Is Leon, IA 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 ↓
86.4/100
waterverge.com Leon, IA — Water Quality Report
Leon's drinking water received a grade of A- (86.4 out of 100), indicating good water quality. The city's 1 water system serves approximately 1,830 residents using surface water.
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 27 violations on record, including 20 health-based violations. 1 remains unresolved.
What to know about Leon's water
Leon ranks #323 out of 436 cities in Iowa for water quality, placing it below average 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, Leon may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Leon, IA water safe to drink?
Leon's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (86.4/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 1,830 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Leon
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Leon's water quality assessment. Grade: A- (86.4/100).
1 health-based. Contaminants: Surface Water Treatment Rule.
1 health-based. Contaminants: Surface Water Treatment Rule.
1 health-based. Contaminants: Surface Water Treatment Rule.
Federal disaster declaration (FEMA DR-4421). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4119). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Leon's water supply.
Well within EPA limits.
Violation history
Leon's water system has 27 total violations on record, including 20 health-based violations. 1 remain unresolved. 5 violations were issued in the last 5 years.
Flood & environmental risk
Decatur County has experienced 7 federally declared disasters since 1969. 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 Thompson River At Davis City.
Where does Leon's water come from?
Leon's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 1,830 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Thompson River At Davis City (river).
What Leon 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.
Leon'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
Decatur County has experienced 7 federally declared disasters since 1969. 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. | 3.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Leon compares by contaminant
Explore where Leon ranks among all Iowa cities for specific contaminants.
Water source & infrastructure
Where Leon's water comes from
Leon'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 local government ownership and serves approximately 1,830 people through 1 water system.
Water bodies near Leon
Leon is located near 1 notable water body. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Leon
| System Name | PWSID | Population | Source |
|---|---|---|---|
| LEON WATER SUPPLY | IA2742076 | 1,830 | SW |
How Leon compares
Full Iowa rankings →Leon's score of 86.4/100 is above the average of 72/100 among major Iowa cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Iowa rankings →About Leon, IA
Learn more about your water
Guides and resources related to Leon's water quality findings.
Explore water quality across Decatur
Frequently asked questions
Is Leon, IA tap water safe to drink?
Leon's water quality earned a grade of A- (86.4/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #323 out of 436 cities tested in Iowa.
What contaminants are in Leon's water?
Lead was measured at 3.0 ppb (90th percentile). 27 violations are on record.
How is Leon'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 Leon?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Leon's water come from?
Leon's water is sourced from Surface water. The city has 1 water system serving approximately 1,830 residents.
What health violations has Leon's water system had?
Leon has 20 health-based violations on record. The most recent violation was recorded in July 2023. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.
How does Leon's water compare to other cities?
Leon ranks #323 out of 436 cities in Iowa (better than 26% of state cities) and #4718 out of 15744 cities nationally (70th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Leon's small water system affect quality?
Leon's system serves approximately 1,830 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 27 violations on record.