EGLENote that this layer contains the same information as Michigan Public Water Supply Sampling Hexbins and Results (Consolidated) . They are distinct in structure only (the data is essentially the same; note a small distinction in the Terms of Use). This is a single flattened file, while the other is a hexbin layer with a related table containing results. The time series data shows the Public Drinking Water Supply PFAS sample results hexbin data from August 2020 to January 2026 (last updated). The data was agregated into 3 mile hexagons (hexbins) to show the distribution of public water supply PFAS sample locations across the State of Michigan. There is a hexbin for each public water supply PFAS sample. So, there will be multiple hexbins for the same public water supply with more than one PFAS drinking water sample taken. 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 sampling results 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 ObjectID Unique identification number generated by the ESRI software 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. 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. 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 DynamicMapLayerhttps://hub.arcgis.com/datasets/6e9212ad9bac41a99b7e7f855d072f17_2engState of Michigan Open Data PortalPublicMichigan Public Water Supply Sampling Hexbins and Results update [Michigan]Web servicesMichiganLast Modified: 2026-02-10