A National Predictive Model for PFAS Occurrence in Groundwater
In October of 2024, USGS Scientist’s published a study where they created a model to predict PFAS occurrence in groundwater at the depths of drinking water supplies. This model can help guide our partners to sample areas where PFAS in drinking water could be an issue for the public.
Per- and polyfluoroalkyl substances (PFAS) are a group of more than 14,000 manmade compounds found in many products, the environment, and the food supply. Domestic (private) well owners, in particular, may not know if PFAS is in their drinking water supply due to a lack of systematic testing. Due to their long-term and widespread use, these compounds have been associated with adverse human health effects and have contaminated drinking water supplies across the United States.
In FY24, USGS scientists created a model to predict the occurrence of PFAS in groundwater. Samples were collected between 2019 and 2022 and individually analyzed for 24 known PFAS compounds. This model indicated that 71 – 95 million people (roughly 25% of the current population of the United States) could have PFAS in their drinking water supply. The three types of well networks included in the model were 1) public supply networks spanning principal aquifers, 2) observation networks targeting urban and agricultural land uses, and 3) domestic supply well networks in principal aquifers.
Additional findings include:
- At least one PFAS out of the 24 individual PFAS compounds analyzed was detected in 37% of the groundwater samples analyzed for the model training set.
- Urban land use and well depth were the two most important model variables for predicting PFAS occurrence.
- Model results indicate the widespread occurrence of PFAS in groundwater at depths of public and domestic drinking water supplies.
- This information can be used by states, resource managers, and domestic well owners to guide sampling toward areas where exposure to PFAS could be an issue.
- The model and the results are available to the public, allowing individuals to look at results in their region. Results can be found in the data release and an interactive dashboard that allows for easy public viewing.
Since its publication, this paper has been in the top 5% of all research outputs scored by Altmetric. Altmetric can measure a publication's attention from various sources, including blogs, X, Facebook, Reddit, Bluesky, and Dimensions citations. Here is the link to view the National News Release. To read about additional research related to this paper, please visit McMahon et al. 2022, and Smalling et al. 2023.
This work was supported by the USGS Ecosystems Mission Area through the Environmental Health Program (Contaminant Biology and Toxic Substances Hydrology), the USGS National Water Quality Program, and the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment Program agreement 20-013-250-1.
In October of 2024, USGS Scientist’s published a study where they created a model to predict PFAS occurrence in groundwater at the depths of drinking water supplies. This model can help guide our partners to sample areas where PFAS in drinking water could be an issue for the public.
Per- and polyfluoroalkyl substances (PFAS) are a group of more than 14,000 manmade compounds found in many products, the environment, and the food supply. Domestic (private) well owners, in particular, may not know if PFAS is in their drinking water supply due to a lack of systematic testing. Due to their long-term and widespread use, these compounds have been associated with adverse human health effects and have contaminated drinking water supplies across the United States.
In FY24, USGS scientists created a model to predict the occurrence of PFAS in groundwater. Samples were collected between 2019 and 2022 and individually analyzed for 24 known PFAS compounds. This model indicated that 71 – 95 million people (roughly 25% of the current population of the United States) could have PFAS in their drinking water supply. The three types of well networks included in the model were 1) public supply networks spanning principal aquifers, 2) observation networks targeting urban and agricultural land uses, and 3) domestic supply well networks in principal aquifers.
Additional findings include:
- At least one PFAS out of the 24 individual PFAS compounds analyzed was detected in 37% of the groundwater samples analyzed for the model training set.
- Urban land use and well depth were the two most important model variables for predicting PFAS occurrence.
- Model results indicate the widespread occurrence of PFAS in groundwater at depths of public and domestic drinking water supplies.
- This information can be used by states, resource managers, and domestic well owners to guide sampling toward areas where exposure to PFAS could be an issue.
- The model and the results are available to the public, allowing individuals to look at results in their region. Results can be found in the data release and an interactive dashboard that allows for easy public viewing.
Since its publication, this paper has been in the top 5% of all research outputs scored by Altmetric. Altmetric can measure a publication's attention from various sources, including blogs, X, Facebook, Reddit, Bluesky, and Dimensions citations. Here is the link to view the National News Release. To read about additional research related to this paper, please visit McMahon et al. 2022, and Smalling et al. 2023.
This work was supported by the USGS Ecosystems Mission Area through the Environmental Health Program (Contaminant Biology and Toxic Substances Hydrology), the USGS National Water Quality Program, and the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment Program agreement 20-013-250-1.