How Do I Test For PFAS In My Well Water?

Are PFAS present in your well water, and how can you confirm it with reliable testing?

How Do I Test For PFAS In My Well Water?

Testing your well water for PFAS (per- and polyfluoroalkyl substances) is a practical step to protect your family’s health and to guide your decisions about treatment. This article walks you through what PFAS are, why testing matters, how to choose a lab and sampling method, how to collect high-quality samples, how to interpret results, and what to do if PFAS are detected.

What are PFAS and why should you care?

PFAS are a large group of man-made chemicals used for decades in products like firefighting foam, nonstick cookware, stain-resistant fabrics, and some industrial processes. They are persistent in the environment and can accumulate in water supplies. You should care because long-term exposure to certain PFAS has been linked to health effects such as changes in cholesterol levels, immune system impacts, developmental effects in children, and increased cancer risk in some studies. Testing tells you whether these chemicals are in your water and at what levels.

Who should test and when to consider testing?

If you rely on a private well, testing makes sense if you live near known contamination sources (industrial sites, airports, military bases where aqueous film-forming foam was used), if there have been local PFAS detections, or if you use water for infants, pregnant people, or other vulnerable household members. You should also test if you notice a change in taste or smell (though many PFAS are not detectable by taste or smell) or if a neighbor or local community water system has confirmed PFAS.

Regular testing schedule

You should test at least once initially to know your baseline. If you find PFAS, test more frequently according to your treatment system’s maintenance schedule (for example, after filter replacement and periodically to monitor breakthrough). If there is a local contamination event or new data from your state, test again. Annual testing is a reasonable default for many well owners who are monitoring potential contamination.

Understand regulatory guidance and health advisory levels

Different agencies provide guidance to help you interpret PFAS concentrations in water. In 2022 the U.S. Environmental Protection Agency (EPA) issued non-enforceable lifetime health advisories for certain PFAS that are very low (for example, PFOA and PFOS values noted by EPA in 2022). In 2023 EPA proposed regulatory standards for combined PFOA and PFOS at a higher level than some advisories; regulatory limits and state standards continue to evolve. Because standards differ by agency and state, you should check with your state health or environmental agency for the most current guidance that applies where you live.

How to think about parts per trillion (ppt)

PFAS are typically measured in parts per trillion (ppt), which is a very small concentration — one part in one trillion. Even when numbers look extremely small, they represent a measurable amount of contaminant in a large volume of water. Your lab report will show numbers in ppt, often alongside method detection limits and reporting limits; these help you judge whether the results are reliable and how they compare to advisory or regulatory values.

Choose the right testing method and certified lab

To get useful results, you need a lab that is experienced and accredited for PFAS analysis. The most commonly used laboratory methods for PFAS in drinking water are EPA Method 537.1 and EPA Method 533, both using liquid chromatography-tandem mass spectrometry (LC-MS/MS). These methods detect multiple PFAS compounds with varying reporting limits.

How to pick a lab

• Choose a state-certified or NELAP-accredited laboratory that lists PFAS testing using EPA 537.1 or 533.
• Ask the lab which PFAS they analyze (some panels cover 18–30 compounds).
• Ask for the method detection limits (MDLs) and reporting limits (RLs) for each PFAS.
• Confirm sample handling and shipping instructions and whether they provide pre-cleaned bottles and chain-of-custody forms.
• Ask about turnaround time and cost.

Typical analyte panels and costs

Labs often offer several panel options: a focused panel (PFOA and PFOS), a larger panel (including GenX, PFNA, PFHxS, PFBS, and short-chain PFAS), and comprehensive panels that test for 20–30 compounds. Costs vary: a single or small-panel test might be around $100–$300, while comprehensive panels commonly range from $200–$600 or more. Check with the lab for current pricing.

Prepare for sampling: what materials and paperwork you’ll need

Good sampling starts before you turn on the tap. Most labs supply pre-cleaned, PFAS-free sample bottles (usually polypropylene or HDPE) and a chain-of-custody form. Follow the lab’s instructions exactly; small deviations can compromise results.

Basic items and documents

• Pre-cleaned sample bottles from the lab (do not substitute other containers).
• Chain-of-custody form and sample labels.
• Cooler and ice packs for transport.
• Clean, PFAS-free gloves if provided or recommended by the lab (avoid anything Teflon-coated).
• Clean paper towels or wipes (check with lab about potential contamination).
• Sharpie or label pen for labeling.

