TapSafetyReport
D30/100

Mesa Tap Water Quality: Is It Safe to Drink? (2026 Report)

Serving 1,740 residents · Washington

What's In Mesa's Tap Water?

1
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals

EPA Violation History

12

Violations (last 5yr)

1

Unresolved

1

Health-Related

TIER 3Resolved

Surface water treatment technique failure

When: July 1, 2025 – September 16, 2025Enforcement: Resolving — corrective action underway
TIER 1 — URGENTUnresolved

Exceeded the Maximum Contaminant Level (single sample)

When: January 1, 2025 – July 31, 2025Verify on EPA.gov
TIER 3Resolved

Monitoring Violation

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: May 1, 2024 – May 31, 2024Rule: Total Coliform RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Surface water treatment technique failure

When: July 1, 2023 – October 3, 2023Enforcement: 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: April 1, 2023 – April 30, 2023Rule: 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: December 1, 2022 – December 31, 2022Rule: 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: September 1, 2022 – September 30, 2022Rule: 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: July 1, 2022 – July 31, 2022Rule: 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, 2022 – December 31, 2022Enforcement: 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: January 1, 2022 – December 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: January 1, 2022 – December 31, 2022Rule: Stage 2 DBPREnforcement: 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: December 1, 2021 – December 31, 2021Rule: Total Coliform RuleEnforcement: 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

Basin City Water Sewer District
Population Served

1,740

Water Source

Groundwater

System ID

WA5304461

Frequently Asked Questions About Mesa Water

Is Mesa tap water safe to drink?

Mesa, Washington tap water receives a grade of D (30/100), which is considered poor. 0 contaminant(s) exceed EPA maximum contaminant levels and 42 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.

What contaminants are in Mesa's water?

1 contaminants were tested in Mesa's water supply. No contaminants exceed EPA legal limits (MCLs) or health goals (MCLGs), which is a positive indicator of water quality.

Does Mesa have any water quality violations?

Yes, Mesa has 42 EPA violation(s) on record, with the most recent in 2025. Violation types include Other, MCL, MON. 7 of these are health-based violations, which are the most serious category.

Do I need a water filter in Mesa?

Mesa 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 Mesa's tap water come from?

Mesa's drinking water is sourced from groundwater and supplied by Basin City Water Sewer District. The system serves approximately 1,740 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.

How often is Mesa'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. Mesa'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 Mesa's water compare to other cities in Washington?

Mesa's water quality score of 30/100 earns a grade of D, which is considered poor. This is a concerning score that suggests significant water quality issues. Visit our Washington state page to see how all cities in the state compare.

What should I do if I'm concerned about Mesa's water quality?

If you have concerns about Mesa'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 (Basin City Water Sewer District) 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.

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