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Tap water quality report

Ynp-Mammoth Hot Springs

EPA monitoring tested this supplier for 79 contaminants and detected 16. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

79
contaminants tested
16
detected
2,600
people served
2
health-based violations
Wyoming rankingsLead in WyomingPFAS in Wyoming
Water source
Surface water
Ownership
Federal government
Counties served
Park

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

2
health-based violations
14
violations on file
0
still open
ViolationTypeStatusPeriod
TT Health-based Resolved 2005-07-01 → 2005-07-31
TT Health-based Resolved 2005-07-01 → 2005-07-31
MR Monitoring Resolved 2023-08-01 → 2023-08-31
MR Monitoring Resolved 2023-08-01 → 2023-08-31
MR Monitoring Resolved 2017-06-01 → 2018-05-31
MR Monitoring Resolved 2017-06-01 → 2018-05-31
MR Monitoring Resolved 2013-09-01 → 2013-09-30
MR Monitoring Resolved 2013-09-01 → 2013-09-30
MR Monitoring Resolved 2005-01-01 → 2005-03-31
MR Monitoring Resolved 2005-01-01 → 2005-03-31

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of this system's samples — over 100% is worth reading, but is not by itself a violation. Where a single sample came in higher than that percentile, it is noted under the bar. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Nitrate-Nitrite
170 µg/L 1.7%
of the EPA limit 10000 µg/L
 16/18 SYR4 2012–2019
TTHM
43.2 µg/L 54%
of the EPA limit 80 µg/L
worst single sample: 51 µg/L
14/14 SYR4 2012–2019
Copper
177.8 µg/L 14%
of the EPA limit 1300 µg/L
worst single sample: 180 µg/L
12/12 SYR4 2015–2018
Chloroform
43 µg/L
No EPA limit set
worst single sample: 49 µg/L
11/11 SYR4 2013–2019
Lead
0.0040 mg/L 27%
of the EPA limit 0.0150 mg/L
 11/11 LCR 2024
Bromodichloromethane
1.965 µg/L
No EPA limit set
worst single sample: 2.1 µg/L
10/11 SYR4 2013–2019
Total Haloacetic Acids (HAA5)
40.6 µg/L 68%
of the EPA limit 60 µg/L
worst single sample: 42 µg/L
8/8 SYR4 2012–2019
Dichloroacetic Acid
20.6 µg/L
No EPA limit set
worst single sample: 22 µg/L
5/5 SYR4 2013–2019
Fluoride
200 µg/L 5%
of the EPA limit 4000 µg/L
 5/10 SYR4 2012–2019
Trichloroacetic Acid
15 µg/L
No EPA limit set
 5/5 SYR4 2013–2019
Barium
70 µg/L 3.5%
of the EPA limit 2000 µg/L
 4/10 SYR4 2012–2019
Lead
1.9 µg/L 13%
of the EPA limit 15 µg/L
worst single sample: 2 µg/L
3/12 SYR4 2015–2018
Monochloroacetic Acid
1.68 µg/L
No EPA limit set
worst single sample: 1.7 µg/L
3/5 SYR4 2013–2019
Combined Radium (-226 And -228)
1.5 pCi/L 30%
of the EPA limit 5 pCi/L
 1/1 SYR4 2019
Combined Uranium
1 µg/L 3.3%
of the EPA limit 30 µg/L
 1/1 SYR4 2019
Gross Alpha, Excl. Radon And U
5.4 pCi/L 36%
of the EPA limit 15 pCi/L
 1/1 SYR4 2019
63 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane2,4,5-TP2,4-DAntimony, TotalArsenicAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalBromoformChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDibromoacetic AcidDibromochloromethaneDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorMonobromoacetic AcidOxamylPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
HOFFMAN, STEVEN
Email
[email protected]

Frequently asked questions about Ynp-Mammoth Hot Springs

Is Ynp-Mammoth Hot Springs tap water safe to drink?

EPA monitoring detected 16 contaminants in Ynp-Mammoth Hot Springs's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in Ynp-Mammoth Hot Springs's water?

EPA monitoring detected Nitrate-Nitrite, TTHM, Copper, Chloroform, Lead, and others. The full list with the level and data source for each is above.

How many people does Ynp-Mammoth Hot Springs serve?

Ynp-Mammoth Hot Springs reports serving 2,600 people in Wyoming, per its EPA record.

Has Ynp-Mammoth Hot Springs had any water quality violations?

The EPA has 14 violations on file for Ynp-Mammoth Hot Springs, of which 2 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.