Step-by-step sampling instructions

Collecting a proper sample is crucial. Follow these general steps, and always follow any specific instructions from your chosen lab or state program.

1. Read the lab instructions thoroughly before starting.
2. Decide whether you’ll collect a single post-flush sample or paired samples (first-draw and flushed). Collecting both can help distinguish contamination from plumbing versus groundwater.
3. Avoid using Teflon-coated items and avoid handling the bottle neck or cap interior.
4. If collecting a flushed sample (to sample groundwater source), run cold water at the tap for 5–10 minutes before sampling to remove standing water from the plumbing. The lab may recommend a specific flush duration.
5. If collecting a first-draw sample (to check for household or plumbing sources), collect immediately without flushing.
6. Remove the cap carefully and hold the bottle by its body. Do not rinse the bottle; fill it to the marked fill line, leaving minimal headspace.
7. Close the bottle tightly and invert once or twice if instructed. Do not over-shake.
8. Label the bottle with sample ID, date, time, and sampler name and complete the chain-of-custody form.
9. Place samples on ice and arrange prompt delivery or shipment to the lab (typically within 48 hours) to meet hold-time requirements.

Sampling tips to avoid contamination

• Do not use products containing PFAS (certain cosmetics, waterproofing sprays) right before sampling.
• Do not touch the inside of bottles or caps.
• If you must use gloves, use nitrile gloves known to be PFAS-free and change them if contaminated.
• Collect samples away from open containers or sources of contamination like gasoline, cleaning agents, or new carpeting.

What types of samples can you collect?

Most well owners collect raw well water samples from an entry point or a kitchen tap. You can choose:

• Raw well water (point of entry) — represents groundwater coming into the house.
• Finished water (after treatment) — shows whether your treatment removes PFAS effectively.
• First-draw vs. flushed samples — first-draw helps find household sources; flushed targets aquifer/well source.

Collecting both raw and finished water samples gives the most information if you are evaluating a treatment system.

Understanding lab reports and quality control

Your lab report will list each PFAS compound tested, the measured concentration (in ppt), the method used, and quality control indicators like reporting limits, detection limits, blank results, and whether values are estimated or confirmed.

Key report elements to check

• Reported concentration (ppt) for each compound.
• Method detection limit (MDL) and reporting limit (RL).
• Whether the compound was detected above the reporting limit.
• Field blank and lab blank results (should show no contamination).
• Duplicate or matrix spike results, if provided, to indicate precision and recovery.
• Chain-of-custody confirmation and sample condition on receipt.

If anything on the report looks unclear, call the lab and ask for explanation. They should walk you through the QA/QC and any qualifiers attached to detected results.

Interpreting results: what counts as “safe”?

Interpreting PFAS results is not always straightforward. Different agencies set different advisories or regulatory limits, and not all PFAS have established guidelines. You’ll want to compare your lab numbers against the latest EPA advisories and any state standards.

Practical interpretation steps

• Identify which PFAS were detected and their concentrations.
• Compare detected values to current EPA health advisories, proposed regulatory values, and any state-specific standards.
• If values are near or above advisory or regulatory levels, treat your water or use alternate sources for drinking and cooking, especially for infants and pregnant people.
• Consider professional consultation with your state health department or an environmental consultant to interpret complex results and recommend actions.

What to do if PFAS are detected in your well water

Detection doesn’t always require immediate panic, but it does require a plan. Your actions depend on concentration, the specific PFAS detected, whether treatment is already in place, and the vulnerability of household members.

Immediate steps

• Stop using the water for drinking and cooking if concentrations are well above advisory levels or if your household includes infants, pregnant people, or immunocompromised individuals.
• Use bottled water or approved alternative sources for drinking and food preparation until you have treatment in place.
• Contact your state or local health department for guidance and to report results if required.
• Identify possible contamination sources around your property (old fire training sites, nearby industrial activity, areas where firefighting foam was used).

Longer-term measures

• Install an appropriate treatment system (see the treatment comparison table below).
• If you already have a treatment system, have it inspected and certified service performed to ensure it’s functioning and filter media haven’t reached capacity.
• Consider testing neighboring wells (your state health department may offer support) to understand the local extent of contamination.
• Explore options like connecting to a municipal supply if available and if that supply meets safe standards.

Treatment options: what works and what to expect

Different treatment technologies remove PFAS with varying effectiveness. Your choice depends on which PFAS are in your water, concentrations, household needs, and budget.

Comparison of common treatment technologies

Note: Removal efficiency can depend on water chemistry, PFAS chain lengths, system design, and maintenance. No single technology suits every situation.

