What was found in ZIP 77346
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 |
|---|---|---|---|
| Fluoride | 538 µg/L 13% of the EPA limit 4000 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 1485.5 µg/L — TRAIL OF THE LAKES MUD · 9,480 people · 2017 | 10/12 | SYR4 |
| Nitrate | 780 µg/L 7.8% of the EPA limit 10000 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 5/12 | SYR4 |
| Copper | 338 µg/L 26% of the EPA limit 1300 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 445.1 µg/L — HARRIS COUNTY MUD 290 · 8,259 people · 2018 | 12/12 | SYR4 |
| Barium | 365.4 µg/L 18% of the EPA limit 2000 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 387.1 µg/L — HARRIS COUNTY MUD 132 · 8,682 people · 2017 | 11/12 | SYR4 |
| Nitrate-Nitrite | 310 µg/L 3.1% of the EPA limit 10000 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 4/12 | SYR4 |
| Cyanide | 93.5 µg/L 47% of the EPA limit 200 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 166.5 µg/L — HARRIS COUNTY MUD 400 - WEST · 5,217 people · 2017 | 2/12 | SYR4 |
| TTHM | 49.635 µg/L 62% of the EPA limit 80 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 122.275 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 7/12 | SYR4 |
| Chloroform | 40.95 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 94.645 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 6/12 | SYR4 |
| Total Haloacetic Acids (HAA5) | 49.97 µg/L 83% of the EPA limit 60 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 62.71 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 6/12 | SYR4 |
| Nitrite | 36.5 µg/L 3.7% of the EPA limit 1000 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 50 µg/L — HARRIS COUNTY MUD 278 · 10,584 people · 2019 | 2/12 | SYR4 |
| Dichloroacetic Acid | 36.39 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 5/12 | SYR4 |
| Trichloroacetic Acid | 12.33 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 36.03 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 4/12 | SYR4 |
| Lithium | 33.9 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2025 | 11/12 | UCMR-5 |
| Bromodichloromethane | 12.9 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 24.055 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 6/12 | SYR4 |
| Lead | 10.74 µg/L 72% of the EPA limit 15 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 20.97 µg/L — HARRIS COUNTY MUD 132 · 8,682 people · 2017 | 11/12 | SYR4 |
| Bromoform | 8.655 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 19.25 µg/L — TRAIL OF THE LAKES MUD · 9,480 people · 2019 | 4/12 | SYR4 |
| Chromium | 14.11 µg/L 14% of the EPA limit 100 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/12 | SYR4 |
| Gross Alpha, Excl. Radon And U | 10.67 pCi/L 71% of the EPA limit 15 pCi/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 11.7 pCi/L — TRAIL OF THE LAKES MUD · 9,480 people · 2017 | 6/12 | SYR4 |
| Combined Uranium | 10.77 µg/L 36% of the EPA limit 30 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/12 | SYR4 |
| Selenium | 10.56 µg/L 21% of the EPA limit 50 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 2/12 | SYR4 |
| Monochloroacetic Acid | 9.275 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 3/12 | SYR4 |
| Dibromochloromethane | 5.2 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 9.065 µg/L — TRAIL OF THE LAKES MUD · 9,480 people · 2019 | 7/12 | SYR4 |
| Xylenes, Total | 8.975 µg/L 0.1% of the EPA limit 10000 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 5/12 | SYR4 |
| Gross Beta Particle Activity | 7.23 pCi/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 4/12 | SYR4 |
| Arsenic | 7.08 µg/L 71% of the EPA limit 10 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 9/12 | SYR4 |
| Monobromoacetic Acid | 3.975 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 2/12 | SYR4 |
| Combined Radium (-226 And -228) | 3.63 pCi/L 73% of the EPA limit 5 pCi/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 9/12 | SYR4 |
| Dibromoacetic Acid | 3.43 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 3/12 | SYR4 |
| Ethylbenzene | 2.075 µg/L 0.3% of the EPA limit 700 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 2/12 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 1.58 µg/L 26% of the EPA limit 6 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 4/12 | SYR4 |
| Toluene | 1 µg/L 0.1% of the EPA limit 1000 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/12 | SYR4 |
| 2,4-D | 0.9000 µg/L 1.3% of the EPA limit 70 µg/L Highest in the ZIP: BRYAN CO. RWS & SWMD #2 · 6,270 people · 2019 | 1/12 | SYR4 |
| Dichloromethane | 0.5000 µg/L 10% of the EPA limit 5 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/12 | SYR4 |
| Atrazine | 0.4650 µg/L 16% of the EPA limit 3 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/12 | SYR4 |
| Hexachlorocyclopentadiene | 0.2150 µg/L 0.4% of the EPA limit 50 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/12 | SYR4 |
| Simazine | 0.2030 µg/L 5.1% of the EPA limit 4 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/12 | SYR4 |
| Bhc-Gamma | 0.0500 µg/L 25% of the EPA limit 0.2000 µg/L Highest in the ZIP: HARRIS COUNTY MUD 152 · 7,314 people · 2019 | 1/12 | SYR4 |
| 6:2 Fts | 0.0426 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2025 | 1/12 | UCMR-5 |
| Benzo(A)Pyrene | 0.0400 µg/L 20% of the EPA limit 0.2000 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/12 | SYR4 |
| Pfba | 0.0106 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2025 | 2/12 | UCMR-5 |
| Endrin | 0.0100 µg/L 0.5% of the EPA limit 2 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/12 | SYR4 |
| Pfpea | 0.0067 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2025 | 2/12 | UCMR-5 |
| Pfhxa | 0.0051 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2025 | 2/12 | UCMR-5 |
| Lead | 0.0050 mg/L 33% of the EPA limit 0.0150 mg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2024 | 12/12 | 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 77346
| Supplier | State | Population served |
|---|---|---|
| CITY OF HOUSTON | TX | 2,970,543 |
| HARRIS COUNTY MUD 153 | TX | 11,781 |
| HARRIS COUNTY MUD 278 | TX | 10,584 |
| TRAIL OF THE LAKES MUD | TX | 9,480 |
| HARRIS COUNTY MUD 132 | TX | 8,682 |
| HARRIS COUNTY MUD 290 | TX | 8,259 |
| HARRIS COUNTY MUD 151 | TX | 7,464 |
| HARRIS COUNTY MUD 152 | TX | 7,314 |
| BRYAN CO. RWS & SWMD #2 | OK | 6,270 |
| HARRIS COUNTY MUD 46 | TX | 5,418 |
| HARRIS COUNTY MUD 400 - WEST | TX | 5,217 |
| HARRIS COUNTY MUD 106 | TX | 4,668 |
Frequently asked questions about ZIP 77346 tap water
Is the tap water in ZIP 77346 safe to drink?
EPA testing detected 44 contaminants across the water suppliers serving ZIP 77346. 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 77346?
12 public water suppliers report EPA drinking-water monitoring for ZIP 77346. Each is listed above with its population served.
What contaminants are in ZIP 77346's water?
EPA monitoring detected Fluoride, Nitrate, Copper, Barium, Nitrate-Nitrite, and others across this ZIP's suppliers. The full list with levels and sources is above.