The locations that have been sampled in this effort include Community Water Supplies (including regional and municipal water supplies, manufactured housing communities, residential apartment buildings, etc.), Nontransient Noncommunity Water Supplies (including schools, businesses, childcare providers, Michigan Head Start locations, etc.), and Transient Noncommunity Water Supplies (children’s camps, medical care providers, adult foster care, motels, and resorts).

Results are provided in parts per trillion. A part per trillion (ppt) is the equivalent of 1 drop of water in 20 Olympic-size swimming pools.

Definitions of the information provided in the sampling results table:

• SystemName: Water supply system name

• WSSN: Water Supply Serial Number; unique identifier for each public water supply

• SampleDate: The date samples were taken at the water supply

• SysLocCode: Location code created by the EQuIS database, used by AECOM

• The SystemType column lists the type of public water supply;

  • CWS: Community Water Supply (Type I)

  • NCWS: Noncommunity Water Supply (Type II)

    • Non-transient: Non-transient noncommunity water supplies (Type II) are monitored for compliance under Michigan's Safe Drinking Water Act.

  • ADFSTC: Non-Community Water Supply (Adult Foster Care Provider)

  • CHLCMP: Non-Community Water Supply (Children's Camp)

  • DAYCARE: Non-Community Water Supply (Child Care Provider)

  • INDUS: Non-Community Water Supply (Industry)

  • MEDCAR: Non-Community Water Supply (Medical Care Provider)

  • MOTEL: Non-Community Water Supply (Hotel or Motel)

  • MUN: Community Water Supply (for example Municipal Supply, Apartment, Nursing Home, Prison, etc.)

• PFAS analytes are listed in individual columns (ppt). These include the 14 PFAS compounds tested under EPA method 537 and the 18 compounds tested under EPA method 537.1. If the result listed is "ND" the lab did not detect, or find, that PFAS was in the water sample above the method reporting limit.

  • HFPO-DA (Hexafluoropropylene oxide-dimer acid, also referred to as "GenX") as of 8/3/2020 is a regulated analyte in Michigan with an MCL = 370 ppt

  • PFBS (Perfluorobutane sulfonic acid) as of 8/3/2020 is a regulated analyte in Michigan with an MCL = 420 ppt

  • PFHxA (perfluorohexanoic acid) as of 8/3/2020 is a regulated analyte in Michigan with an MCL = 400,000 ppt

  • PFHxS (perfluorohexane sulfonic acid) as of 8/3/2020 is a regulated analyte in Michigan with an MCL = 51 ppt

  • PFNA (perfluorononanoic acid) as of 8/3/2020 is a regulated analyte in Michigan with an MCL = 6 ppt

  • PFOA (perfluorooctanoic acid) as of 8/3/2020 is a regulated analyte in Michigan with an MCL = 8 ppt

  • PFOS (perfluorooctane sulfonic acid) as of 8/3/2020 is a regulated analyte in Michigan with an MCL = 16 ppt

  • 11Cl-PF3OUdS (11-chloroeicosafluoro-3-oxaundecane-1-sulfonic Acid) is currently a non-regulated analyte in Michigan

  • 9Cl-PF3ONS (9-chlorohexadecafluoro-3-oxanone-1-sulfonic acid) is currently a non-regulated analyte in Michigan

  • ADONA (4,8-dioxa-3H-perfluorononanoic acid) is currently a non-regulated analyte in Michigan

  • FOSA (Perfluorooctanesulfonamide acid) is currently a non-regulated analyte in Michigan

  • 4:2FTS (4:2 Fluorotelomer acid) is currently a non-regulated analyte in Michigan

  • 6:2FTS (6:2 Fluorotelomer acid) is currently a non-regulated analyte in Michigan

  • 8:2FTS (8:2 Fluorotelomer acid) is currently a non-regulated analyte in Michigan

  • NEtFOSAA (2-(N-ethylperfluorooctanesulfonamido) acetic acid) is currently a non-regulated analyte in Michigan

  • NMeFOSAA (2-(N-methylperfluorooctanesulfonamido) acetic acid) is currently a non-regulated analyte in Michigan

  • PFBA (Perfluorobutanoic acid) is currently a non-regulated analyte in Michigan

  • PFDA (perfluorodecanoic acid) is currently a non-regulated analyte in Michigan

  • PFDoA (perfluorododecanoic acid) is currently a non-regulated analyte in Michigan

  • PFDS (Perfluorodecanesulfonic acid) is currently a non-regulated analyte in Michigan

  • PFHpA (perfluoroheptanoic acid) is currently a non-regulated analyte in Michigan

  • PFHpS (Perfluoroheptanesulfonic acid) is currently a non-regulated analyte in Michigan

  • PFNS (Perfluorononanesulfonic acid) is currently a non-regulated analyte in Michigan

  • PFPeA (Perfluoropentanoic acid) is currently a non-regulated analyte in Michigan

  • PFPeS (Perfluoropentanesulfonic acid) is currently a non-regulated analyte in Michigan

  • PFTeDA (perfluorotetradecanoic acid) is currently a non-regulated analyte in Michigan

  • PFTrDA (perfluorotridecanoic acid) is currently a non-regulated analyte in Michigan

  • PFUnA (perfluoroundecanoic acid) is currently a non-regulated analyte in Michigan

• SysSampleCode: The identification number that corresponds to the sample taken.

• LabName: Laboratory providing PFAS analysis via EPA method 537 or 537.1.

• LocName: Specific sample location, when applicable.

• LabNumber: The certified lab code number. Note: LabName indicated values may vary for the same lab (issue with data coming from two different databases). LabNumber will help clarify these cases.

• PhaseCode: Sampling phase code

• TaskCode: Sampling task code

• Labsdg: Lab work order code

• AnalyticMethod: EPA analytical method used

• na: not applicable

• TreatmentStatus: MP = The midpoint of the influent and effluent points, Raw = The water was not treated for any analytes or compounds, Treated = The water was treated, but not necessarily for PFAS.

The data represents the PFAS sample sites, with each site having multiple samples taken, dates for each sample, and the analytical results for each sample. These analytical results include detections for 14 – 28 PFAS analytes, depending on the analytical method used. Each result has a "flags" column that corresponds to important data qualifiers.

Understanding the flags: Contaminant data often include flags, also known as qualifiers, which are notes attached to data that gives detailed information about that particular result. In the drinking water PFAS data layer, PFAS analytes associated with a “U” flag were not detected in the sample and therefore a null value is displayed. “J” flagged results indicates an estimated concentration as the result is above the minimum detection limit (MDL) but below the laboratory reporting limit. “J-“ flagged results indicates an estimated concentration as the result is above the minimum MDL, below the laboratory reporting limit, but biased low. “UJ” flagged results indicates a not detected at the value estimated reporting limit. “R” flagged results indicates a rejected sample as serious quality control issues render the result value bot usable. “*” flagged results indicates that the result values have not been verified.

Questions regarding the drinking water sampling PFAS data can be directed to EGLE-PFAS-DrinkingWater@michigan.gov.