What was found in ZIP 77546
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 |
|---|---|---|---|
| Nitrate | 780 µg/L 7.8% of the EPA limit 10000 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 1130 µg/L — HARRIS COUNTY MUD 55 HERITAGE PARK · 16,392 people · 2019 | 3/4 | 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: 958 µg/L — CITY OF FRIENDSWOOD · 43,190 people · 2018 | 4/4 | 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
Highest in the ZIP: 898 µg/L — HARRIS COUNTY MUD 55 HERITAGE PARK · 16,392 people · 2015 | 4/4 | SYR4 |
| 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: 796.5 µg/L — CITY OF FRIENDSWOOD · 43,190 people · 2017 | 3/4 | SYR4 |
| Barium | 365.4 µg/L 18% of the EPA limit 2000 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 4/4 | 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 | 4/4 | 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: 99.5 µg/L — HARRIS COUNTY MUD 55 HERITAGE PARK · 16,392 people · 2017 | 3/4 | 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 | 4/4 | 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: 65.545 µg/L — CITY OF FRIENDSWOOD · 43,190 people · 2019 | 4/4 | 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: 49 µg/L — HARRIS COUNTY MUD 55 HERITAGE PARK · 16,392 people · 2015 | 3/4 | SYR4 |
| Dichloroacetic Acid | 36.39 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 44.35 µg/L — CITY OF FRIENDSWOOD · 43,190 people · 2019 | 4/4 | 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 | 4/4 | SYR4 |
| Lithium | 33.9 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2025 | 3/4 | UCMR-5 |
| Bromoform | 8.655 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 25.2 µg/L — CITY OF FRIENDSWOOD · 43,190 people · 2019 | 4/4 | SYR4 |
| 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 | 4/4 | SYR4 |
| Dibromochloromethane | 5.2 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019
Highest in the ZIP: 21.75 µg/L — CITY OF FRIENDSWOOD · 43,190 people · 2019 | 4/4 | 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: 18.392 µg/L — BRYAN CO. RWS & SWMD #2 · 6,270 people · 2018 | 4/4 | SYR4 |
| Chromium | 14.11 µg/L 14% of the EPA limit 100 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/4 | 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 | 1/4 | 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 | 1/4 | SYR4 |
| Selenium | 10.56 µg/L 21% of the EPA limit 50 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/4 | SYR4 |
| Monochloroacetic Acid | 9.275 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 4/4 | 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 | 2/4 | SYR4 |
| Gross Beta Particle Activity | 7.23 pCi/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 4/4 | SYR4 |
| Arsenic | 7.08 µg/L 71% of the EPA limit 10 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/4 | SYR4 |
| Dalapon | 4.32 µg/L 2.2% of the EPA limit 200 µg/L Highest in the ZIP: CITY OF FRIENDSWOOD · 43,190 people · 2019 | 1/4 | 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
Highest in the ZIP: 4.1 µg/L — HARRIS COUNTY MUD 55 HERITAGE PARK · 16,392 people · 2019 | 2/4 | SYR4 |
| Monobromoacetic Acid | 3.975 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 4/4 | 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 | 3/4 | SYR4 |
| Dibromoacetic Acid | 3.43 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 4/4 | 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 | 2/4 | SYR4 |
| Toluene | 1 µg/L 0.1% of the EPA limit 1000 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 1/4 | 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 | 2/4 | SYR4 |
| Dichloromethane | 0.5000 µg/L 10% of the EPA limit 5 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 2/4 | SYR4 |
| Atrazine | 0.4650 µg/L 16% of the EPA limit 3 µg/L Main supplier: CITY OF HOUSTON · 2,970,543 people · 2019 | 3/4 | 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 | 2/4 | 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 | 3/4 | SYR4 |
| 6:2 Fts | 0.0426 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2025 | 1/4 | 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 | 1/4 | SYR4 |
| Pfpea | 0.0067 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2025
Highest in the ZIP: 0.0138 µg/L — HARRIS COUNTY MUD 55 HERITAGE PARK · 16,392 people · 2025 | 3/4 | UCMR-5 |
| Pfba | 0.0106 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2025 | 3/4 | 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 | 1/4 | SYR4 |
| Pfhxa | 0.0051 µg/L No EPA limit set Main supplier: CITY OF HOUSTON · 2,970,543 people · 2025 | 3/4 | 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 | 4/4 | LCR |
| PFBS | 0.0030 µg/L No EPA limit set Highest in the ZIP: HARRIS COUNTY MUD 55 HERITAGE PARK · 16,392 people · 2025 | 1/4 | 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.
Water suppliers serving ZIP 77546
| Supplier | State | Population served |
|---|---|---|
| CITY OF HOUSTON | TX | 2,970,543 |
| CITY OF FRIENDSWOOD | TX | 43,190 |
| HARRIS COUNTY MUD 55 HERITAGE PARK | TX | 16,392 |
| BRYAN CO. RWS & SWMD #2 | OK | 6,270 |
Frequently asked questions about ZIP 77546 tap water
Is the tap water in ZIP 77546 safe to drink?
EPA testing detected 45 contaminants across the water suppliers serving ZIP 77546. 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 77546?
4 public water suppliers report EPA drinking-water monitoring for ZIP 77546. Each is listed above with its population served.
What contaminants are in ZIP 77546's water?
EPA monitoring detected Nitrate, Copper, Nitrate-Nitrite, Fluoride, Barium, and others across this ZIP's suppliers. The full list with levels and sources is above.