What was found in ZIP 93257
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 | 8163.46 µg/L 82% of the EPA limit 10000 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 2/2 | SYR4 |
| Nitrate-Nitrite | 4795 µg/L 48% of the EPA limit 10000 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 1/2 | SYR4 |
| Copper | 91.9298 µg/L 7.1% of the EPA limit 1300 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019
Highest in the ZIP: 690 µg/L — PORTERVILLE, CITY OF · 63,487 people · 2019 | 2/2 | SYR4 |
| Fluoride | 180 µg/L 4.5% of the EPA limit 4000 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019
Highest in the ZIP: 300 µg/L — PORTERVILLE, CITY OF · 63,487 people · 2019 | 2/2 | SYR4 |
| Barium | 115.5 µg/L 5.8% of the EPA limit 2000 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019
Highest in the ZIP: 200 µg/L — PORTERVILLE, CITY OF · 63,487 people · 2019 | 2/2 | SYR4 |
| Cyanide | 180 µg/L 90% of the EPA limit 200 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 1/2 | SYR4 |
| Tetrachloroethylene | 121.1 µg/L 2422% of the EPA limit, at the 95th percentile of samples — 5 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 2/2 | SYR4 |
| Lithium | 11.6 µg/L No EPA limit set Highest in the ZIP: PORTERVILLE, CITY OF · 63,487 people · 2023 | 1/2 | UCMR-5 |
| Combined Uranium | 10.5768 µg/L 35% of the EPA limit 30 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 2/2 | SYR4 |
| TTHM | 4.6 µg/L 5.8% of the EPA limit 80 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019
Highest in the ZIP: 7.925 µg/L — PORTERVILLE, CITY OF · 63,487 people · 2019 | 2/2 | SYR4 |
| Arsenic | 5.94245 µg/L 59% of the EPA limit 10 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 2/2 | SYR4 |
| Chloroform | 4.6815 µg/L No EPA limit set Main supplier: CWS - VISALIA · 148,496 people · 2019 | 2/2 | SYR4 |
| Bromoform | 0.9950 µg/L No EPA limit set Main supplier: CWS - VISALIA · 148,496 people · 2019
Highest in the ZIP: 4 µg/L — PORTERVILLE, CITY OF · 63,487 people · 2019 | 2/2 | SYR4 |
| Chromium | 3.2878 µg/L 3.3% of the EPA limit 100 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 1/2 | SYR4 |
| Toluene | 2.94 µg/L 0.3% of the EPA limit 1000 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 2/2 | SYR4 |
| Dibromochloromethane | 1.376 µg/L No EPA limit set Main supplier: CWS - VISALIA · 148,496 people · 2019
Highest in the ZIP: 2.52 µg/L — PORTERVILLE, CITY OF · 63,487 people · 2019 | 2/2 | SYR4 |
| Dibromoacetic Acid | 2 µg/L No EPA limit set Highest in the ZIP: PORTERVILLE, CITY OF · 63,487 people · 2019 | 1/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 2 µg/L 3.3% of the EPA limit 60 µg/L Highest in the ZIP: PORTERVILLE, CITY OF · 63,487 people · 2019 | 1/2 | SYR4 |
| Bromodichloromethane | 1.2955 µg/L No EPA limit set Main supplier: CWS - VISALIA · 148,496 people · 2019
Highest in the ZIP: 1.71 µg/L — PORTERVILLE, CITY OF · 63,487 people · 2019 | 2/2 | SYR4 |
| 1,1-Dichloroethylene | 1.18 µg/L 17% of the EPA limit 7 µg/L Highest in the ZIP: PORTERVILLE, CITY OF · 63,487 people · 2019 | 1/2 | SYR4 |
| Trichloroacetic Acid | 1 µg/L No EPA limit set Highest in the ZIP: PORTERVILLE, CITY OF · 63,487 people · 2019 | 1/2 | SYR4 |
