National PFAS Soil Inventory
Where does PFAS actually sit in the soil — and how much? We harmonized measured soil concentrations from public agency reports across 41 states into one depth-resolved, source-anchored inventory — to our knowledge, the largest harmonized dataset of measured PFAS in U.S. soils. Free to browse, free to download.
The inventory at a glance
Free and open — browse it, download it, cite it
This is, to our knowledge, the largest harmonized, depth-resolved inventory of measured PFAS in United States soils — and it is completely free. It is open research data, not a commercial product: browse every record in the Watershed Explorer without an account, or download the full dataset with a citable DOI. SWATGenX never charges for data — pay-as-you-go pricing applies only to cloud compute for model calibration.
Why it exists
No national layer of measured soil PFAS exists — the data is scattered across thousands of pages of state and federal investigation reports, in inconsistent formats, mostly as PDFs. A watershed or groundwater PFAS model that wants a real source term instead of a guess has nowhere to look.
This inventory is that missing layer. Every value is transcribed as-reported from a public document — no interpolation, no modeled substitutes — and kept depth-resolved, so a model can read the actual concentration profile from the surface down toward the water table. The dominant setting is AFFF fire-training areas, the same legacy sources that drive most groundwater PFAS plumes.
The extraction combines deterministic table parsing with a vision-language pipeline for scanned reports, behind ten quality-assurance gates. The method and dataset are described in our national PFAS soil inventory manuscript.
What it feeds
The inventory is the source-term half of coupled PFAS modeling on SWATGenX. Paired with the national groundwater lithology inventory, it lets a SWAT+MODFLOW-6 model start from measured soil concentrations and carry them through the unsaturated zone, the aquifer, and back to the stream — instead of prescribing a plume out of thin air. At sites like Gabreski (Long Island) and Wurtsmith (Michigan), the measured soil profile is the model's input. For the mechanisms that carry PFAS from that soil down through the vadose zone and aquifer, see the PFAS fate & transport guide.