What was found in Royal Oaks'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 |
|---|---|---|---|
| Nitrate-Nitrite | 500000 µg/L 5000% of the EPA limit, at the 95th percentile of samples — 10000 µg/L Main supplier: PSMCSD - PAJARO · 6,500 people · 2018
Highest in the city: 950110 µg/L — MAHER RD WS #05 · 48 people · 2016 | 11/17 | SYR4 |
| Nitrate | 100 µg/L 1% of the EPA limit 10000 µg/L Main supplier: PSMCSD - PAJARO · 6,500 people · 2019
Highest in the city: 65406.7 µg/L — PSMCSD - SPRINGFIELD WS · 200 people · 2019 | 16/17 | SYR4 |
| Fluoride | 200 µg/L 5% of the EPA limit 4000 µg/L Main supplier: PSMCSD - PAJARO · 6,500 people · 2018
Highest in the city: 1212 µg/L — PSMCSD - SUNNY MESA · 880 people · 2019 | 14/17 | SYR4 |
| Nitrite | 395 µg/L 40% of the EPA limit 1000 µg/L Main supplier: PSMCSD - PAJARO · 6,500 people · 2018
Highest in the city: 585 µg/L — PSMCSD - VIERRA ESTATES WS · 164 people · 2018 | 11/17 | SYR4 |
| Barium | 38.88 µg/L 1.9% of the EPA limit 2000 µg/L Main supplier: PSMCSD - PAJARO · 6,500 people · 2018
Highest in the city: 119.5 µg/L — MAHER RD WS #05 · 48 people · 2016 | 13/17 | SYR4 |
| Arsenic | 1 µg/L 10% of the EPA limit 10 µg/L Main supplier: PSMCSD - PAJARO · 6,500 people · 2018
Highest in the city: 65.65 µg/L — PSMCSD - LANGLEY/VALLE PACIFICO WS · 81 people · 2019 | 10/17 | SYR4 |
| TTHM | 7.45 µg/L 9.3% of the EPA limit 80 µg/L Main supplier: PSMCSD - PAJARO · 6,500 people · 2019
Highest in the city: 44.5 µg/L — PSMCSD - LANGLEY/VALLE PACIFICO WS · 81 people · 2018 | 7/17 | SYR4 |
| Copper | 38 µg/L 2.9% of the EPA limit 1300 µg/L Highest in the city: PSMCSD - VEGA RD WS #01 · 438 people · 2017 | 7/17 | SYR4 |
| Bromoform | 4.45 µg/L No EPA limit set Main supplier: PSMCSD - PAJARO · 6,500 people · 2019
Highest in the city: 34.65 µg/L — PSMCSD - LANGLEY/VALLE PACIFICO WS · 81 people · 2018 | 7/17 | SYR4 |
| Chromium | 5 µg/L 5% of the EPA limit 100 µg/L Main supplier: PSMCSD - PAJARO · 6,500 people · 2018
Highest in the city: 24.1 µg/L — PSMCSD - SUNNY MESA · 880 people · 2019 | 14/17 | SYR4 |
| Selenium | 23 µg/L 46% of the EPA limit 50 µg/L Highest in the city: PSMCSD - SPRINGFIELD WS · 200 people · 2014 | 7/17 | SYR4 |
| Dibromochloromethane | 2 µg/L No EPA limit set Main supplier: PSMCSD - PAJARO · 6,500 people · 2019
Highest in the city: 11 µg/L — PSMCSD - VIERRA ESTATES WS · 164 people · 2018 | 6/17 | SYR4 |
| Total Haloacetic Acids (HAA5) | 2 µg/L 3.3% of the EPA limit 60 µg/L Main supplier: PSMCSD - PAJARO · 6,500 people · 2019
Highest in the city: 9 µg/L — PSMCSD - VEGA RD WS #01 · 438 people · 2017 | 6/17 | SYR4 |
| Combined Uranium | 8.642 µg/L 29% of the EPA limit 30 µg/L Highest in the city: PSMCSD - SPRINGFIELD WS · 200 people · 2018 | 2/17 | SYR4 |
| Dibromoacetic Acid | 2 µg/L No EPA limit set Main supplier: PSMCSD - PAJARO · 6,500 people · 2019
Highest in the city: 7 µg/L — PSMCSD - VEGA RD WS #01 · 438 people · 2017 | 6/17 | SYR4 |
| Bromodichloromethane | 1 µg/L No EPA limit set Main supplier: PSMCSD - PAJARO · 6,500 people · 2019
Highest in the city: 6 µg/L — PSMCSD - VIERRA ESTATES WS · 164 people · 2018 | 5/17 | SYR4 |
| Lead | 2.1 µg/L 14% of the EPA limit 15 µg/L Highest in the city: PSMCSD - SUNNY MESA · 880 people · 2019 | 5/17 | SYR4 |
| Chloroform | 2 µg/L No EPA limit set Highest in the city: PSMCSD - VIERRA ESTATES WS · 164 people · 2018 | 1/17 | SYR4 |
| Dichloroacetic Acid | 2 µg/L No EPA limit set Highest in the city: PSMCSD - VIERRA ESTATES WS · 164 people · 2018 | 1/17 | SYR4 |
| Monobromoacetic Acid | 2 µg/L No EPA limit set Highest in the city: PSMCSD - VEGA RD WS #01 · 438 people · 2017 | 2/17 | SYR4 |
| Trichloroacetic Acid | 1 µg/L No EPA limit set Highest in the city: PSMCSD - VIERRA ESTATES WS · 164 people · 2018 | 1/17 | SYR4 |
| Lead | 0.0012 mg/L 8% of the EPA limit 0.0150 mg/L Main supplier: PSMCSD - PAJARO · 6,500 people · 2025
Highest in the city: 0.0089 mg/L — PSMCSD - VIERRA ESTATES WS · 164 people · 2024 | 17/17 | 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.
These are the utilities' own EPA-reported results, not a city-wide
average. A detection means the lab measured the
substance — it isn't the same as exceeding a legal limit. Hover a source
tag to see the EPA program and years behind each figure.
Water suppliers serving Royal Oaks
| Supplier | Population served |
|---|---|
| PSMCSD - PAJARO | 6,500 |
| PSMCSD - NORMCO | 928 |
| PSMCSD - SUNNY MESA | 880 |
| PSMCSD - MOSS LANDING HARBOR WS | 520 |
| PSMCSD - VEGA RD WS #01 | 438 |
| PSMCSD - SPRINGFIELD WS | 200 |
| PSMCSD - VIERRA ESTATES WS | 164 |
| SAN MIGUEL WS #01 | 100 |
| PSMCSD - LANGLEY/VALLE PACIFICO WS | 81 |
| MANZANITA HILLS WA | 75 |
| PSMCSD - BLACKIE RD WS | 60 |
| DELANY WC | 60 |
| ROYAL OAK PLACE WS | 60 |
| CHETMOORE ACRES WA | 59 |
| APRICOT LN WS | 53 |
| MAHER RD WS #05 | 48 |
| SAN MIGUEL WS #03 | 45 |
Frequently asked questions about Royal Oaks tap water
Is Royal Oaks tap water safe to drink?
EPA testing detected 22 contaminants in the water serving Royal Oaks. 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 Royal Oaks?
17 public water suppliers report drinking-water monitoring for Royal Oaks, California to the EPA. Each is listed above with its population served.
What contaminants are in Royal Oaks's water?
The contaminants EPA monitoring detected in Royal Oaks include Nitrate-Nitrite, Nitrate, Fluoride, Nitrite, Barium. 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.