Forever Chemicals (PFAS) in Well Water: The Complete Homeowner’s Guide to Risks, Testing, and Proven Filtration
If you draw from a private well, you’re responsible for your family’s water quality. This guide explains what PFAS “forever chemicals” are, why they show up in wells, how to test properly, and exactly which home systems remove them—using live, working links to recommended products on Water Softener Plus.
Contents
- What Are PFAS and Why They Persist
- How PFAS Reach Private Wells
- Potential Health Risks & Evolving Limits
- PFAS Testing for Private Wells (Step-by-Step)
- Treatment That Works: RO, Carbon & Anion Exchange
- System Designs for Real Homes (Good, Better, Best)
- Installation Tips, Flow Sizing & Plumbing Layout
- Maintenance Intervals, Breakthrough & Verification
- Frequently Asked Questions (Quick Answers)
- Troubleshooting: Pressure, Taste, & Service Life
- Buyer’s Checklist & Next Steps
- References & Further Reading
1) What Are PFAS—and Why Are They Called “Forever Chemicals”?
PFAS (per- and polyfluoroalkyl substances) are a large family of man-made chemicals prized for their oil- and water-repellent performance in cookware, textiles, firefighting foams, and industrial processes. Their carbon-fluorine bonds are among the strongest in organic chemistry, which makes them unusually persistent in soil and water. Once PFAS reach groundwater aquifers, they can travel with the water and show up in private wells—even in rural areas.
2) How Do PFAS Get Into Private Wells?
Common Sources
- Historic use of firefighting foams (AFFF) at military bases and airports
- Industrial discharges and landfill leachate
- Wastewater biosolids applied as fertilizer
- Stormwater runoff from treated textiles and coated packaging
Pathways Into Aquifers
- Infiltration through permeable soils and fractured bedrock
- Migration along shallow groundwater flow toward well screens
- Intermittent spikes after heavy rain or nearby construction
Tip: Even if your neighbor’s test is “clean,” your well can differ due to local geology, depth, and pumping patterns. Always test your well.
3) Potential Health Risks & Evolving Limits
Public-health guidance around PFAS continues to evolve as more data emerges. Research has associated certain PFAS exposures with increased cholesterol, decreased vaccine response in children, some cancers (e.g., kidney and testicular for legacy PFOS/PFOA), thyroid disruption, and pregnancy-related hypertension. Many states have introduced health advisory levels measured in parts-per-trillion (ppt), and U.S. EPA is adopting enforceable drinking-water standards for several PFAS.
What this means for well owners: Proactive testing and layered filtration are prudent, especially for homes with infants, frequent bottle preparation, or immunocompromised family members.
4) PFAS Testing for Private Wells (Step-by-Step)
- Choose an appropriate test. Use a laboratory method capable of parts-per-trillion detection for a PFAS panel. See our Water Testing Procedures Guide for collection basics.
- Use PFAS-safe containers. Follow the lab’s kit instructions; avoid Teflon-containing materials during sampling.
- Collect at the right locations. For whole-home decisions, test at a kitchen cold tap (pre-treatment). For performance verification, sample post-filter.
- Document chain of custody. Fill out labels and forms completely; ship cold if required.
- Interpret results in context. Compare against state guidance and EPA values where applicable. Plan filtration based on highest-concern compounds and total PFAS load.
5) Treatment That Works: RO, Catalytic Carbon & Anion Exchange
At the home scale, three technologies are the backbone of PFAS reduction:
Reverse Osmosis (RO)
RO forces water through a semi-permeable membrane that rejects many dissolved contaminants, including PFAS. Pair with sediment and carbon prefilters for best longevity.
- Excellent for drinking and cooking water
- Compact, under-sink installation
- High rejection with proper maintenance
Under-Sink RO Drinking Water System
Learn more: Reverse Osmosis 101 (How RO Removes Contaminants)
Catalytic / Granular Activated Carbon (GAC)
PFAS compounds adsorb onto high-surface-area carbon media. Catalytic carbon broadens reactivity and handles chloramines and organics that would otherwise compete.
- Ideal as a whole-home “polish” for showers, laundry, and taps
- Backwashing tanks extend media life
- Often paired with anion exchange for tougher chains
Whole-Home Catalytic Carbon Filter Activated Carbon Filter Collection
Anion Exchange (AIX)
Specialized resins exchange negative ions (like many PFAS species) at the whole-home point-of-entry. AIX is frequently combined with catalytic carbon to manage both short- and long-chain PFAS plus competing organics.
Note: On complex wells, we recommend pairing anion media with carbon and verifying performance with post-install testing.
Disinfection ≠ PFAS removal: UV systems are superb for microbial safety, and many well owners include them—but UV does not remove PFAS. If you need disinfection alongside PFAS control, consider adding a VIQUA UV after your filters: browse VIQUA UV systems.
