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Water utility · Yellowstone NP · Wyoming

Ynp-Mammoth Hot Springs

No health-based violations on EPA record since 2016.

Serves about 2,600 people (274 connections) with surface water from its own intake.

  • PWSID WY5680092
  • EPA registered name: YNP-MAMMOTH HOT SPRINGS
  • EPA record checked June 29, 2026
Contact

Contact Ynp-Mammoth Hot Springs

From EPA's record for WY5680092. PurityMap is independent of Ynp-Mammoth Hot Springs.

Mailing address
P.O. Box 168
YELLOWSTONE, WY 82190
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EPA compliance record

What EPA's record shows

No health-based violations in the last 10 years, from EPA's SDWIS compliance database.

  • Lead: the 90th-percentile result in the latest lead and copper round (the round ending December 31, 2024) was 4 µg/L. The federal action level is 15 µg/L, a trigger for more treatment steps, not a legal limit.
  • Missed or late tests or reports: 3 in 10 years.
  • EPA lists 3 enforcement actions in 10 years; the latest on November 8, 2023.

No lab results for other contaminants (like PFAS) are on file for this system. EPA required that testing from systems serving more than 3,300 people, plus a sample of smaller ones.

Commercial · test your own tap

The system record stops at your property line

Screening tells you if something is worth a closer look; a lab result is the number you can act on.

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  • Screening: quick check, not lab-grade

    Safe Home DIY Lead in Drinking Water Combo Test Kit

    Safe Home (EnviroTestKits)

    Lead, read as one of three ranges: 0–4, 5–15 or 15+ ppb

    Turnaround: 5 minutes

    What it can't tell you: It shows a lead range, not an exact level, and tests nothing else unless you pay extra for the optional lab test.

Questions

About Ynp-Mammoth Hot Springs

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Where does Ynp-Mammoth Hot Springs get its water?

According to EPA's record, Ynp-Mammoth Hot Springs uses surface water from its own intake.

Does Ynp-Mammoth Hot Springs have any EPA violations?

No health-based violations on EPA record since 2016. EPA also lists 3 missed or late tests or reports in 10 years. The record comes from EPA's SDWIS compliance database.

What is Ynp-Mammoth Hot Springs's latest lead result?

The 90th-percentile lead result in Ynp-Mammoth Hot Springs's latest lead and copper round, which ended in December 2024, was 4 µg/L, below the federal action level of 15 µg/L.

Who do I contact about my Ynp-Mammoth Hot Springs water bill?

PurityMap has no verified website for Ynp-Mammoth Hot Springs. Its mailing address on EPA record is P.O. Box 168, YELLOWSTONE, WY 82190. Your water bill lists the ways to contact your supplier and pay. PurityMap does not take payments.