What was found in ZIP 77377
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 | 1419.4999999999995 µg/L 35% of the EPA limit 4000 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019
Highest in the ZIP: 1977 µg/L — HARRIS COUNTY MUD 281 · 3,573 people · 2019 | 4/4 | SYR4 |
| Nitrate | 840 µg/L 8.4% of the EPA limit 10000 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019
Highest in the ZIP: 1020 µg/L — MALCOMSON ROAD UTILITY DISTRICT · 7,231 people · 2019 | 4/4 | SYR4 |
| Nitrate-Nitrite | 796 µg/L 8% of the EPA limit 10000 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2015
Highest in the ZIP: 872.9999999999999 µg/L — MALCOMSON ROAD UTILITY DISTRICT · 7,231 people · 2015 | 4/4 | SYR4 |
| Barium | 309.6 µg/L 15% of the EPA limit 2000 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 4/4 | SYR4 |
| Copper | 158.25 µg/L 12% of the EPA limit 1300 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2018
Highest in the ZIP: 259.19999999999993 µg/L — NORTHWEST HARRIS COUNTY MUD 15 · 6,915 people · 2018 | 4/4 | SYR4 |
| Cyanide | 112 µg/L 56% of the EPA limit 200 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 1/4 | SYR4 |
| TTHM | 103.06499999999997 µg/L 129% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 4/4 | SYR4 |
| Nitrite | 89.49999999999997 µg/L 8.9% of the EPA limit 1000 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2017 | 2/4 | SYR4 |
| Lithium | 87.4 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2023 | 4/4 | UCMR-5 |
| Chloroform | 39.48499999999999 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 4/4 | SYR4 |
| Total Haloacetic Acids (HAA5) | 36.55999999999995 µg/L 61% of the EPA limit 60 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 4/4 | SYR4 |
| Bromodichloromethane | 25.5 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 4/4 | SYR4 |
| Dichloroacetic Acid | 19.8 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019
Highest in the ZIP: 22.31 µg/L — MALCOMSON ROAD UTILITY DISTRICT · 7,231 people · 2019 | 3/4 | SYR4 |
| Dibromochloromethane | 20.859999999999992 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 4/4 | SYR4 |
| Dibromoacetic Acid | 19.619999999999997 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 4/4 | SYR4 |
| Bromoform | 13.784999999999998 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 4/4 | SYR4 |
| Chromium | 12.6 µg/L 13% of the EPA limit 100 µg/L Highest in the ZIP: HARRIS COUNTY MUD 281 · 3,573 people · 2019 | 1/4 | SYR4 |
| Arsenic | 8.799999999999997 µg/L 88% of the EPA limit 10 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 4/4 | SYR4 |
| Selenium | 3.1 µg/L 6.2% of the EPA limit 50 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019
Highest in the ZIP: 8.6 µg/L — HARRIS COUNTY MUD 281 · 3,573 people · 2019 | 3/4 | SYR4 |
| Monochloroacetic Acid | 7.4 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 2/4 | SYR4 |
| Trichloroacetic Acid | 6.919999999999996 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 3/4 | SYR4 |
| Gross Beta Particle Activity | 6.095 pCi/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2017 | 2/4 | SYR4 |
| Lead | 3.049999999999999 µg/L 20% of the EPA limit 15 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2018
Highest in the ZIP: 5.797999999999997 µg/L — MALCOMSON ROAD UTILITY DISTRICT · 7,231 people · 2018 | 4/4 | SYR4 |
| Combined Radium (-226 And -228) | 2.9 pCi/L 58% of the EPA limit 5 pCi/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2014 | 2/4 | SYR4 |
| Monobromoacetic Acid | 2.19 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 1/4 | SYR4 |
| Carbon Tetrachloride | 0.6000 µg/L 12% of the EPA limit 5 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2019 | 1/4 | SYR4 |
| Atrazine | 0.3735 µg/L 12% of the EPA limit 3 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2018 | 1/4 | SYR4 |
| Simazine | 0.2225 µg/L 5.6% of the EPA limit 4 µg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2018 | 1/4 | SYR4 |
| Benzo(A)Pyrene | 0.0200 µg/L 10% of the EPA limit 0.2000 µg/L Highest in the ZIP: NORTHWEST HARRIS COUNTY MUD 15 · 6,915 people · 2019 | 1/4 | SYR4 |
| Pfba | 0.0192 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2024 | 2/4 | UCMR-5 |
| Pfpea | 0.0119 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2024 | 2/4 | UCMR-5 |
| Pfhxa | 0.0060 µg/L No EPA limit set Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2024 | 2/4 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: NORTHWEST HARRIS COUNTY MUD 5 · 25,425 people · 2023 | 4/4 | 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 77377
| Supplier | State | Population served |
|---|---|---|
| NORTHWEST HARRIS COUNTY MUD 5 | TX | 25,425 |
| MALCOMSON ROAD UTILITY DISTRICT | TX | 7,231 |
| NORTHWEST HARRIS COUNTY MUD 15 | TX | 6,915 |
| HARRIS COUNTY MUD 281 | TX | 3,573 |
Frequently asked questions about ZIP 77377 tap water
Is the tap water in ZIP 77377 safe to drink?
EPA testing detected 33 contaminants across the water suppliers serving ZIP 77377. 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 77377?
4 public water suppliers report EPA drinking-water monitoring for ZIP 77377. Each is listed above with its population served.
What contaminants are in ZIP 77377's water?
EPA monitoring detected Fluoride, Nitrate, Nitrate-Nitrite, Barium, Copper, and others across this ZIP's suppliers. The full list with levels and sources is above.