10,000

0.52

Well 06

ND

PFODA

400,000

na

--

na

DONA

3000

ND

--

ND

GenX

300

ND

--

ND

 

* Recommended that combined level of six PFAS compounds (PFOA, PFOS, FOSA, NEtFOSE, NEtFOSA, & NEtFOSAA) be below 20 ng/L

^Present in laboratory method blank; may reflect cross-contamination at lab

ND = not detected

na = not analyzed