Is O Fallon, MI Tap Water Safe to Drink?
Graded A-, with 1 unresolved violation on record. See what was cited — and what it means for your tap. What to do next ↓
86.6/100
waterverge.com O Fallon, MI — Water Quality Report
O Fallon's drinking water received a grade of A- (86.6 out of 100), indicating good water quality. The city's 1 water system serves approximately 580 residents using purchased surface water.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 2 violations on record, including 0 health-based violations. 1 remains unresolved.
What to know about O Fallon's water
O Fallon ranks #208 out of 520 cities in Michigan for water quality, placing it mid-range in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
As a small community water system, O Fallon may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is O Fallon, MI water safe to drink?
O Fallon's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (86.6/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 580 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for O Fallon
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into O Fallon's water quality assessment. Grade: A- (86.6/100).
Contaminants: Consumer Confidence Rule.
Federal disaster declaration (FEMA DR-4757). Flood event — may have impacted local water infrastructure.
Contaminants: Revised Total Coliform Rule.
Federal disaster declaration (FEMA DR-4195). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for O Fallon's water supply.
Well within EPA limits.
Violation history
O Fallon's water system has 2 total violations on record, including 0 health-based violations. 1 remain unresolved. 2 violations were issued in the last 5 years.
Flood & environmental risk
Oakland County has experienced 4 federally declared disasters since 1975. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include River Rouge, Upper River Rouge, Johnson Creek, Middle River Rouge.
Where does O Fallon's water come from?
O Fallon's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 580 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include River Rouge (river), Upper River Rouge (river), Johnson Creek (river), Middle River Rouge (river).
What O Fallon residents can do
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
O Fallon's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Flood & disaster history
Oakland County has experienced 4 federally declared disasters since 1975. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how O Fallon compares by contaminant
Explore where O Fallon ranks among all Michigan cities for specific contaminants.
Water source & infrastructure
Where O Fallon's water comes from
O Fallon's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by private ownership and serves approximately 580 people through 1 water system.
Water bodies near O Fallon
O Fallon is located near 4 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving O Fallon
| System Name | PWSID | Population | Source |
|---|---|---|---|
| VALLEY VIEW ESTATES | IL1631150 | 580 | SWP |
How O Fallon compares
Full Michigan rankings →O Fallon's score of 86.6/100 is above the average of 70/100 among major Michigan cities. It outscores 8 of 10 nearby cities.
Nearby cities
View Michigan rankings →About O Fallon, MI
Wikipedia →Farmington Hills is a city in Oakland County in the U.S. state of Michigan. A northwestern suburb of Detroit, Farmington Hills is located roughly 22 miles (35.4 km) from downtown Detroit. As of the 2020 census, the city's population was 83,986, making it the second-largest community in Oakland County.
Learn more about your water
Guides and resources related to O Fallon's water quality findings.
Explore water quality across St. Clair
Frequently asked questions
Is O Fallon, MI tap water safe to drink?
O Fallon's water quality earned a grade of A- (86.6/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #208 out of 520 cities tested in Michigan.
What contaminants are in O Fallon's water?
Lead was measured at 0.0 ppb (90th percentile). 2 violations are on record.
How is O Fallon's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in O Fallon?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does O Fallon's water come from?
O Fallon's water is sourced from Purchased surface water. The city has 1 water system serving approximately 580 residents.
How does O Fallon's water compare to other cities?
O Fallon ranks #208 out of 520 cities in Michigan (better than 60% of state cities) and #4626 out of 15744 cities nationally (71th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does O Fallon's small water system affect quality?
O Fallon's system serves approximately 580 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 2 violations on record.