Is Mount Sterling, IL Tap Water Safe to Drink?
Graded A-, with 6 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
85/100
waterverge.com Mount Sterling, IL — Water Quality Report
Mount Sterling's drinking water received a grade of A- (85 out of 100), indicating good water quality. The city's 2 water systems serve approximately 4,871 residents using purchased ground 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 12 violations on record, including 1 health-based violation. 6 remain unresolved.
What to know about Mount Sterling's water
Mount Sterling ranks #388 out of 891 cities in Illinois for water quality, placing it mid-range in the state.
Mount Sterling purchases its water from a regional wholesaler, meaning quality depends on both the supplier's treatment and the local distribution system's condition.
Water quality score
See methodology →Is Mount Sterling, IL water safe to drink?
Mount Sterling's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (85/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 4,871 residents using groundwater (wells).
Recent water quality updates for Mount Sterling
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Mount Sterling's water quality assessment. Grade: A- (85/100).
Contaminants: Chlorine, Revised Total Coliform Rule.
Contaminants: LEAD AND COPPER RULE REVISIONS.
Contaminants: Consumer Confidence Rule.
Federal disaster declaration (FEMA DR-4116). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-3230). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Mount Sterling's water supply.
Well within EPA limits.
Violation history
Mount Sterling's water system has 12 total violations on record, including 1 health-based violation. 6 remain unresolved. 3 violations were issued in the last 5 years.
Flood & environmental risk
Brown County has experienced 6 federally declared disasters since 1973. 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 La Moine River.
Where does Mount Sterling's water come from?
Mount Sterling's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 4,871 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include La Moine River (river).
What Mount Sterling residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Mount Sterling'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.
Mount Sterling'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
Brown County has experienced 6 federally declared disasters since 1973. 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 Mount Sterling compares by contaminant
Explore where Mount Sterling ranks among all Illinois cities for specific contaminants.
Water source & infrastructure
Where Mount Sterling's water comes from
Mount Sterling purchases its water supply from a regional wholesale provider rather than treating raw water directly.
Water quality depends on both the wholesaler's treatment standards and the condition of Mount Sterling's local distribution pipes and storage facilities.
Purchased water systems are common in suburban areas and smaller communities that lack the infrastructure for independent treatment.
The system is operated by local government ownership and serves approximately 4,871 people through 2 water systems.
Water bodies near Mount Sterling
Mount Sterling is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Mount Sterling
| System Name | PWSID | Population | Source |
|---|---|---|---|
| MOUNT STERLING | IL0090100 | 3,271 | GWP |
| WESTERN IL CORRECTIONAL CENTER | IL0090010 | 1,600 | GWP |
How Mount Sterling compares
Full Illinois rankings →Mount Sterling's score of 85/100 is above the average of 56/100 among major Illinois cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Illinois rankings →About Mount Sterling, IL
Learn more about your water
Guides and resources related to Mount Sterling's water quality findings.
Explore water quality across Brown
Frequently asked questions
Is Mount Sterling, IL tap water safe to drink?
Mount Sterling's water quality earned a grade of A- (85/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #388 out of 891 cities tested in Illinois.
What contaminants are in Mount Sterling's water?
Lead was measured at 0.0 ppb (90th percentile). 12 violations are on record.
How is Mount Sterling'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 Mount Sterling?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Mount Sterling's water come from?
Mount Sterling's water is sourced from Purchased ground water. The city has 2 water systems serving approximately 4,871 residents.
What health violations has Mount Sterling's water system had?
Mount Sterling has 1 health-based violation on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 6 violations remain unresolved.
Is Mount Sterling's groundwater at risk of contamination?
Mount Sterling 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 12 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 Mount Sterling's water compare to other cities?
Mount Sterling ranks #388 out of 891 cities in Illinois (better than 56% of state cities) and #5555 out of 15744 cities nationally (65th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.