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WaterSafeCheck

ZIP Code 63366 Water Quality Report

O Fallon, MO · St Charles County County

Safety Score
C

Water Safety Grade

Fair — Some compliance concerns

Health Violations

0

Total Violations

6

Lead Risk

Low

Contaminants

0

About Tap Water in ZIP Code 63366

Tap water in ZIP code 63366 (O Fallon, MO) receives a C grade (score: 64/100) based on EPA monitoring data. While the water from St Charles County Pwsd 2 is treated and regulated, this area has a moderate violation history that residents should be aware of.

Water System

St Charles County Pwsd 2

EPA ID: MO6024530

Water Source

Surface Water

Population Served

100,587 residents

County

St Charles County County, Missouri

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Lead Levels in ZIP 63366

EPA action level: 15 ppb | Public health goal: 0 ppb

Lead Level: 1.1 ppb — Very Low

The 90th percentile lead level in 63366 is 1.1 ppb, well below the EPA action level of 15 ppb. While this is a reassuring result, the EPA's public health goal for lead is actually zero — no amount of lead is considered completely safe, particularly for children under 6 and pregnant women. Running your tap for 30 seconds before use and using a certified NSF/ANSI 53 filter adds an extra layer of protection.

Lead exposure risk in 63366 is rated Low. EPA models estimate a 18% probability of lead exposure risk in this ZIP code based on housing age, infrastructure age, and water system data. This rating reflects newer infrastructure, lower housing age, and/or low detected lead levels. Standard precautions — flushing taps before use, using filtered water for infants — are still recommended.

Lead Level (90th percentile)
1.10 ppb (0.0011 mg/L)
Lead (Consumer Confidence Report)

From annual CCR filing

90 ppb
Lead Exposure Risk Rating
Low
Lead Exposure Probability

EPA model estimate based on housing age and infrastructure

18%
Note: Lead levels above are the 90th percentile from EPA monitoring — meaning 90% of samples were at or below this level. Even "undetected" tap water lead doesn't account for lead leaching from home plumbing. If your home was built before 1986, individual tap testing is recommended.
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Violation History

Past 5 years — EPA SDWIS data

St Charles County Pwsd 2 has recorded 6 violations, but none are health-based. Administrative or reporting violations don't directly indicate unsafe water, but they do signal gaps in documentation or monitoring procedures. 1 violation is currently unresolved — meaning the issue has not yet been formally corrected in EPA records. This is a serious concern that residents should follow up on with their water utility.

Total Violations (5 yr)
6
Health-Based Violations
0
Unresolved Violations
1
Boil Water Advisories
0
Compliance Risk
High

Regulatory compliance risk is rated High. St Charles County Pwsd 2 has a pattern of compliance issues that goes beyond isolated incidents. Residents should stay informed via their utility's Consumer Confidence Report.

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Contaminants Detected

Contaminants with health-based violations on record

No health-based contaminant violations are on record for ZIP code 63366. This means EPA monitoring has not found levels of regulated contaminants exceeding the Maximum Contaminant Levels (MCLs) set under the Safe Drinking Water Act — a positive indicator of water quality compliance.

From Consumer Confidence Report:

Lead (90 ppb*)

⚖ Enforcement Actions

10 enforcement actions have been issued against St Charles County Pwsd 2 — a high number that reflects sustained compliance struggles. Enforcement actions escalate from administrative orders to financial penalties when utilities repeatedly fail to meet safe drinking water standards.
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Water Source & Environmental Factors

Surface Water

This system draws water from lakes, rivers, or reservoirs. Surface water is treated to remove sediment, microorganisms, and chemical contaminants before reaching taps.

Water Source Type
Surface Water
CCR Source Classification
Surface Water and Ground Water
EPA Radon Zone

Moderate potential

Zone 2
Annual Flood Risk Cost

Estimated annual flood-related costs per property

$8
Energy Burden

% of household income spent on energy — indicator of older infrastructure

1.54%

EPA Radon Zone 2 — moderate radon potential. The EPA recommends testing your home regardless of zone designation.

🛡 What Should You Do? — ZIP 63366 Recommendations

  • ⚠ Use a certified NSF/ANSI 53 filter for drinking and cooking water if you have young children
  • ⚠ Never give unfiltered tap water to infants in formula — use certified bottled or filtered water
  • ⚠ Request a copy of the Consumer Confidence Report to see what was detected and when
  • ⚠ Call the EPA Safe Drinking Water Hotline: 1-800-426-4791

Frequently Asked Questions — ZIP 63366 Water Quality

Is tap water safe to drink in ZIP code 63366?+
Tap water in 63366 (O Fallon, MO) is treated and regulated, but has a grade of C due to past violations. For most healthy adults, treated tap water is generally safe. Families with infants, young children, or immunocompromised individuals may want to use a certified water filter as a precaution.
What is the lead level in 63366 tap water?+
The 90th percentile lead level in 63366 is 1.1 ppb (parts per billion). The EPA action level is 15 ppb. This is a low level, well below the EPA action level of 15 ppb.
Who provides tap water to 63366?+
Tap water in ZIP code 63366 is provided by St Charles County Pwsd 2 (EPA ID: MO6024530). This system serves approximately 100,587 residents. You can contact them directly for Consumer Confidence Reports, current advisories, and billing information.
What is the water source for 63366?+
ZIP code 63366 is served by surface water. Surface water systems draw from rivers, lakes, or reservoirs and must meet strict EPA treatment requirements including filtration and disinfection.
Does 63366 have any active water quality violations?+
Yes — there are currently 1 unresolved violation on record for this water system. Unresolved violations indicate issues that have not yet been formally corrected in EPA tracking systems. Contact St Charles County Pwsd 2 for the latest update.
How do I get a copy of my water quality report for 63366?+
Your water utility — St Charles County Pwsd 2 — is required by law to send you an annual Consumer Confidence Report (CCR) by July 1 each year. You can also request it directly from the utility or find it online by searching "St Charles County Pwsd 2 Consumer Confidence Report." The EPA's ECHO database also has historical compliance data.
What water filter should I use in 63366?+
The right filter depends on what contaminants are present. For lead, look for a filter certified to NSF/ANSI Standard 53. For chlorine byproducts (like THMs), NSF/ANSI 42 filters work well. For a broad range of contaminants including PFAS, look for NSF/ANSI 58 (reverse osmosis) systems. For ZIP code 63366, with a clean compliance record, a standard carbon block filter meeting NSF/ANSI 42 is a good choice for taste and as a precaution.
Is 63366 tap water safe for babies and infants?+
Infants are especially vulnerable to lead, nitrates, and microbial contaminants in drinking water. Current EPA data for 63366 shows a lead level of 1.1 ppb — below the action level, but as an extra precaution, run your tap for 30 seconds before use and consider a certified lead filter for infant formula. Always consult your pediatrician for guidance specific to your child's health.

Data Sources & Methodology

Water quality data for ZIP code 63366 is compiled from the EPA Safe Drinking Water Information System (SDWIS), EPA ECHO enforcement database, UCMR5 unregulated contaminant monitoring, and Consumer Confidence Reports filed by St Charles County Pwsd 2. Safety scores are composite metrics derived from violation history, lead levels, enforcement actions, and infrastructure risk indicators. Data reflects a 5-year monitoring window. Last dataset update: 2024. View EPA source data →