Water Quality in Saint Mary, MO: No Violations — Grade D
Grade D · Score 50/100 · 1 water system · Updated 2026-05-03
Saint Mary'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 compliance data for Saint Mary, MO: no violations across 1 monitored system.
Water Quality by ZIP Code in Saint Mary
Water quality varies across Saint Mary's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 63673 | D | 50 | 0 | 0 | View report → |
Water Quality Overview
Saint Mary, Missouri receives a water quality grade of D with an overall score of 50 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
No EPA violations have been recorded for the 1 water system serving Saint Mary. This is a positive indicator, though it does not guarantee the absence of all contaminants — some substances (like PFAS) are not yet fully regulated.
What Grade D Means
A grade of D indicates significant compliance issues. Saint Mary'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
Lead testing data for Saint Mary is currently being collected. The EPA requires all community water systems to test for lead under the Lead and Copper Rule.
With 61% of homes built before 1986, Saint Mary 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
Saint Mary is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Saint Mary
Saint Mary is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 8,555 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
How to Check Your Water in Saint Mary
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
Saint Mary vs. Nearby Missouri Cities
How Saint Mary's water quality compares to similar cities in Missouri:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Saint Mary | D | 0 | 1 | 8,555 |
| Mc Bride | C | 0 | 1 | 8,555 |
| Willard | B | 1 | 2 | 8,475 |
| Lathrop | C | 4 | 3 | 8,663 |
Common Questions About Saint Mary Water
These are the most common questions residents search for about water quality in Saint Mary, Missouri:
Is Saint Mary water hard or soft? Water hardness varies by source. Saint Mary's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Saint Mary tap water? Saint Mary's water receives a grade of D (50/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Saint Mary? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Saint Mary vs. Missouri Average
Understanding how Saint Mary 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 Saint Mary.
ZIP Codes in Saint Mary
Saint Mary spans 1 ZIP code. 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.