B72/100
Winthrop Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 1,350 residents · Washington
What's In Winthrop'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) | 0.001 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
6
Violations (last 5yr)
1
Unresolved
0
Health-Related
TIER 3Resolved
Monitoring Violation
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: December 1, 2024 – December 31, 2024Rule: Total Coliform 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: August 1, 2024 – August 31, 2024Rule: Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2024 – February 19, 2025Enforcement: 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: June 1, 2024 – June 30, 2024Rule: Total Coliform RuleEnforcement: 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: January 1, 2024 – December 31, 2024Enforcement: Resolving — corrective action underway
TIER 3Unresolved
Failed to issue ongoing public notification
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
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
WINTHROP TOWN OF
Population Served
1,350
Water Source
Groundwater
System ID
WA5397750
Frequently Asked Questions About Winthrop Water
Is Winthrop tap water safe to drink?
Winthrop, Washington tap water receives a grade of B (72/100), which is considered good. Out of 1 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 Winthrop's water?
Of the 1 contaminants tested in Winthrop'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 Winthrop have any water quality violations?
Yes, Winthrop has 17 EPA violation(s) on record, with the most recent in 2024. Violation types include MON, Other, MR. 2 of these are health-based violations, which are the most serious category.
Do I need a water filter in Winthrop?
Winthrop 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 Winthrop's tap water come from?
Winthrop's drinking water is sourced from groundwater and supplied by WINTHROP TOWN OF. The system serves approximately 1,350 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Winthrop'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. Winthrop'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 Winthrop's water compare to other cities in Washington?
Winthrop's water quality score of 72/100 earns a grade of B, which is considered good. This is an above-average score compared to many cities nationwide. Visit our Washington state page to see how all cities in the state compare.
What should I do if I'm concerned about Winthrop's water quality?
If you have concerns about Winthrop'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 (WINTHROP TOWN 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.