Is Arlington, VA Tap Water Safe to Drink?
Yes, Arlington tap water is safe to drink. Hardness is low at 38 PPM, and no contaminants exceed health guidelines. Most homes here don't need treatment.
Hardness Scale: Where Arlington Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How Arlington Compares
Arlington's water is 72% softer than the national average of 138 PPM - ranking in the bottom 77% for hardness nationwide. Most homes here do not need a softener. Within Virginia, it ranks #12 of 22 cities (25% below the state average of 51 PPM). Among large cities (200k-500k), Arlington ranks #131 of 165 for hardness.
What Arlington's Water Means for Your Home
Hardness: 38 PPM - Low Concern
Arlington's water is slightly hard at 38 PPM. Most households won't notice any issues at this level. Scale buildup is minimal, and a water softener would be overkill. Arlington is softer than 77% of US cities. If you're thinking about water treatment, contaminant filtration is where to focus your money, not softening.
Contaminants & Safety
Disinfection byproducts are the notable finding here. Arlington's water has TTHMs at 50.8 ppb and HAA5 at 34.8 ppb — both within legal limits, but the EWG health guidelines are far stricter. These byproducts form when chlorine reacts with organic matter during treatment. A whole-house activated carbon filter reduces both chlorine and its byproducts. Want the full picture? Request your utility's annual Consumer Confidence Report.
What's in the Treatment Process
Arlington's surface water supply requires heavy chlorination to stay safe — but that creates a tradeoff. The treatment process generates disinfection byproducts: TTHMs at 50.8 ppb (64% of the legal limit, but 339x the EWG guideline) and HAA5 at 34.8 ppb (58% of the legal limit, but 348x the EWG guideline). These are within legal limits, but the EWG sets much tighter thresholds based on cancer-risk research. A whole-house activated carbon filter reduces both chlorine and byproducts.
Chromium-6 was detected at 0.0918 ppb, which is 4.6x the EWG health guideline. There's no separate federal limit for chromium-6, only total chromium. A reverse osmosis system is the most effective removal method. All measurements are within federal legal limits. The EWG guidelines represent a more conservative, health-based standard.
| Contaminant | Detected | Health Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Hardness (as CaCO₃) | 38 PPM | < 60 PPM | No federal limit | ✓ OK |
| Total Dissolved Solids | 63 PPM | < 300 PPM | 500 PPM | ✓ OK |
| PFAS (total) | 7.15 ppt | — | No total limit | Detected |
| ↳ PFOA | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| ↳ PFOS | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| Lead | 0.6 ppb | 0 ppb (no safe level) | 15 ppb (10 ppb in 2027) | ✓ Low |
| Chlorine / Chloramine | 0.7 mg/L | Taste threshold ~1.0 | 4.0 mg/L | ✓ Normal |
| Nitrate | 1.09 mg/L | 5 mg/L | 10 mg/L | ✓ OK |
Good news for Arlington residents. Your water quality is generally good. Most homes in this area do not need a water softener. If you have concerns about lead (especially in buildings constructed before 1986) or chlorine taste, a point-of-use filter is the most practical and cost-effective solution.
How to Test Your Water in Arlington
City-wide data is a solid starting point, but your specific tap might differ based on plumbing age, distance from the treatment plant, or seasonal changes.
Free option: Request Arlington County DES's annual Consumer Confidence Report for official city-level data.
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About Arlington's Water Supply
Water Utility: Arlington County DES
Water Source: Potomac River (Surface Water)
Population Served: 215,000
Hardness: 38 PPM (2.2 grains per gallon)
Arlington's drinking water comes from surface sources — Potomac River. Surface water requires more extensive treatment than groundwater, including coagulation, filtration, and disinfection. This heavier chlorination is why disinfection byproducts tend to be higher in surface-supplied systems. On the upside, surface sources often deliver softer water than deep aquifers. The system serves 215,000 residents.
Water quality can vary by neighborhood and season. For your exact numbers, request Arlington County DES's Consumer Confidence Report (CCR) or test your own tap.
ZIP Codes Covered by This Report
This water quality data applies to all areas served by Arlington County DES in Arlington, VA, including ZIP codes:
20812, 20816, 20818, 22003, 22027, 22040, 22041, 22042, 22043, 22044, 22046, 22081, 22082, 22101, 22102, 22106, 22107, 22108, 22109, 22116, 22201, 22202, 22203, 22204, 22205, 22206, 22207, 22209, 22210, 22211, 22212, 22213, 22214, 22215, 22216, 22217, 22219, 22225, 22226, 22227, 22230, 22240, 22241, 22242, 22243, 22244, 22245, 22246
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Compare Arlington to Other Virginia Cities
Frequently Asked Questions About Arlington Water
Is Arlington tap water safe to drink?
Where does Arlington's water come from?
Do I need a water softener in Arlington?
What are disinfection byproducts in Arlington's water?
Is chromium-6 in Arlington's water?
Can I drink Arlington tap water straight from the faucet?
What water filter is best for Arlington?
Data sources: Lead and copper data from EPA Safe Drinking Water Act LCR reporting. Contaminant data from utility-reported testing results. PFAS data from EPA UCMR5 (2023–2025). Hardness from USGS and municipal reports. Data reflects system-level testing results and may not match your specific tap due to neighborhood plumbing, season, or recent utility changes. For your utility's latest results, request their Consumer Confidence Report (CCR). Our methodology. Last updated: 2026-02-24.