District of Columbia Water Quality Report: 41 Water-System Violations Mapped to 36 ZIPs
4 water systems · 36 ZIP codes · 41 violations
Data: EPA Safe Drinking Water Information System (SDWIS), EPA ECHO
ZipCheckup tracks EPA drinking-water compliance for 4 public water systems serving 36 ZIP codes in District of Columbia. The state record shows 41 EPA violations, 3 health-based.
City Water Quality Map: District of Columbia
Each circle represents a city. Size indicates population, color indicates water quality grade. Tap a circle for details.
Cities with Most Violations in District of Columbia
| # | City | Grade | Violations | Systems | Population | |
|---|---|---|---|---|---|---|
| 1 | Washington | 33 | 2 | 671,768 | Details → | |
| 2 | Washington Navy Yard | 4 | 1 | 632,323 | Details → | |
| 3 | Naval Anacost Annex | 4 | 1 | 311 | Details → |
Most Common Contaminants in District of Columbia
| Contaminant | Category | Violations | ZIPs Affected | Health Risk |
|---|---|---|---|---|
| Surface Water Treatment Rule | Treatment Technique | 80 | 36 | Yes |
| Public Notice Rule | Reporting | 4 | 1 | No |
| Nitrate | Inorganic | 3 | 1 | No |
| Lead and Copper Rule | Treatment Technique | 2 | 1 | No |
| Consumer Confidence Rule | Reporting | 2 | 1 | No |
| Interim Enhanced Surface Water Treatment Rule | Treatment Technique | 1 | 1 | No |
| Nitrite | Inorganic | 1 | 1 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 1 | 1 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 1 | 1 | No |
Water Quality Overview
District of Columbia has 4 community water systems represented across 36 directly mapped ZIP records. The associated city records cover approximately 1,304,402 people. The available records contain 41 EPA violations, including 3 health-based violations.
Health-based violations account for 7% of all violations in District of Columbia. These violations indicate contaminant levels that may pose direct risks to human health, as opposed to monitoring or reporting failures.
Violation Breakdown
| Violation Type | Count | Percentage |
|---|---|---|
| Health-based | 3 | 7.3% |
| Monitoring/Reporting | 38 | 92.7% |
| Total | 41 | 100% |
Health-based violations are MCL, MRDL (disinfectant) and treatment-technique violations. Monitoring violations indicate failures to test or report - these do not necessarily mean unsafe water, but they mean the water was not properly verified.
Cities with Most Violations
The following cities in District of Columbia have the highest number of EPA violations:
| Rank | City | Violations | Water Systems | Population |
|---|---|---|---|---|
| 1 | Washington | 33 | 2 | 671,768 |
| 2 | Washington Navy Yard | 4 | 1 | 632,323 |
| 3 | Naval Anacost Annex | 4 | 1 | 311 |
Violation counts are cumulative across all water systems serving each city. Higher counts may reflect larger systems with more monitoring requirements, not necessarily worse water quality.
Violation Trend Over Time
Year-by-year EPA violations recorded across all water systems in District of Columbia:
| Year | Health-based violations |
|---|---|
| 2022 | 1 |
| 2025 | 1 |
Most Common Contaminants
The following contaminants have caused the most violations across District of Columbia water systems:
| Contaminant | Category | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|
| Surface Water Treatment Rule | Treatment Technique | 80 | 36 | Yes |
| Public Notice Rule | Reporting | 4 | 1 | No |
| Nitrate | Inorganic | 3 | 1 | No |
| Lead and Copper Rule | Treatment Technique | 2 | 1 | No |
| Consumer Confidence Rule | Reporting | 2 | 1 | No |
| Interim Enhanced Surface Water Treatment Rule | Treatment Technique | 1 | 1 | No |
| Nitrite | Inorganic | 1 | 1 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 1 | 1 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 1 | 1 | No |
How to Check Your Water in District of Columbia
Enter your ZIP code on ZipCheckup for detailed water-system data including contaminant levels and violation history; the separate Home Safety Score is a multi-source index
Request your CCR - every water utility must provide an annual Consumer Confidence Report
Get a home test - certified kits ($20-$50) or professional lab tests ($150-$400)
Consider filtration - NSF-certified filters can address specific contaminants found in your area
EPA Enforcement
The EPA and state regulators have taken enforcement actions against water systems in District of Columbia. Enforcement actions range from compliance assistance to formal orders and penalties.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Enforcement: EPA ECHO
Updated daily.
Understanding water quality grades
ZipCheckup grades water systems from A to F based on EPA violation history, contaminant levels, and system compliance. Grades summarize ZipCheckup's scoring inputs; review the underlying records for specific issues. Grades are calculated per ZIP code and aggregated at the city, county, and state level.
Wondering about your tap water?
Water quality varies by ZIP code. Enter yours to see contaminant data, violations, and filtration recommendations specific to your area.
Check Your ZIP Code Water Quality →Frequently Asked Questions
Is the tap water safe to drink in District of Columbia?
Records for 4 community water systems mapped to ZIPs in District of Columbia show 41 reported violations, including 3 health-based. Water quality varies by city and ZIP code - check your specific location for detailed results.
How many violations are on record for water systems serving District of Columbia?
District of Columbia has 41 EPA violations on record across 36 ZIP codes; 3 are classified as health-based violations. The remainder are monitoring or reporting violations.
Which city in District of Columbia has the worst water quality?
Washington, DC has the most recorded EPA violations (33) among the cities with mapped water systems in District of Columbia in our data. Check your water supplier's report and test your tap water for the most accurate picture of your local water quality.
Which city in District of Columbia has the best water quality?
Violation records vary by water system across District of Columbia. Check individual city reports for details.
What contaminants are found in District of Columbia drinking water?
EPA regulates over 90 drinking-water contaminants nationally; water systems in District of Columbia monitor those applicable to each system, which can include lead, copper, nitrate, disinfection byproducts, and bacteria. The most common violations vary by region - check your ZIP code for contaminant-specific data.