B66/100
Centennial Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 105,000 residents · Colorado
What's In Centennial's Tap Water?
1
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.009 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
This system has a clean compliance history.
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
WILLOWS WD
Population Served
19,000
Water Source
Purchased Surface Water
System ID
CO0103100
SOUTHGATE WSD
Population Served
55,000
Water Source
Purchased Surface Water
System ID
CO0103721
ARAPAHOE CNTY WWWA
Population Served
31,000
Water Source
Groundwater
System ID
CO0203002
Frequently Asked Questions About Centennial Water
Is Centennial tap water safe to drink?
Centennial, Colorado tap water receives a grade of B (66/100), which is considered good. Out of 67 contaminants tested, 1 exceed EPA maximum contaminant levels (MCLs) and 3 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 Centennial's water?
Of the 67 contaminants tested in Centennial's water supply, the most notable include Copper (90th percentile), Lead (90th percentile), manganese. 1 contaminant(s) exceed EPA legal limits (MCLs). 3 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Centennial have any water quality violations?
Yes, Centennial has 173 EPA violation(s) on record, with the most recent in 2019. Violation types include Other, MR. None of these are classified as health-based violations.
Do I need a water filter in Centennial?
Based on EPA data, using a water filter in Centennial is recommended. 1 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.
Where does Centennial's tap water come from?
Centennial's drinking water is sourced from purchased surface water and supplied by WILLOWS WD and 2 other water system(s). The system serves approximately 105,000 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Centennial'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. Centennial'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 Centennial's water compare to other cities in Colorado?
Centennial's water quality score of 66/100 earns a grade of B, which is considered good. This is an above-average score compared to many cities nationwide. Visit our Colorado state page to see how all cities in the state compare.
What should I do if I'm concerned about Centennial's water quality?
If you have concerns about Centennial'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 (WILLOWS WD) 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.