As part of the Unregulated Contaminate Monitoring Rule, we tested for PFAS-related compounds on four occasions in 2014, 2015, and 2017, and the results were non-detect. In 2018, and with improved test methods, our test results mirrored testing conducted by the state.
In April of 2019, the State of Michigan began a statewide sampling program and sampled all the surface water systems in the state for six consecutive months. Our test results showed that our tap water concentration of PFOS and PFOA are well below the USEPA lifetime health advisory of 70 part per trillion (ppt) established by the U.S. Environmental Protection Agency and the Department of Environment, Great Lakes, and Energy (EGLE) as well as regulatory limits being discussed. See table below for our PFAS testing results.
What are the differences in results between the EPA Method 537 & Isotope Dilution Method?
PFAS testing is in its infancy, and we are limited in what the laboratory equipment is able to detect. As testing methods continue to be developed, the reporting limits of these tests have improved. In previous testing using the EPA Method 537, the detection limits were in the 20 ppt to 30 ppt range. Detection limits are now as low as 2 ppt. As laboratories improve methods to better detect these compounds, we will continue to monitor our results and publish them.
Current and Proposed PFAS Regulation in Drinking Water
Currently, there is no regulatory drinking water standard for PFAS chemicals. In May 2016, the USEPA established a non-regulatory lifetime health advisory (LHA) for two of these chemicals; PFOS and PFOA. The LHA for PFOS and PFOA is 70 ppt combined, or individually if only one of the chemical is present. The State of Michigan has adopted the 70 ppt combined limit as well. There are other states and regulatory institutions that are recommending lower limits. We welcome this proactive approach sharing commitment to our community’s health. The State of Michigan is currently working on new lower limits. Below are the current and proposed regulations.
|
Current State Regulations |
Agency for Toxic Substances Disease Registry Report (proposed) |
PFOS (Perfluorooctane sulfonic acid)
|
70 ppt |
7 ppt |
PFNA (Perfluorononanoic acid)
|
N/A |
10.5 ppt |
PFOA (Perfluorooctanoic acid)
|
70 ppt |
11 ppt |
PFHxS (Perfluorohexane sulfonic acid) |
N/A |
70 ppt |
1 parts per trillion (ppt) is equal to 1 drop of water in 18 million gallons of water
We recently sampled the City water system’s Lake Michigan source water and tap water to parallel similar testing the Michigan Department of Environment, Great Lakes, and Energy (EGLE) is conducting across the state. Our test results showed that our tap water concentration of PFOS and PFOA are well below the USEPA lifetime health advisory of 70 part per trillion (ppt) established by the U.S. Environmental Protection Agency and EGLE as well as regulatory limits being discussed. See table below of our PFAS testing results.
Our test results showed what was expected: PFAS-related compounds have been in use around Lake Michigan for decades and a very small amount is present. We expect PFAS levels to remain relatively consistent since Lake Michigan is a stable source of water. We will continue to aggressively sample and test our water in accordance with state regulatory requirements and release our results. We also will continue to use the best available methods and technology in our water testing.
Sampling Date |
Raw Water or Treated Drinking Water? |
Method |
PFOS |
PFOA |
6:2 Fluorotelomer Sulfonates |
Compounds Tested |
April 2018 |
Treated Drinking Water |
EPA 537 |
ND |
2 |
NA |
14 compounds |
|
Raw Water |
Isotope Dilution |
ND |
2 |
ND |
24 compounds |
|
Treated Drinking Water |
Isotope Dilution |
ND |
ND |
3 |
24 compounds |
June 2018 |
Treated Drinking Water |
EPA 537 |
ND |
ND |
NA |
14 compounds |
|
Raw Water |
Isotope Dilution |
1.40 ppt |
1.09 ppt |
ND |
24 compounds |
|
Treated Drinking Water |
Isotope Dilution |
1.81 ppt |
1.38 ppt |
1.55 ppt |
24 compounds |
April 2019 |
Treated Drinking Water |
EPA 537 |
ND |
ND |
NA |
14 compounds |
|
Raw Water |
Isotope Dilution |
ND |
ND |
4 ppt |
24 compounds |
|
Treated Drinking Water |
Isotope Dilution |
ND |
ND |
6 ppt |
24 compounds |
May 2019 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
ND |
ND |
ND |
14 compounds |
June 2019 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
ND |
ND |
NA |
14 compounds |
July 209 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
ND |
ND |
NA |
14 compounds |
August 2019 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
2 ppt |
ND |
ND |
14 compounds |
September 2019 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
ND |
ND |
N/A |
14 compounds |
December 2019 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
2 ppt |
ND |
N/A |
14 compounds |
January 2020 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
ND |
ND |
N/A |
14 compounds |
February 2020 |
Raw Water |
Isotope Dilution |
ND |
2.6 ppt |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
2.14 ppt |
ND |
N/A |
14 compounds |
March 2020 |
Raw Water |
Isotope Dilution |
ND |
2.56 ppt |
2.28 ppt |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
2.41 |
ND |
N/A |
14 compounds |
April 2020 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
2.17 |
ND |
N/A |
14 compounds |
May 2020 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
NA |
ND |
N/A |
14 compounds |
June 2020 |
Raw Water |
Isotope Dilution |
ND |
2.34 |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
2.23 |
ND |
N/A |
14 compounds |
July 2020 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
2.37 |
ND |
N/A |
14 compounds |
August 2020 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
2.19 |
ND |
N/A |
14 compounds |
November 2020 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
ND |
ND |
N/A |
14 compounds |
March 2021 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
ND |
ND |
N/A |
14 compounds |
July 2021 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
ND |
ND |
N/A |
14 compounds |
September 2021 |
Raw Water |
Isotope Dilution |
ND |
ND |
ND |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
ND |
ND |
N/A |
14 compounds |
November 2021 |
Raw Water |
Isotope Dilution |
ND |
ND |
N/A |
24 compounds |
|
Treated Drinking Water |
EPA 537 |
ND |
ND |
N/A |
14 compounds |
Note: ND= Not-Detected NA=Not Applicable, compound is not analyzed in the EPA 537 method.
One ppt is equal to 1 drop of water in 18 million gallons of water. The reporting limit for EGLE testing is 2ppt. This provides explanation as to why we have inconsistent detectable vs. non-detectable values in each test. All other results are non-detected unless noted.
If you have any questions about our results, testing or anything related to your water, please contact 311 or (616) 456-3000.
For more on PFAS compounds, tests and other information, visit the State of Michigan’s PFAS Response Team.