| Nitrite | 0.8000 µg/L 0.1% of the EPA limit 1000 µg/L Highest in the ZIP: PORTERVILLE, CITY OF · 63,487 people · 2019 | 1/2 | SYR4 |
| 1,2-Dichloropropane | 0.7580 µg/L 15% of the EPA limit 5 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 1/2 | SYR4 |
| Trichloroethylene | 0.7220 µg/L 14% of the EPA limit 5 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 1/2 | SYR4 |
| Combined Radium (-226 And -228) | 0.5900 pCi/L 12% of the EPA limit 5 pCi/L Main supplier: CWS - VISALIA · 148,496 people · 2018 | 1/2 | SYR4 |
| Selenium | 0.3222 µg/L 0.6% of the EPA limit 50 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 1/2 | SYR4 |
| Lead | 0.2272 µg/L 1.5% of the EPA limit 15 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 1/2 | SYR4 |
| 1,2-DIBROMO-3-CHLOROPROPANE | 0.1800 µg/L 90% of the EPA limit 0.2000 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 2/2 | SYR4 |
| Antimony, Total | 0.1638 µg/L 2.7% of the EPA limit 6 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 1/2 | SYR4 |
| Cadmium | 0.0894 µg/L 1.8% of the EPA limit 5 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 1/2 | SYR4 |
| Pfpea | 0.0340 µg/L No EPA limit set Main supplier: CWS - VISALIA · 148,496 people · 2025 | 2/2 | UCMR-5 |
| Pfba | 0.0280 µg/L No EPA limit set Main supplier: CWS - VISALIA · 148,496 people · 2025 | 2/2 | UCMR-5 |
| PFOS | 0.0069 µg/L No EPA limit set Main supplier: CWS - VISALIA · 148,496 people · 2025
Highest in the ZIP: 0.0230 µg/L — PORTERVILLE, CITY OF · 63,487 people · 2023 | 2/2 | UCMR-5 |
| PFOA | 0.0042 µg/L No EPA limit set Main supplier: CWS - VISALIA · 148,496 people · 2025
Highest in the ZIP: 0.0220 µg/L — PORTERVILLE, CITY OF · 63,487 people · 2023 | 2/2 | UCMR-5 |
| Pfhxa | 0.0150 µg/L No EPA limit set Main supplier: CWS - VISALIA · 148,496 people · 2025 | 2/2 | UCMR-5 |
| Mercury | 0.0120 µg/L 0.6% of the EPA limit 2 µg/L Main supplier: CWS - VISALIA · 148,496 people · 2019 | 1/2 | SYR4 |
| PFBS | 0.0043 µg/L No EPA limit set Main supplier: CWS - VISALIA · 148,496 people · 2025
Highest in the ZIP: 0.0091 µg/L — PORTERVILLE, CITY OF · 63,487 people · 2023 | 2/2 | UCMR-5 |
| Pfhpa | 0.0065 µg/L No EPA limit set Highest in the ZIP: PORTERVILLE, CITY OF · 63,487 people · 2023 | 1/2 | UCMR-5 |
| PFHXS | 0.0036 µg/L No EPA limit set Highest in the ZIP: PORTERVILLE, CITY OF · 63,487 people · 2023 | 1/2 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: CWS - VISALIA · 148,496 people · 2025 | 2/2 | 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 93257
| Supplier | State | Population served |
|---|---|---|
| CWS - VISALIA | CA | 148,496 |
| PORTERVILLE, CITY OF | CA | 63,487 |
Frequently asked questions about ZIP 93257 tap water
Is the tap water in ZIP 93257 safe to drink?
EPA testing detected 40 contaminants across the water suppliers serving ZIP 93257. 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 93257?
2 public water suppliers report EPA drinking-water monitoring for ZIP 93257. Each is listed above with its population served.
What contaminants are in ZIP 93257's water?
EPA monitoring detected Nitrate, Nitrate-Nitrite, Copper, Fluoride, Barium, and others across this ZIP's suppliers. The full list with levels and sources is above.