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States → District of Columbia

State profile · EPA SDWIS + UCMR5

District of Columbia Drinking Water Quality

5 public water systems serve 667,575 people across District of Columbia, with every Safe Drinking Water Act violation and UCMR5 PFAS result on record.

5
Water systems
263
Total violations
100%
Systems w/ a violation
100%
PFAS detection rate

The verdict

Across District of Columbia, 5 of 5 water systems (100.0%) carry at least one EPA violation, and 3 of 3 UCMR5-tested systems show PFAS.

263
Total EPA violations on record
27%
Health-based (MCL / treatment)
100.0%
Systems with ≥1 violation
100%
UCMR5 PFAS detection rate
Water Systems
5
Total Violations
263
Violation Rate
100%
PFAS Detection
100%
3 of 3 tested

Violation Composition

How District of Columbia's 263 violations break down by type, per EPA SDWIS classification.

Health-based (72) Monitoring/Reporting (191)
Metric Value Share
Public water systems5-
Population served667,575-
Total violations263100%
Health-based violations7227.4%
Systems with violations5100.0%
PFAS detection rate3 of 3100%

Health-based violations indicate the contaminant exceeded an EPA Maximum Contaminant Level (MCL) or treatment-technique requirement. Monitoring/reporting violations indicate procedural issues (missed tests, late reports) - not necessarily a contamination event.

Largest Water Systems

D.C. Water and Sewer Authority
Washington, DC · 632,323 served
82 violations
Joint Base Anacostia - Bolling
Washington, DC · 19,312 served
81 violations
Naval Station Washington - Wny
Washington, DC · 15,690 served
62 violations
Naval Observatory
Washington, DC · 250 served
25 violations
Washington Aqueduct Division.
Washington, DC · 0 served
13 violations

Most Violations

#1 D.C. Water and Sewer Authority Washington
82
#2 Joint Base Anacostia - Bolling Washington
81
#3 Naval Station Washington - Wny Washington
62
#4 Naval Observatory Washington
25
#5 Washington Aqueduct Division. Washington
13

Counties in District of Columbia

District of Columbia
5 systems · 667,575 served · 263 violations
View all 5 systems in District of Columbia →

Drinking Water Guides

Is Your Tap Water Safe?

How to interpret water quality reports and know when to take action.
PFAS in Drinking Water

What forever chemicals are, EPA testing results, and 2024 standards.
Check Your Water System

Step-by-step guide to finding and understanding your local water data.

Frequently Asked Questions

How many water systems are in District of Columbia? ▼
District of Columbia has 5 public water systems serving approximately 667,575 people. These include community water systems, non-transient non-community systems, and transient non-community systems regulated under the Safe Drinking Water Act.
How many drinking water violations are in District of Columbia? ▼
District of Columbia has 263 total drinking water violations on record, with 72 classified as health-based violations. 100.0% of water systems in the state have at least one violation.
Has PFAS been found in District of Columbia drinking water? ▼
Of 3 water systems tested for PFAS in District of Columbia, 3 had PFAS detected, a 100% detection rate. PFAS are persistent "forever chemicals" that do not break down in the environment.
What is the violation rate for District of Columbia water systems? ▼
District of Columbia's violation rate is 100%. This measures the percentage of public water systems that have at least one recorded violation in the EPA SDWIS database, including both health-based and monitoring/reporting violations.
Where does this District of Columbia water data come from? ▼
All drinking water data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS is the federal database that tracks compliance for all public water systems regulated under the Safe Drinking Water Act.

Data Sources & Methodology

Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). PFAS testing data from the UCMR5 monitoring program. SDWIS tracks all public water systems regulated under the Safe Drinking Water Act.

Read our methodology - how this data is sourced, computed, and verified.

Related

All states → | Most violations → | Compare counties →
Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.