What was found in ZIP 78566
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 |
|---|---|---|---|
| Chlorite | 812.2 µg/L 81% of the EPA limit 1000 µg/L Main supplier: OLMITO WSC · 8,952 people · 2014 | 1/2 | SYR4 |
| Fluoride | 486 µg/L 12% of the EPA limit 4000 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019
Highest in the ZIP: 486.5 µg/L — CITY OF LOS FRESNOS · 6,009 people · 2019 | 2/2 | SYR4 |
| Nitrate | 300 µg/L 3% of the EPA limit 10000 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Copper | 168.4 µg/L 13% of the EPA limit 1300 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019
Highest in the ZIP: 202.3 µg/L — CITY OF LOS FRESNOS · 6,009 people · 2017 | 2/2 | SYR4 |
| Barium | 190.1 µg/L 9.5% of the EPA limit 2000 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Cyanide | 137 µg/L 69% of the EPA limit 200 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| TTHM | 77.28 µg/L 97% of the EPA limit 80 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Lithium | 77 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2024 | 2/2 | UCMR-5 |
| Total Haloacetic Acids (HAA5) | 34.725 µg/L 58% of the EPA limit 60 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Monobromoacetic Acid | 30.12 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Bromodichloromethane | 27.295 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Dibromochloromethane | 25.47 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Bromoform | 22.08 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Chloroform | 18.26 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Dichloroacetic Acid | 16.925 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Dibromoacetic Acid | 13.8 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Gross Beta Particle Activity | 7.5 pCi/L No EPA limit set Highest in the ZIP: CITY OF LOS FRESNOS · 6,009 people · 2017 | 1/2 | SYR4 |
| Trichloroacetic Acid | 6.17 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Lead | 1.409 µg/L 9.4% of the EPA limit 15 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019
Highest in the ZIP: 5.22 µg/L — CITY OF LOS FRESNOS · 6,009 people · 2017 | 2/2 | SYR4 |
| Selenium | 4.65 µg/L 9.3% of the EPA limit 50 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Monochloroacetic Acid | 3.83 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Arsenic | 2.1 µg/L 21% of the EPA limit 10 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019
Highest in the ZIP: 2.185 µg/L — CITY OF LOS FRESNOS · 6,009 people · 2019 | 2/2 | SYR4 |
| Combined Uranium | 1.9 µg/L 6.3% of the EPA limit 30 µg/L Highest in the ZIP: CITY OF LOS FRESNOS · 6,009 people · 2017 | 1/2 | SYR4 |
| Chromium | 1.58 µg/L 1.6% of the EPA limit 100 µg/L Highest in the ZIP: CITY OF LOS FRESNOS · 6,009 people · 2019 | 1/2 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 1.566 µg/L 26% of the EPA limit 6 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019 | 1/2 | SYR4 |
| Xylenes, Total | 1.1 µg/L 0% of the EPA limit 10000 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019 | 1/2 | SYR4 |
| Thallium, Total | 0.5300 µg/L 27% of the EPA limit 2 µg/L Highest in the ZIP: CITY OF LOS FRESNOS · 6,009 people · 2019 | 1/2 | SYR4 |
| Atrazine | 0.2815 µg/L 9.4% of the EPA limit 3 µg/L Main supplier: OLMITO WSC · 8,952 people · 2019 | 2/2 | SYR4 |
| Antimony, Total | 0.2760 µg/L 4.6% of the EPA limit 6 µg/L Highest in the ZIP: CITY OF LOS FRESNOS · 6,009 people · 2019 | 1/2 | SYR4 |
| Pfba | 0.0106 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2025 | 1/2 | UCMR-5 |
| Pfpea | 0.0053 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2025 | 1/2 | UCMR-5 |
| Pfhxa | 0.0049 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2025 | 1/2 | UCMR-5 |
| PFOS | 0.0045 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2025 | 1/2 | UCMR-5 |
| PFHXS | 0.0036 µg/L No EPA limit set Main supplier: OLMITO WSC · 8,952 people · 2025 | 1/2 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: OLMITO WSC · 8,952 people · 2025
Highest in the ZIP: 0.0018 mg/L — CITY OF LOS FRESNOS · 6,009 people · 2023 | 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 78566
| Supplier | State | Population served |
|---|---|---|
| OLMITO WSC | TX | 8,952 |
| CITY OF LOS FRESNOS | TX | 6,009 |
Frequently asked questions about ZIP 78566 tap water
Is the tap water in ZIP 78566 safe to drink?
EPA testing detected 35 contaminants across the water suppliers serving ZIP 78566. 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 78566?
2 public water suppliers report EPA drinking-water monitoring for ZIP 78566. Each is listed above with its population served.
What contaminants are in ZIP 78566's water?
EPA monitoring detected Chlorite, Fluoride, Nitrate, Copper, Barium, and others across this ZIP's suppliers. The full list with levels and sources is above.