Is Columbus, MT Tap Water Safe? Quality & Contaminants

What was found in Columbus'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.

Contaminant	Level vs EPA limit	Suppliers	Source
Nitrate-Nitrite	3530 µg/L 35% of the EPA limit 10000 µg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	3/5	SYR4
Copper	427.1 µg/L 33% of the EPA limit 1300 µg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2017 Highest in the city: 613.5 µg/L — EAGLE MOUNTAIN RURAL PWS · 50 people · 2019	2/5	SYR4
Fluoride	500 µg/L 13% of the EPA limit 4000 µg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	3/5	SYR4
Barium	90 µg/L 4.5% of the EPA limit 2000 µg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019 Highest in the city: 109 µg/L — SHERWOOD WATER STATION · 25 people · 2016	3/5	SYR4
TTHM	17 µg/L 21% of the EPA limit 80 µg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	1/5	SYR4
Gross Alpha, Excl. Radon And U	8.636 pCi/L 58% of the EPA limit 15 pCi/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	1/5	SYR4
Arsenic	8.45 µg/L 85% of the EPA limit 10 µg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	2/5	SYR4
Dibromochloromethane	7.3 µg/L No EPA limit set Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	1/5	SYR4
Lead	6.4 µg/L 43% of the EPA limit 15 µg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2017	2/5	SYR4
Combined Uranium	5.99 µg/L 20% of the EPA limit 30 µg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	3/5	SYR4
Bromoform	5.785 µg/L No EPA limit set Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	1/5	SYR4
Selenium	5.6 µg/L 11% of the EPA limit 50 µg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	3/5	SYR4
Total Haloacetic Acids (HAA5)	5.15 µg/L 8.6% of the EPA limit 60 µg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	1/5	SYR4
Chromium	5 µg/L 5% of the EPA limit 100 µg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	1/5	SYR4
Chloroform	3.72 µg/L No EPA limit set Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	1/5	SYR4
Bromodichloromethane	3.35 µg/L No EPA limit set Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	1/5	SYR4
Dichloroacetic Acid	3.3 µg/L No EPA limit set Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	1/5	SYR4
Dibromoacetic Acid	2.825 µg/L No EPA limit set Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	1/5	SYR4
Combined Radium (-226 And -228)	2.4 pCi/L 48% of the EPA limit 5 pCi/L Highest in the city: SHERWOOD WATER STATION · 25 people · 2016	2/5	SYR4
Monobromoacetic Acid	0.5300 µg/L No EPA limit set Main supplier: COLUMBUS TOWN OF · 1,900 people · 2019	1/5	SYR4
Lead	0.0040 mg/L 27% of the EPA limit 0.0150 mg/L Main supplier: COLUMBUS TOWN OF · 1,900 people · 2017	5/5	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 Columbus

Supplier	Population served
COLUMBUS TOWN OF	1,900
COUNTRY HAVEN ESTATES WHISPERING PINES	100
EAGLE MOUNTAIN RURAL PWS	50
HILLTOP WATER	50
SHERWOOD WATER STATION	25

Frequently asked questions about Columbus tap water

Is Columbus tap water safe to drink?

EPA testing detected 21 contaminants in the water serving Columbus. 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 Columbus?

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

What contaminants are in Columbus's water?

The contaminants EPA monitoring detected in Columbus include Nitrate-Nitrite, Copper, Fluoride, Barium, TTHM. 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.