Fluoride in Fairfax Water tap water, month by month

By Shield Dental Care · Published November 11, 2026 · Data through August 2026

Fluoride, month by month

Fairfax Water says about 2.2 million people in Northern Virginia depend on its water, in Fairfax, Loudoun, Prince William, Alexandria, Falls Church and other communities. It treats water at two plants. Fairfax Water says homes toward the north end of Fairfax County generally get water from its Corbalis Treatment Plant and more southern locations from its Griffith Treatment Plant. Each month its laboratory publishes results for the water leaving each plant and for a sampling site in the distribution pipes that represents each plant. The chart shows the two distribution sites, the closest of the four to what comes out of a tap; the table gives all four.

• Griffith area (south)
• Corbalis area (north)
• 0.7 mg/L recommended level
• Below 0.2 mg/L

Each point is the one result Fairfax Water publishes for that month at that sampling site. Gaps are months with no sample (February 2026). The EPA limit, 4.0 mg/L, is far above the top of this chart. Source: Fairfax Water monthly water quality analytical reports, January 2024 to August 2026.

Monthly fluoride results, mg/L, January 2024 to August 2026

“In the pipes” is the report Fairfax Water labels “Distribution Site Representing” each plant; “leaving the plant” is the plant’s finished water. Below 0.2 means the report shows BQL, below the lowest level its lab measures. ^** The report marks these two results with a double asterisk and prints no note explaining it. Reports by year: 2024 (Griffith pipes, Griffith plant, Corbalis pipes, Corbalis plant); 2025 (Griffith pipes, Griffith plant, Corbalis pipes, Corbalis plant); 2026 (Griffith pipes, Griffith plant, Corbalis pipes, Corbalis plant). Download this table as a CSV.

What the reports show

• Close to 0.7 mg/L in most months. Over 32 months the median result was 0.7 mg/L at both distribution sites, and 53% of the 112 numeric results across all four sampling points were exactly 0.7 mg/L.
• North and south moved together, with two exceptions. In January 2024 and June 2025 both southern sampling points, the Griffith plant and its distribution site, reported fluoride below 0.2 mg/L, while the northern points read 0.7 mg/L. Both southern points also read 0.4 mg/L in January 2025. The reports do not give a reason, and we do not guess at one.
• Well under the federal limits. The highest result in the period, 0.8 mg/L, is 20% of EPA's enforceable limit of 4.0 mg/L and below its secondary standard of 2.0 mg/L.
• Still fluoridated in the latest report. August 2026, the latest month published, was 0.6 mg/L at all four sampling points, and Fairfax Water's fluoride page gives its current treatment target as 0.7 ppm.

Recommendations and rules, with dates

• In 2015 the U.S. Public Health Service set 0.7 mg/L as the recommended fluoride level for community water systems that add fluoride, replacing the range of 0.7 to 1.2 mg/L it had recommended since 1962. (Virginia Department of Health, Fluoridation)
• Virginia's State Board of Health and Department of Health recommend that community water systems deliver that level, and systems that adjust fluoride monitor it daily. (Virginia Department of Health, Fluoridation)
• Fairfax Water says it adds fluoride at the request of federal and state public health agencies and that its current treatment target is 0.7 ppm. A part per million (ppm) is the same as a milligram per liter (mg/L). (Fairfax Water, Facts About Fluoride)
• EPA's enforceable limit for fluoride in drinking water is 4.0 mg/L, set in 1986 and most recently reviewed in 2024. Its secondary, non-enforceable standard is 2.0 mg/L. (EPA; Virginia Department of Health)
• On January 22, 2026, EPA released a preliminary plan for a new assessment of fluoride's health effects, and on August 3, 2026 it released the protocol for that assessment. EPA says the finished assessment will inform potential revisions to federal drinking water rules. (EPA, Fluoride in Drinking Water; EPA news release)
• In Virginia's 2026 legislative session, House Bill 537, which would have required the Board of Health to prohibit fluoridation of water, was left in committee on February 18, 2026. The legislature's bill record lists it as failed. (Virginia Legislative Information System, HB 537 (2026))

This page reports measured levels and official guidance. It does not take a position on whether communities should fluoridate their water.

What this means for families in Burke and Springfield

• If your home is on Fairfax Water, your tap water is fluoridated. The latest published results were 0.6 mg/L in August 2026, and in most months since January 2024 the results sat between 0.6 and 0.8 mg/L. The table above lists every month, including the exceptions.
• Which plant serves your street is not published address by address. Fairfax Water says northern homes generally get Corbalis water and more southern homes Griffith water, and its annual water quality report has a service area map. The chart shows both.
• What you drink can differ from the tap. Reverse osmosis filters, most bottled water and private wells change how much fluoride you get. Our article Is Springfield, VA tap water fluoridated? explains those cases.
• Mention your water source at checkups. Tell your dentist and your child's pediatrician which water your household mainly drinks.

Method

We downloaded the 12 Fairfax Water monthly water quality analytical reports (inorganics) for its two treatment plants and the two distribution sampling sites that represent them, for 2024, 2025 and 2026, on November 11, 2026. A script reads the Fluoride row of each report by column position, so a blank month cannot shift a result into the wrong month, and records each month as a number, as below the quantitation limit (BQL), or as not sampled. Counts and medians use the numeric results only. “0.6 to 0.8 mg/L” counts results of 0.6, 0.7 and 0.8; BQL months count as outside that range. The August figures come from the 2026 report generated September 8, 2026, which Fairfax Water updates as months are added. The script, the raw reports and their checksums are kept with the site's source code.

Sources

• Fairfax Water, Water Quality Analytical Reports, Fairfax Water service area: Griffith and Corbalis treatment plant finished water and the distribution sites representing each plant, January 2024 to August 2026. fairfaxwater.org/imar_fairfax-water-service-area
• Fairfax Water, Facts About Fluoride (treatment target). fairfaxwater.org/fluoride
• Fairfax Water, About Us (people served, water purchased from the Washington Aqueduct). fairfaxwater.org/about-us
• Virginia Department of Health, Office of Drinking Water, Fluoridation. vdh.virginia.gov/drinking-water/office-of-drinking-water/fluoridation
• U.S. EPA, Fluoride in Drinking Water (page updated August 3, 2026). epa.gov/sdwa/fluoride-drinking-water
• Virginia Legislative Information System, HB 537, 2026 Regular Session. lis.virginia.gov/bill-details/20261/HB537

Limits

• The reports give one result per sampling point per month. Systems that adjust fluoride monitor it daily (Virginia Department of Health), so a monthly figure cannot show changes within a month.
• The sampling sites represent each plant's water in the system. They are not your tap, and the water a given street receives can come from either plant.
• Results are published to one decimal place, and the lab reports anything under 0.2 mg/L only as BQL.
• The plants were not sampled every month: 5 of 32 months have no plant result for Griffith and 5 for Corbalis.
• Fairfax Water also buys water from the Washington Aqueduct's McMillan and Dalecarlia plants in Washington, D.C. Those plants are not covered by the reports used here. Other Northern Virginia water utilities are not included.
• This is a summary of public data, not medical advice.

Cite this study

Shield Dental Care. “Fluoride in Fairfax Water tap water, month by month.” Published November 11, 2026. Data: Fairfax Water monthly water quality analytical reports, January 2024 to August 2026. https://shielddentalcare.com/research/fluoride-northern-virginia-tap-water/

The table is free to reuse under a Creative Commons Attribution 4.0 license with a link to this page: download the CSV (128 rows: one per month and sampling point, with the source report for each).