D23/100
Derby Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 25,413 residents · Kansas
What's In Derby's Tap Water?
70
Contaminants Tested
1
Exceed EPA Limits
1
Above EPA Goals
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.41 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.001 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
5
Violations (last 5yr)
0
Unresolved
0
Health-Related
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: October 6, 2022 – May 30, 2023Rule: Ground Water 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: June 1, 2022 – August 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: June 1, 2022 – August 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: June 1, 2021 – August 31, 2021Rule: 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: June 1, 2021 – August 31, 2021Rule: 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
DERBY, CITY OF
Population Served
25,413
Water Source
Purchased Surface Water
System ID
KS2017328
Frequently Asked Questions About Derby Water
Is Derby tap water safe to drink?
Derby, Kansas tap water receives a grade of D (23/100), which is considered poor. 1 contaminant(s) exceed EPA maximum contaminant levels and 22 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Derby's water?
Of the 70 contaminants tested in Derby's water supply, the most notable include Copper (90th percentile), Lead (90th percentile). 1 contaminant(s) exceed EPA legal limits (MCLs). 2 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Derby have any water quality violations?
Yes, Derby has 22 EPA violation(s) on record, with the most recent in 2022. Violation types include Other, MR, MCL. 11 of these are health-based violations, which are the most serious category.
Do I need a water filter in Derby?
Based on EPA data, using a water filter in Derby 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 Derby's tap water come from?
Derby's drinking water is sourced from purchased surface water and supplied by DERBY, CITY OF. The system serves approximately 25,413 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Derby'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. Derby'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 Derby's water compare to other cities in Kansas?
Derby's water quality score of 23/100 earns a grade of D, which is considered poor. This is a concerning score that suggests significant water quality issues. Visit our Kansas state page to see how all cities in the state compare.
What should I do if I'm concerned about Derby's water quality?
If you have concerns about Derby'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 (DERBY, 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.