Water Quality in Bethesda, MD: No Violations — Grade C
Grade C · Score 65/100 · 1 water system · Updated 2026-05-03
Bethesda's water has moderate compliance issues. Residents in affected areas should consider filtration.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Unlike many metros where compliance gaps appear somewhere in the record, Bethesda, MD holds a violation-free federal history — EPA data covers 1 local water system and every one has cleared every applicable threshold without a single flagged event.
Water Quality Map: Bethesda, MD
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Water Quality by ZIP Code in Bethesda
Water quality varies across Bethesda's 11 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 20817 | C | 60 | 0 | 0 | View report → |
| 20814 | C | 65 | 0 | 0 | View report → |
| 20816 | C | 65 | 0 | 0 | View report → |
| 20810 | C | 66 | 0 | 0 | View report → |
| 20811 | C | 66 | 0 | 0 | View report → |
| 20813 | C | 66 | 0 | 0 | View report → |
| 20824 | C | 66 | 0 | 0 | View report → |
| 20827 | C | 66 | 0 | 0 | View report → |
| 20889 | C | 66 | 0 | 0 | View report → |
| 20892 | C | 66 | 0 | 0 | View report → |
| 20894 | C | 66 | 0 | 0 | View report → |
Water Quality Overview
Bethesda, Maryland receives a water quality grade of C with an overall score of 65 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
No EPA violations have been recorded for the 1 water system serving Bethesda. This is a positive indicator, though it does not guarantee the absence of all contaminants — some substances (like PFAS) are not yet fully regulated.
What Grade C Means
A grade of C indicates moderate compliance issues. Bethesda'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 Bethesda water systems is 0.0044 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 55% of homes built before 1986, Bethesda 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
Bethesda 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 Bethesda
Bethesda is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 96 people across 11 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
How to Check Your Water in Bethesda
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
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
Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts
Bethesda vs. Nearby Maryland Cities
How Bethesda's water quality compares to similar cities in Maryland:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Bethesda | C | 0 | 1 | 96 |
| Cabin John | D | 0 | 1 | 96 |
| Chevy Chase | D | 0 | 1 | 96 |
| Derwood | D | 0 | 1 | 96 |
Water Quality by ZIP Code in Bethesda
Water quality varies across Bethesda's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
| ZIP Code | Score | Grade | Violations | Health-Based |
|---|---|---|---|---|
| 20817 | 60 | C | 0 | 0 |
| 20814 | 65 | C | 0 | 0 |
| 20816 | 65 | C | 0 | 0 |
| 20810 | 66 | C | 0 | 0 |
| 20811 | 66 | C | 0 | 0 |
| 20813 | 66 | C | 0 | 0 |
| 20824 | 66 | C | 0 | 0 |
| 20827 | 66 | C | 0 | 0 |
| 20889 | 66 | C | 0 | 0 |
| 20892 | 66 | C | 0 | 0 |
| 20894 | 66 | C | 0 | 0 |
| 20892 | 66 | C | 0 | 0 |
| 20889 | 66 | C | 0 | 0 |
| 20827 | 66 | C | 0 | 0 |
| 20824 | 66 | C | 0 | 0 |
Common Questions About Bethesda Water
These are the most common questions residents search for about water quality in Bethesda, Maryland:
Is Bethesda water hard or soft? Water hardness varies by source. Bethesda's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Bethesda tap water? Bethesda's water receives a grade of C (65/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Bethesda? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Bethesda vs. Maryland Average
Understanding how Bethesda compares to the broader Maryland 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 Bethesda.
ZIP Codes in Bethesda
Bethesda spans 11 ZIP codes. 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.