Proudly Serving Maryland, DC & NoVa for 46 Years
480+ Google 5 Star Reviews
Logo for National Water Service with a large blue N stylized to include a water droplet and circular design, followed by the words ational water service in dark blue text.
301-854-1333
Schedule Your Free Water Test

#1 Rated

Water Treatment & Filtration Services in Maryland, DC & NoVA

Clean, safe water for your family. Serving Montgomery, Howard, Frederick, Baltimore, Carroll, Prince George’s Counties in Maryland, District of Columbia & Northern Virginia

  • 47+ Years of Experience
  • Precision Workmanship
  • Emergency Services
  • Innovative Solutions
  • Family Atmosphere
  • Upfront & Competitive Pricing
  • Trusted Customer Service

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Green graphic with white text reading Winner of and a circular badge that says 2024 Neighborhood Faves nextdoor, featuring a trophy icon above—celebrating National Water Service for top-notch plumbing and well pump expertise.
A digital badge from Expertise.com reads Best Plumbers in Washington DC 2021 with a laurel wreath and geometric logo on a black background.
A dark blue circular badge with gold laurel leaves around the edge, a white star symbol at the top, and the text LOC8NEARME RECOMMENDS National Water Service above gold stars at the bottom.
Logo featuring MEMBER Water Quality Association in blue text with gold wave-like shapes and a gold star, highlighting BUSINESS EXCELLENCE below—ideal for businesses in well pump, plumbing, or water treatment industries.
Logo for the Eastern Water Quality Association. The text reads “Member EWQA” with a blue wave graphic under the large “A” and “Eastern Water Quality Association” below, representing excellence in Plumbing and Well Pump services.
A graphic with the text 5 Star Google Reviews Company featuring five gold stars above the Google logo, highlighting National Water Service as a highly rated well pump and water treatment company. The background is dark blue and white.

Maryland, DC & Northern VA

Water treatment

A basement utility area with water heaters, pipes, filters, tanks, and a water softener system mounted on a cinder block wall with exposed insulation and wiring.

Home Water Filtration

A reverse osmosis water filtration system for advanced water treatment, featuring three vertical filter housings, cylindrical tanks, and a curved metal faucet—all in white.

Reverse Osmosis Water Treatment

A water test kit for water testing is spread out on a paper towel atop a kitchen counter. Items include a blue box, test strips, liquid bottles, a dropper, a color chart, scissors, and a packet.

Water Testing

A Maryland Water Treatment water softener system with a tall, cylindrical resin tank and digital control head stands beside a round, lidded brine tank. Both light-colored units are set against a clean white background.

Water Softener

A tall, cylindrical beige water softener tank with a black base and a black control valve at the top, set against a plain white background—ideal for Maryland Water Treatment and reliable water testing.

Acid Neutralizer

A large, white, rectangular plastic water storage tank with a circular screw cap on top and a vertical rectangular cutout in the center front.

Storage Tanks

Water Treatment system in a basement with three large filter tanks and various pipes; text on the image lists functions: iron fighter, sulfur removal, water softener, radon reduction, sediment filter. Water testing ensures effective filtration.

Iron Breaker Sulphur Breaker - IBSB

A basement setup featuring a DurMax Booster Pump, pipes leading into a sump pit, and a large black tank labeled 99% Radon in Well Water Reduction—showcasing Maryland Water Treatment expertise with control panels and wiring on the wall.

Radon Removal

A water softener system with a tall fiberglass tank, digital control head, white brine tank, and pipes is installed in a Maryland basement with foil-covered insulation on the walls—perfect for homes needing reliable water testing.

KX Pro's

A large white plastic tank with black markings for liquid levels from 0 to 50 stands upright in a utility area beside a wall, pipes, a control box, and a smaller jug labeled Soft Clean—typical components of a water softener and filtration setup.

Chemical Feeder

A person uses a black plastic wrench to unscrew a blue and transparent water filter housing on plumbing pipes, an essential step in water treatment for cleaner, safer tap water.

Sediment Filtration

A blue industrial water pump with a cylindrical motor, mounted on a metal base, features bolts, labels, and an inlet opening on the front—ideal for Maryland water treatment or as part of a comprehensive water softener system.

Booster Pumps

Water treatment and purification system mounted on a wooden board, featuring multiple filter cartridges, a blue cylindrical filter, various pipes, labeled components, and reflective wall insulation—ideal for enhanced water quality and easy water testing.

UV Disinfection

A tall, cylindrical water softener tank with a light-colored fiberglass body, black base, and a black control valve on top featuring two red handles—ideal for efficient water filtration and treatment in Maryland homes.

Carbon Tanks

A water softener system with a large cylindrical tank, water treatment digital control head, and connected pipes is installed against a basement wall with a concrete block background.

Multi Media Systems

A Maryland Water Treatment system featuring large tanks, a blue pressure tank, water filtration units, and pipes is installed against a wall with reflective insulation. The concrete floor remains clear and clean.

Multi Media Systems

And More!

Water Treatment Repair

Water Treatment Install

Water Treatment Leak Fix

Emergency Water Services

How do I know which water treatment system is right for my home?

