Is Cottleville, MO Tap Water Safe to Drink?
Graded A-, with 9 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
87.7/100
waterverge.com Cottleville, MO — Water Quality Report
Cottleville's drinking water received a grade of A- (87.7 out of 100), indicating good water quality. The city's 3 water systems serve approximately 1,717 residents using groundwater.
Lead levels were measured at 3.0 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 40 violations on record, including 15 health-based violations. 9 remain unresolved.
What to know about Cottleville's water
Cottleville ranks #153 out of 509 cities in Missouri for water quality, placing it mid-range in the state.
Cottleville relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
As a small community water system, Cottleville may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Cottleville, MO water safe to drink?
Cottleville's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (87.7/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 3 water systems serve approximately 1,717 residents using groundwater (wells).
Recent water quality updates for Cottleville
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Cottleville's water quality assessment. Grade: A- (87.7/100).
Contaminants: E. COLI.
Contaminants: Coliform (TCR), Consumer Confidence Rule.
Contaminants: Public Notice.
Key contaminant findings
Based on the most recent EPA sampling data for Cottleville's water supply.
Well within EPA limits.
Violation history
Cottleville's water system has 40 total violations on record, including 15 health-based violations. 9 remain unresolved.
Where does Cottleville's water come from?
Cottleville's drinking water comes from groundwater (wells), supplied by 3 water systems serving approximately 1,717 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Dardenne Creek At O'Fallon (river), Dardenne Creek At Old Town St. Peters (river), Bonhomme Creek Near Ellisville (river), Bonhomme Creek Near Clarkson Valley (river), Caulks Creek At Chesterfield (river).
What Cottleville residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Cottleville's water.
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.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Cottleville
Industrial polluters nearby
Reported releases to surface water by facilities near Cottleville, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
BELTSERVICE CORP EARTH CITY, MO63045 | — | — | 9.9 mi |
BMK CORP EARTH CITY, MO63045 | — | — | 10.0 mi |
NEWCO ENTERPRISES INC SAINT CHARLES, MO63301 | — | — | 9.3 mi |
DIAGRAPH MARKING & CODING SAINT CHARLES, MO63304 | — | — | 3.2 mi |
O'FALLON CASTING O FALLON, MO63366 | — | — | 3.7 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Cottleville
Superfund sites nearby
Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
- WELDON SPRING QUARRY PLANT PITS USDOE ARMY5.2 mi
- WELDON SPRING FORMER ARMY ORDNANCE WORKS5.4 mi
Source: EPA Superfund National Priorities List
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. | 3.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Cottleville compares by contaminant
Explore where Cottleville ranks among all Missouri cities for specific contaminants.
Water source & infrastructure
Where Cottleville's water comes from
Cottleville's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by private ownership and serves approximately 1,717 people through 3 water systems.
Water bodies near Cottleville
Cottleville is located near 5 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Cottleville
| System Name | PWSID | Population | Source |
|---|---|---|---|
| MO AMERICAN WARREN COUNTY WATER & SEWER | MO6036149 | 1,200 | GW |
| MO AMERICAN ANNA MEADOWS | MO6031475 | 412 | GW |
| MO AMERICAN RED FIELD SUBDIVISION | MO3031301 | 105 | GW |
How Cottleville compares
Full Missouri rankings →Cottleville's score of 87.7/100 is above the average of 62/100 among major Missouri cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Missouri rankings →About Cottleville, MO
Wikipedia →Cottleville is a city in St. Charles County, Missouri, United States. The population was 5,611 at the 2020 census.
Learn more about your water
Guides and resources related to Cottleville's water quality findings.
Explore water quality across Lincoln
Frequently asked questions
Is Cottleville, MO tap water safe to drink?
Cottleville's water quality earned a grade of A- (87.7/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #153 out of 509 cities tested in Missouri.
What contaminants are in Cottleville's water?
Lead was measured at 3.0 ppb (90th percentile). 40 violations are on record.
How is Cottleville'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 Cottleville?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Cottleville's water come from?
Cottleville's water is sourced from Groundwater. The city has 3 water systems serving approximately 1,717 residents.
What health violations has Cottleville's water system had?
Cottleville has 15 health-based violations on record. The most recent violation was recorded in August 2014. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 9 violations remain unresolved.
Is Cottleville's groundwater at risk of contamination?
Cottleville uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 40 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Cottleville's water compare to other cities?
Cottleville ranks #153 out of 509 cities in Missouri (better than 70% of state cities) and #3888 out of 15744 cities nationally (75th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.