A90/100
Knoxville Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 14,087 residents · Iowa
What's In Knoxville's Tap Water?
31
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.008 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 1992.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
KNOXVILLE WATER WORKS
Population Served
8,400
Water Source
Groundwater
System ID
IA6342036
MARION CO. RURAL WATER DISTRICT
Population Served
5,687
Water Source
Purchased Groundwater
System ID
IA6342711
Frequently Asked Questions About Knoxville Water
Is Knoxville tap water safe to drink?
Knoxville, Iowa tap water receives a grade of A (90/100), which is considered excellent. Out of 31 contaminants tested, none exceed EPA maximum contaminant levels (MCLs) and 1 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Knoxville's water?
Of the 31 contaminants tested in Knoxville's water supply, the most notable include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Knoxville have any water quality violations?
Yes, Knoxville has 5 EPA violation(s) on record, with the most recent in 2025. Violation types include Other, MR, MCL. 2 of these are health-based violations, which are the most serious category.
Do I need a water filter in Knoxville?
Knoxville water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.
Where does Knoxville's tap water come from?
Knoxville's drinking water is sourced from groundwater and supplied by KNOXVILLE WATER WORKS and 1 other water system(s). The system serves approximately 14,087 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Knoxville's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Knoxville's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Knoxville's water compare to other cities in Iowa?
Knoxville's water quality score of 90/100 earns a grade of A, which is considered excellent. This places Knoxville among the better-performing water systems in Iowa. Visit our Iowa state page to see how all cities in the state compare.
What should I do if I'm concerned about Knoxville's water quality?
If you have concerns about Knoxville's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (KNOXVILLE WATER WORKS) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.