Is Arlington, VA Tap Water Safe to Drink? A Detailed Look

Arlington tap water meets every federal and state standard, and the county says so in its annual report. That doesn't mean it's pure. The water is treated Potomac River water that contains a disinfectant, small amounts of byproducts from that disinfection, and trace levels of PFAS. Lead is rarely a problem in the county's pipes, but it can come from older plumbing inside your home. This guide covers what's in Arlington, VA tap water, what the testing shows, and how to filter it if you want extra protection.

Where does Arlington, VA tap water come from?

Arlington doesn't clean its own water. The county buys it from the Washington Aqueduct, which is run by the U.S. Army Corps of Engineers. The Aqueduct takes water from the Potomac River and treats it at two plants in Washington, D.C. Arlington's water comes from the Dalecarlia plant, then gets pumped across the river to the county. It serves about 38,000 service connections and delivered roughly 7.2 billion gallons in 2023. One section of the county, called the Willston zone, gets its water through Fairfax Water, which also buys from the Aqueduct. That zone is tested separately and has its own report.

Does Arlington tap water have PFAS?

PFAS are the "forever chemicals" found in things like nonstick pans and stain-resistant fabrics. Arlington's PFAS page says the county has joined several rounds of testing and no result went above the new federal limits. Those limits are 4 parts per trillion each for the two best-known PFAS, PFOA and PFOS. A few other PFAS do appear at very low levels. Fairfax Water's tests of treated Aqueduct water found two of them, at 4 and 5 parts per trillion at most, and neither has a federal limit. EWG lists one of them, PFPeA, at 1.5 parts per trillion in Arlington, compared with its own guideline of 1,000.

The PFAS rules may change. In May 2026, EPA proposed keeping the 4 parts per trillion limits but giving utilities the option to take two extra years to meet them, moving the deadline from 2029 to 2031. It also proposed dropping limits on four other PFAS. As of my last check, those were still proposals and not final.

Is there lead in Arlington's water?

Lead is mostly a problem inside homes, not in the water leaving the plant. The county checked its pipes in 2024 and found no lead service lines in its system, and it says it never used lead pipe on its side of the connection. If lead shows up at your tap, it most likely comes from older solder, faucets, or pipes inside your house. The region does have a history here. In 2000, the Aqueduct changed its disinfectant without adjusting how it protected pipes from corrosion, and lead leached into water across D.C. Arlington was part of the 2004 response because it received the same water. Since then, the Aqueduct has added a chemical called orthophosphate that coats pipes and keeps lead from dissolving.

The rules are getting stricter. A 2024 federal rule lowers the lead action level from 15 to 10 parts per billion and requires utilities to replace lead service lines within 10 years, with compliance starting November 1, 2027. Water industry groups have challenged the rule in court, so check the latest status.

Why does Arlington tap water smell like chlorine?

For most of the year, the water is disinfected with chloramine, a mix of chlorine and ammonia. It stays active in the pipes longer than chlorine alone, and it creates fewer unwanted byproducts. Every spring, the Aqueduct switches to plain chlorine for several weeks to clean out the water mains. In 2026 that ran from March 23 to May 4 for most of Arlington, and through May 26 for the Willston zone. During that time your tap water may smell like a pool. Leaving an open pitcher in the fridge for a few hours makes the smell fade. If you keep fish or use dialysis equipment, you need to remove chloramine from your water, and the same steps work for chlorine.

What are disinfection byproducts in Arlington water?

This is the most debated part of Arlington's water. When chlorine kills germs, it also reacts with natural material in river water and creates byproducts. The two main groups are called TTHMs and HAA5. The legal limits are 80 parts per billion for TTHMs and 60 for HAA5, measured as yearly averages. The county's reports show the plant removes more natural material than required before disinfecting, which keeps byproducts down. In 2017, for example, the county's highest yearly average for TTHMs was 48, well under the limit of 80. The environmental group EWG also found the system met federal health standards for the most recent period it checked, April to June 2024.

