Fairfax County Water Authority water quality
Herndon, VA · serves 1.1 million people (281,686 connections) · Surface water · Local government · EPA ID VA6059501
Data: U.S. EPA · How we read the data · How we check it
Buys water from Washington Aqueduct Division.. Treated water bought from another system can carry that system's contaminants.
Summary
PFAS above the 2024 federal limits. Systems have until 2029 to meet the PFAS limits.
Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, and nothing in EPA's data calls for you to stop drinking the water today. If your utility ever issues a boil-water or do-not-drink notice, follow it.
- PFAS
- Above limitPFOA above the federal limit in EPA's 2023–2025 testing (PFOA 4.63 ppt vs a limit of 4 ppt, where ppt = parts per trillion).
- Lead
- Below action level1.2 ppb (parts per billion) at the 90th percentile: 9 in 10 homes sampled were at or below it. Action level 15 ppb, falling to 10 ppb in Nov 2027. Monitoring period ending Dec 2023. Your home's pipes can make yours higher.
- Violations
- None health-basedNo health-based violations since 2016.
- Pregnant, or mixing baby formula with tap water? Babies drink more water for their size, so PFAS exposure matters more for them. Consider bottled water or a filter certified for PFAS for formula, and ask your doctor. Health effects.
- To lower your PFAS exposure now, a home filter certified for PFAS reduction works (reverse osmosis, or activated carbon certified to NSF/ANSI 53 or 58). Filters for these results.
- Built before 1986, or not sure what your service line is made of? Check your service line and test your tap. Utility data can't show your pipes.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read Fairfax County Water Authority's 2026 water quality report (Consumer Confidence Report, from the utility). It lists every regulated contaminant tested, including ones not on this page. Questions: (703) 289-6568.
PFAS (“forever chemicals”)
EPA UCMR 5: 6 entry points tested Mar 2024 to Feb 2025. "Average" is the highest entry-point average (non-detects counted as zero), the way EPA compares UCMR 5 results to the limits. ppt = parts per trillion. These results do not determine compliance.
| Contaminant | Highest average |
|---|---|
| PFOA Above limit Limit 4 ppt | 4.63 ppt 1.16× the limit |
| PFOS One sample above limit Limit 4 ppt | 2.6 ppt 65% of the limit |
| PFHxS Not detected Limit 10 ppt | – |
| PFNA Not detected Limit 10 ppt | – |
| HFPO-DA (GenX) Not detected Limit 10 ppt | – |
| Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit) Detected, below limit Limit 1 | 0.003 |
| PFBS Detected, below limit Guideline 2,000 ppt | 5.95 ppt |
| PFBA Detected, below limit Guideline 6,000 ppt | 11.2 ppt |
| PFHxA Detected, below limit Guideline 3,000 ppt | 11.5 ppt |
| PFPeA Detected, no limit | 14.1 ppt |
| PFHpA Detected, no limit | 3.6 ppt |
| 6:2 FTS Detected, no limit | 2.52 ppt |
What the utility says it is doing: In a February 2026 presentation, Fairfax Water said its board approved a contract in November 2025 to replace the Griffith plant's powdered activated carbon feed system, with construction from fall 2026 to December 2027. It is also evaluating biofilters and new GAC/ion-exchange filters.
Source: The PFAS Challenge at Fairfax Water (Feb. 23, 2026), 2026-02-23. Collected by us on Nov 14, 2026, not from EPA's data. Ask the utility for the latest.
For context: the PFOA average is higher than at 96% of the Virginia systems EPA tested.
29 PFAS tested, 8 detected at least once. "Not detected" means below EPA's reporting limit (about 2 to 20 ppt depending on the chemical), not proven zero. PFAS not listed were not detected. The limits for PFHxS, PFNA, GenX and the Hazard Index were proposed for rescission in May 2026. That proposal is not final. Systems have until 2029 to meet the limits.
Lithium
Not detected in 24 samples (reporting limit 9 ppb). About lithium.
Lead and copper
Latest 90th percentile: 1.2 ppb lead (Jan 2021 – Dec 2023). Below action level
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2021 – Dec 2023 | 1.2 ppb |
| Jan 2018 – Dec 2020 | 1 ppb |
| Jan 2015 – Dec 2017 | 0.63 ppb |
Earlier results (9)
| Jan 2012 – Dec 2014 | 0.78 ppb |
| Jan 2009 – Dec 2011 | 0.8 ppb |
| Jul 2007 – Dec 2007 | 1 ppb |
| Jan 2007 – Jun 2007 | 1.3 ppb |
| Jan 2003 – Dec 2005 | 1 ppb |
| Jan 2002 – Dec 2002 | 2 ppb |
| Jan 2001 – Dec 2001 | 13 ppb |
| Jan 2000 – Jun 2000 | 12 ppb |
| Jul 1999 – Dec 1999 | 13 ppb |
Lead comes from pipes and fixtures, not the source water, so it varies home to home. The 90th percentile means 9 in 10 sampled homes were at or below it. More on lead.
