What was found in Libby'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 | 46.5 µg/L 0.5% of the EPA limit 10000 µg/L Main supplier: LIBBY CITY OF · 4,892 people · 2019
Highest in the city: 1940 µg/L — EMKAYAN VILLAGE CO WATER AND SEWER DIST · 160 people · 2019 | 6/7 | SYR4 |
| Fluoride | 20 µg/L 0.5% of the EPA limit 4000 µg/L Main supplier: LIBBY CITY OF · 4,892 people · 2013
Highest in the city: 1500 µg/L — EMKAYAN VILLAGE CO WATER AND SEWER DIST · 160 people · 2012 | 5/7 | SYR4 |
| Copper | 320 µg/L 25% of the EPA limit 1300 µg/L Main supplier: LIBBY CITY OF · 4,892 people · 2019
Highest in the city: 855 µg/L — EMKAYAN VILLAGE CO WATER AND SEWER DIST · 160 people · 2019 | 6/7 | SYR4 |
| Nitrate | 30 µg/L 0.3% of the EPA limit 10000 µg/L Main supplier: LIBBY CITY OF · 4,892 people · 2013
Highest in the city: 540 µg/L — RIVERS EDGE MOBILE PARK LIBBY · 60 people · 2013 | 2/7 | SYR4 |
| Barium | 170 µg/L 8.5% of the EPA limit 2000 µg/L Highest in the city: PINEWOOD VILLAGE · 160 people · 2013 | 3/7 | SYR4 |
| Total Haloacetic Acids (HAA5) | 27.1 µg/L 45% of the EPA limit 60 µg/L Main supplier: LIBBY CITY OF · 4,892 people · 2019 | 2/7 | SYR4 |
| TTHM | 23.65 µg/L 30% of the EPA limit 80 µg/L Main supplier: LIBBY CITY OF · 4,892 people · 2019 | 2/7 | SYR4 |
| Chloroform | 22.65 µg/L No EPA limit set Main supplier: LIBBY CITY OF · 4,892 people · 2019 | 1/7 | SYR4 |
| Trichloroacetic Acid | 17 µg/L No EPA limit set Main supplier: LIBBY CITY OF · 4,892 people · 2019 | 1/7 | SYR4 |
| Dichloroacetic Acid | 10.05 µg/L No EPA limit set Main supplier: LIBBY CITY OF · 4,892 people · 2019 | 1/7 | SYR4 |
| Lead | 6.55 µg/L 44% of the EPA limit 15 µg/L Main supplier: LIBBY CITY OF · 4,892 people · 2019
Highest in the city: 8.55 µg/L — JOHNSONS MOBILE HOME PARK · 35 people · 2019 | 5/7 | SYR4 |
| Gross Alpha, Excl. Radon And U | 2.1 pCi/L 14% of the EPA limit 15 pCi/L Main supplier: LIBBY CITY OF · 4,892 people · 2013
Highest in the city: 6.95 pCi/L — POSTS TRAILER COURT · 45 people · 2016 | 4/7 | SYR4 |
| Combined Uranium | 6 µg/L 20% of the EPA limit 30 µg/L Highest in the city: POSTS TRAILER COURT · 45 people · 2016 | 5/7 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 4.345 µg/L 72% of the EPA limit 6 µg/L Highest in the city: EMKAYAN VILLAGE CO WATER AND SEWER DIST · 160 people · 2018 | 1/7 | SYR4 |
| Combined Radium (-226 And -228) | 2.6 pCi/L 52% of the EPA limit 5 pCi/L Highest in the city: POSTS TRAILER COURT · 45 people · 2019 | 4/7 | SYR4 |
| Arsenic | 2 µg/L 20% of the EPA limit 10 µg/L Highest in the city: EMKAYAN VILLAGE CO WATER AND SEWER DIST · 160 people · 2018 | 1/7 | SYR4 |
| Monochloroacetic Acid | 1.55 µg/L No EPA limit set Main supplier: LIBBY CITY OF · 4,892 people · 2019 | 1/7 | SYR4 |
| Bromodichloromethane | 1.17 µg/L No EPA limit set Main supplier: LIBBY CITY OF · 4,892 people · 2019 | 1/7 | SYR4 |
| Dibromoacetic Acid | 0.3000 µg/L No EPA limit set Highest in the city: EMKAYAN VILLAGE CO WATER AND SEWER DIST · 160 people · 2019 | 1/7 | SYR4 |
| Lead | 0.0020 mg/L 13% of the EPA limit 0.0150 mg/L Main supplier: LIBBY CITY OF · 4,892 people · 2025
Highest in the city: 0.0050 mg/L — JOHNSONS MOBILE HOME PARK · 35 people · 2025 | 6/7 | 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 Libby
| Supplier | Population served |
|---|---|
| LIBBY CITY OF | 4,892 |
| PINEWOOD VILLAGE | 160 |
| EMKAYAN VILLAGE CO WATER AND SEWER DIST | 160 |
| RIVERS EDGE MOBILE PARK LIBBY | 60 |
| POSTS TRAILER COURT | 45 |
| JOHNSONS MOBILE HOME PARK | 35 |
| LIBBY CREEK MOBILE PARK LLC-UNAPPROVED | 35 |
Frequently asked questions about Libby tap water
Is Libby tap water safe to drink?
EPA testing detected 20 contaminants in the water serving Libby. 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 Libby?
7 public water suppliers report drinking-water monitoring for Libby, Montana to the EPA. Each is listed above with its population served.
What contaminants are in Libby's water?
The contaminants EPA monitoring detected in Libby include Nitrate-Nitrite, Fluoride, Copper, Nitrate, Barium. 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.