Private wells are not regulated under the Safe Drinking Water Act, so well owners are responsible for testing and for any treatment their household needs if contaminants are found.[1]
EPA has finalized a national PFAS drinking‑water regulation (NPDWR) that sets enforceable Maximum Contaminant Levels (MCLs) for specific PFAS for public water systems; those MCLs provide a helpful screening benchmark for private wells but are not enforceable on private wells. Homeowners can compare private‑well results to the EPA MCLs for context and decision‑making.[2][1]
Occurrence of PFAS in private wells varies locally; peer‑reviewed studies and state testing programs show prevalence is influenced by nearby PFAS sources (for example, industrial sites or historical firefighting foam use). Check local/state occurrence data when deciding whether to sample.[13][12]
Should you test your well for PFAS?
Consider testing if you live near known PFAS sources, areas where state or local testing found PFAS in groundwater, or where your state health/environment agency recommends sampling.[13][7]
Contact your state health or environmental agency for area‑specific guidance and to learn about any local testing programs or assistance—state agencies are the primary resource for private‑well owners on interpretation and next steps.[1][7][8]
How to get a valid PFAS result: lab method and sampling practices
Choose the right lab and methods
Use a state‑certified laboratory that analyzes PFAS using EPA drinking‑water methods—most commonly EPA Method 537.1 and EPA Method 533 (labs often run them together) so results are comparable to drinking‑water benchmarks.[3][11]
Follow method and lab instructions exactly
EPA method documentation includes method holding times and other sample requirements; follow the lab's written instructions for collection, preservation, and shipping to meet method requirements and ensure a valid result.[3][10]
Prevent contamination during sampling
Strict anti‑contamination practices are essential: use pre‑cleaned PFAS‑free containers supplied by the lab, avoid Teflon/PTFE tools and sampling materials, complete chain‑of‑custody forms, keep samples chilled, and ship promptly to meet holding times. Do not improvise bottles or supplies.[10][3]
Always check the lab's analyte list and reporting limits on the certificate of analysis (COA); EPA methods commonly report dozens of individual PFAS (for example, panels of ~29 analytes) in parts per trillion (ppt, equivalent to ng/L). Knowing the lab's reporting limit is critical because many health benchmarks are in the low‑ppt range.[3]
Typical costs and state assistance
Retail/private‑lab costs for a PFAS panel sample vary substantially by lab, analyte list, and turnaround time; consumer guides and lab outreach materials report typical ranges roughly in the $200–$600 range per sample. Get a written quote from a state‑certified lab for the exact methods and analytes you want.[11][12]
Some states provide financial assistance for private‑well PFAS testing or treatment. For example, New Hampshire DES operates a PFAS Removal Rebate Program for Private Wells that can reimburse eligible sampling/analysis and treatment installation costs per program rules; other states such as Massachusetts provide outreach and guidance in affected areas—check your state program for details.[9][7]
Reading and interpreting lab results
Lab reports typically list individual PFAS concentrations in ppt or report "non‑detect" with an associated method detection or reporting limit. Because health benchmarks are often in the low‑ppt range, compare reported concentrations to the EPA MCLs for context and check the COA reporting limits to understand what a "non‑detect" means relative to benchmarks.[3][2]
Use the EPA MCLs as a screening benchmark but contact your state health department for state‑specific interpretation and next steps—state guidance and advisories may differ from federal benchmarks and often include local context or assistance information.[2][1][7]
If multiple PFAS are present, EPA technical materials and the final rule describe methods (for example, a Hazard Index approach) for assessing combined risk from PFAS mixtures; for combined‑risk assessment, use state public‑health resources or a qualified consultant.[2]
Treatment options to reduce PFAS exposure
Treatment choice depends on which PFAS are detected, their concentrations, whether you want whole‑house (point‑of‑entry) or tap‑only (point‑of‑use) protection, and your willingness to perform routine maintenance—consult a qualified water‑treatment professional and verify product testing/certifications for the PFAS analytes you need to remove.[4][6]
Granular activated carbon (GAC)
GAC adsorption is widely used and effective for many long‑chain PFAS (for example, PFOA and PFOS). It is commonly applied in residential whole‑house or point‑of‑use systems. Pros include relatively lower capital cost; tradeoffs include media exhaustion (requiring replacement or regeneration) and variable performance on short‑chain PFAS.[4][12]
Reverse osmosis (RO)
RO point‑of‑use systems reduce many PFAS at the tap and are appropriate when you only need to treat drinking and food‑prep water. RO systems require proper installation and maintenance (membrane and prefilter replacement) to perform as expected.[4]
Ion‑exchange resins
Anion exchange resins are used for some PFAS removal applications; effectiveness depends on resin type and the specific PFAS present. Engineered ion‑exchange systems are used in full‑scale and some residential applications with operational controls tuned to the site conditions.[4]
Certification and claims
Check product listings for NSF/ANSI test/certification information: NSF has updated protocols and guidance addressing PFAS reduction claims (including PFOA/PFOS and related updates such as P473 and changes to NSF/ANSI 53 & 58). Look for active NSF listings and the specific standard or protocol used to validate PFAS reduction claims for the analytes of concern.[6]
Choosing POE (whole‑house) vs POU (tap) treatment
Decide whether you need point‑of‑entry (whole‑house) treatment or point‑of‑use (tap) systems based on where you want protection (all water outlets vs drinking/cooking taps), the PFAS detected, and your maintenance capacity. For help sizing and comparing POE vs POU options, consult a qualified professional and verify system testing for the target analytes.[4][6] For more on the general tradeoffs between whole‑house and point‑of‑use systems, see our guide on Whole‑House (POE) vs Point‑of‑Use (POU) Water Treatment.
Practical next steps after you get results
Confirm the lab methods and COA: verify the analyte list, units (ppt/ng/L), and reporting limits so you understand non‑detects and low‑level detections.[3]
Compare concentrations to the EPA MCLs for context, then contact your state health or environmental agency for state‑specific guidance and recommended actions; states may have different advisories or assistance programs.[2][1][7]
If treatment is recommended, choose a technology that is proven for the PFAS present and sized for your flow and water use; confirm product testing/certification and plan for maintenance (media or membrane changes, monitoring for exhaustion, or replacement schedules).[4][6]
Ask about financial assistance or rebates from your state—some programs reimburse sampling or treatment costs if you qualify.[9]
Where to get reliable help and more information
Start with your state health or environmental agency for private‑well guidance, interpretation, and information about local programs or testing events.[1][7][8]
Use a state‑certified lab that runs EPA Method 533/537.1 and provides a clear COA; lab outreach pages often list expected analyte panels and typical costs.[3][11]
For sampling technique and anti‑contamination protocols, follow ITRC and EPA sampling guidance and your lab’s instructions—these resources describe required supplies, chain‑of‑custody, holding times, and shipping practices.[10][3]
Sources: EPA private‑well guidance and PFAS rule materials; EPA laboratory methods; ITRC sampling guidance; EPA treatment technology overview; NSF protocol updates; state program pages and peer‑reviewed occurrence studies (see full source list).