Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03

Water systems in Washington, DC have accumulated 9042 EPA violations across the full compliance record — a dataset that captures reportable health-based exceedances, monitoring lapses, and enforcement actions filed with the federal Safe Drinking Water Information System.

Water Quality Map: Washington, DC

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Water Quality by ZIP Code in Washington

Water quality varies across Washington's 274 ZIP codes. Check your specific ZIP for detailed contaminant data.

ZIP Code	Grade	Score	Violations	Health
20007	C	62	33	6	View report →
20019	C	62	33	6	View report →
20001	C	67	33	6	View report →
20002	C	67	33	6	View report →
20008	C	67	33	6	View report →
20009	C	67	33	6	View report →
20010	C	67	33	6	View report →
20011	C	67	33	6	View report →
20012	C	67	33	6	View report →
20015	C	67	33	6	View report →
20016	C	67	33	6	View report →
20017	C	67	33	6	View report →
20018	C	67	33	6	View report →
20020	C	67	33	6	View report →
20013	C	69	33	6	View report →

Violation Trend

EPA violations recorded for water systems serving Washington.

2022

2023

2025

Total violations Health-based

Water Quality Overview

Washington, District of Columbia receives a water quality grade of C with an overall score of 69 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).

The 4 water systems serving Washington have accumulated 9042 EPA violations, including 1644 health-based violations. These violations are tracked across 274 ZIP codes serving approximately 667,325 people.

What Grade C Means

A grade of C indicates moderate compliance issues. Washington's water systems have some violations that warrant attention. While the water may still be safe for most people, residents in affected ZIP codes should consider additional testing or filtration.

Lead Levels

The average 90th percentile lead level across Washington water systems is 0.0010 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.

With 73% of homes built before 1986, Washington has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.

Radon Risk

Washington is in EPA Radon Zone 1 (High risk). The EPA recommends all homes in Zone 1 areas be tested for radon. Radon is the second leading cause of lung cancer after smoking.

Water Systems Serving Washington

Washington is served by 4 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 667,325 people across 274 ZIP codes.

Each water system is identified by a Public Water System ID (PWSID) and is required to:

• Test for over 90 regulated contaminants on a regular schedule
• Report results to the EPA and state regulators
• Issue an annual Consumer Confidence Report (CCR) to all customers
• Take corrective action when violations occur

The EPA has taken 2740 enforcement actions against water systems serving Washington. Enforcement actions range from informal compliance assistance to formal orders and penalties.

How to Check Your Water in Washington

1. Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores

2. Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants

3. Get a home test — certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel

4. Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics

5. Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts

Contaminants Detected in Washington Water Systems

The following contaminants have been detected or caused violations across Washington's water systems:

MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.

Violation Trend Over Time

Year-by-year EPA violations recorded for water systems serving Washington:

Violations have increased from 274 in 2022 to 822 in 2025. This trend warrants monitoring.

EPA Enforcement History

The EPA and state regulators have taken 10 enforcement actions against water systems serving Washington. Recent actions:

Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-09-19.

Washington vs. Nearby District of Columbia Cities

How Washington's water quality compares to similar cities in District of Columbia:

Recommended Water Filters for Washington

Based on contaminants detected in Washington's water supply, these filter types are recommended:

Granular Activated Carbon (GAC, whole-house or under-sink)

• Removes: Chlorine
• Effectiveness: 95-99%
• Cost range: $100–$600
• Certification: NSF/ANSI 42
• Recommended products:
  • Aquasana AQ-5200
  • Waterdrop Chubby Pitcher
  • Berkey Travel

Granular Activated Carbon (GAC, whole-house POE)

• Removes: Total Trihalomethanes (TTHMs), Perfluorooctanoic acid (PFOA)
• Effectiveness: 80-99%
• Cost range: $400–$2000
• Certification: NSF/ANSI 53
• Recommended products:
  • Aquasana AQ-5200
  • Aquasana EQ-1000 Rhino
  • Waterdrop G3P800

Granular Activated Carbon (GAC, under-sink or whole-house)

• Removes: Haloacetic Acids (HAA5)
• Effectiveness: 60-80%
• Cost range: $100–$600
• Certification: NSF/ANSI 53
• Recommended products:
  • Aquasana AQ-5200
  • Aquasana EQ-1000 Rhino

Water Quality by ZIP Code in Washington

Water quality varies across Washington's ZIP codes. The table below shows the worst-scoring and best-scoring areas:

Common Questions About Washington Water

These are the most common questions residents search for about water quality in Washington, District of Columbia:

Is Washington water hard or soft? Water hardness varies by source. Washington's 4 water systems use multiple sources. Check your ZIP code report for specific hardness data.

Can I drink Washington tap water? Washington's water receives a grade of C (69/100). There are 1644 health-based violations — consider filtration.

What is the best water filter for Washington? Based on detected contaminants, a granular activated carbon (gac, whole-house or under-sink) filter is most recommended. See our Water Filter Matcher for personalized recommendations.

Washington vs. District of Columbia Average

Understanding how Washington compares to the broader District of Columbia average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.

To see how individual neighborhoods compare, check the ZIP code reports below — water quality can vary significantly even within Washington.

ZIP Codes in Washington

Washington spans 274 ZIP codes. The ZIP with the lowest water quality score is 20001. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.

Data Sources

• Water quality: EPA Safe Drinking Water Information System (SDWIS)
• Lead/copper: EPA Lead and Copper Rule sampling data
• Radon: EPA Map of Radon Zones
• Enforcement: EPA ECHO database
• Filter recommendations: NSF/ANSI certified products

Updated daily.