Every home’s water is different. We start by performing a free water test to identify specific contaminants (like iron, sulfur, sediment or chlorine). Based on the results, we recommend a customized solution—whether it’s a whole‑house filtration system, a reverse osmosis unit, a UV disinfection lamp or a combinationEvery home’s water is different. We start by performing a free water test to identify specific contaminants (like iron, sulfur, sediment or chlorine). Based on the results, we recommend a customized solution—whether it’s a whole‑house filtration system, a reverse osmosis unit, a UV disinfection lamp or a combination

Yes. We install and service systems for private wells and for city‑supplied water. For well water we often use sediment filters, neutralizers and softeners to address hardness, iron and odor issues. For municipal water we focus on removing chlorine, improving taste and protecting plumbing with carbon tanks and whole‑house filters.

A whole‑house (point‑of‑entry) system treats all the water coming into your home. It can remove sediments, chlorine, heavy metals and other contaminants, so every tap—from kitchen sink to shower—delivers clean, filtered water. It also helps extend the life of appliances and plumbing by reducing scale and corrosion

Most residential water‑treatment installations take 2–4 hours. We’ll schedule a convenient appointment, arrive on time and complete the work efficiently. You may experience a brief water shut‑off during installation, but we’ll keep interruptions to a minimum and test the system before we leave.

Maintenance frequency depends on the type of system and your water quality. Sediment and carbon filters typically need replacement every 6–12 months; UV lamps are usually changed annually; and reverse osmosis membranes last 2–3 years. We offer maintenance plans to ensure your system runs efficiently and to remind you when it’s time to service or replace filters.

We proudly serve homeowners across Montgomery, Howard, Frederick, Baltimore and Carroll counties, including cities like Rockville, Bethesda, Columbia, Ellicott City, Frederick, Westminster, Towson and surrounding communities. If you’re unsure whether we cover your area, just give us a call!

Coupons

An older man in military uniform salutes while facing a large American flag, blurred in the background—honoring service much like the dedication seen at the National Water Service.

$ 25 OFF

Installation and Service

For Active Duty Military, Veterans Or First Responders

A home water filtration and softener system is mounted on a wooden wall, featuring pipes, filters, a large white tank, two tall black and grey cylinders, control panels, and various components for water treatment.

$ 75 OFF

New Water Treatment

For New Customers Getting New Water Treatment Installs Only

A white plastic pipe with a capped top stands upright on a grassy lawn near a residential street, possibly related to leak detection services, with houses and trees visible in the background.

$ 100 OFF

New Well Pumps Installation

For New Customers Getting New Well Pump Installs Only

Two men stand at a table working together to repair or assemble an open electronic device. One man points while the other uses a tool, possibly for leak detection. Papers, a drink tumbler, and a thermos are on the table.

$ 25 OFF

Customer First Service Call

For New Customers Getting First Service Call

A plumber kneels on a cloth in a kitchen, working under the sink cabinet. Tools and cleaning supplies are on the counter, with a red plumbing machine in the foreground. The kitchen features wooden floors and dark wood cabinets.

$ 40 off

Any Plumbers Service Call

For use only one time per customer

Schedule Your Free Water Test

National Water Service

2878 Daisy Road, Woodbine, Maryland, 21798

301-854-1333

Service Area

Counties:

Montgomery County, Howard County, Frederick County, Baltimore county and Carroll County in Maryland.

Fairfax County, Alexandria County, Manassas County, Falls Church County, Arlington County, Loudoun County in Virginia

Areas and cities:

Rockville, Bethesda, Potomac, Silver Spring, Columbia, Ellicott City, Clarksville, Woodbine, Savage, North Laurel, Dayton, Glenwood, Cooksville, Ilchester, West Friendship, Jessup, Lisbon, Highland, Woodstock, Elkridge, Sykesville, Marriottsville, Glenelg, Frederick, Urbana, and Middletown, Westminster, Sykesville, Eldersburg, New Windsor, Union Bridge, Hampstead, Manchester, Taneytown, Towson, Kingsville, White Marsh, Lochearn, Reisterstown, Dundalk, Accokeek, Adelphi, Andrews AFB, Aquasco, Baden, Beltsville, Bladensburg, Bowie, Brandywine, Brock Hall, Camp Springs, Capitol Heights, Cedar Heights, Cheltenham, Chillum, Clinton, Coral Hills, Croom, District Heights, East Riverdale, Fairmount Heights, Fairwood, Forestville, Fort Washington, Friendly, Glassmanor, Glenarden, Glenn Dale, Greenbelt, Hyattsville, Kettering, Konterra, Lake Arbor, Landover, Landover Hills, Langley Park, Lanham, Largo, Marlboro Meadows, Marlboro Village, Marlton, Mitchellville, National Harbor, Oxon Hill, Palmer Park, Peppermill Village, Queen Anne, Queens Chapel, Queensdale, Queensland, Riverdale, Riverdale Park, Rosaryville, Seat Pleasant, Seabrook, Silver Hill, Springdale, Suitland, Summerfield, Temple Hills, Upper Marlboro, Walker Mill, Westphalia, West Laurel and Woodmore.

Fairfax, Reston, Herndon, McLean, Vienna, Great Falls, Annandale, Springfield, Burke, Lorton, Chantilly, Centreville, Clifton, Oakton, Falls Church, Arlington, Alexandria, Ashburn, Sterling, Leesburg, Purcellville, Middleburg, South Riding, Aldie, Brambleton, Cascades, Broadlands, Lovettsville, Round Hill, Manassas, Manassas Park, Haymarket, Gainesville, and Falls Church City.

District of Columbia

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Logo for National Water Service. The letter N is stylized with a blue water droplet below it, and the words “ational water service” appear to the right of the droplet design.