PFAS in Michigan wastewater: the industrial sources behind each treatment plant
236 industrial users sampled at 49 treatment plants · 133 above 12 ng/L PFOS · 1,736 samples, 2023–2024
- Industrial users sampled
- 236
- Above 12 ng/L PFOS
- 133
- More than 10× the level
- 66
- Receiving treatment plants
- 49
What is the PFAS limit for wastewater in Michigan?
Michigan has no single PFAS limit for wastewater. EGLE applies its Rule 57 surface water quality values to what a treatment plant discharges: 12 ng/L (parts per trillion) for PFOS and 170 ng/L for PFOA, or 11 and 66 ng/L where the receiving water is a drinking-water source. A plant above them has to find and reduce its industrial sources.
Source: EGLE, Rule 57 water quality values and the IPP PFAS Initiative.
Since 2018 Michigan has required every municipal treatment plant with an industrial pretreatment programme, 95 statewide, to find the industrial users that send PFOS and PFOA into its sewer, sample the probable sources and make confirmed sources reduce their discharge. The plants report their sampling to EGLE, and those reports are the source of this page.
Klarifi has extracted 1,736 samples (7,231 measurements of 5 PFAS compounds) taken at 236 industrial users discharging to 49 treatment plants in Michigan, nearly all from 2023–2024. 133 of them had at least one sample with PFOS above 12 ng/L, 66 more than ten times above it. 16 have PFAS pretreatment on record.
How to read the numbers. 12 ng/L is Michigan’s surface water quality value for PFOS and the screening criterion of the initiative; 170 ng/L is the value for PFOA since July 2022. Both apply to what a treatment plant discharges to a river or lake, not to what a factory sends to the sewer. An industrial user above the level has not broken a limit: it is a source the receiving plant has to follow up with sampling, a reduction plan or pretreatment.
The 10 treatment plants with the most PFOS sources
34 of the 49 plants receive wastewater from at least one industrial user above 12 ng/L PFOS. For each of the 10 with the most: the industrial users on record in its pretreatment programme, how many have been sampled and how many were above the level. Plant names link to the list of industrial users behind the plant.
| # | Treatment plant | Flow (MGD) | Industrial users | Sampled | Above 12 ng/L | Highest PFOS | Latest sample |
|---|---|---|---|---|---|---|---|
| 1 | GLWA Water Resource Recovery Facility · Detroit | 426.09 | 229 | 55 | 35 | 2,000 ng/L | Nov 2024 |
| 2 | City Of Grand Rapids Wastewater Treatment Plant · Grand Rapids | 42.36 | 87 | 12 | 11 | 46,000 ng/L | Aug 2024 |
| 3 | City Of Wyoming Clean Water Plant · Grandville | 16.35 | 35 | 13 | 9 | 1,100 ng/L | Dec 2024 |
| 4 | Anthony Ragnone Wastewater Treatment Plant · Montrose | 32.03 | 15 | 10 | 9 | 650 ng/L | May 2024 |
| 5 | Wyandotte Wastewater Plant · Wyandotte | 34.4 | 46 | 10 | 7 | 4,420 ng/L | Jun 2024 |
| 6 | Kalamazoo Water Reclamation Plant · Kalamazoo | 27.1 | 35 | 18 | 7 | 400 ng/L | Jun 2024 |
| 7 | Warren Waste Water Treatment Plant · Warren | 16.5 | 14 | 6 | 6 | 11,000 ng/L | Nov 2023 |
| 8 | Clinton River WRRF · Pontiac | 13.91 | 15 | 5 | 5 | 1,450 ng/L | Dec 2023 |
| 9 | Traverse City WWTP · Traverse City | 4.63 | 15 | 10 | 5 | 290 ng/L | May 2024 |
| 10 | South Huron Valley Utility Authority POTW · Rockwood | 8.02 | 12 | 6 | 4 | 230 ng/L | Apr 2024 |
The 10 highest PFOS samples by industrial user
The highest PFOS concentration in any sample from each industrial user, with the latest sample next to it: several of the largest sources have since cut their discharge by installing pretreatment or cleaning out tanks and pipework.
