What was found in ZIP 93401
The level at this ZIP's main supplier, the highest level anywhere in it, the EPA limit for each, and where the figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate-Nitrite | 200000 µg/L 2000% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Nitrate | 4300 µg/L 43% of the EPA limit 10000 µg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Fluoride | 800 µg/L 20% of the EPA limit 4000 µg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Barium | 159.3 µg/L 8% of the EPA limit 2000 µg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| TTHM | 91.8 µg/L 115% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Chloroform | 59.3 µg/L No EPA limit set Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Total Haloacetic Acids (HAA5) | 43.85 µg/L 73% of the EPA limit 60 µg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Bromodichloromethane | 22.86 µg/L No EPA limit set Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Trichloroacetic Acid | 19.7 µg/L No EPA limit set Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Dibromochloromethane | 16.875 µg/L No EPA limit set Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Dichloroacetic Acid | 16.6 µg/L No EPA limit set Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Chromium | 15.1 µg/L 15% of the EPA limit 100 µg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Lithium | 10 µg/L No EPA limit set Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2024 | 1/1 | UCMR-5 |
| Bromate | 8.4 µg/L 84% of the EPA limit 10 µg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Lead | 7.185 µg/L 48% of the EPA limit 15 µg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Dibromoacetic Acid | 4 µg/L No EPA limit set Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Bromoform | 3.815 µg/L No EPA limit set Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Arsenic | 3.55 µg/L 36% of the EPA limit 10 µg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Selenium | 3 µg/L 6% of the EPA limit 50 µg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Monochloroacetic Acid | 2.6 µg/L No EPA limit set Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Monobromoacetic Acid | 2 µg/L No EPA limit set Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2019 | 1/1 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: SAN LUIS OBISPO WATER DEPARTMENT · 47,788 people · 2025 | 1/1 | 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.
Water suppliers serving ZIP 93401
| Supplier | State | Population served |
|---|---|---|
| SAN LUIS OBISPO WATER DEPARTMENT | CA | 47,788 |
Frequently asked questions about ZIP 93401 tap water
Is the tap water in ZIP 93401 safe to drink?
EPA testing detected 22 contaminants across the water suppliers serving ZIP 93401. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and your utility's annual Consumer Confidence Report for the official status.
Which water suppliers serve ZIP 93401?
1 public water supplier report EPA drinking-water monitoring for ZIP 93401. Each is listed above with its population served.
What contaminants are in ZIP 93401's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Fluoride, Barium, TTHM, and others across this ZIP's suppliers. The full list with levels and sources is above.