Short answer: In the 2024–2026 records we hold for Washington, DC, no listed result is above a legal limit. Also worth knowing: the water is hard. 4 substances were detected and 28 were tested and not detected. The water is from DC Water, serving 632,323 residents.
Your water bill or annual water quality report names your actual supplier.
Surface water
The treatment details are not on record.
Mains, then your building’s service line.
Plumbing inside the building is outside this record.
No measured result is above a legal limit; the water is hard.
2 µg/L, sampled 2026–2026 monitoring period (still open). EPA SDWIS (Lead & Copper Rule).
15 µg/L federal action level. EPA health goal (MCLG): 0.
The 90th-percentile tap result was 2.0 µg/L (below the 15 µg/L action level).
Usually from lead service lines, solder and fixtures inside buildings, after the water leaves treatment.
Test your own tap first. To reduce it: Lead-certified carbon filter, or reverse osmosis (NSF/ANSI 53 (lead)).
3.1 ng/L, sampled 2024-02-07 to 2024-10-16. EPA UCMR 5.
400,000 ng/L Michigan EGLE state MCL (strictest US state): a state limit.
Detected at up to 3.1 ng/L (below the 400,000 ng/L historical comparison reference).
Comes with the source water; home plumbing does not add it.
Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFHxA named on the listing).
7.4 gpg, sampled 2025. Utility CCR.
Aesthetic, no federal health limit.
126 mg/L as CaCO3 (7.4 grains/gal), hard. Aesthetic (scale/appliances), not a health finding.
Shows up as scale in kettles, water heaters and fixtures.
Test your own tap first. To reduce it: Ion-exchange water softener (NSF/ANSI 44 (softeners)).
4.7 ng/L, sampled 2024-02-07 to 2024-10-16. EPA UCMR 5.
No federal limit is on record for it.
Detected at up to 4.7 ng/L. No federal or state limit exists for this substance; shown for transparency, not graded.
Comes with the source water; home plumbing does not add it.
Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFPeA named on the listing).
D.C. WATER AND SEWER AUTHORITY (EPA PWSID DC0000002) delivers surface water to 632,323 residents. This report reflects 29 individual PFAS result(s) from the source UCMR5 observations and the latest Lead & Copper Rule 90th-percentile result. The utility's 2025 CCR reports hard water.
0health-based violations in the last 10 years
From EPA SDWIS. A clean violation history means no enforcement action was recorded; it does not cover contaminants without a limit.
No result is not a pass. Your utility's annual water quality report may list them, and a certified lab test covers your own tap.
The record describes water leaving treatment and samples across the system. Pipes, solder and fixtures inside a building can add lead the record can’t see, especially in older buildings with lead service lines.
Test your waterMeasured in this report
Sampled across the system
Not in this record
Only a tap test measures it
Know what comes from your tap, starting with a first-draw lead sample.
Compare each result with its named reference in our test reader.
Choose a technology certified for what your test found.
Screening tells you if something is worth a closer look; a lab result is the number you can act on.
As an Amazon Associate, PurityMap earns from qualifying purchases. Affiliate disclosure.
Lab-certified results
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.
Screening: quick check, not lab-grade
Varify
17 strip readings, including lead, chlorine, fluoride, iron and hardness, plus 2 coliform bacteria tests
What it can't tell you: Strip colors give rough ranges, not lab numbers, and it cannot detect PFAS or arsenic.
When your results arrive, read them here → · Compare every kit we list
| Finding | Reference type | Technology | Certification to check |
|---|---|---|---|
| Lead (90th percentile)2 µg/L | Action level | Lead-certified carbon filter, or reverse osmosis | NSF/ANSI 53 (lead) |
| Perfluorohexanoic acid (PFHxA)3.1 ng/L | State limit | Reverse osmosis, or carbon certified for PFAS | NSF/ANSI 53 or 58, with PFHxA named on the listing |
| Water hardness7.4 gpg | Aesthetic, no health limit | Ion-exchange water softener | NSF/ANSI 44 (softeners) |
| Perfluoropentanoic acid (PFPeA)4.7 ng/L | No federal limit | Reverse osmosis, or carbon certified for PFAS | NSF/ANSI 53 or 58, with PFPeA named on the listing |
★ Best available: Aquasana Claryum 3-Stage Max Flow Under-Sink Filter (AQ-6300M), the best fit here; nothing in this group is certified yet.
| Pick | Product | Details and price | Certification | Why it’s listed | Link |
|---|---|---|---|---|---|
| ★ Best available | Under-sinkAquasana Claryum 3-Stage Max Flow Under-Sink Filter (AQ-6300M) | Price$$ | Not certified for Perfluorohexanoic acid (PFHxA) and Perfluoropentanoic acid (PFPeA) | See the evidence | Check price at Aquasana |
| Also good | CountertopAquasana Clean Water Machine Countertop Filter (AQ-CWM2) | Price$$ | Not certified for Perfluorohexanoic acid (PFHxA) and Perfluoropentanoic acid (PFPeA) | See the evidence | Check price at Aquasana |
| Also good | Reverse osmosisSmartFlow® Reverse Osmosis | TechnologyReverse osmosisPrice$$$ | Not certified for Perfluorohexanoic acid (PFHxA) and Perfluoropentanoic acid (PFPeA) | See the evidence | Check price at Aquasana |
★ Best available: iSpring WGB32B-PFKS PFAS & Heavy Metals Whole House Filter, the best fit here; nothing in this group is certified yet.
