Fairfax Water water, explained
Fairfax Water meets or exceeds state and federal standards. The everyday complaints in its territory are scale on fixtures and glassware, dry skin after showering, and a chlorine taste that gets stronger in spring.
Water utility
Fairfax Water
- Hardness
- 5 to 10 grains per gallon
- Moderately hard to hard
- Disinfectant
- Chloramine
- Needs catalytic carbon
- Source
- Potomac River (Corbalis plant) and the Occoquan Reservoir (Griffith plant)
Serves: Fairfax County, the City of Fairfax, Herndon, Vienna and Fort Belvoir directly, and wholesale to Alexandria, Loudoun Water and Prince William Water.
Checked September 2026. Source: Fairfax Water annual water quality report.
Hardness: 5 to 10 grains per gallon
Fairfax Water reports 5 to 10 grains per gallon (84 to 170 mg/L), varying with location, season and rainfall. Anything above 7 grains per gallon is classified as hard. In practice that means scale on fixtures and shower glass, spotted dishes and mineral buildup inside water heaters and tankless units.
Disinfectant: Chloramine
Fairfax Water disinfects with chloramine (chlorine bonded to ammonia). Standard carbon cartridges remove chloramine poorly; catalytic carbon is the right media.
Seasonal changes: Each spring the system switches to free chlorine for several weeks to flush the distribution pipes. Many homeowners notice a stronger pool smell during that window.
PFAS
Utilities that draw from the Potomac have reported low-level PFAS detections in routine monitoring. EPA finalized limits for PFOA and PFOS in 2024. An under-sink reverse osmosis system certified to NSF/ANSI 58 is the practical fix at the tap you drink from.
Lead
Lead does not come from the treatment plant. It comes from older home plumbing: pre-1986 solder, older brass fixtures and, in some neighborhoods, lead service lines. A point-of-use filter certified to NSF/ANSI 53 for lead, or reverse osmosis, addresses it at the tap.
What we recommend on Fairfax Water water
A whole-home softener sized for 5 to 10 grains, catalytic carbon for chloramine, and an under-sink reverse osmosis unit for drinking and cooking water.
Figures checked September 2026 against Fairfax Water annual water quality report. Utilities update reports annually; if you see a newer figure, tell us and we will update this page.
Pricing for Fairfax Water homes
Prices include equipment, a licensed plumber's installation and startup for a standard install. If anything about your home changes the price, you hear it before we book the plumber, not after.
Whole-Home + Drinking Water
The complete package for a municipal-water home.
$2,499installed
- Metered whole-home softener
- Catalytic carbon for chloramine and chlorine
- Sediment pre-filter and bypass
- 5-stage under-sink reverse osmosis with faucet
- Licensed installation, startup and salt
Whole-Home Only
Soft, chlorine-free water at every tap and shower.
$1,899installed
- Metered whole-home softener
- Catalytic carbon media
- Sediment pre-filter and bypass
- Licensed installation, startup and salt
- Add reverse osmosis any time
Reverse Osmosis Only
Clean drinking water for condos and kitchens.
$799installed
- 5-stage NSF/ANSI 58 system
- Removes lead, PFAS and dissolved solids
- Dedicated lead-free faucet
- Optional fridge and ice line
- Licensed installation and first filters
Standard install covers
- Main water line, a drain and an outlet within reach in a basement, garage or utility room
- Kitchen sink with cabinet space for the reverse osmosis unit
- Copper or PEX supply lines in serviceable condition
- Permit where your jurisdiction requires one
Quoted before we book
- Long plumbing runs to reach the main line, or adding a drain or outlet
- Crawlspace or exterior installs, and galvanized pipe that needs replacing
- Private wells: lab test first, then a system designed to the results
- Fridge and ice maker line for the reverse osmosis unit