WATER QUALITY MD

Water Quality in Cabin John, MD: No Violations — Grade D

Grade D · Score 45/100 · 1 water system · Updated 2026-05-03

Cabin John's water has significant violations. Water testing and filtration are recommended.

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

Federal EPA data for Cabin John, MD shows no violations on record — 1 system, all clear.

Water Grade

Total Violations

Water Systems

ZIPs with Violations

ZIP Codes Monitored

Water Quality by ZIP Code in Cabin John

Water quality varies across Cabin John's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.

ZIP Code	Grade	Score	Violations	Health
20818	D	45	0	0	View report →

Water Quality Overview

Cabin John, Maryland receives a water quality grade of D with an overall score of 45 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 Cabin John. 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 D Means

A grade of D indicates significant compliance issues. Cabin John's water systems have accumulated violations that suggest ongoing water quality challenges. Residents should check their specific ZIP code report and consider water testing or filtration.

Lead Levels

Lead testing data for Cabin John is currently being collected. The EPA requires all community water systems to test for lead under the Lead and Copper Rule.

With 66% of homes built before 1986, Cabin John 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

Cabin John 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 Cabin John

Cabin John is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 96 people across 1 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 Cabin John

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

Cabin John vs. Nearby Maryland Cities

How Cabin John's water quality compares to similar cities in Maryland:

City	Grade	Systems	Population
Cabin John	D	1	96
Bethesda	C	1	96
Chevy Chase	D	1	96
Derwood	D	1	96

Common Questions About Cabin John Water

These are the most common questions residents search for about water quality in Cabin John, Maryland:

Is Cabin John water hard or soft? Water hardness varies by source. Cabin John's 1 water system uses a single source. Check your ZIP code report for specific hardness data.

Can I drink Cabin John tap water? Cabin John's water receives a grade of D (45/100). No health-based violations have been recorded, but home testing is always recommended.

What is the best water filter for Cabin John? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.

Cabin John vs. Maryland Average

Understanding how Cabin John 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 Cabin John.

ZIP Codes in Cabin John

Cabin John spans 1 ZIP code. 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.

Frequently Asked Questions

Is Cabin John tap water safe to drink?

Cabin John's water receives a grade of D (45/100). 0 health-based violations have been recorded. Independent water testing and filtration are recommended.

What contaminants are found in Cabin John water?

Cabin John water systems have zero recorded violations. While this is excellent, the EPA recommends annual testing as contaminants can enter your water through home plumbing.

How many water violations does Cabin John have?

Cabin John has 0 total EPA violations across 1 water system. 0 of 1 ZIP codes have at least one violation.

How many water systems serve Cabin John?

Cabin John is served by 1 public water system supplying drinking water across 1 ZIP codes. Water quality can vary between systems — check your specific ZIP code for localized data.

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