Water Quality in Gilbert, AZ: 357 Violations — Grade B
Grade B · Score 70/100 · 5 water systems · Updated 2026-05-03
Gilbert's water is mostly safe. Minor violations exist but are primarily monitoring-related.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Available EPA records for Gilbert, AZ: 357 water compliance violations tied to local public water systems.
Water Quality Map: Gilbert, AZ
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Water Quality by ZIP Code in Gilbert
Water quality varies across Gilbert's 7 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 85299 | C | 67 | 51 | 4 | View report → |
| 85233 | B | 70 | 51 | 4 | View report → |
| 85234 | B | 70 | 51 | 4 | View report → |
| 85295 | B | 70 | 51 | 4 | View report → |
| 85296 | B | 70 | 51 | 4 | View report → |
| 85297 | B | 70 | 51 | 4 | View report → |
| 85298 | B | 70 | 51 | 4 | View report → |
Violation Trend
EPA violations recorded for water systems serving Gilbert.
Water Quality Overview
Gilbert, Arizona receives a water quality grade of B with an overall score of 70 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 5 water systems serving Gilbert have accumulated 357 EPA violations, including 28 health-based violations. These violations are tracked across 7 ZIP codes serving approximately 248,286 people.
What Grade B Means
A grade of B indicates good compliance with EPA drinking water standards. While not perfect, Gilbert's water systems meet the vast majority of federal requirements. Minor violations may exist but typically relate to monitoring or reporting rather than health-based standards.
Lead Levels
The average 90th percentile lead level across Gilbert water systems is 0.0003 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
Radon Risk
Gilbert is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Gilbert
Gilbert is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 248,286 people across 7 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 70 enforcement actions against water systems serving Gilbert. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Gilbert
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 Gilbert Water Systems
The following contaminants have been detected or caused violations across Gilbert's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Chlorite | Disinfection Byproducts | 1 mg/L | 56 | 7 | No |
| Fecal Coliform | Microbiological | N/A | 42 | 7 | No |
| Barium | Inorganic | 2 mg/L | 35 | 7 | No |
| E. coli | Microbiological | N/A | 35 | 7 | No |
| Surface Water Treatment Rule | Treatment Technique | N/A | 28 | 7 | No |
| Stage 2 DBP Rule | Treatment Technique | N/A | 28 | 7 | Yes |
| Lead and Copper Rule | Treatment Technique | N/A | 21 | 7 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 14 | 7 | No |
| Lead | Inorganic | 0.015 mg/L | 14 | 7 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 14 | 7 | Yes |
| Total Organic Carbon | Disinfection Byproducts | N/A | 7 | 7 | 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 Gilbert:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2024 | 28 | 28 |
| 2025 | 28 | 28 |
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 Gilbert. Recent actions:
| Date | Action Type |
|---|---|
| 2025-08-29 | State Informal Action |
| 2025-08-29 | State Order Extension |
| 2025-08-03 | State Informal Action |
| 2025-08-03 | State Order Extension |
| 2025-07-30 | State Order Extension |
| 2025-07-29 | State Informal Action |
| 2025-07-07 | State Order Extension |
| 2025-07-01 | State Informal Action |
| 2025-07-01 | State Informal Enforcement |
| 2025-06-30 | State Informal Action |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-08-29.
Gilbert vs. Nearby Arizona Cities
How Gilbert's water quality compares to similar cities in Arizona:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Gilbert | B | 357 | 5 | 248,286 |
| Bapchule | D | 0 | 1 | 247,328 |
| Glendale | C | 816 | 5 | 245,461 |
| Scottsdale | B | 315 | 5 | 242,690 |
Water Quality by ZIP Code in Gilbert
Water quality varies across Gilbert's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
| ZIP Code | Score | Grade | Violations | Health-Based |
|---|---|---|---|---|
| 85299 | 67 | C | 51 | 4 |
| 85233 | 70 | B | 51 | 4 |
| 85234 | 70 | B | 51 | 4 |
| 85295 | 70 | B | 51 | 4 |
| 85296 | 70 | B | 51 | 4 |
| 85297 | 70 | B | 51 | 4 |
| 85298 | 70 | B | 51 | 4 |
Common Questions About Gilbert Water
These are the most common questions residents search for about water quality in Gilbert, Arizona:
Is Gilbert water hard or soft? Water hardness varies by source. Gilbert's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Gilbert tap water? Gilbert's water receives a grade of B (70/100). There are 28 health-based violations — consider filtration.
What is the best water filter for Gilbert? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Gilbert vs. Arizona Average
Understanding how Gilbert compares to the broader Arizona 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 Gilbert.
ZIP Codes in Gilbert
Gilbert spans 7 ZIP codes. The ZIP with the lowest water quality score is 85233. 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
Your Water is Safe — Here's How to Keep It That Way
Grade B is excellent news. Here's what proactive homeowners do to maintain water quality:
Annual Water Testing
EPA recommends annual testing even with clean water. Home test kits: $20-$50. Catches changes before they become problems.
Maintenance Filtration
A basic carbon filter removes chlorine taste and catches emerging contaminants like PFAS that aren't yet fully regulated.
Plumbing Check
Even safe city water picks up lead from home pipes. If your home was built before 1986, a one-time pipe inspection is recommended.