A96/100
Herndon Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 1,146,214 residents · Virginia
What's In Herndon's Tap Water?
76
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.001 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
FAIRFAX COUNTY WATER AUTHORITY
Population Served
1,121,613
Water Source
Surface Water
System ID
VA6059501
HERNDON, TOWN OF
Population Served
24,601
Water Source
Purchased Surface Water
System ID
VA6059550
Frequently Asked Questions About Herndon Water
Is Herndon tap water safe to drink?
Herndon, Virginia tap water receives a grade of A (96/100), which is considered excellent. Out of 76 contaminants tested, none exceed EPA maximum contaminant levels (MCLs) and 1 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 Herndon's water?
Of the 76 contaminants tested in Herndon'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 Herndon have any water quality violations?
Yes, Herndon has 1 EPA violation(s) on record, with the most recent in 2007. Violation types include MCL. 1 of these are health-based violations, which are the most serious category.
Do I need a water filter in Herndon?
Herndon 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 Herndon's tap water come from?
Herndon's drinking water is sourced from surface water and supplied by FAIRFAX COUNTY WATER AUTHORITY and 1 other water system(s). The system serves approximately 1,146,214 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Herndon'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. Herndon'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 Herndon's water compare to other cities in Virginia?
Herndon's water quality score of 96/100 earns a grade of A, which is considered excellent. This places Herndon among the better-performing water systems in Virginia. Visit our Virginia state page to see how all cities in the state compare.
What should I do if I'm concerned about Herndon's water quality?
If you have concerns about Herndon'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 (FAIRFAX COUNTY WATER AUTHORITY) 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.