What was found in St Maries'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 | 3150 µg/L 32% of the EPA limit 10000 µg/L Highest in the city: COTTONWOOD POINT WATER ASSN · 151 people · 2019 | 3/5 | SYR4 |
| Nitrate-Nitrite | 2960 µg/L 30% of the EPA limit 10000 µg/L Highest in the city: COTTONWOOD POINT WATER ASSN · 151 people · 2019 | 3/5 | SYR4 |
| Fluoride | 287 µg/L 7.2% of the EPA limit 4000 µg/L Main supplier: ST MARIES CITY OF · 4,173 people · 2019
Highest in the city: 375 µg/L — CASSANDRA HILLS OWNERS ASSN · 57 people · 2019 | 5/5 | SYR4 |
| Barium | 59.155 µg/L 3% of the EPA limit 2000 µg/L Main supplier: ST MARIES CITY OF · 4,173 people · 2019
Highest in the city: 116.4 µg/L — CASSANDRA HILLS OWNERS ASSN · 57 people · 2019 | 4/5 | SYR4 |
| Combined Uranium | 3.35 µg/L 11% of the EPA limit 30 µg/L Main supplier: ST MARIES CITY OF · 4,173 people · 2018
Highest in the city: 46.96 µg/L — CASSANDRA HILLS OWNERS ASSN · 57 people · 2019 | 4/5 | SYR4 |
| Gross Alpha, Excl. Radon And U | 3.7475 pCi/L 25% of the EPA limit 15 pCi/L Main supplier: ST MARIES CITY OF · 4,173 people · 2018
Highest in the city: 46.85 pCi/L — CASSANDRA HILLS OWNERS ASSN · 57 people · 2019 | 3/5 | SYR4 |
| Total Haloacetic Acids (HAA5) | 20.235 µg/L 34% of the EPA limit 60 µg/L Main supplier: ST MARIES CITY OF · 4,173 people · 2019 | 2/5 | SYR4 |
| TTHM | 15.745 µg/L 20% of the EPA limit 80 µg/L Main supplier: ST MARIES CITY OF · 4,173 people · 2019 | 3/5 | SYR4 |
| Arsenic | 5.01 µg/L 50% of the EPA limit 10 µg/L Main supplier: ST MARIES CITY OF · 4,173 people · 2018 | 2/5 | SYR4 |
| Gross Beta Particle Activity | 1.7 pCi/L No EPA limit set Main supplier: ST MARIES CITY OF · 4,173 people · 2016
Highest in the city: 2.44 pCi/L — EVERGREEN TERRACE WATER ASSOCIATION · 85 people · 2013 | 2/5 | SYR4 |
| Combined Radium (-226 And -228) | 0.5824 pCi/L 12% of the EPA limit 5 pCi/L Main supplier: ST MARIES CITY OF · 4,173 people · 2018
Highest in the city: 2.0904 pCi/L — CASSANDRA HILLS OWNERS ASSN · 57 people · 2017 | 4/5 | SYR4 |
| Chromium | 1.47 µg/L 1.5% of the EPA limit 100 µg/L Main supplier: ST MARIES CITY OF · 4,173 people · 2019 | 1/5 | SYR4 |
| Lead | 0.0010 mg/L 6.7% of the EPA limit 0.0150 mg/L Main supplier: ST MARIES CITY OF · 4,173 people · 2025
Highest in the city: 0.0040 mg/L — COTTONWOOD POINT WATER ASSN · 151 people · 2025 | 5/5 | LCR |
Water suppliers serving St Maries
| Supplier | Population served |
|---|---|
| ST MARIES CITY OF | 4,173 |
| COTTONWOOD POINT WATER ASSN | 151 |
| EMIDA WATER AND SEWER ASSOCIATION | 120 |
| EVERGREEN TERRACE WATER ASSOCIATION | 85 |
| CASSANDRA HILLS OWNERS ASSN | 57 |
Frequently asked questions about St Maries tap water
Is St Maries tap water safe to drink?
EPA testing detected 13 contaminants in the water serving St Maries. 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 St Maries?
5 public water suppliers report drinking-water monitoring for St Maries, Idaho to the EPA. Each is listed above with its population served.
What contaminants are in St Maries's water?
The contaminants EPA monitoring detected in St Maries include Nitrate, Nitrate-Nitrite, Fluoride, Barium, Combined Uranium. 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.