What was found in North Fork'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 |
|---|---|---|---|
| Fluoride | 526 µg/L 13% of the EPA limit 4000 µg/L Main supplier: SIERRA LINDA MUTUAL WATER CO · 200 people · 2018
Highest in the city: 2600 µg/L — CASCADEL MUTUAL WATER SYSTEM · 137 people · 2019 | 3/3 | SYR4 |
| Nitrate | 836.2 µg/L 8.4% of the EPA limit 10000 µg/L Main supplier: SIERRA LINDA MUTUAL WATER CO · 200 people · 2019 | 1/3 | SYR4 |
| Combined Uranium | 571.527 µg/L 1905% of the EPA limit, at the 95th percentile of samples — 30 µg/L Main supplier: SIERRA LINDA MUTUAL WATER CO · 200 people · 2019 | 2/3 | SYR4 |
| Copper | 28.3 µg/L 2.2% of the EPA limit 1300 µg/L Main supplier: SIERRA LINDA MUTUAL WATER CO · 200 people · 2018
Highest in the city: 45 µg/L — CASCADEL MUTUAL WATER SYSTEM · 137 people · 2019 | 2/3 | SYR4 |
| Arsenic | 30.6 µg/L 306% of the EPA limit, at the 95th percentile of samples — 10 µg/L Main supplier: SIERRA LINDA MUTUAL WATER CO · 200 people · 2019 | 3/3 | SYR4 |
| Barium | 10.545 µg/L 0.5% of the EPA limit 2000 µg/L Main supplier: SIERRA LINDA MUTUAL WATER CO · 200 people · 2018
Highest in the city: 30.5 µg/L — CASCADEL MUTUAL WATER SYSTEM · 137 people · 2019 | 2/3 | SYR4 |
| Chromium | 7.6 µg/L 7.6% of the EPA limit 100 µg/L Highest in the city: LEISURE ACRES MUTUAL WATER COMPANY · 45 people · 2012 | 1/3 | SYR4 |
| Lead | 5.67 µg/L 38% of the EPA limit 15 µg/L Highest in the city: CASCADEL MUTUAL WATER SYSTEM · 137 people · 2019 | 1/3 | SYR4 |
| Cyanide | 5.5 µg/L 2.8% of the EPA limit 200 µg/L Main supplier: SIERRA LINDA MUTUAL WATER CO · 200 people · 2018 | 1/3 | SYR4 |
| Combined Radium (-226 And -228) | 0.6100 pCi/L 12% of the EPA limit 5 pCi/L Main supplier: SIERRA LINDA MUTUAL WATER CO · 200 people · 2017 | 1/3 | SYR4 |
| Mercury | 0.2600 µg/L 13% of the EPA limit 2 µg/L Highest in the city: LEISURE ACRES MUTUAL WATER COMPANY · 45 people · 2012 | 1/3 | SYR4 |
| Lead | 0.0031 mg/L 21% of the EPA limit 0.0150 mg/L Main supplier: SIERRA LINDA MUTUAL WATER CO · 200 people · 2025
Highest in the city: 0.0080 mg/L — CASCADEL MUTUAL WATER SYSTEM · 137 people · 2025 | 3/3 | LCR |
Water suppliers serving North Fork
| Supplier | Population served |
|---|---|
| SIERRA LINDA MUTUAL WATER CO | 200 |
| CASCADEL MUTUAL WATER SYSTEM | 137 |
| LEISURE ACRES MUTUAL WATER COMPANY | 45 |
Frequently asked questions about North Fork tap water
Is North Fork tap water safe to drink?
EPA testing detected 12 contaminants in the water serving North Fork. 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 North Fork?
3 public water suppliers report drinking-water monitoring for North Fork, California to the EPA. Each is listed above with its population served.
What contaminants are in North Fork's water?
The contaminants EPA monitoring detected in North Fork include Fluoride, Nitrate, Combined Uranium, Copper, Arsenic. 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.