Violations
Health-based violations mean a contaminant exceeded a limit or a required treatment step was missed. Monitoring and reporting violations mean required tests or reports were late or missing, so the water's quality during that time is unknown. The total includes every violation in EPA's records, most of them paperwork.
Earlier EPA testing (2013–2020)
| Contaminant | Highest | Guideline |
|---|---|---|
| Manganese | 3.1 ppb | 300 ppb |
| Strontium | 0.18 ppm | 1.5 ppm |
| Chromium-6 | 0.18 ppb | – |
| Chlorate | 400 ppb | 210 ppb |
| Vanadium | 0.76 ppb | 21 ppb |
| Molybdenum | 1.7 ppb | 40 ppb |
Where it serves
Herndon, Arlington, Great Falls, McLean, Reston, Alexandria, Bull Run, Mason Neck, Chantilly, Union Mill, Wolf Trap, Oakton, Fairfax Station, Fort Belvoir, Burke, Difficult Run, Annandale, Springfield, Braddock, Fort Hunt, Rose Hill, Sterling, Mount Vernon, Fair Oaks, West Falls Church, West Springfield, Franklin Farm, Lincolnia, Vienna, Groveton, Newington Forest, Kings Park West, Kingstowne, Idylwood, Lake Barcroft, Mantua, Dunn Loring, Bailey's Crossroads, Falls Church, Belle Haven, North Springfield, Huntington
61 ZIP codes the system reported serving
20120, 20121, 20124, 20151, 20153, 20164, 20170, 20171, 20190, 20191, 20192, 20194, 20195, 22003, 22015, 22027, 22030, 22031, 22032, 22033, 22035, 22039, 22040, 22041, 22042, 22043, 22044, 22046, 22060, 22066, 22079, 22096, 22101, 22102, 22122, 22124, 22150, 22151, 22152, 22153, 22180, 22181, 22182, 22203, 22204, 22206, 22209, 22301, 22302, 22303, 22304, 22305, 22306, 22307, 22308, 22309, 22310, 22311, 22312, 22314, 22315
Nearby utilities
- Loudoun Water – Central System Ashburn · 6 mi
- Town of Leesburg Leesburg · 13 mi
- Arlington County Water System Arlington · 17 mi
- Prince William Water – West Buckhall · 18 mi
- City of Alexandria Alexandria · 19 mi
- Town of Purcellville Purcellville · 21 mi · PFAS above limit
Questions
Is Fairfax County Water Authority water safe to drink?
Fairfax County Water Authority has no health-based violations since 2016. EPA testing found PFAS above the 2024 federal limits, which systems must meet by 2029. Federal data can't tell you about your own pipes: lead comes from service lines and plumbing, so test your tap if your home was built before 1986. For the official word, read the utility's annual Consumer Confidence Report.
Does Fairfax County Water Authority water have PFAS?
Yes. EPA's 2023–2025 testing of Fairfax County Water Authority found 8 PFAS at least once. The highest entry-point averages were above the federal limit for PFOA: PFOA 4.63 ppt (limit 4 ppt for PFOA and PFOS, 10 ppt for the others).
What is the lead level in Fairfax County Water Authority water?
The most recent 90th-percentile lead result for Fairfax County Water Authority is 1.2 ppb, for the period ending Dec 2023. The federal action level is 15 ppb, falling to 10 ppb in November 2027. The 90th percentile means 9 in 10 homes sampled were at or below this number. Individual homes can be higher.
Check these numbers yourself
Every figure on this page comes from public EPA records. You don't have to take our word for it:
- EPA's own report for VA6059501: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID VA6059501).
- EPA SDWIS download: the lead results, population and violation records we use.
- Fairfax County Water Authority's 2026 water quality report: the utility's own annual report, including contaminants EPA's national database doesn't carry (link checked Nov 14, 2026). Phone: (703) 289-6568.
- Fairfax County Water Authority website
Found something that doesn't match? Tell us and we'll check it against EPA's records. How we check our data.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.