DC Water water, explained
DC water is only moderately hard, so the softener conversation is about comfort and appliance life rather than heavy scale. The bigger issues for DC homeowners are chloramine taste and the age of home plumbing.
Water utility
DC Water
- Hardness
- 4 to 7 grains per gallon
- Moderately hard
- Disinfectant
- Chloramine
- Needs catalytic carbon
- Source
- Potomac River, treated by the Washington Aqueduct (Dalecarlia and McMillan plants)
Serves: All of Washington, DC.
Checked September 2026. Source: DC Water drinking water quality FAQ.
Hardness: 4 to 7 grains per gallon
DC Water describes its water as moderately hard and publishes a range of 70 to 120 ppm, which is roughly 4 to 7 grains per gallon. 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
DC Water uses chloramine year-round. It is gentler on taste than free chlorine but harder to filter; catalytic carbon media is required.
Seasonal changes: Every spring DC Water temporarily switches to free chlorine to clean the pipes. The chlorine smell is strongest during those 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
DC still has lead service lines in many older neighborhoods, and DC Water runs a replacement program (Lead Free DC). If your home was built before 1960, treat lead as a real possibility until the service line is confirmed. DC Water itself recommends point-of-use filters certified for 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 DC Water water
For rowhouses and single-family homes, a compact softener with catalytic carbon plus under-sink reverse osmosis. For condos and apartments, an under-sink reverse osmosis system certified for lead and PFAS is the right-sized answer.
Figures checked September 2026 against DC Water drinking water quality FAQ. Utilities update reports annually; if you see a newer figure, tell us and we will update this page.
Pricing for DC 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