B61/100
Cornelius Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 14,490 residents · Oregon
What's In Cornelius's Tap Water?
69
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals
EPA Violation History
5
Violations (last 5yr)
1
Unresolved
0
Health-Related
TIER 3Unresolved
Monitoring / Reporting Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2023 – July 20, 2023Enforcement: 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, 2022Rule: Revised Total Coliform RuleEnforcement: 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: July 1, 2022 – September 30, 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: July 1, 2022 – September 30, 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
CORNELIUS, CITY OF
Population Served
14,490
Water Source
Purchased Surface Water
System ID
OR4100218
Frequently Asked Questions About Cornelius Water
Is Cornelius tap water safe to drink?
Cornelius, Oregon tap water receives a grade of B (61/100), which is considered good. Out of 69 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 Cornelius's water?
69 contaminants were tested in Cornelius's water supply. No contaminants exceed EPA legal limits (MCLs) or health goals (MCLGs), which is a positive indicator of water quality.
Does Cornelius have any water quality violations?
Yes, Cornelius has 39 EPA violation(s) on record, with the most recent in 2024. Violation types include MR, Other, MON. None of these are classified as health-based violations.
Do I need a water filter in Cornelius?
Cornelius 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 Cornelius's tap water come from?
Cornelius's drinking water is sourced from purchased surface water and supplied by CORNELIUS, CITY OF. The system serves approximately 14,490 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Cornelius'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. Cornelius'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 Cornelius's water compare to other cities in Oregon?
Cornelius's water quality score of 61/100 earns a grade of B, which is considered good. This is an above-average score compared to many cities nationwide. Visit our Oregon state page to see how all cities in the state compare.
What should I do if I'm concerned about Cornelius's water quality?
If you have concerns about Cornelius'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 (CORNELIUS, 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.