Michigan Dept. of Environment, Great Lakes, and EnergyNote that this layer contains the same information as Michigan Public Water Supply Sampling Hexbins and Results . They are distinct in structure only (the data is essentially the same). This is a hexbin layer with a related table containing results, while the other is a single flattened file. The data includes information on State of Michigan drinking water Per- and Polyfluoroalkyl Substances (PFAS) compliance sampling, including, but not limited to, sample location, sample date, sample results, etc. The hexbins layer (hexagons are 3 miles in height) show the general location of all samples with the sample results. This data is static and was last pulled 1/12/2026. The units for all drinking water PFAS results are measured in PPT (parts per trillion), equivalent to ng/l. Hexbin data (PFAS test results) for public water supplies come from the PFAS MCL monitoring results for compliance under Michigan's Safe Drinking Water Act (2020 - present). 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.), and Nontransient Noncommunity Water Supplies (including schools, businesses, childcare providers, Michigan Head Start locations, etc.) Definitions of the information provided in the hexbin polygon layer: Field Description HexID Unique ID for each hexbin polygon Shape_Area Esri create field for the area in square meters Shape_Length Esri created field for the length of the perimeter in meters Definitions of the information provided in the sampling results related table: Please note that the PFAS analytes are listed in individual columns (ppt). These include the 7 regulated PFAS compounds tested under EPA method 537.1. If the results listed is "ND", the lab did not detect, or find, that PFAS was in the water sample above the method reporting limit. Field Description HexID Unique ID associated with the specific sampling results hexbin System Name Water supply system name WSSN Water Supply Serial Number; unique identifier for each public water supply Sample Date The date samples were taken at the water supply HFPO-DA (Hexafluoropropylene oxide-dimer acid, also referred to as "GenX"); a regulated analyte in Michigan with an MCL = 370 ppt PFBS (Perfluorobutane sulfonic acid); a regulated analyte in Michigan with an MCL = 420 ppt PFHxA (perfluorohexanoic acid); a regulated analyte in Michigan with an MCL = 400,000 ppt PFHxS (perfluorohexane sulfonic acid); a regulated analyte in Michigan with an MCL = 51 ppt PFNA (perfluorononanoic acid); a regulated analyte in Michigan with an MCL = 6 ppt PFOA (perfluorooctanoic acid); a regulated analyte in Michigan with an MCL = 8 ppt PFOS (perfluorooctane sulfonic acid); a regulated analyte in Michigan with an MCL = 16 ppt Sys Sample Code The identification number that corresponds to the sample taken Lab Name Laboratory providing PFAS analysis via EPA menthod 537.1 Location Name Specific sample location, when applicable Lab Number 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. <2: Analyte was not detected above the minimum reporting limit (2 ppt). The data represents the PFAS sample locations, with each location having multiple samples taken, dates for each sample, and the analytical results for each sample. These analytical results include detections for 7 PFAS compounds. 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. This contains one hexbins layer (3 miles in height) showing the general location of the water sampling. The hexbins were created by EGLE using ArcGIS Online"s Aggregate Points tool . The layer contains one field called "HexID" that connects the general location with the results of samples found within the hexbin area. There is no precise location attached to the results for security. This data is used in the MPART: PFAS Geographic Information System ( item details ). For more information about Michigan"s PFAS response, please visit our State of Michigan PFAS Response website . Call 800-662-9278 for assistance with reading or interpreting this data. Questions regarding the drinking water sampling PFAS data can be directed to EGLE-PFAS-DrinkingWater@michigan.gov . To submit feedback on the data, please reach out to EGLE-Maps@Michigan.gov .ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/90d36aa2964b41f1903d04c61d1de91a_0engState of Michigan Open Data PortalPublicPublicWaterSupplySamplingHexbins [Michigan]Web servicesMichiganLast Modified: 2026-02-10