Washington
DC

Is Washington, DC Tap Water Safe to Drink?

Washington, DC tap water is generally treated and meets federal standards for most contaminants, but recent EPA testing detected low levels of PFAS chemicals and lithium above EPA benchmarks. Most residents face low overall risk, though people with heightened sensitivity and those who want extra caution may want to consider a certified filter.

4Water systems
266ZIP codes
1.1%ZIPs above EPA guideline
Metro areaWashington-Arlington-Alexandria, DC-VA-MD-WV
Latest data2024-10-16

Where Does Washington Get Its Water?

Washington, DC draws its drinking water from surface water sources, with DC Water and Sewer Authority serving as the primary utility for the vast majority of residents. The system also includes water service for Joint Base Anacostia-Bolling and Naval Station Washington, which operate separate, smaller systems within the District.

The Dalecarlia and McMillan facilities are the major recognized water connections and treatment points in the DC system. These sites have historically handled the bulk of water processing before distribution across the city.

Because the city is served primarily by one large utility, treated water quality is generally consistent across the District rather than varying significantly by neighborhood or ZIP code.

How Is Washington Tap Water Treated?

DC's water undergoes conventional treatment that includes coagulation and filtration to remove particles and sediment. Additional steps address taste, odor, and chemical contaminants before water enters the distribution pipes.

Disinfection uses both chlorine-based and non-disinfectant treatment approaches depending on the facility and stage of treatment. Chlorine residuals help keep water safe as it travels through the distribution system to your tap.

The treatment process is designed to meet federal drinking water standards across a wide range of contaminants, and DC Water has operated under EPA oversight for decades.

What's in Washington Tap Water?

The most notable finding from recent EPA testing is PFPeA, a type of PFAS (per- and polyfluoroalkyl substance), detected at a peak of 0.005 micrograms per liter. The EPA benchmark for PFPeA is 0.003 micrograms per liter, meaning the peak sample came in above that threshold. This was detected across a large number of ZIP codes in the dataset, with two ZIPs registering values above the guideline.

Lithium was also detected at a peak of 12 micrograms per liter, above the EPA benchmark of 10 micrograms per liter, with one ZIP registering a value above that level. Several other PFAS compounds, including PFTrDA, 11Cl-PF3OUdS, and HFPO-DA, were detected but at levels at or below their respective reporting thresholds and not above any guideline.

PFAS compounds are a large family of synthetic chemicals used in industrial and consumer products for decades. They can enter drinking water sources through industrial discharge, firefighting foam, and other pathways. Lithium occurs naturally in some water sources and can also enter through industrial or agricultural activity.

ContaminantPeak detectedEPA guidelineZIPs detectedStatus
PFPeA 0.005 µg/L 0.003 µg/L 2 ZIPs Above guideline
lithium 12 µg/L 10 µg/L 1 ZIP Above guideline
PFTrDA 0.007 µg/L — 0 ZIPs Within guideline
11Cl-PF3OUdS 0.005 µg/L — 0 ZIPs Within guideline
HFPO-DA 0.005 µg/L — 0 ZIPs Within guideline

Health Risk Profile for Washington

PFPeA was detected at 0.005 micrograms per liter against an EPA benchmark of 0.003 micrograms per liter. It is important to note that this benchmark is not an enforceable federal legal limit but rather a reporting and health reference level. Lithium reached 12 micrograms per liter against a benchmark of 10 micrograms per liter, also a non-enforceable reference rather than a legal maximum.

Infants, pregnant individuals, and people with compromised immune systems are generally considered more sensitive to low-level chemical exposures. For these groups, even modest detections above health benchmarks are worth taking seriously, even when the exceedance is small.

Given the PFAS detections and chlorine-based disinfection in Washington's system, a filter certified to NSF/ANSI standards (NSF/ANSI is an independent third-party certification that tells you a product has been tested and verified) is a reasonable step. For PFAS, look for filters certified to NSF/ANSI 58 (reverse osmosis) or NSF/ANSI 53 with P473 certification. For general taste and chlorine concerns, NSF/ANSI 42 covers those.

The detected levels of PFAS and lithium are relatively close to their benchmarks rather than dramatically over them. The science on long-term low-level PFAS exposure continues to evolve, and EPA is actively updating its guidance in this area.

Best Broad-Spectrum Filters for This Water Profile

This city profile includes PFAS detections, chlorine disinfection, and other dissolved contaminants. Reverse osmosis (RO) systems certified under NSF/ANSI 58 provide broad reduction coverage; for PFAS specifically, confirm NSF/ANSI P473 or equivalent PFAS reduction certification.

Waterdrop G3P600 Reverse Osmosis System
Under-sink RO system

8-stage tankless RO system certified to NSF/ANSI 58, reduces 1,000+ contaminants including PFAS, lead, arsenic, fluoride, and nitrates.

See recommendations matched to your exact address: choose your ZIP code below.

Frequently Asked Questions about Washington Tap Water

Is Washington, DC tap water safe to drink?

For most healthy adults, Washington, DC tap water meets federal standards and is generally considered safe. However, recent EPA testing found PFPeA and lithium above EPA health benchmarks, though neither has an enforceable federal legal limit. People who are pregnant, have infants, or have weakened immune systems may want to use a certified filter as an added precaution.

What contaminants are in Washington, DC tap water?

Recent EPA testing detected PFPeA (a PFAS chemical) at 0.005 micrograms per liter, above the EPA benchmark of 0.003 micrograms per liter. Lithium was found at 12 micrograms per liter, above its 10 micrograms per liter benchmark. Other PFAS compounds including PFTrDA, 11Cl-PF3OUdS, and HFPO-DA were detected but did not exceed any guideline.

Where does Washington, DC get its drinking water?

Washington, DC receives its drinking water from surface water sources, processed primarily through DC Water and Sewer Authority. The Dalecarlia and McMillan facilities are the main recognized water infrastructure points in the system. Smaller, separate water systems serve Joint Base Anacostia-Bolling and Naval Station Washington within the District.

Do I need a water filter in Washington, DC?

A filter is not strictly required, but it can reduce exposure to PFAS and other trace contaminants. For PFAS, choose a filter certified to NSF/ANSI 58 (reverse osmosis) or NSF/ANSI 53 with P473. NSF/ANSI certification means an independent lab has verified the filter's performance claims, so look for it on the product label or packaging.

How often is Washington, DC tap water tested?

Washington, DC water is monitored on an ongoing basis under federal EPA rules. The results shown here come from EPA testing conducted through late 2024, with the most recent samples collected in October 2024. Utilities are also required to publish annual Consumer Confidence Reports summarizing water quality results for their customers.

What is the best water filter for Washington, DC?

Given PFAS detections and chlorine-based disinfection in DC's water, the best options are a reverse osmosis filter certified to NSF/ANSI 58, or a pitcher or under-sink filter certified to NSF/ANSI 53 with P473 for PFAS removal. For chlorine taste and odor alone, a filter certified to NSF/ANSI 42 is sufficient. Look for the NSF mark on the box to confirm third-party verification.

Tap water reports by ZIP in Washington

Water utilities serving Washington, DC

Service area boundaries are approximate and based on state filings or modeled estimates. Contact your utility to confirm exact service at a specific address.

Modeled boundaries are shown with a dashed outline.

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