The disagreement comes down to which standard you use. EWG sets its own health guidelines, and they're far stricter than the law. One rating site uses them and gives Arlington a D, since the levels look hundreds of times higher than those targets. The legal limits are higher because they also account for cost and what's practical for utilities. Some of these byproducts are suspected to raise cancer risk after many years of heavy exposure, so the concern is real. Still, Arlington is within the law.

Was Arlington's water affected by the 2026 Potomac sewage spill?

No. On January 19, 2026, a large sewer pipe collapsed near the Clara Barton Parkway in Maryland and sent hundreds of millions of gallons of sewage into the Potomac. The county's figure is more than 200 million gallons, and EPA's is at least 240 million. Officials said drinking water was not affected, since the main intake at Great Falls is upstream of the break, and a backup intake downstream was not in use. The county kept testing its water and its local streams, and found low bacteria levels. Routine testing in 2024 also looked good. The highest monthly rate of total coliform bacteria was 1.44%, well under the 5% limit, and none of the monthly samples had E. coli.

Is Arlington water hard? What about fluoride?

Arlington's water is hard, with about 142 milligrams of minerals per liter, or 8 grains per gallon. That means you may see white scale on kettles and shower heads, and soap won't lather as well. It's a nuisance and not a health issue. Sodium is low at 34 parts per million, which works out to about 8 milligrams in a glass, compared with a daily limit of 2,300.

Fluoride is at 0.7 parts per million, which matches the level U.S. health officials have recommended since 2015 for preventing cavities. The legal maximum is 4. Fluoride is being debated right now. EPA started a faster review in early 2026, and Utah and Florida banned adding it in 2025, although local and state governments usually make that decision. If you'd rather avoid it, a reverse osmosis system removes fluoride, and most carbon pitcher filters do not.

Why do Arlington water quality ratings disagree?

If you search for Arlington's water quality, you'll find a D on one site and an A on another. They use the same public data but ask different questions. One site compares what's in the water to strict health guidelines, and the other checks whether the utility broke any legal limits. Arlington has no health-based violations, so it scores well on the second and poorly on the first. Neither site is wrong.

How to filter and protect your Arlington tap water Test for lead if your home is older. Lead solder was common until it was banned in 1986. A state-certified lab can test a sample from your tap. This matters most if you're pregnant or mixing baby formula. Flush your tap. DC Water suggests running cold water for two minutes, or five to 10 if it has sat for hours. Use cold water for drinking and cooking. Pick a filter that fits your concern. For lead, look for the NSF/ANSI 53 label. For PFAS, look for a PFOA/PFOS claim under NSF/ANSI 53 or 58. These filters reduce PFAS to 20 parts per trillion, which is above the 4 federal limit, so they cut it down but don't remove it all. For chlorine taste, look for NSF/ANSI 42. Always read the exact claims on the label. Read the yearly report. Every water utility must publish one by July 1, and Arlington posts its reports on the county website. Arlington tap water FAQ

Is Arlington, VA tap water safe to drink? Yes by legal standards. The county reports that it meets all federal and Virginia requirements, and the main concerns are low-level PFAS, chlorine byproducts, and lead from older home plumbing.

Does Arlington, VA have lead pipes? The county's 2024 inventory found no lead service lines in its system. Lead can still come from older solder and fixtures inside a home.

Does Arlington tap water have PFAS? Trace amounts of some PFAS have been detected in the Aqueduct's treated water. The county says none of its results exceeded the federal limits for PFOA and PFOS.

Why does Arlington water taste like chlorine in spring? The Aqueduct switches from chloramine to chlorine each spring to clean the water mains. In 2026 it ran from March 23 to May 4 for most of the county.

Is Arlington water hard or soft? It's hard, at about 142 mg/L, so expect some scale on kettles and fixtures.

The bottom line

Arlington tap water is safe by legal standards, and it comes from a closely monitored source. Three things are worth keeping an eye on. Disinfection byproducts are the most debated, PFAS rules are still changing, and lead risk comes from older plumbing inside individual homes. If you want extra peace of mind, a certified filter matched to your concern is an easy and affordable step.

These figures come from Arlington County's reports, the EWG Tap Water Database, EPA and DC Water notices, and coverage of EPA's 2026 proposals, current as of October 1, 2026. Check the county's latest report for updated numbers.