Most PFAS testing today asks a narrow question: how much of these specific compounds are in this water? It’s a reasonable question. It’s also the tip of the iceberg.

The regulated few

In 2024, the U.S. EPA finalized enforceable drinking-water limits for a small set of per- and polyfluoroalkyl substances — including a maximum contaminant level of 4.0 parts per trillion for PFOA and PFOS. That’s a landmark, and it gives labs and regulators clear, measurable targets.

But the regulated list is short. Standard targeted methods look for named analytes — a few dozen at most. They’re precise, accredited, and essential for compliance reporting.

The unregulated thousands

The problem is scale. There are thousands of PFAS compounds in commerce, bound together by the same exceptionally stable carbon-fluorine bond that makes them useful — and persistent. Targeted analysis, by design, can only see what it’s told to look for. Everything else passes through unmeasured.

This isn’t hypothetical. Consider that in 2023 the FDA approved a topical eye treatment whose active ingredient is itself a PFAS — perfluorohexyloctane. A compound nobody is screening drinking water for, applied directly and intentionally, is a small reminder of how wide the class really is. The molecules we regulate are the visible peak; the rest of the iceberg sits below the waterline.

Why class-based screening matters

If you only measure the named compounds, you can declare a site “clean” while a broader PFAS burden goes undetected. For environmental consultants and remediation teams, that’s a real risk: contamination maps built only on targeted analytes can be incomplete, and the gaps are invisible until someone goes looking.

Class-based screening flips the question. Instead of asking “how much PFOA?”, it asks “is there PFAS-class contamination here at all — and where is it concentrated?” That’s a wider net, and it’s the right first question when you’re trying to find contamination worth confirming.

Where on-site field screening fits

This is the gap Wave Lumina is built for. Our field-ready sensor pairs in-field liquid-liquid extraction with surface-enhanced Raman spectroscopy (SERS) to screen for PFAS-class surfactants — not just a handful of regulated targets — and returns a quantitative measurement in about 20 minutes, right at the sample point.

In real groundwater, the method has shown R² ≥ 0.98 linearity and 65–125% spike recovery, with sensitivity to roughly 300 ppt. That’s lab-grade analytical performance at field speed.

To be clear about what it is and isn’t: this is a screening tool, not a certified regulatory method. It’s designed to help you find and prioritize contamination fast, so you can sample smarter and move remediation forward. Confirmatory laboratory analysis is still required for regulatory reporting. Screening and the lab are complementary — one tells you where to look, the other tells you exactly what’s there.

The takeaway

Targeting the regulated few will always be part of PFAS work. But if that’s the only lens, the rest of the iceberg stays hidden. Class-based, on-site screening is how teams start seeing below the waterline — and act on it before the lab queue catches up.

Want to put field screening to the test on your own contaminated sites? Join the Wave Lumina pilot program.