Water Quality in Gaithersburg, MD: No Violations — Grade D
Grade D · Score 45/100 · 2 water systems · Updated 2026-05-03
Gaithersburg's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
When EPA compliance data is reviewed for Gaithersburg, MD, the result holds consistent: zero violations documented across 2 tracked water systems, with every health-based limit and monitoring requirement met through the full dataset available in SDWIS.
Water Quality Map: Gaithersburg, MD
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Water Quality by ZIP Code in Gaithersburg
Water quality varies across Gaithersburg's 9 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 20883 | D | 40 | 0 | 0 | View report → |
| 20884 | D | 40 | 0 | 0 | View report → |
| 20885 | D | 40 | 0 | 0 | View report → |
| 20898 | D | 40 | 0 | 0 | View report → |
| 20899 | D | 40 | 0 | 0 | View report → |
| 20878 | D | 45 | 0 | 0 | View report → |
| 20877 | D | 53 | 0 | 0 | View report → |
| 20879 | D | 53 | 0 | 0 | View report → |
| 20882 | D | 53 | 0 | 0 | View report → |
Water Quality Overview
Gaithersburg, 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 2 water systems serving Gaithersburg. 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. Gaithersburg'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 Gaithersburg is currently being collected. The EPA requires all community water systems to test for lead under the Lead and Copper Rule.
With 55% of homes built before 1986, Gaithersburg 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
Gaithersburg 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 Gaithersburg
Gaithersburg is served by 2 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 246 people across 9 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 Gaithersburg
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
Gaithersburg vs. Nearby Maryland Cities
How Gaithersburg's water quality compares to similar cities in Maryland:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Gaithersburg | D | 0 | 2 | 246 |
| Colora | D | 6 | 1 | 250 |
| Conowingo | C | 0 | 1 | 250 |
| Maryland Line | C | 0 | 1 | 250 |
Water Quality by ZIP Code in Gaithersburg
Water quality varies across Gaithersburg's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
| ZIP Code | Score | Grade | Violations | Health-Based |
|---|---|---|---|---|
| 20883 | 40 | D | 0 | 0 |
| 20884 | 40 | D | 0 | 0 |
| 20885 | 40 | D | 0 | 0 |
| 20898 | 40 | D | 0 | 0 |
| 20899 | 40 | D | 0 | 0 |
| 20878 | 45 | D | 0 | 0 |
| 20877 | 53 | D | 0 | 0 |
| 20879 | 53 | D | 0 | 0 |
| 20882 | 53 | D | 0 | 0 |
Common Questions About Gaithersburg Water
These are the most common questions residents search for about water quality in Gaithersburg, Maryland:
Is Gaithersburg water hard or soft? Water hardness varies by source. Gaithersburg's 2 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Gaithersburg tap water? Gaithersburg'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 Gaithersburg? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Gaithersburg vs. Maryland Average
Understanding how Gaithersburg 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 Gaithersburg.
ZIP Codes in Gaithersburg
Gaithersburg spans 9 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.