Is Casper, WY Tap Water Safe? Quality & Contaminants

What was found in Casper's water

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

Contaminant	Level vs EPA limit	Suppliers	Source
Nitrate-Nitrite	3000 µg/L 30% of the EPA limit 10000 µg/L	2/12	SYR4
Copper	1770 µg/L 136% of the EPA limit, in the worst sample — 1300 µg/L	12/12	SYR4
Bromate	504 µg/L 5040% of the EPA limit, in the worst sample — 10 µg/L	1/12	SYR4
Fluoride	400 µg/L 10% of the EPA limit 4000 µg/L	2/12	SYR4
Nitrate	400 µg/L 4% of the EPA limit 10000 µg/L	1/12	SYR4
Barium	100 µg/L 5% of the EPA limit 2000 µg/L	1/12	SYR4
TTHM	34 µg/L 43% of the EPA limit 80 µg/L	2/12	SYR4
Lead	29 µg/L 193% of the EPA limit, in the worst sample — 15 µg/L	9/12	SYR4
Total Haloacetic Acids (HAA5)	15 µg/L 25% of the EPA limit 60 µg/L	2/12	SYR4
Bromodichloromethane	12 µg/L No EPA limit set	2/12	SYR4
Chloroform	12 µg/L No EPA limit set	2/12	SYR4
Combined Uranium	11 µg/L 37% of the EPA limit 30 µg/L	1/12	SYR4
Selenium	10 µg/L 20% of the EPA limit 50 µg/L	1/12	SYR4
Dichloroacetic Acid	9.2 µg/L No EPA limit set	2/12	SYR4
Dibromochloromethane	9.1 µg/L No EPA limit set	2/12	SYR4
Gross Alpha, Excl. Radon And U	8.7 pCi/L 58% of the EPA limit 15 pCi/L	2/12	SYR4
Trichloroacetic Acid	4.3 µg/L No EPA limit set	2/12	SYR4
Monochloroacetic Acid	3.7 µg/L No EPA limit set	1/12	SYR4
Combined Radium (-226 And -228)	3.5 pCi/L 70% of the EPA limit 5 pCi/L	2/12	SYR4
Dibromoacetic Acid	2.8 µg/L No EPA limit set	2/12	SYR4
Thallium, Total	2.7 µg/L 135% of the EPA limit, in the worst sample — 2 µg/L	1/12	SYR4
Monobromoacetic Acid	1.9 µg/L No EPA limit set	1/12	SYR4
Bromoform	1.6 µg/L No EPA limit set	1/12	SYR4
Arsenic	1 µg/L 10% of the EPA limit 10 µg/L	1/12	SYR4
Lead	0.0030 mg/L 20% of the EPA limit 0.0150 mg/L	12/12	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 Casper

Supplier	Population served
CASPER, CITY OF	59,000
VISTA WEST WATER COMPANY	1,600
NATRONA COUNTY INT'L AIRPORT	423
TERRACE I MHC	336
RIVERSIDE MOBILE HOME COURT	330
HIDDEN HILLS MHP	324
TERRACE II MHC	320
GREEN VALLEY MHP	265
SANDY LAKE ESTATES I&S DISTRICT	150
MILE-HI I&S DISTRICT	48
BROKEN WRENCH LLC	30
CENTRAL WY REGIONAL WATER SYSTEM JPB	25

Frequently asked questions about Casper tap water

Is Casper tap water safe to drink?

EPA testing detected 25 contaminants in the water serving Casper. 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 Casper?

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

What contaminants are in Casper's water?

The contaminants EPA monitoring detected in Casper include Nitrate-Nitrite, Copper, Bromate, Fluoride, Nitrate. 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.