Water Quality in Cary, NC: 645 Violations — Grade C
Grade C · Score 63/100 · 5 water systems · Updated 2026-05-03
Cary'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
Reviewing EPA compliance files for Cary, NC surfaces 645 documented water violations — each categorized by violation type and linked to the utility that drew the federal citation.
Water Quality Map: Cary, NC
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Water Quality by ZIP Code in Cary
Water quality varies across Cary's 5 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 27511 | C | 59 | 129 | 5 | View report → |
| 27518 | C | 59 | 129 | 5 | View report → |
| 27513 | C | 64 | 129 | 5 | View report → |
| 27512 | C | 66 | 129 | 5 | View report → |
| 27519 | C | 69 | 129 | 5 | View report → |
Violation Trend
EPA violations recorded for water systems serving Cary.
Water Quality Overview
Cary, North Carolina receives a water quality grade of C with an overall score of 63 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 5 water systems serving Cary have accumulated 645 EPA violations, including 25 health-based violations. These violations are tracked across 5 ZIP codes serving approximately 281,828 people.
What Grade C Means
A grade of C indicates moderate compliance issues. Cary'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 Cary water systems is 0.0030 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
Radon Risk
Cary is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Cary
Cary is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 281,828 people across 5 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 50 enforcement actions against water systems serving Cary. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Cary
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 Cary Water Systems
The following contaminants have been detected or caused violations across Cary's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Surface Water Treatment Rule | Treatment Technique | N/A | 395 | 5 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 70 | 5 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 40 | 5 | No |
| Lead | Inorganic | 0.015 mg/L | 20 | 5 | No |
| Gross Alpha | Radionuclides | 15 pCi/L | 20 | 5 | Yes |
| Revised Total Coliform Rule | Microbiological | N/A | 15 | 5 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 15 | 5 | No |
| Lead and Copper Rule | Treatment Technique | N/A | 10 | 5 | No |
| Combined Radium | Radionuclides | 5 pCi/L | 5 | 5 | No |
| Radium-228 | Radionuclides | 5 pCi/L | 5 | 5 | No |
| Copper | Inorganic | 1.3 mg/L | 5 | 5 | No |
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 Cary:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2022 | 5 | 5 |
| 2023 | 5 | 5 |
Violation counts have remained stable over the observed period.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving Cary. Recent actions:
| Date | Action Type |
|---|---|
| 2025-09-23 | State Order Extension |
| 2025-08-14 | State Filed Judgment |
| 2025-08-14 | State Filed Suit |
| 2025-08-14 | State Informal Enforcement |
| 2025-07-01 | State Order Extension |
| 2025-06-11 | State Filed Judgment |
| 2025-06-11 | State Filed Suit |
| 2025-06-11 | State Informal Enforcement |
| 2025-04-30 | State Order Extension |
| 2025-02-03 | State Order Extension |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-09-23.
Cary vs. Nearby North Carolina Cities
How Cary's water quality compares to similar cities in North Carolina:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Cary | C | 645 | 5 | 281,828 |
| Fayetteville | A | 110 | 5 | 311,870 |
| Greensboro | A | 1073 | 5 | 321,181 |
| Bahama | B | 0 | 1 | 322,083 |
Water Quality by ZIP Code in Cary
Water quality varies across Cary's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
| ZIP Code | Score | Grade | Violations | Health-Based |
|---|---|---|---|---|
| 27511 | 59 | C | 129 | 5 |
| 27518 | 59 | C | 129 | 5 |
| 27513 | 64 | C | 129 | 5 |
| 27512 | 66 | C | 129 | 5 |
| 27519 | 69 | C | 129 | 5 |
Common Questions About Cary Water
These are the most common questions residents search for about water quality in Cary, North Carolina:
Is Cary water hard or soft? Water hardness varies by source. Cary's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Cary tap water? Cary's water receives a grade of C (63/100). There are 25 health-based violations — consider filtration.
What is the best water filter for Cary? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Cary vs. North Carolina Average
Understanding how Cary compares to the broader North Carolina 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 Cary.
ZIP Codes in Cary
Cary spans 5 ZIP codes. The ZIP with the lowest water quality score is 27511. 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.