Size and placement of treatment systems

• Point-of-use (under-sink RO): Treats only a specific faucet used for drinking/cooking. Good if only drinking water is a concern.
• Point-of-entry (whole-house GAC or ion exchange): Treats all water entering the house. Important if you are concerned about PFAS exposure through bathing or household uses (though dermal absorption and inhalation risks are generally lower than ingestion).
• Combination systems: Sometimes a point-of-entry GAC followed by point-of-use RO provides broad protection.

Maintenance and monitoring

All PFAS treatment systems require maintenance. GAC media can become exhausted; RO membranes and pre/post-filters need periodic replacement. After installation, plan for periodic testing to confirm continued PFAS removal and to detect breakthrough. Follow manufacturer and certified installer guidance.

Disposal and handling of used media

Spent GAC and used ion exchange resins can contain concentrated PFAS and must be managed properly. When changing media, work with the system supplier or a licensed waste handler to ensure compliant disposal or regeneration. Do not dispose of PFAS-contaminated media to a typical landfill or drain without confirming regulatory compliance.

Costs and funding assistance

Testing and treatment costs vary. Testing can range from about $100 to several hundred dollars depending on the panel. Treatment systems range from a few hundred dollars for a basic point-of-use RO to several thousand for whole-house systems and installations. Some states offer financial assistance, grants, or technical support for private well owners; check with your state environmental or health agency for available programs.

Working with professionals

If your results show elevated PFAS, consult professionals for thorough evaluation:

• State or local health department for health guidance and local context.
• Certified water treatment professionals for system selection and installation.
• Environmental consultants for wellhead investigation or if contamination appears widespread.
• Licensed labs for confirmatory testing and ongoing monitoring.

Sampling checklist (quick reference)

Common questions and troubleshooting

• Can my regular water test (for bacteria, nitrates) find PFAS? No. PFAS require specific laboratory methods; request PFAS testing explicitly.
• If my neighbor’s water has PFAS, will mine? Not necessarily. PFAS distribution depends on geology, well depth, historic contamination sources, and groundwater flow. Testing your own well is the only way to know.
• My lab reports “non-detect” — does that mean zero? “Non-detect” means below the lab’s reporting limit. Check the reporting limit to understand the sensitivity.
• Can I filter PFAS with a pitcher filter? Most standard pitcher filters (carbon-based) may not reliably remove PFAS to low levels. Certified RO or properly designed GAC systems are recommended for PFAS reduction.

Reporting results and next steps with local agencies

If you detect PFAS, notify your state health department according to their guidance. Many states have private well programs that can advise you about treatment options, funding assistance, or local sampling programs. If you believe the contamination source is industrial or related to firefighting foam, local environmental authorities or the EPA may need to be involved.

Practical examples of action plans

• Low-level detections near advisory levels: Test again to confirm. If confirmed, install point-of-use RO for drinking water and monitor quarterly until stable.
• Elevated long-chain PFAS: Consider whole-house GAC point-of-entry followed by point-of-use RO; test both raw and treated water after installation.
• Short-chain PFAS present at high levels: Consult an expert about ion exchange or advanced membrane solutions; GAC may be less effective.

Keep records and keep testing

Maintain a record of sampling dates, lab reports, treatment installations, and maintenance. Periodic testing helps you confirm continued protection and offers a documented history if you sell your property or seek funding. If you install a treatment system, test right after installation and on a schedule recommended by the manufacturer and your state agency.

Additional resources

Your state health department and environmental agency are primary resources for current advisories, recommended labs, and funding options. Federal resources such as the EPA and technical organizations provide guidance documents and technical assistance. If you need help interpreting technical lab reports or choosing a treatment system, contact a certified water treatment professional or environmental consultant.

Summary and next steps you can take today

• Order PFAS testing from a certified lab that uses EPA 537.1 or 533 and confirms reporting limits.
• Follow the lab’s sampling instructions exactly; consider collecting both first-draw and flushed samples to differentiate sources.
• Compare results to current EPA advisories and state standards and consult your local health department for guidance.
• If PFAS are detected, consider treatment options such as point-of-use RO or point-of-entry GAC/ion exchange depending on the compounds present.
• Keep records, maintain your treatment system, and test periodically to ensure ongoing protection.

If you’d like, tell me where you live (state) and whether you already have a treatment system — I can point you to likely state lab lists, agency contacts, and treatment recommendations tailored to your situation.