Testing Labs
Find a Certified Water Testing Lab
Use a state-certified or NELAP-accredited lab for drinking water and private well testing. Always verify current certification directly with the lab or your state program before submitting samples.
Verify Before Submitting Samples
Lab certifications change. Always confirm that a lab's current certification covers the specific contaminants you need tested before submitting samples. Check with your state's laboratory certification program for the authoritative, up-to-date list.
Authoritative Resource
EPA National Certified Lab Directory
The EPA maintains the definitive national database of certified drinking water testing laboratories organized by state and contaminant type. This is the most comprehensive and current resource — always use it to find certified labs.
Search EPA Certified Lab DatabaseHow to Choose a Water Testing Lab
Match certification to contaminant
Not all labs are certified for all tests. A lab may be NELAP accredited but not specifically certified for PFAS analysis using EPA Method 533 or 537.1. Ask for the specific certification before submitting.
Use state-certified labs for legal purposes
If results will be used for regulatory compliance, real estate transactions, or formal documentation, the lab must be certified by your state program — not just nationally accredited.
Mail-in kits vs. local labs
Many certified labs offer mail-in sampling kits with chain-of-custody forms. These are valid for most purposes. Local labs can provide faster turnaround and in-person guidance on sampling technique.
State Certification Programs
Each state runs its own laboratory certification program. These are the authoritative sources for finding certified labs in your state.
Testing Private Well Water?
Private well testing requirements vary by state. See our state-specific well water guides for testing recommendations and links to each state's certified lab program.
View Well Water Testing Guides →