Your family deserves reliable, high-quality water. At National Water Service, we provide expert residential water treatment solutions throughout Maryland, Washington D.C., and Northern Virginia (NoVA). Whether you’re on city water or a private well, our specialists diagnose problems and install customized home water filtration systems to ensure safe, clean water for your household.
Before choosing a water treatment system, it’s essential to know what’s in your water. That’s why we offer a free basic water analysis for homeowners across MD, DC, and Northern Virginia. Our tests identify:
Hard water minerals (calcium, magnesium)
Iron, rust, and sediment buildup
Chlorine, sulfur, or other odors
Corrosion or acidic water
Harmful bacteria and contaminants
Need deeper insight? We also provide advanced water testing services for virtually any contaminant.
From Rockville to Darnestown, Arlington to Alexandria, Bethesda to Washington D.C., our residential water treatment services fix issues like:
At National Water Service, we provide comprehensive solutions to keep your home’s water clean, safe, and reliable. From advanced filtration to well and plumbing services, we cover every aspect of residential water treatment across Maryland, Washington D.C., and Northern Virginia.






We diagnose and solve home water-quality issues, whether you’re on city water or a private well. Our services include whole-home filtration systems, water softeners, corrosion control, iron/sediment removal, odor and taste improvement, flow/pressure optimization, and pump/pressure-tank support.
Yes. We provide a free basic water analysis for homeowners in Maryland, D.C., and Northern Virginia. The test identifies hard-water minerals (calcium, magnesium), iron/rust/sediment, chlorine/odor issues, acidic or corrosive water, and more. For deeper issues we also provide advanced contaminant testing.
Some common signs include:
Scale buildup on fixtures or appliances (hard water)
Brown, rusty or cloudy water (iron/sediment)
Chlorine or sulfur (rotten-egg) smells/odors
Corrosion/pinhole leaks in plumbing
Low water pressure or unpleasant taste
If you’re noticing one or more of these, an evaluation is highly recommended.
Yes — our residential water treatment services cover both municipal water connections and private well systems. If you have a well, we also integrate pump, pressure tank, and well-yield solutions into the treatment plan.
We serve homeowners across Maryland, Washington D.C., and Northern Virginia (NoVA).
Typically the process is:
Perform water testing and analysis to identify what’s in the water.
Based on the results, design a customized solution tailored to your water quality and household usage.
Install the system — whole-home filtration, softener, corrosion/iron control, etc.
Provide maintenance plan and monitoring to ensure system remains effective over time.
Annual maintenance is strongly recommended for most systems to ensure the media, filters, and components are performing correctly, preventing system degradation or failures. Regular inspections extend equipment life and maintain water quality.
Yes. We evaluate your current setup (if you already have a water treatment or well-pump system) and provide upgrades or replacements as needed. We also install new systems where none exist.
Our services can address hard water minerals (calcium, magnesium), iron/rust/sediment, chlorine/odor issues, corrosion/acidic water, bacteria (for well systems), and more advanced contaminants via proper testing.
Simply contact us at 301-854-1333, or submit a request online. We’ll schedule your free basic water test and walk you through the options tailored for your home.
Don’t wait until water problems damage your home or health. Contact National Water Service today for free water testing and consultation in Maryland, DC, or Northern Virginia.
We proudly serve homeowners across:
Maryland: Montgomery County, Frederick County, Howard County, and more
Washington D.C.: All neighborhoods, from Capitol Hill to Georgetown
Northern Virginia (NoVA): Arlington, Alexandria, Fairfax, Loudoun County, and surrounding areas
With over 45+ years of experience in water repair and management, we are proud to offer dedicated Water Techs & Master Plumbers to homes and businesses. Get affordable pricing, competitive quotes, and quality materials that last.