What was found in Catalina'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 | 3970 µg/L 40% of the EPA limit 10000 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2019
Highest in the city: 5700 µg/L — ORCHARD VALLEY MOBILE HOME PARK · 130 people · 2019 | 6/6 | SYR4 |
| Nitrate-Nitrite | 3955 µg/L 40% of the EPA limit 10000 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2019
Highest in the city: 4670 µg/L — ORCHARD VALLEY MOBILE HOME PARK · 130 people · 2018 | 6/6 | SYR4 |
| Fluoride | 534 µg/L 13% of the EPA limit 4000 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2017
Highest in the city: 579.5 µg/L — GW OCOTILLO WATER - CATALINA · 1,168 people · 2019 | 5/6 | SYR4 |
| Copper | 250 µg/L 19% of the EPA limit 1300 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2018
Highest in the city: 269.5 µg/L — CS LOS CERROS WATER COMPANY INC · 2,613 people · 2017 | 6/6 | SYR4 |
| Barium | 20 µg/L 1% of the EPA limit 2000 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2017
Highest in the city: 60.2 µg/L — CS LOS CERROS WATER COMPANY INC · 2,613 people · 2018 | 5/6 | SYR4 |
| TTHM | 13.1 µg/L 16% of the EPA limit 80 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2019
Highest in the city: 46.8 µg/L — GOODMAN WATER COMPANY · 2,656 people · 2019 | 4/6 | SYR4 |
| Lead | 3.12 µg/L 21% of the EPA limit 15 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2018
Highest in the city: 33.8 µg/L — ORCHARD VALLEY MOBILE HOME PARK · 130 people · 2017 | 6/6 | SYR4 |
| Lithium | 20 µg/L No EPA limit set Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2025 | 1/6 | UCMR-5 |
| Total Haloacetic Acids (HAA5) | 4.65 µg/L 7.8% of the EPA limit 60 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2019
Highest in the city: 15.73 µg/L — GOODMAN WATER COMPANY · 2,656 people · 2019 | 3/6 | SYR4 |
| Combined Uranium | 7.725 µg/L 26% of the EPA limit 30 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2015 | 1/6 | SYR4 |
| Dibromochloromethane | 6.03 µg/L No EPA limit set Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2019 | 3/6 | SYR4 |
| Xylenes, Total | 0.6000 µg/L 0% of the EPA limit 10000 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2018
Highest in the city: 5.97 µg/L — GW OCOTILLO WATER - CATALINA · 1,168 people · 2019 | 2/6 | SYR4 |
| Arsenic | 3.24 µg/L 32% of the EPA limit 10 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2017 | 3/6 | SYR4 |
| Bromoform | 3.175 µg/L No EPA limit set Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2019 | 3/6 | SYR4 |
| Bromodichloromethane | 3.165 µg/L No EPA limit set Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2019 | 2/6 | SYR4 |
| Dibromoacetic Acid | 2.555 µg/L No EPA limit set Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2019 | 1/6 | SYR4 |
| Selenium | 2.54 µg/L 5.1% of the EPA limit 50 µg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2017 | 1/6 | SYR4 |
| Chloroform | 0.9950 µg/L No EPA limit set Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2019
Highest in the city: 2.035 µg/L — GOODMAN WATER COMPANY · 2,656 people · 2019 | 2/6 | SYR4 |
| Gross Alpha, Excl. Radon And U | 1.8 pCi/L 12% of the EPA limit 15 pCi/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2015 | 1/6 | SYR4 |
| Ethylbenzene | 1.175 µg/L 0.2% of the EPA limit 700 µg/L Highest in the city: GW OCOTILLO WATER - CATALINA · 1,168 people · 2019 | 1/6 | SYR4 |
| Combined Radium (-226 And -228) | 0.9550 pCi/L 19% of the EPA limit 5 pCi/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2015 | 2/6 | SYR4 |
| 1,2-DIBROMO-3-CHLOROPROPANE | 0.0290 µg/L 14% of the EPA limit 0.2000 µg/L Highest in the city: CS LOS CERROS WATER COMPANY INC · 2,613 people · 2019 | 1/6 | SYR4 |
| Pfpea | 0.0065 µg/L No EPA limit set Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2025 | 1/6 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2024
Highest in the city: 0.0045 mg/L — ORCHARD VALLEY MOBILE HOME PARK · 130 people · 2023 | 6/6 | LCR |
| Pfhxa | 0.0041 µg/L No EPA limit set Main supplier: LAGO DEL ORO WATER COMPANY · 18,132 people · 2025 | 1/6 | 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.
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 Catalina
| Supplier | Population served |
|---|---|
| LAGO DEL ORO WATER COMPANY | 18,132 |
| GOODMAN WATER COMPANY | 2,656 |
| CS LOS CERROS WATER COMPANY INC | 2,613 |
| GW OCOTILLO WATER - CATALINA | 1,168 |
| ORCHARD VALLEY MOBILE HOME PARK | 130 |
| CORONADO FOREST DRIVE WATER COOP | 30 |
Frequently asked questions about Catalina tap water
Is Catalina tap water safe to drink?
EPA testing detected 25 contaminants in the water serving Catalina. 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 Catalina?
6 public water suppliers report drinking-water monitoring for Catalina, Arizona to the EPA. Each is listed above with its population served.
What contaminants are in Catalina's water?
The contaminants EPA monitoring detected in Catalina include Nitrate, Nitrate-Nitrite, Fluoride, Copper, 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.