A83/100
Johnston City Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 3,509 residents · Illinois
What's In Johnston City's Tap Water?
38
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals
EPA Violation History
4
Violations (last 5yr)
2
Unresolved
1
Health-Related
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: August 22, 2025 – September 19, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Unresolved
Failed to issue ongoing public notification
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: July 1, 2025Rule: Ground Water RuleEnforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 2Unresolved
Treatment technique violation
When: October 17, 2024Rule: Ground Water RuleEnforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2024 – November 1, 2024Enforcement: Resolving — corrective action underway
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
JOHNSTON CITY
Population Served
3,509
Water Source
Purchased Surface Water
System ID
IL1990500
Frequently Asked Questions About Johnston City Water
Is Johnston City tap water safe to drink?
Johnston City, Illinois tap water receives a grade of A (83/100), which is considered excellent. Out of 38 contaminants tested, none exceed EPA maximum contaminant levels (MCLs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Johnston City's water?
38 contaminants were tested in Johnston City's water supply. No contaminants exceed EPA legal limits (MCLs) or health goals (MCLGs), which is a positive indicator of water quality.
Does Johnston City have any water quality violations?
Yes, Johnston City has 9 EPA violation(s) on record, with the most recent in 2025. Violation types include Other, MR, TT. 2 of these are health-based violations, which are the most serious category.
Do I need a water filter in Johnston City?
Johnston City 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. All contaminants are within health goals.
Where does Johnston City's tap water come from?
Johnston City's drinking water is sourced from purchased surface water and supplied by JOHNSTON CITY. The system serves approximately 3,509 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Johnston City'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. Johnston City'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 Johnston City's water compare to other cities in Illinois?
Johnston City's water quality score of 83/100 earns a grade of A, which is considered excellent. This places Johnston City among the better-performing water systems in Illinois. Visit our Illinois state page to see how all cities in the state compare.
What should I do if I'm concerned about Johnston City's water quality?
If you have concerns about Johnston City'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 (JOHNSTON CITY) 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.