TapSafetyReport
C41/100

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

Serving 13,600 residents · Wyoming

What's In Yellowstone's Tap Water?

31
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
ContaminantDetectedLimit (MCL)Status
Lead (90th percentile)
0.006 mg/L0.015 mg/LAbove Goal

EPA Violation History

16

Violations (last 5yr)

0

Unresolved

9

Health-Related

TIER 3Resolved

Consumer confidence report — inadequate or unavailable

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

When: July 1, 2024 – March 6, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 2Resolved

Consumer confidence report — content deficiency

When: July 1, 2024 – March 6, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 2Resolved

Other non-health-based violation

When: June 1, 2024 – May 1, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 2Resolved

Other non-health-based violation

When: March 1, 2024 – May 1, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Monitoring / Reporting Violation

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

When: December 30, 2023 – February 3, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 2Resolved

Other non-health-based violation

When: November 30, 2023 – March 10, 2025Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 2Resolved

Exceeded the Maximum Contaminant Level (running average)

When: October 1, 2023 – December 31, 2023Enforcement: Formal — state order issued
TIER 3Resolved

Failed to issue ongoing public notification

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

When: October 1, 2023 – May 1, 2025Rule: Ground Water RuleEnforcement: Formal — state order issued
TIER 2Resolved

Exceeded the Maximum Contaminant Level (running average)

When: July 1, 2023 – September 30, 2023Enforcement: Formal — state order issued
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: July 1, 2023 – September 30, 2023Rule: 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: July 1, 2023 – September 30, 2023Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
TIER 2Resolved

Exceeded the Maximum Contaminant Level (running average)

When: April 1, 2023 – June 30, 2023Enforcement: Formal — state order issued
TIER 2Resolved

Violation related to Lead and Copper Rule

When: September 17, 2022 – October 16, 2024Rule: Surface Water Treatment RuleEnforcement: Formal — state order issued
TIER 1 — URGENTResolved

Violation related to Nitrate

When: June 1, 2022 – June 30, 2022Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Failed to complete routine monitoring

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

When: April 1, 2022 – April 30, 2022Rule: Surface Water Treatment 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: April 1, 2022 – April 30, 2022Rule: 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

YNP - LAKE VILLAGE
Population Served

5,925

Water Source

Groundwater

System ID

WY5680079

YNP-OLD FAITHFUL
Population Served

7,675

Water Source

Surface Water

System ID

WY5680085

Frequently Asked Questions About Yellowstone Water

Is Yellowstone tap water safe to drink?

Yellowstone, Wyoming tap water receives a grade of C (41/100), which is considered fair. 0 contaminant(s) exceed EPA maximum contaminant levels and 59 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.

What contaminants are in Yellowstone's water?

Of the 31 contaminants tested in Yellowstone'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 Yellowstone have any water quality violations?

Yes, Yellowstone has 59 EPA violation(s) on record, with the most recent in 2024. Violation types include MR, TT, MCL. 13 of these are health-based violations, which are the most serious category.

Do I need a water filter in Yellowstone?

Yellowstone 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 Yellowstone's tap water come from?

Yellowstone's drinking water is sourced from groundwater and supplied by YNP - LAKE VILLAGE and 1 other water system(s). The system serves approximately 13,600 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.

How often is Yellowstone'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. Yellowstone'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 Yellowstone's water compare to other cities in Wyoming?

Yellowstone's water quality score of 41/100 earns a grade of C, which is considered fair. This is a below-average score that indicates room for improvement. Visit our Wyoming state page to see how all cities in the state compare.

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

If you have concerns about Yellowstone'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 (YNP - LAKE VILLAGE) 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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