Water Quality in Mosby, MO: 17 Violations — Grade D
Grade D · Score 45/100 · 1 water system · Updated 2026-05-03
Mosby's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
The public EPA compliance record for Mosby, MO holds 17 documented water violations — sourced from the federal Safe Drinking Water Information System, which tracks every reportable event for registered public water systems in the state.
Water Quality by ZIP Code in Mosby
Water quality varies across Mosby's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 64073 | D | 45 | 17 | 11 | View report → |
Violation Trend
EPA violations recorded for water systems serving Mosby.
Water Quality Overview
Mosby, 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 1 water system serving Mosby have accumulated 17 EPA violations, including 11 health-based violations. These violations are tracked across 1 ZIP codes serving approximately 115 people.
What Grade D Means
A grade of D indicates significant compliance issues. Mosby'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 Mosby water systems is 0.0012 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
Radon Risk
Mosby 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 Mosby
Mosby is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 115 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 Mosby. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Mosby
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 Mosby Water Systems
The following contaminants have been detected or caused violations across Mosby's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 11 | 1 | Yes |
| Surface Water Treatment Rule | Treatment Technique | N/A | 3 | 1 | No |
| Lead and Copper Rule | Treatment Technique | N/A | 2 | 1 | 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 Mosby:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2021 | 3 | 3 |
| 2022 | 4 | 4 |
| 2023 | 2 | 2 |
| 2025 | 1 | 1 |
Violations have decreased from 3 in 2021 to 1 in 2025, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving Mosby. Recent actions:
| Date | Action Type |
|---|---|
| 2025-09-09 | State Informal Action |
| 2025-09-01 | State Order Extension |
| 2025-08-26 | State Order Extension |
| 2025-08-20 | State Informal Action |
| 2025-08-20 | State Informal Enforcement |
| 2025-08-14 | State Order Extension |
| 2025-05-23 | State Informal Enforcement |
| 2025-05-23 | State Filed Judgment |
| 2024-10-24 | State Informal Action |
| 2024-10-17 | State Order Extension |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-09-09.
Mosby vs. Nearby Missouri Cities
How Mosby's water quality compares to similar cities in Missouri:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Mosby | D | 17 | 1 | 115 |
| Westboro | B | 1 | 1 | 115 |
| Mill Spring | C | 22 | 1 | 112 |
| Bridgeton | D | 0 | 1 | 120 |
Common Questions About Mosby Water
These are the most common questions residents search for about water quality in Mosby, Missouri:
Is Mosby water hard or soft? Water hardness varies by source. Mosby's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Mosby tap water? Mosby's water receives a grade of D (45/100). There are 11 health-based violations — consider filtration.
What is the best water filter for Mosby? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Mosby vs. Missouri Average
Understanding how Mosby 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 Mosby.
ZIP Codes in Mosby
Mosby spans 1 ZIP code. The ZIP with the lowest water quality score is 64073. 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.