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Tap water quality report

Eureka, MT

EPA monitoring detected 20 contaminants across the 6 water suppliers serving Eureka. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier for each below, with its EPA source and period.

6
water suppliers
3,065
people served
20
contaminants found
Montana rankings Lead in Montana PFAS in Montana

What was found in Eureka's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate-Nitrite
730 µg/L 7.3%
of the EPA limit 10000 µg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
Highest in the city: 1447 µg/L — CREEKSIDE MOTEL RV AND TRLR PK · 35 people · 2019
6/6 SYR4
Nitrate
1320 µg/L 13%
of the EPA limit 10000 µg/L
Highest in the city: CREEKSIDE MOTEL RV AND TRLR PK · 35 people · 2018
3/6 SYR4
Copper
836 µg/L 64%
of the EPA limit 1300 µg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
4/6 SYR4
Barium
223 µg/L 11%
of the EPA limit 2000 µg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2012
Highest in the city: 455.5 µg/L — BARNABY LAKE HOA · 75 people · 2019
4/6 SYR4
Fluoride
126 µg/L 3.2%
of the EPA limit 4000 µg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2012
Highest in the city: 255 µg/L — CREEKSIDE MOTEL RV AND TRLR PK · 35 people · 2018
4/6 SYR4
TTHM
22.5 µg/L 28%
of the EPA limit 80 µg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
1/6 SYR4
Chloroform
20 µg/L
No EPA limit set
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
1/6 SYR4
Total Haloacetic Acids (HAA5)
14.25 µg/L 24%
of the EPA limit 60 µg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
1/6 SYR4
Lead
11.75 µg/L 78%
of the EPA limit 15 µg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
3/6 SYR4
Trichloroacetic Acid
10.85 µg/L
No EPA limit set
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
1/6 SYR4
Gross Alpha, Excl. Radon And U
8.68 pCi/L 58%
of the EPA limit 15 pCi/L
Highest in the city: CREEKSIDE MOTEL RV AND TRLR PK · 35 people · 2018
3/6 SYR4
Dichloroacetic Acid
5.93 µg/L
No EPA limit set
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
1/6 SYR4
Arsenic
1 µg/L 10%
of the EPA limit 10 µg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
Highest in the city: 5 µg/L — BARNABY LAKE HOA · 75 people · 2019
2/6 SYR4
Combined Uranium
4 µg/L 13%
of the EPA limit 30 µg/L
Highest in the city: CREEKSIDE MOTEL RV AND TRLR PK · 35 people · 2018
1/6 SYR4
Combined Radium (-226 And -228)
2.975 pCi/L 60%
of the EPA limit 5 pCi/L
Highest in the city: CREEKSIDE MOTEL RV AND TRLR PK · 35 people · 2019
3/6 SYR4
Bromodichloromethane
2.33 µg/L
No EPA limit set
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
1/6 SYR4
Tetrachloroethylene
1.45 µg/L 29%
of the EPA limit 5 µg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
1/6 SYR4
Toluene
0.9500 µg/L 0.1%
of the EPA limit 1000 µg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
1/6 SYR4
Dichloromethane
0.5400 µg/L 11%
of the EPA limit 5 µg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2019
1/6 SYR4
Lead
0.0010 mg/L 6.7%
of the EPA limit 0.0150 mg/L
Main supplier: EUREKA TOWN OF · 1,995 people · 2024
5/6 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 95th percentile of the system's samples — 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 Eureka

SupplierPopulation served
EUREKA TOWN OF 1,995
INDIAN SPRINGS RANCH SUB 455
WILDERNESS CLUB THE 440
BARNABY LAKE HOA 75
CARPENTER LAKE HOA 65
CREEKSIDE MOTEL RV AND TRLR PK 35

Frequently asked questions about Eureka tap water

Is Eureka tap water safe to drink?

EPA testing detected 20 contaminants in the water serving Eureka. 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 Eureka?

6 public water suppliers report drinking-water monitoring for Eureka, Montana to the EPA. Each is listed above with its population served.

What contaminants are in Eureka's water?

The contaminants EPA monitoring detected in Eureka include Nitrate-Nitrite, Nitrate, Copper, Barium, Fluoride. The full list, with the level at the main supplier 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.