Water Quality in Chesterfield, MO: 24 Violations — Grade D
Grade D · Score 45/100 · 4 water systems · Updated 2026-05-03
Chesterfield'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 Chesterfield, MO shows 24 water compliance events in the record — the table below identifies system names and violation types.
Water Quality by ZIP Code in Chesterfield
Water quality varies across Chesterfield's 3 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 63005 | D | 51 | 8 | 8 | View report → |
| 63017 | C | 56 | 8 | 8 | View report → |
| 63006 | C | 66 | 8 | 8 | View report → |
Violation Trend
EPA violations recorded for water systems serving Chesterfield.
Water Quality Overview
Chesterfield, Missouri 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).
The 4 water systems serving Chesterfield have accumulated 24 EPA violations, including 24 health-based violations. These violations are tracked across 3 ZIP codes serving approximately 1,113,079 people.
What Grade D Means
A grade of D indicates significant compliance issues. Chesterfield'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 Chesterfield water systems is 0.0010 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 50% of homes built before 1986, Chesterfield 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
Chesterfield 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 Chesterfield
Chesterfield is served by 4 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 1,113,079 people across 3 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 30 enforcement actions against water systems serving Chesterfield. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Chesterfield
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 Chesterfield Water Systems
The following contaminants have been detected or caused violations across Chesterfield's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 18 | 3 | Yes |
| Chlorine residual | Disinfectant | 4 mg/L | 3 | 3 | Yes |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 3 | 3 | Yes |
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 Chesterfield:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2022 | 9 | 9 |
| 2023 | 3 | 3 |
| 2024 | 12 | 12 |
| 2025 | 3 | 3 |
Violations have decreased from 9 in 2022 to 3 in 2025, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving Chesterfield. Recent actions:
| Date | Action Type |
|---|---|
| 2025-01-31 | State Order Extension |
| 2024-10-25 | State Informal Action |
| 2024-10-01 | State Informal Enforcement |
| 2024-10-01 | State Filed Judgment |
| 2024-09-05 | State Informal Enforcement |
| 2024-09-05 | State Filed Judgment |
| 2024-04-16 | State Informal Action |
| 2024-02-29 | State Informal Enforcement |
| 2024-02-29 | State Filed Judgment |
| 2024-02-28 | State Informal Enforcement |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-01-31.
Chesterfield vs. Nearby Missouri Cities
How Chesterfield's water quality compares to similar cities in Missouri:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Chesterfield | D | 24 | 4 | 1,113,079 |
| Ballwin | D | 0 | 1 | 1,111,000 |
| Earth City | D | 0 | 1 | 1,111,000 |
| Glencoe | D | 0 | 1 | 1,111,000 |
Recommended Water Filters for Chesterfield
Based on contaminants detected in Chesterfield's water supply, these filter types are recommended:
Granular Activated Carbon (GAC, under-sink or whole-house)
- Removes: HAA5
- Effectiveness: 60-80%
- Cost range: $100–$600
- Certification: NSF/ANSI 53
- Recommended products:
Granular Activated Carbon (GAC, whole-house POE)
- Removes: TTHM
- Effectiveness: 80-99%
- Cost range: $400–$2000
- Certification: NSF/ANSI 53
- Recommended products:
Water Quality by ZIP Code in Chesterfield
Water quality varies across Chesterfield's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
Common Questions About Chesterfield Water
These are the most common questions residents search for about water quality in Chesterfield, Missouri:
Is Chesterfield water hard or soft? Water hardness varies by source. Chesterfield's 4 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Chesterfield tap water? Chesterfield's water receives a grade of D (45/100). There are 24 health-based violations — consider filtration.
What is the best water filter for Chesterfield? Based on detected contaminants, a granular activated carbon (gac, under-sink or whole-house) filter is most recommended. See our Water Filter Matcher for personalized recommendations.
Chesterfield vs. Missouri Average
Understanding how Chesterfield compares to the broader Missouri 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 Chesterfield.
ZIP Codes in Chesterfield
Chesterfield spans 3 ZIP codes. The ZIP with the lowest water quality score is 63005. 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.