6) Real-World System Designs (Good • Better • Best)
GOOD: Drinking-Water RO at the Kitchen
- Under-sink stack: Sediment → Carbon Block → RO Membrane → Post Carbon
- Product: Under-Sink RO Drinking Water System
- Use case: Apartments, small households, renters, or those prioritizing drinking water first
- Add-ons: Inline remineralization cartridge for taste, fridge line connection
BETTER: Whole-Home Carbon + RO at Kitchen
- Point-of-entry: Catalytic Carbon Filter (Backwashing Upflow)
- Prefilter: Big Blue Sediment Prefilter to protect the carbon bed
- Point-of-use: Under-Sink RO for drinking/cooking
- Optional: VIQUA UV after carbon if bacteria are a concern
BEST: Whole-Home Carbon + Anion Exchange + RO
- Point-of-entry train: Sediment Prefilter → Catalytic Carbon → Anion Exchange Tank (contact us for sizing)
- Point-of-use: Under-Sink RO at kitchen (optionally second RO at bar/ice maker)
- Optional: VIQUA UV (microbial barrier)
7) Installation: Sizing, Flow, and Plumbing Layout
Layout (Point-of-Entry)
- Well pressure tank → Sediment Prefilter
- Catalytic Carbon Tank (backwashing)
- Anion Exchange Tank (where used)
- UV (optional) → House cold/hot distribution
Sizing Checklist
- Peak flow (gpm) based on fixtures (target ≥ system service flow)
- Carbon bed contact time (EBCT) ≥ 10–20 minutes (series tanks for high demand)
- Bypass valves for service
- Drain routing for backwash
Pro tip: If iron, sulfur, or manganese are present, tackle them upstream—these can foul carbon and reduce PFAS capacity. See our broader Well Water Treatment Guide.
8) Maintenance, Breakthrough & Verification Testing
- RO: Replace sediment and carbon prefilters every 6–12 months; membranes 2–3 years depending on TDS and usage. Post-carbon polisher annually.
- Catalytic/GAC: Monitor pressure drop and water quality; typical service life 1–3 years, longer with backwashing and low organics.
- Anion Exchange: Follow manufacturer capacity estimates; resin may be replaced or regenerated depending on model.
- UV: Annual lamp replacement; keep quartz sleeve clean.
- Verification: Re-test post-filter water at 6–12 months or sooner if taste/odor returns, usage spikes, or plumbing work occurs.
9) Frequently Asked Questions (Quick Answers)
Do water softeners remove PFAS?
No. Softeners address hardness (calcium/magnesium). Pair softening with catalytic carbon, optional anion exchange, and RO at the sink.
Should I choose whole-house or just under-sink?
Under-sink RO protects what you ingest; whole-home carbon/anion protects showers, laundry, and secondary taps. Many households do both for layered protection.
Will boiling remove PFAS?
No. PFAS are heat-stable. Boiling concentrates some contaminants through evaporation loss.
Do refrigerator filters remove PFAS?
Most fridge filters are not rated for PFAS. Use a dedicated RO system or a PFAS-oriented carbon/anion setup.
Can I shower in water with PFAS?
PFAS have very low volatility; inhalation exposure during showering is less of a concern than ingestion. Still, many families prefer a whole-home carbon stage to reduce overall exposure.
What about short- vs long-chain PFAS?
Short-chain PFAS can be more challenging for carbon alone. Combining catalytic carbon with anion media, and adding RO at the tap, improves capture across species.
How often do I replace media?
Plan 6–12 months for RO prefilters, 2–3 years for RO membranes, and 1–3 years for carbon/anion tanks depending on water quality and usage. Confirm with periodic lab tests.
Is UV required?
Not for PFAS, but for wells with bacterial risk, UV is a smart addition after filtration. Browse VIQUA UV systems.
Does backwashing carbon matter?
Yes. Backwashing helps redistribute media, remove fines, and extend life—especially important on wells with organics.
What if my PFAS level is very high?
Consider the BEST layout above (sediment → catalytic carbon → anion exchange + RO at the sink), and test post-install. For unusual profiles, contact us for customized sizing.
10) Troubleshooting: Pressure, Taste, & When to Service
Low Pressure After Install
- Check the Big Blue sediment cartridge for clogging
- Verify carbon tank backwash frequency and flow rate
- Inspect for iron fouling upstream (treat iron/sulfur first)
Taste/Odor Returns
- Replace RO post-carbon polisher
- Service carbon/anion tanks approaching end of capacity
- Re-test to confirm breakthrough
Pro move: Put calendar reminders for filter changes and a simple log near your pressure tank.
11) Buyer’s Checklist & Next Steps
- Order a PFAS-capable lab test and collect samples properly
- Address sediment and iron/sulfur upstream to protect carbon
- Size carbon/anion tanks for peak flow and adequate contact time
- Add an RO at the kitchen sink for maximum drinking-water protection
- Consider UV for microbial safety (PFAS needs filtration; UV is for microbes)
- Set maintenance reminders and plan periodic verification testing
12) References & Further Reading
- EPA: Identifying Drinking Water Filters Certified to Reduce PFAS.
- Consumer Reports: How to Get PFAS Out of Your Drinking Water.
- Water Softener Plus: Reverse Osmosis: How Membrane Filtration Removes Contaminants.
- Water Softener Plus: America’s Contaminated Drinking Water: Health Risks from Metals and PFAS.
- Water Softener Plus: Water Testing Procedures: Step-by-Step Guide.
All internal product links in this article point to live pages on WaterSoftenerPlus.com at time of publication.