Water Quality in Cobalt, CT: 11 Violations — Grade D
Grade D · Score 41/100 · 1 water system · Updated 2026-05-03
Cobalt's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Local water systems serving Cobalt, CT carry 11 EPA violations on record in the federal compliance database — documented events spanning categories from maximum contaminant level exceedances to monitoring requirements tracked by the national Safe Drinking Water program.
Water Quality by ZIP Code in Cobalt
Water quality varies across Cobalt's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 06414 | D | 41 | 11 | 1 | View report → |
Water Quality Overview
Cobalt, Connecticut receives a water quality grade of D with an overall score of 41 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 1 water system serving Cobalt have accumulated 11 EPA violations, including 1 health-based violation. These violations are tracked across 1 ZIP codes serving approximately 130 people.
What Grade D Means
A grade of D indicates significant compliance issues. Cobalt'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
The average 90th percentile lead level across Cobalt water systems is 0.0149 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 52% of homes built before 1986, Cobalt 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
Cobalt 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 Cobalt
Cobalt is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 130 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
The EPA has taken 10 enforcement actions against water systems serving Cobalt. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Cobalt
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
Contaminants Detected in Cobalt Water Systems
The following contaminants have been detected or caused violations across Cobalt's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Total Coliform | Microbiological | N/A | 3 | 1 | No |
| Stage 2 DBP Rule | Treatment Technique | N/A | 2 | 1 | Yes |
| Lead and Copper Rule | Treatment Technique | N/A | 1 | 1 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 1 | 1 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving Cobalt. Recent actions:
| Date | Action Type |
|---|---|
| 2025-09-10 | State Order Extension |
| 2025-01-17 | State Informal Action |
| 2024-11-15 | State Informal Action |
| 2024-11-15 | State Informal Enforcement |
| 2024-08-06 | State Informal Action |
| 2024-07-24 | State Informal Action |
| 2024-07-24 | State Informal Enforcement |
| 2024-06-30 | State Order Extension |
| 2024-02-26 | State Informal Action |
| 2024-02-26 | State Informal Enforcement |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-09-10.
Cobalt vs. Nearby Connecticut Cities
How Cobalt's water quality compares to similar cities in Connecticut:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Cobalt | D | 11 | 1 | 130 |
| Middle Haddam | D | 0 | 1 | 130 |
| Bantam | B | 15 | 2 | 136 |
| Beacon Falls | D | 0 | 1 | 138 |
Common Questions About Cobalt Water
These are the most common questions residents search for about water quality in Cobalt, Connecticut:
Is Cobalt water hard or soft? Water hardness varies by source. Cobalt's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Cobalt tap water? Cobalt's water receives a grade of D (41/100). There are 1 health-based violations — consider filtration.
What is the best water filter for Cobalt? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Cobalt vs. Connecticut Average
Understanding how Cobalt compares to the broader Connecticut 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 Cobalt.
ZIP Codes in Cobalt
Cobalt spans 1 ZIP code. The ZIP with the lowest water quality score is 06414. 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.