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National Water Service
A Maryland water treatment and plumbing company that says it serves all of Washington, DC. Its DC page covers compact softeners for condos and townhomes, catalytic carbon filtration for chloramine, reverse osmosis and free in-home water testing; it also handles well water and commercial systems.
Services listed on its website
- Water softeners
- Reverse osmosis
- Whole-house filtration
- Well water treatment
- Water testing
- UV disinfection
- Iron and sulfur removal
- Commercial water treatment
- Water heater/plumbing
Areas it says it serves
- Washington, DC
- Georgetown
- Capitol Hill
- Dupont Circle
- Columbia Heights
- Petworth
- Anacostia
- Montgomery County
- Howard County
- Frederick County
- Loudoun County
- Fairfax County
- Prince William County
Information taken from the company's own website (nationalwaterservice.com) in November 2026. We have not verified licenses and do not rate or endorse this company. Request a correction or removal.