Prince William Water water, explained
Prince William Water (formerly the Prince William County Service Authority) delivers Fairfax-quality water to a county full of 1980s to 2010s single-family homes with basements and garages, which makes installs straightforward.
Water utility
Prince William Water
- Hardness
- about 5 to 10 grains per gallon
- Moderately hard to hard (approximate, confirm with latest report)
- Disinfectant
- Chloramine
- Needs catalytic carbon
- Source
- Mostly treated water purchased from Fairfax Water (Occoquan), with some supply from the City of Manassas (Lake Manassas)
Serves: Woodbridge, Dale City, Lake Ridge, Dumfries, Gainesville, Bristow, Haymarket and unincorporated Prince William County.
Checked September 2026. Source: Prince William Water.
Hardness: about 5 to 10 grains per gallon
Most Prince William Water customers receive Fairfax Water supply (5 to 10 grains). Western areas blended with Manassas supply can differ. Confirm in the annual report. 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-supplied areas carry a chloramine residual, so catalytic carbon is the correct media.
Seasonal changes: Expect a spring free-chlorine period in step with Fairfax Water.
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 Prince William Water water
Whole-home softener with catalytic carbon in the basement or garage, plus under-sink reverse osmosis.
Figures checked September 2026 against Prince William Water. Utilities update reports annually; if you see a newer figure, tell us and we will update this page.
Areas on Prince William Water water
Pricing for Prince William 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