Do You Need a Test?
Public System vs. Private Well
If you are on a public water system
Public water systems serving 3,300 or more people were required to test for 29 PFAS compounds under EPA’s Unregulated Contaminant Monitoring Rule 5, which ran from 2023 to 2025. Results are publicly available. Before you pay for a home test, check what your utility has already found.
Search the EWG Tap Water Database at ewg.org/tapwater with your zip code. You can also access raw UCMR5 data at epa.gov/dwucmr or request your utility’s Consumer Confidence Report directly.
A home PFAS water test is still an option if you want confirmation at your specific tap, want to test water after your filter, or if your utility is small and may not have been covered by UCMR5 requirements.
If you have a private well
Private wells are not covered by any federal PFAS testing requirement. No federal agency is monitoring your well. If your well is contaminated, you will not know unless you conduct a test. Private well testing for PFAS is strongly recommended if any of the following apply:
- You live within a few miles of a military base, airport, or industrial facility that has used or manufactured PFAS
- You live near a landfill where PFAS-containing products or AFFF stocks have been disposed
- You live near farmland where municipal biosolids have been applied as fertilizer
- Your neighbors or local news have reported PFAS contamination nearby
- You have pregnant women, infants, or young children in your household
What Tests Measure
Choosing the Right Test
Not all PFAS water tests are the same. Understanding what a test covers helps you choose the right one and interpret results accurately.
Test Type
Compounds Covered
Typical Cost
Best For
EPA Method 533
25 PFAS (short-chain and long-chain)
$150–$400
Most comprehensive standard test. Covers the six compounds subject to EPA MCLs plus many others. Recommended as first choice for private wells.
EPA Method 537.1
18 PFAS (primarily long-chain)
$100
–$300
Strong coverage for the most-studied PFAS including PFOA and PFOS. Misses some short-chain compounds. Widely available from certified labs.
TOP Assay
Estimates total PFAS including precursors
$300
–$600
Research-grade. Measures PFAS that standard methods miss. More useful for detailed site investigations than routine consumer testing.
Rapid home screening kits
Estimates total PFAS including precursors
$40–$150
Quick preliminary screening only. Results should be confirmed with certified lab testing if PFAS are detected.
How to Test
Step by Step
01
Check Publicly Available Data First
Search ewg.org/tapwater with your zip code. If you are on a public system and results are already available, you may not need to test at all.
02
Find a State-Certified Laboratory
Use the EPA’s database of certified drinking water laboratories at epa.gov/dwlabcert. Only certified labs produce results usable for regulatory, legal, or insurance purposes.
03
Request a PFAS Sampling Kit
Contact the lab and specify EPA Method 533 or 537.1. The lab will send you certified sampling containers with instructions. Do not use your own containers — PFAS can leach from some plastics, contaminating the sample.
04
Collect Your Sample Correctly
Follow the lab’s instructions precisely. For tap water, flush the tap for 1 to 5 minutes before collecting. For well water, collect at the wellhead tap before any filtration or treatment. If you want to test before and after a filter, collect two separate labeled samples.
05
Return the Sample Promptly
PFAS samples have holding times — typically 28 days for EPA Method 533. Ship the sample back to the lab as soon as possible after collection, ideally with overnight shipping.
06
Receive and Interpret Your Results
If you have a PFAS-related illness or property damage connected to a military contamination source, legal options may exist. Statutes of limitations vary. Do not delay.
Reading Your Results
What the Numbers Mean
PFAS water test results list each compound and its detected concentration in parts per trillion (ppt). Here is how to read those numbers against the current federal standards.
Below 4 ppt
Your water meets the current federal standard for PFOA and PFOS. Whether to filter is a personal decision based on health situation and proximity to contamination sources.
4–10 ppt
Your water exceeds the EPA MCL for PFOA or PFOS. Filtration is strongly recommended. Report the result to your state drinking water agency.
Above 10 ppt
Significant contamination. Install a certified filter immediately. Do not use this water for drinking, cooking, or formula preparation until treated. File a formal complaint with your state agency.
Litigation
Legal Proceedings
Filter Type
PFAS Removal
Certification
Notes
Reverse Osmosis (under-sink)
Up to 94%
NSF/
ANSI 58
Most effective point-of-use option. Removes PFOA, PFOS, and most other PFAS. Requires installation and periodic membrane replacement every 1 to 2 years.
Activated Carbon (pitcher or faucet)
Moder
-ate to high
NSF/
ANSI 53
Effective for long-chain PFAS. Less effective for short-chain compounds. Replace filter cartridges on schedule — an overloaded carbon filter stops working.
Whole-house RO or ion exchange
High
NSF
/ANSI 58
Treats all water entering the home. More expensive to install and maintain. Most appropriate for high contamination levels.
Standard pitcher filter (Brita etc.)
Low to none
Not certif
-ied for PFAS
Standard activated carbon pitchers are not certified to remove PFAS. Do not rely on these for PFAS reduction.
Take a Water Test