| # | Industrial user | Industry | Discharges to | Highest PFOS | Latest PFOS | Samples |
|---|---|---|---|---|---|---|
| 1 | Lacks Industries Inc · Kentwood | Metal finishing and plating | City Of Grand Rapids Wastewater Treatment Plant | 46,000 ng/L3,833× · Feb 2023 | 13.3 ng/LFeb 2024 | 68 |
| 2 | Modern Hard Chrome Service Co · Warren | Metal finishing and plating | Warren Waste Water Treatment Plant | 11,000 ng/L917× · Jun 2023 | 440 ng/LNov 2023 | 5 |
| 3 | Daggett Recycling · Lansing | Landfills and waste management | Lansing WWTP | 7,330 ng/L611× · Jun 2024 | 7,330 ng/LJun 2024 | 3 |
| 4 | Algoma Products · Grand Rapids | Chemicals, plastics and petroleum | City Of Grand Rapids Wastewater Treatment Plant | 4,450 ng/L371× · Feb 2024 | 22 ng/LJun 2024 | 6 |
| 5 | Riverview Land Preserve · Riverview | Landfills and waste management | Wyandotte Wastewater Plant | 4,420 ng/L368× · Dec 2023 | 3,350 ng/LMay 2024 | 66 |
| 6 | Lapeer Plating & Plastics, Inc. · Lapeer | Metal finishing and plating | Lapeer WWTP | 4,300 ng/L358× · May 2023 | 4 ng/LDec 2024 | 78 |
| 7 | Sauk Trail Hills Development · Canton | Landfills and waste management | YCUA Regional Wastewater Treatment Plant | 3,000 ng/L250× · Aug 2023 | 2,400 ng/LMar 2024 | 6 |
| 8 | Auto Anodics · Port Huron | Metal finishing and plating | City Of Port Huron Wastewater Treatment Plant | 2,900 ng/L242× · Apr 2024 | 1,400 ng/LMay 2024 | 8 |
| 9 | Valicor · InksterPFAS pretreatment | Landfills and waste management | GLWA Water Resource Recovery Facility | 2,000 ng/L167× · Apr 2024 | 43 ng/LSep 2024 | 27 |
| 10 | Marquette Sawyer Regional Airport · Gwinn | Airports and military sites | Ki Sawyer WWTP-Marquette Co | 1,900 ng/L158× · Jan 2023 | 335 ng/LMay 2024 | 6 |
PFOS sources by industry
| Industry | Sampled | Above 12 ng/L | Highest PFOS |
|---|---|---|---|
| Landfills and waste management | 56 | 53 (95%) | 7,330 ng/L |
| Metal finishing and plating | 46 | 26 (57%) | 46,000 ng/L |
| Automotive, metal and equipment manufacturing | 33 | 16 (48%) | 451 ng/L |
| Chemicals, plastics and petroleum | 15 | 10 (67%) | 4,450 ng/L |
| Water, sewer and power utilities | 9 | 7 (78%) | 220 ng/L |
| Airports and military sites | 7 | 7 (100%) | 1,900 ng/L |
| Other industries | 32 | 6 (19%) | 1,800 ng/L |
| Contaminated sites and remediation | 6 | 3 (50%) | 1,890 ng/L |
| Laundries | 11 | 2 (18%) | 21 ng/L |
| Paper and packaging | 7 | 2 (29%) | 150 ng/L |
| Food and beverage | 6 | 1 (17%) | 22 ng/L |
| Hospitals and public institutions | 8 | 0 (0%) | 9.3 ng/L |
Sampling by compound
| Compound | Samples | Median | Highest | Above level |
|---|---|---|---|---|
| PFOSPerfluorooctanesulfonic acid | 1,627 | 12 ng/L | 46,000 ng/L | 768of 12 ng/L |
| PFOAPerfluorooctanoic Acid | 1,466 | 7.7 ng/L | 44,800 ng/L | 295of 170 ng/L |
| PFHxSPerfluorohexane Sulfonate | 1,370 | 5.5 ng/L | 3,300 ng/L | 207of 210 ng/L |
| PFNAPerfluorononanoic acid | 1,335 | 4 ng/L | 2,450 ng/L | 187of 30 ng/L |
| PFBSPerfluorobutane Sulfonate | 1,433 | 6.4 ng/L | 36,800 ng/L | 0of 670,000 ng/L |
Sampling by year
| Year | Industrial users sampled | Samples | Analysed for PFOS | PFOS above 12 ng/L |
|---|---|---|---|---|
| 2018 | 4 | 6 | 5 | 4 (80%) |
| 2019 | 2 | 4 | 4 | 4 (100%) |
| 2020 | 2 | 8 | 8 | 8 (100%) |
| 2021 | 2 | 8 | 8 | 8 (100%) |
| 2022 | 2 | 9 | 9 | 4 (44%) |
| 2023 | 149 | 978 | 904 | 423 (47%) |
| 2024 | 168 | 723 | 689 | 317 (46%) |
PFAS in Michigan wastewater: questions
What is the PFAS limit for wastewater in Michigan?
Michigan has no single PFAS limit for wastewater. EGLE applies its Rule 57 surface water quality values to what a treatment plant discharges: 12 ng/L (parts per trillion) for PFOS and 170 ng/L for PFOA, or 11 and 66 ng/L where the receiving water is a drinking-water source. A plant above them has to find and reduce its industrial sources.
How many industrial sources of PFAS have been found at Michigan wastewater treatment plants?
The sampling reported by 49 Michigan treatment plants covers 236 industrial users. 133 of them had at least one sample with PFOS above 12 ng/L, the state’s screening level, 66 were more than ten times above it and 15 more than a hundred times.
Which industries send the most PFOS to Michigan sewers?
Landfills and waste management: 53 of 56 sampled sites were above the screening level, followed by metal finishing and plating with 26 of 46. Landfill leachate carries PFOS from decades of consumer and industrial waste, and chrome platers used PFOS-based fume suppressants until they were banned in 2015; tanks and pipework still release it.
Which Michigan treatment plant receives wastewater from the most PFOS sources?
GLWA Water Resource Recovery Facility in Detroit: 35 of its 55 sampled industrial users were above the screening level, out of 229 industrial users on record.
Does a sample above 12 ng/L mean a company broke the law?
No. 12 ng/L is Michigan’s surface water quality value for PFOS and the screening criterion of the initiative; 170 ng/L is the value for PFOA since July 2022. Both apply to what a treatment plant discharges to a river or lake, not to what a factory sends to the sewer. An industrial user above the level has not broken a limit: it is a source the receiving plant has to follow up with sampling, a reduction plan or pretreatment.
Where does the data come from, and how reliable is it?
From the PFAS sampling spreadsheets that treatment plants file with EGLE, 1,736 samples taken between 2018 and 2024, which Klarifi extracts and links to the receiving plant. Values reported at the laboratory’s reporting limit (non-detects) are not counted as detections. The median PFOS concentration is 12 ng/L; the highest is 46,000 ng/L.
PFAS data: PFAS sampling reports that treatment plants file with EGLE under the IPP PFAS Initiative (MiEnviro Portal), extracted by Klarifi. Values are as reported by the receiving plant. A value shared by several compounds in one sample is read as the laboratory's reporting limit and not counted as a detection. Spotted an error? Tell us and we correct it.
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