What was found in ZIP 95231
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 | 825000 µg/L 8250% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Nitrate | 5857 µg/L 59% of the EPA limit 10000 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019
Highest in the ZIP: 7751 µg/L — CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 2/2 | SYR4 |
| Copper | 544 µg/L 42% of the EPA limit 1300 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Barium | 290 µg/L 14% of the EPA limit 2000 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Fluoride | 160 µg/L 4% of the EPA limit 4000 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| TTHM | 88.85 µg/L 111% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Chloroform | 62 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 48 µg/L 80% of the EPA limit 60 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Lead | 30.2 µg/L 201% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Bromate | 26.95 µg/L 270% of the EPA limit, at the 95th percentile of samples — 10 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 1/2 | SYR4 |
| Dichloroacetic Acid | 26.41 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Dibromochloromethane | 26 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Arsenic | 7.62 µg/L 76% of the EPA limit 10 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019
Highest in the ZIP: 23.8416 µg/L — CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 2/2 | SYR4 |
| Bromoform | 23 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Bromodichloromethane | 22 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Trichloroacetic Acid | 17.3 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Combined Uranium | 16.688 µg/L 56% of the EPA limit 30 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Chromium | 11.8 µg/L 12% of the EPA limit 100 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Dibromoacetic Acid | 10.75 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Monochloroacetic Acid | 9.99 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Selenium | 5.885 µg/L 12% of the EPA limit 50 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| Gross Beta Particle Activity | 1.3185 pCi/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2012
Highest in the ZIP: 5.5315 pCi/L — CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 2/2 | SYR4 |
| Trichloroethylene | 0.6100 µg/L 12% of the EPA limit 5 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019
Highest in the ZIP: 4.62 µg/L — CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 2/2 | SYR4 |
| Monobromoacetic Acid | 2 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 1/2 | SYR4 |
| Tetrachloroethylene | 1.659 µg/L 33% of the EPA limit 5 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 1/2 | SYR4 |
| Xylenes, Total | 1.3 µg/L 0% of the EPA limit 10000 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 1/2 | SYR4 |
| 1,2-Dichloropropane | 0.6035 µg/L 12% of the EPA limit 5 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 1/2 | SYR4 |
| Cadmium | 0.1600 µg/L 3.2% of the EPA limit 5 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 1/2 | SYR4 |
| Antimony, Total | 0.1350 µg/L 2.3% of the EPA limit 6 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 1/2 | SYR4 |
| Mercury | 0.0460 µg/L 2.3% of the EPA limit 2 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 1/2 | SYR4 |
| Thallium, Total | 0.0442 µg/L 2.2% of the EPA limit 2 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 1/2 | SYR4 |
| Beryllium, Total | 0.0261 µg/L 0.7% of the EPA limit 4 µg/L Highest in the ZIP: CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2019 | 1/2 | SYR4 |
| 1,2-DIBROMO-3-CHLOROPROPANE | 0.0100 µg/L 5% of the EPA limit 0.2000 µg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2019 | 2/2 | SYR4 |
| PFOS | 0.0048 µg/L No EPA limit set Main supplier: CITY OF STOCKTON · 191,302 people · 2025
Highest in the ZIP: 0.0052 µg/L — CALIFORNIA WATER SERVICE - STOCKTON · 176,266 people · 2025 | 2/2 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: CITY OF STOCKTON · 191,302 people · 2026 | 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 95231
| Supplier | State | Population served |
|---|---|---|
| CITY OF STOCKTON | CA | 191,302 |
| CALIFORNIA WATER SERVICE - STOCKTON | CA | 176,266 |
Frequently asked questions about ZIP 95231 tap water
Is the tap water in ZIP 95231 safe to drink?
EPA testing detected 35 contaminants across the water suppliers serving ZIP 95231. 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 95231?
2 public water suppliers report EPA drinking-water monitoring for ZIP 95231. Each is listed above with its population served.
What contaminants are in ZIP 95231's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Copper, Barium, Fluoride, and others across this ZIP's suppliers. The full list with levels and sources is above.