PFAS and the water beneath your land

PFAS — per- and polyfluoroalkyl substances — are a class of around 14,000 synthetic chemicals manufactured since the 1950s. They're called "forever chemicals" because their carbon-fluorine bonds resist environmental breakdown. The EPA's UCMR 5 program tests the public water systems that serve most American homes — 9,799 sampling locations mapped to date, with confirmed contamination clustering near military bases, commercial airports, fluorochemical manufacturing sites, and wastewater treatment plants where biosolids were land-applied as fertilizer. A UCMR 5 hit at a sampling point means the public water utility serving that area tested positive — every property on that utility's drinking and irrigation supply is affected via tap water, not just neighbors of the sample. The 2022 EPA health advisory level is 4 parts per trillion — among the lowest contaminant thresholds in federal regulation.

PFAS rewards a precise reading. Bioaccumulation factors vary dramatically by crop — leafy greens show values of 15–46 (meaning the plant concentrates PFAS far above soil levels), while fruiting crops show factors below 1. The first question is which water you actually drink and irrigate from: if your land is on a flagged municipal utility, you are in scope, and the consumer confidence report makes the result public. If your land draws from a private well within range of a known plume, direct testing is the lever. UCMR 5 is the dataset; the service area is the unit. The class of risk is real; so is the resolution available to read it.

Identify your water source first. If you're on a public water utility, check the consumer confidence report and the EPA's UCMR 5 public dashboard — if your system has tested positive, every property on that utility is exposed via tap and irrigation, regardless of distance from the sample point. Private-well users within ~6 mi of a federal PFAS sampling location with a confirmed hit need direct testing (~$200-$400 for EPA Method 537.1, which covers PFOA, PFOS, and GenX). Activated carbon and reverse-osmosis filtration both reduce PFAS in irrigation water meaningfully. In affected areas, lean toward fruiting crops (tomatoes, peppers, cucumbers) over leafy greens. The pathway is water; the lever is the test — done at the right level.

1. 1Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
2. 2If using a private well, test for PFOA, PFOS, and GenX compounds (EPA method 537.1).
3. 3Favor fruiting crops (tomatoes, peppers, cucumbers) over leafy greens in areas with known PFAS contamination.
4. 4Activated carbon water filters can reduce PFAS in irrigation water.
5. 5Municipal water systems test for PFAS under EPA UCMR 5 — check your water utility's consumer confidence report.

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