How to Test Your Well Water for PFAS (And What to Do About the Results)

If you're on a private well, the EPA's PFAS rules don't apply to you. No utility is testing your water. No regulator is going to notify you of contamination. You are the public works department.

That's the bad news. The good news: PFAS testing is straightforward, affordable, and has gotten much better in the last five years. Here's how to do it right.

Why Well Owners Should Test (Even If You Feel "Fine")

PFAS is invisible. No color, no smell, no taste — even at concentrations 1,000x higher than the EPA limit. You won't know it's there without testing.

You're at elevated risk if your well is within a few miles of:

• A military base or National Guard facility (firefighting foam contamination)
• An airport — especially one with a fire training area
• A fire training facility of any kind
• A chemical, electroplating, paper, or textile manufacturer (current or historical)
• A landfill or industrial wastewater discharge point
• A wastewater treatment plant outfall upstream
• A farm field where biosolids ("sludge") were applied as fertilizer

Even without any obvious source, PFAS has been detected in well water across all 50 states. EPA's latest data (August 2025) added another 7 million Americans to the count of people with detectable PFAS in their water supply.

Step 1: Find a Certified Lab

You need a lab certified for EPA Method 537.1 or the newer EPA Method 533. These are the two standard analytical methods for PFAS in drinking water. Don't use a lab that "tests for PFAS" without specifying the method — results from non-standard tests may not be defensible if you later need to demonstrate contamination.

Major labs that serve U.S. private well owners by mail:

• Eurofins (Eaton Analytical division)
• Pace Analytical
• Cyclopure — newer, sells a direct-to-consumer kit
• Tap Score (SimpleLab) — consumer-friendly intake
• Babcock Laboratories (West Coast focused)

State health departments sometimes maintain a list of certified labs. In Arizona, ADEQ publishes a certified-lab list on its PFAS resources page.

Step 2: Choose the Right Test

Three options:

Test Type	What It Covers	Cost	When to Choose
Screening (5–6 PFAS)	PFOA, PFOS, PFNA, PFHxS, PFBS, sometimes GenX	$150–$250	Quick check, no known contamination source
Standard EPA Method 537.1	18 PFAS compounds	$300–$450	First serious test, most well owners
Expanded Method 533	25–30+ PFAS compounds	$400–$600	Known industrial source nearby, or initial test showed detections

For most well owners doing a first test, EPA Method 537.1 (18 compounds) is the right balance of cost and coverage.

Step 3: Order the Kit and Sample Correctly

PFAS sampling is fussy because PFAS contamination is everywhere in modern materials. Critical rules:

• Use only the lab-provided bottles (HDPE or polypropylene). Don't substitute kitchen glass.
• No PTFE (Teflon) anywhere — PTFE is itself a PFAS source.
• No soap, hand sanitizer, or lotion the morning of the test. Personal care products contain PFAS.
• Don't wear waterproof or stain-resistant clothing while sampling.
• Sample from an indoor tap (usually the kitchen) per the lab's run-time instructions.
• Fill to the line, cap immediately, label, ship overnight.

Read the instruction card twice. A contaminated sample means a wasted $400 test.

Step 4: Wait, and Read Your Results

Turnaround is typically 2–3 weeks for standard tests.

Results come back as a table listing each PFAS compound and a concentration in ng/L (nanograms per liter) — which is the same as parts per trillion (ppt).

How to interpret:

Result	What It Means
All "ND" (non-detect)	No PFAS detected at the lab's reporting limit (typically 2–4 ppt). Retest every 2–3 years if you're near a known source.
Some detections, all under 4 ppt	Trace PFAS present. Below the federal MCL for PFOA/PFOS but worth treating — public health research is trending toward "no safe level."
Any compound at 4–10 ppt	Above the federal MCL. Install certified PFAS treatment.
Any compound at 10+ ppt	Significant contamination. Treatment is essential. Whole-house plus point-of-use polishing is the right call.
Short-chain PFAS (PFBS, PFBA, GenX) detected at any level	You need a filter technology that handles short-chain — RO or PFAS-selective anion exchange. Carbon alone won't do it.

Step 5: Decide on Treatment

Match the system to the contamination:

• Long-chain only, under 10 ppt total — under-sink RO at the kitchen, or whole-house GAC
• Short-chain present, any level — whole-house GAC + PFAS-selective anion exchange + under-sink RO
• High total PFAS (20+ ppt) or multiple compounds — full stack: sediment → GAC → anion exchange → under-sink RO ($2,500–$5,000 installed)

In all cases, look for NSF/ANSI 53 (point-of-use) or NSF/ANSI 58 (RO) certification for PFOA and PFOS reduction. Generic "PFAS certified" without NSF isn't reliable.

Step 6: Retest After Installation

Once installed, sample from the filtered tap to confirm performance — most manufacturers recommend a 30-day post-installation retest. After that, retest the unfiltered well every 2–3 years (more often if you're near a known source).

The Bottom Line

If you own a private well, you are the regulator. Testing for PFAS costs $200–$600 and gives you a clear answer. Treatment, if needed, is affordable and effective. Ignoring it is the only option that's actually expensive — measured in long-term health risk.

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Got results back? Compare PFAS-rated filter systems sized for well water at our PFAS water filter collection. Need help interpreting your lab report? Send it over and we'll match a system to the contamination profile.

Related reading: PFAS in Arizona Drinking Water · Best Water Filter for PFAS Removal