What was found in ZIP 93420
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 | 443490 µg/L 4435% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2018 | 3/3 | SYR4 |
| Nitrate | 7910 µg/L 79% of the EPA limit 10000 µg/L Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019
Highest in the ZIP: 9700 µg/L — GOLDEN STATE WATER COMPANY - NIPOMO · 4,506 people · 2019 | 3/3 | SYR4 |
| Fluoride | 310 µg/L 7.8% of the EPA limit 4000 µg/L Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2018
Highest in the ZIP: 360 µg/L — OCEANO COMM SERVICES DIST. · 7,601 people · 2019 | 3/3 | SYR4 |
| Selenium | 7.675 µg/L 15% of the EPA limit 50 µg/L Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2018
Highest in the ZIP: 130 µg/L — OCEANO COMM SERVICES DIST. · 7,601 people · 2019 | 2/3 | SYR4 |
| Copper | 89 µg/L 6.8% of the EPA limit 1300 µg/L Highest in the ZIP: OCEANO COMM SERVICES DIST. · 7,601 people · 2019 | 1/3 | SYR4 |
| TTHM | 78.06 µg/L 98% of the EPA limit 80 µg/L Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019 | 3/3 | SYR4 |
| Lithium | 60 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2024 | 2/3 | UCMR-5 |
| Chloroform | 39.96 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019 | 2/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 31.56 µg/L 53% of the EPA limit 60 µg/L Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019 | 3/3 | SYR4 |
| Arsenic | 23.8 µg/L 238% of the EPA limit, at the 95th percentile of samples — 10 µg/L Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2018 | 2/3 | SYR4 |
| Bromodichloromethane | 22.54 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019 | 3/3 | SYR4 |
| Dibromochloromethane | 18.54 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019 | 3/3 | SYR4 |
| Dichloroacetic Acid | 18.1 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019 | 2/3 | SYR4 |
| Combined Uranium | 9.20075 µg/L 31% of the EPA limit 30 µg/L Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2013
Highest in the ZIP: 12.3223 µg/L — OCEANO COMM SERVICES DIST. · 7,601 people · 2017 | 2/3 | SYR4 |
| Bromoform | 10.3 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019
Highest in the ZIP: 11.34 µg/L — OCEANO COMM SERVICES DIST. · 7,601 people · 2019 | 3/3 | SYR4 |
| Trichloroacetic Acid | 9.25 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019 | 2/3 | SYR4 |
| Dibromoacetic Acid | 8.285 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019 | 3/3 | SYR4 |
| Lead | 6.88 µg/L 46% of the EPA limit 15 µg/L Highest in the ZIP: OCEANO COMM SERVICES DIST. · 7,601 people · 2019 | 1/3 | SYR4 |
| Monochloroacetic Acid | 3.44 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019 | 3/3 | SYR4 |
| Cadmium | 2 µg/L 40% of the EPA limit 5 µg/L Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2018 | 2/3 | SYR4 |
| Monobromoacetic Acid | 1.495 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2019 | 1/3 | SYR4 |
| PFBS | 0.0110 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2024 | 1/3 | UCMR-5 |
| PFOS | 0.0068 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2024 | 1/3 | UCMR-5 |
| PFOA | 0.0058 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2024 | 1/3 | UCMR-5 |
| PFHXS | 0.0055 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2024 | 1/3 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2026
Highest in the ZIP: 0.0052 mg/L — GOLDEN STATE WATER COMPANY - NIPOMO · 4,506 people · 2023 | 3/3 | LCR |
| Pfpea | 0.0045 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2024 | 2/3 | UCMR-5 |
| Pfhxa | 0.0035 µg/L No EPA limit set Main supplier: CITY OF ARROYO GRANDE UTILITIES DIVISION · 17,963 people · 2024 | 1/3 | UCMR-5 |
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 93420
| Supplier | State | Population served |
|---|---|---|
| CITY OF ARROYO GRANDE UTILITIES DIVISION | CA | 17,963 |
| OCEANO COMM SERVICES DIST. | CA | 7,601 |
| GOLDEN STATE WATER COMPANY - NIPOMO | CA | 4,506 |
Frequently asked questions about ZIP 93420 tap water
Is the tap water in ZIP 93420 safe to drink?
EPA testing detected 28 contaminants across the water suppliers serving ZIP 93420. 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 93420?
3 public water suppliers report EPA drinking-water monitoring for ZIP 93420. Each is listed above with its population served.
What contaminants are in ZIP 93420's water?
EPA monitoring detected Nitrate-Nitrite, Nitrate, Fluoride, Selenium, Copper, and others across this ZIP's suppliers. The full list with levels and sources is above.