TapSafetyReport
F0/100

Ottawa Tap Water Quality: Is It Safe to Drink? (2026 Report)

Serving 18,097 residents · Illinois

What's In Ottawa's Tap Water?

66
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals

EPA Violation History

8

Violations (last 5yr)

1

Unresolved

1

Health-Related

TIER 3Unresolved

Reporting Violation

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: July 2, 2025Rule: Ground Water RuleEnforcement: Informal — resolved cooperativelyVerify on EPA.gov
TIER 2Resolved

Exceeded the Maximum Contaminant Level (running average)

When: July 1, 2023 – September 30, 2023Enforcement: Formal — state order issued
TIER 3Resolved

Failed Level 2 Assessment under Revised Total Coliform Rule

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: January 1, 2023 – December 31, 2023Rule: Stage 2 DBPREnforcement: Formal — state order issued
TIER 3Resolved

Failed Level 2 Assessment under Revised Total Coliform Rule

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: January 1, 2023 – December 31, 2023Rule: Stage 2 DBPREnforcement: Formal — state order issued
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: October 1, 2022 – December 31, 2022Enforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: July 1, 2022 – September 30, 2022Enforcement: Resolving — corrective action underway
TIER 3Resolved

Failed Level 2 Assessment under Revised Total Coliform Rule

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: January 1, 2022 – December 31, 2022Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
TIER 3Resolved

Failed Level 2 Assessment under Revised Total Coliform Rule

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: January 1, 2022 – December 31, 2022Rule: Stage 2 DBPREnforcement: 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

OTTAWA
Population Served

18,097

Water Source

Groundwater

System ID

IL0990800

Frequently Asked Questions About Ottawa Water

Is Ottawa tap water safe to drink?

Ottawa, Illinois tap water receives a grade of F (0/100), which is considered failing. 0 contaminant(s) exceed EPA maximum contaminant levels and 85 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.

What contaminants are in Ottawa's water?

66 contaminants were tested in Ottawa's water supply. No contaminants exceed EPA legal limits (MCLs) or health goals (MCLGs), which is a positive indicator of water quality.

Does Ottawa have any water quality violations?

Yes, Ottawa has 85 EPA violation(s) on record, with the most recent in 2025. Violation types include RPT, MCL, MR. 21 of these are health-based violations, which are the most serious category.

Do I need a water filter in Ottawa?

Ottawa 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 Ottawa's tap water come from?

Ottawa's drinking water is sourced from groundwater and supplied by OTTAWA. The system serves approximately 18,097 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.

How often is Ottawa'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. Ottawa'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 Ottawa's water compare to other cities in Illinois?

Ottawa's water quality score of 0/100 earns a grade of F, which is considered failing. This is a concerning score that suggests significant water quality issues. Visit our Illinois state page to see how all cities in the state compare.

What should I do if I'm concerned about Ottawa's water quality?

If you have concerns about Ottawa'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 (OTTAWA) 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.

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