| Pick | Product | Details and price | Certification | Why it’s listed | Link |
|---|---|---|---|---|---|
| ★ Best available | Whole-houseiSpring WGB32B-PFKS PFAS & Heavy Metals Whole House FilterUse code REFISPRING at checkout: 10% off your first iSpring order. | Price$$$ | Brand lab-tested for PFAS, not independently certified for Perfluorohexanoic acid (PFHxA) and Perfluoropentanoic acid (PFPeA) | See the evidence | Check price at iSpring |
| Also good | Whole-houseHealthShield™ | Price$$$$ | Not certified for Perfluorohexanoic acid (PFHxA) and Perfluoropentanoic acid (PFPeA) | See the evidence | Check price at Aquasana |
Also: lead picks → · hard water picks →
PurityMap earns a commission from these links. "Best choice" and "Budget pick" go to certified products first; commission never decides them. Affiliate disclosure.
Lead service lines
DC Water reported 16,935 lead and 190 galvanized service lines to replace in EPA’s inventory (2026Q2). Many utilities replace these lines for free or share the cost. Ask DC Water whether your home’s line is on its list before you pay anyone.
Local help
Call to be connected with a local plumbing provider about lead service lines, repiping or fixture replacement.
Older buildings may have lead service lines, solder or fixtures. Washington, DC’s record shows lead at 2 µg/L (15 µg/L federal action level). Test first-draw water, then filter if needed.
2 of 29 PFAS tested were detected in Washington, DC’s record (PFHxA 3.1 ng/L and PFPeA 4.7 ng/L). If PFAS matters to you, a filter certification names each compound it covers.
Most utilities keep chlorine or chloramine in the pipes. A carbon filter certified for taste and odor reduces either; your utility can tell you which it uses.
Scale is a comfort and appliance issue, not a health one.
Reverse osmosis reduces many dissolved contaminants, including lead and minerals, at a single faucet, with some water sent to drain.
Get one email when Washington, DC’s record changes.
One email when a new sampling round is published, a result moves above or below its reference, or the system's score changes.PurityMap does not give a safe/unsafe verdict; it shows what the public records measured. For Washington, DC, PFAS were detected below their limits, and PFPeA 4.7 ng/L with no federal or state limit; the lead 90th-percentile result was 2 µg/L against the 15 µg/L action level. D.C. WATER AND SEWER AUTHORITY (PWSID DC0000002) has a Purity Score of 98/100 (confidence: moderate), assessed at the water-system level and computed only from contaminants that were measured. Water can change in your own pipes, so a certified test is the only way to know what comes out of your tap. What we found →
D.C. WATER AND SEWER AUTHORITY (PWS ID DC0000002) is the public water system on record for Washington, DC, serving about 632,323 people. Confirm the utility on your water bill before acting on a specific finding. Water utility →
Surface water (primary source of record in EPA SDWIS). Water utility →
In EPA's UCMR 5 testing (2024-02-07 to 2024-10-16), PFHxA was detected at 3.1 ng/L, below the 400,000 ng/L state limit. PFPeA (4.7 ng/L) was also detected; it has no federal or state limit. What we found →
D.C. WATER AND SEWER AUTHORITY's most recent lead 90th-percentile result (2026) was 2 µg/L, below the 15 µg/L action level. That figure comes from sampled homes; lead usually enters from a building's own pipes and fixtures, so only a test at your tap tells you what you drink. Your household →
PurityMap's current record for Washington, DC holds 32 findings: 1 above a reference, 2 detected within the reference, 1 detected with no limit and 28 not detected. Each finding links to its dated public record; a parameter that was never monitored is shown as pending, not as a pass. Records →
Washington, DC's water is recorded as 7.4 gpg, hard. Hardness is an aesthetic and plumbing characteristic, not a health-based limit. Choose your situation →
UCMR5 Analytical Results
UCMR5 Analytical Results: D.C. WATER AND SEWER AUTHORITY (DC0000002)
US EPA
State SDWIS Compliance Record
Lead & Copper Rule 90th-percentile: D.C. WATER AND SEWER AUTHORITY (DC0000002)
US EPA SDWIS
Consumer Confidence Report (CCR)
DC Water (District of Columbia Water and Sewer Authority) 2025 Consumer Confidence Report (CCR)
DC Water (District of Columbia Water and Sewer Authority)
Methodology: how we analyze water. Prepared with AI assistance and reviewed by the PurityMap Editorial Team before publication.
EPA SDWIS, EPA UCMR 5 and utility reports, each dated and linked.
Units converted to one basis; a non-detect kept distinct from zero.
Each result tagged by reference type: MCL, action level, screening level or aesthetic.
Every value sits against its own reference, never a blended one.
Measured subjects summarised at the water-system level; an open health-based violation caps the score.
Treatment is matched to what was found; a product is called certified only when its current certification names it.
What the Purity Score means: a summary of this water system’s published record, capped while a health-based violation is open. It is not a test of any tap. D.C. WATER AND SEWER AUTHORITY · PWSID DC0000002 · Purity Score 98/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
Full methodology →Start with the hot-or-cold tap check. Where DC Water reported something related, it's shown below.
Lead at DC Water: 2 µg/L (90th percentile, 2026 monitoring period (still open)). Lead has no taste, so a taste neither shows nor rules it out.