PFOS/PFOA (PFAS) in Drinking Water
Synthetic Chemical · MCL: 4 ppt · 5 systems exceeding limit
Overview
PFAS are a group of thousands of synthetic chemicals used since the 1950s in non-stick cookware, waterproof clothing, food packaging, and firefighting foam. In April 2024, the EPA finalized the first-ever national drinking water standard for six PFAS compounds, setting maximum contaminant levels at 4 parts per trillion for PFOS and PFOA individually. The EPA Safe Drinking Water program sets and enforces the maximum contaminant levels shown here.
Health Effects
PFAS (per- and polyfluoroalkyl substances) are linked to cancer (kidney, testicular), thyroid disease, immune system suppression, reproductive problems, and developmental effects in children. PFAS accumulate in the body over time because they do not break down naturally, earning the nickname 'forever chemicals.'
Sources of Contamination
PFAS contamination comes from industrial facilities manufacturing or using PFAS, military bases where AFFF firefighting foam was used, wastewater treatment plants, and landfills. PFAS can travel through soil and groundwater for miles from the original contamination source.
Treatment & Removal
Granular activated carbon (GAC) filters, ion exchange treatment, and reverse osmosis can remove PFAS from drinking water. Home filters certified for PFAS removal (NSF P473) are effective at the point of use. Many water utilities are installing new treatment systems to meet the 2024 EPA PFAS standards.
How to Remove PFOS/PFOA (PFAS) From Water
These filtration methods are effective for reducing PFOS/PFOA (PFAS) in drinking water:
| Filter Method | Effectiveness | Cost Range | Certification |
|---|---|---|---|
| Reverse Osmosis (RO) | 90-99% removal | $200-500 (under-sink) | NSF/ANSI 58 |
| Activated Carbon Block | 70-95% removal | $40-100 (pitcher/under-sink) | NSF P473 |
| Ion Exchange Resin | 90-95% removal | $500-2000 (whole-house) | NSF/ANSI 53 |
| Nanofiltration | 90-99% removal | $1000-3000 (whole-house) | Varies |
Reverse Osmosis (RO), details
Most effective consumer option for PFAS. Removes PFOA, PFOS, and most other PFAS compounds.
Activated Carbon Block, details
Must have NSF P473 certification specifically for PFAS. Standard carbon pitchers are NOT effective.
Ion Exchange Resin, details
Effective for PFAS but requires regular media replacement. Higher upfront cost.
Nanofiltration, details
Professional installation required. Very effective but expensive.
Water Systems with PFOS/PFOA (PFAS) Detected
Tucson City Of
Tucson, Arizona
Mesa City Of
Mesa, Arizona
Tulsa
Tulsa, Oklahoma
Mobile, Bd. Of W&s Comm. Of the City Of
Mobile, Alabama
Gilbert, Town Of
Gilbert, Arizona
Chandler City Of
Chandler, Arizona
Provo City
Provo, Utah
Frequently Asked Questions
PFOS/PFOA (PFAS) has been detected in 5 water systems that exceed the EPA maximum contaminant level (MCL) of 4 ppt, affecting approximately 1,586,000 people. Check your local water system's annual Consumer Confidence Report or search by ZIP code on this site.
PFAS (per- and polyfluoroalkyl substances) are linked to cancer (kidney, testicular), thyroid disease, immune system suppression, reproductive problems, and developmental effects in children. PFAS accumulate in the body over time because they do not break down naturally, earning the nickname 'forever chemicals.'
Effective filtration methods for PFOS/PFOA (PFAS) include Reverse Osmosis (RO), Activated Carbon Block, Ion Exchange Resin, Nanofiltration. Look for filters certified to NSF/ANSI standards for PFOS/PFOA (PFAS) removal. See the detailed comparison table above for effectiveness ratings and cost ranges.
The EPA Maximum Contaminant Level (MCL) for PFOS/PFOA (PFAS) is 4 ppt. The MCL Goal (MCLG), the level with no known health risk, is 0 ppt. Water systems must test regularly and notify customers if levels exceed the MCL.