Loudoun Water water, explained
Loudoun Water serves the newer, fast-growing part of the county. Hardness shows up quickly in the tankless water heaters and high-end fixtures common in Ashburn and Brambleton homes.
Water utility
Loudoun Water
- Hardness
- about 5 to 10 grains per gallon
- Moderately hard to hard (approximate, confirm with latest report)
- Disinfectant
- Chloramine
- Needs catalytic carbon
- Source
- Potomac River (Trap Rock plant) plus water purchased from Fairfax Water
Serves: Eastern and central Loudoun County: Ashburn, Sterling, South Riding, Brambleton, Broadlands, Lansdowne and the Dulles corridor.
Checked September 2026. Source: Loudoun Water drinking water quality page.
Hardness: about 5 to 10 grains per gallon
Loudoun Water treats Potomac water and blends in Fairfax Water supply, so hardness is in the same moderately hard to hard band. Confirm the current value 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
Loudoun Water reports chloramine disinfection for its central system. Catalytic carbon is needed to remove it.
Seasonal changes: Loudoun Water performs a spring free-chlorine conversion in step with Fairfax Water. Taste and smell change for a few weeks.
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
Most of eastern Loudoun was built after 1986, so lead solder is rare. 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 Loudoun Water water
Whole-home softener with catalytic carbon to protect tankless heaters and glass shower enclosures, plus under-sink reverse osmosis. Western Loudoun homes on wells need a lab test first.
Figures checked September 2026 against Loudoun Water drinking water quality page. Utilities update reports annually; if you see a newer figure, tell us and we will update this page.
Areas on Loudoun Water water
Pricing for Loudoun 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