TapSafetyReport
F0/100

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

Serving 14,465 residents · Oregon

What's In Ontario's Tap Water?

69
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
ContaminantDetectedLimit (MCL)Status
Lead (90th percentile)
0.002 mg/L0.015 mg/LAbove Goal

EPA Violation History

7

Violations (last 5yr)

0

Unresolved

0

Health-Related

TIER 3Resolved

Failed to complete routine monitoring

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

When: March 1, 2023 – March 31, 2023Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Failed to complete routine monitoring

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

When: March 1, 2023 – March 31, 2023Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Failed to complete routine monitoring

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

When: March 1, 2023 – March 31, 2023Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Missed required monitoring deadline

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

When: March 1, 2023 – March 31, 2023Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Missed required monitoring deadline

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

When: March 1, 2023 – March 31, 2023Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Failed to complete routine monitoring

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

When: March 1, 2023 – March 31, 2023Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Monitoring Violation

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

When: January 1, 2023 – January 31, 2023Rule: Total Coliform RuleEnforcement: 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

ONTARIO, CITY OF
Population Served

14,465

Water Source

Surface Water

System ID

OR4100587

Frequently Asked Questions About Ontario Water

Is Ontario tap water safe to drink?

Ontario, Oregon tap water receives a grade of F (0/100), which is considered failing. 0 contaminant(s) exceed EPA maximum contaminant levels and 101 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.

What contaminants are in Ontario's water?

Of the 69 contaminants tested in Ontario'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 Ontario have any water quality violations?

Yes, Ontario has 101 EPA violation(s) on record, with the most recent in 2023. Violation types include MR, MON, TT. 1 of these are health-based violations, which are the most serious category.

Do I need a water filter in Ontario?

Ontario 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 Ontario's tap water come from?

Ontario's drinking water is sourced from surface water and supplied by ONTARIO, CITY OF. The system serves approximately 14,465 people. Surface water sources include rivers, lakes, and reservoirs.

How often is Ontario'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. Ontario'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 Ontario's water compare to other cities in Oregon?

Ontario'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 Oregon state page to see how all cities in the state compare.

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

If you have concerns about Ontario'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 (ONTARIO, CITY OF) 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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