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Tap water quality report

Yellowstone Np, WY

EPA monitoring detected 25 contaminants across the 2 water suppliers serving Yellowstone Np. A detection doesn't automatically mean the water is unsafe — see the highest level found for each below, with its EPA source and period.

2
water suppliers
10,275
people served
25
contaminants found
Wyoming rankings Lead in Wyoming PFAS in Wyoming

What was found in Yellowstone Np's water

The highest level seen across the city's suppliers, the EPA limit for each, and where the figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Fluoride
2600 µg/L 65%
of the EPA limit 4000 µg/L
 2/2 SYR4
Copper
180 µg/L 14%
of the EPA limit 1300 µg/L
 2/2 SYR4
Nitrate-Nitrite
170 µg/L 1.7%
of the EPA limit 10000 µg/L
 2/2 SYR4
TTHM
73 µg/L 91%
of the EPA limit 80 µg/L
 2/2 SYR4
Barium
70 µg/L 3.5%
of the EPA limit 2000 µg/L
 1/2 SYR4
Chloroform
52 µg/L
No EPA limit set
 2/2 SYR4
Total Haloacetic Acids (HAA5)
50 µg/L 83%
of the EPA limit 60 µg/L
 2/2 SYR4
Trichloroacetic Acid
26 µg/L
No EPA limit set
 2/2 SYR4
Dichloroacetic Acid
22 µg/L
No EPA limit set
 2/2 SYR4
Arsenic
21 µg/L 210%
of the EPA limit, in the worst sample — 10 µg/L
 1/2 SYR4
Bromodichloromethane
17 µg/L
No EPA limit set
 2/2 SYR4
Lead
9 µg/L 60%
of the EPA limit 15 µg/L
 2/2 SYR4
Dibromochloromethane
7.4 µg/L
No EPA limit set
 1/2 SYR4
Gross Alpha, Excl. Radon And U
5.4 pCi/L 36%
of the EPA limit 15 pCi/L
 2/2 SYR4
Monochloroacetic Acid
4 µg/L
No EPA limit set
 2/2 SYR4
Selenium
3 µg/L 6%
of the EPA limit 50 µg/L
 1/2 SYR4
Thallium, Total
2.3 µg/L 115%
of the EPA limit, in the worst sample — 2 µg/L
 1/2 SYR4
Di(2-ethylhexyl) Phthalate
2.1 µg/L 35%
of the EPA limit 6 µg/L
 1/2 SYR4
Antimony, Total
2 µg/L 33%
of the EPA limit 6 µg/L
 1/2 SYR4
Combined Radium (-226 And -228)
1.6 pCi/L 32%
of the EPA limit 5 pCi/L
 2/2 SYR4
Dibromoacetic Acid
1.3 µg/L
No EPA limit set
 1/2 SYR4
Bromoform
1.2 µg/L
No EPA limit set
 1/2 SYR4
Combined Uranium
1 µg/L 3.3%
of the EPA limit 30 µg/L
 1/2 SYR4
Monobromoacetic Acid
0.8000 µg/L
No EPA limit set
 1/2 SYR4
Lead
0.0060 mg/L 40%
of the EPA limit 0.0150 mg/L
 2/2 LCR
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 single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Yellowstone Np

SupplierPopulation served
YNP-OLD FAITHFUL 7,675
YNP-MAMMOTH HOT SPRINGS 2,600

Frequently asked questions about Yellowstone Np tap water

Is Yellowstone Np tap water safe to drink?

EPA testing detected 25 contaminants in the water serving Yellowstone Np. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Yellowstone Np?

2 public water suppliers report drinking-water monitoring for Yellowstone Np, Wyoming to the EPA. Each is listed above with its population served.

What contaminants are in Yellowstone Np's water?

The contaminants EPA monitoring detected in Yellowstone Np include Fluoride, Copper, Nitrate-Nitrite, TTHM, Barium. The full list, with the highest level found and the data source, is in the table above.

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.