What was found in ZIP 77386
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 | 1075 µg/L 27% of the EPA limit 4000 µg/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 2201 µg/L — HARRIS COUNTY IMPROVEMENT DISTRICT 18 · 5,025 people · 2018 | 10/10 | SYR4 |
| Nitrate | 110 µg/L 1.1% of the EPA limit 10000 µg/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 887.5 µg/L — HARRIS COUNTY WCID 110 · 9,807 people · 2019 | 10/10 | SYR4 |
| Nitrate-Nitrite | 110 µg/L 1.1% of the EPA limit 10000 µg/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2015
Highest in the ZIP: 848 µg/L — HARRIS COUNTY WCID 110 · 9,807 people · 2015 | 8/10 | SYR4 |
| Copper | 223.7 µg/L 17% of the EPA limit 1300 µg/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 389.79999999999995 µg/L — MONTGOMERY COUNTY MUD 94 · 5,184 people · 2017 | 10/10 | SYR4 |
| Barium | 211.79999999999998 µg/L 11% of the EPA limit 2000 µg/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 389.05 µg/L — EL DORADO UTILITY DISTRICT · 3,591 people · 2019 | 10/10 | SYR4 |
| Xylenes, Total | 1.51 µg/L 0% of the EPA limit 10000 µg/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 152.88499999999993 µg/L — EL DORADO UTILITY DISTRICT · 3,591 people · 2019 | 2/10 | SYR4 |
| TTHM | 52.62 µg/L 66% of the EPA limit 80 µg/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 76.33499999999998 µg/L — RAYFORD ROAD MUD · 11,550 people · 2019 | 9/10 | SYR4 |
| Cyanide | 59 µg/L 30% of the EPA limit 200 µg/L Highest in the ZIP: HARRIS COUNTY WCID 110 · 9,807 people · 2017 | 1/10 | SYR4 |
| Chloroform | 38.02 µg/L No EPA limit set Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 46.14999999999999 µg/L — RAYFORD ROAD MUD · 11,550 people · 2019 | 7/10 | SYR4 |
| Lithium | 24.6 µg/L No EPA limit set Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2024
Highest in the ZIP: 44.6 µg/L — HARRIS COUNTY IMPROVEMENT DISTRICT 18 · 5,025 people · 2025 | 10/10 | UCMR-5 |
| Total Haloacetic Acids (HAA5) | 21.889999999999997 µg/L 36% of the EPA limit 60 µg/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 36.54000000000001 µg/L — RAYFORD ROAD MUD · 11,550 people · 2019 | 6/10 | SYR4 |
| Toluene | 34.23 µg/L 3.4% of the EPA limit 1000 µg/L Highest in the ZIP: EL DORADO UTILITY DISTRICT · 3,591 people · 2019 | 1/10 | SYR4 |
| Bromoform | 6.475 µg/L No EPA limit set Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 25.67 µg/L — HARRIS COUNTY IMPROVEMENT DISTRICT 18 · 5,025 people · 2019 | 8/10 | SYR4 |
| Lead | 9.077999999999994 µg/L 61% of the EPA limit 15 µg/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 24.699999999999996 µg/L — SPRING CREEK UTILITY DISTRICT · 8,919 people · 2019 | 10/10 | SYR4 |
| Dichloroacetic Acid | 11.7 µg/L No EPA limit set Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 21.11000000000001 µg/L — RAYFORD ROAD MUD · 11,550 people · 2019 | 5/10 | SYR4 |
| Bromodichloromethane | 14.439999999999998 µg/L No EPA limit set Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 21 µg/L — EL DORADO UTILITY DISTRICT · 3,591 people · 2019 | 9/10 | SYR4 |
| Nitrite | 20 µg/L 2% of the EPA limit 1000 µg/L Highest in the ZIP: HARRIS COUNTY WCID 110 · 9,807 people · 2015 | 1/10 | SYR4 |
| Ethylbenzene | 18.075 µg/L 2.6% of the EPA limit 700 µg/L Highest in the ZIP: EL DORADO UTILITY DISTRICT · 3,591 people · 2019 | 1/10 | SYR4 |
| Dibromochloromethane | 12.05 µg/L No EPA limit set Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 15 µg/L — EL DORADO UTILITY DISTRICT · 3,591 people · 2019 | 9/10 | SYR4 |
| Trichloroacetic Acid | 7.4399999999999995 µg/L No EPA limit set Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 14.84 µg/L — RAYFORD ROAD MUD · 11,550 people · 2019 | 5/10 | SYR4 |
| Gross Alpha, Excl. Radon And U | 4.5 pCi/L 30% of the EPA limit 15 pCi/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 7 pCi/L — EL DORADO UTILITY DISTRICT · 3,591 people · 2018 | 5/10 | SYR4 |
| Gross Beta Particle Activity | 6.1 pCi/L No EPA limit set Highest in the ZIP: EL DORADO UTILITY DISTRICT · 3,591 people · 2018 | 2/10 | SYR4 |
| Arsenic | 5.15 µg/L 52% of the EPA limit 10 µg/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 5.405 µg/L — HARRIS COUNTY WCID 110 · 9,807 people · 2019 | 7/10 | SYR4 |
| Selenium | 4.2 µg/L 8.4% of the EPA limit 50 µg/L Highest in the ZIP: MONTGOMERY COUNTY MUD 119 SPRING TRAILS · 6,621 people · 2018 | 3/10 | SYR4 |
| Dibromoacetic Acid | 3.119999999999999 µg/L No EPA limit set Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 4.0649999999999995 µg/L — HARRIS COUNTY IMPROVEMENT DISTRICT 18 · 5,025 people · 2019 | 5/10 | SYR4 |
| Monochloroacetic Acid | 2 µg/L No EPA limit set Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2019
Highest in the ZIP: 4.029999999999999 µg/L — HARRIS COUNTY WCID 110 · 9,807 people · 2019 | 4/10 | SYR4 |
| Combined Radium (-226 And -228) | 0.5600 pCi/L 11% of the EPA limit 5 pCi/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2016
Highest in the ZIP: 3.3 pCi/L — SPRING CREEK UTILITY DISTRICT · 8,919 people · 2019 | 8/10 | SYR4 |
| Combined Uranium | 2.9 µg/L 9.7% of the EPA limit 30 µg/L Highest in the ZIP: EL DORADO UTILITY DISTRICT · 3,591 people · 2018 | 2/10 | SYR4 |
| Atrazine | 1.6600000000000001 µg/L 55% of the EPA limit 3 µg/L Highest in the ZIP: HARRIS COUNTY WCID 110 · 9,807 people · 2019 | 1/10 | SYR4 |
| Dalapon | 1.39 µg/L 0.7% of the EPA limit 200 µg/L Highest in the ZIP: RAYFORD ROAD MUD · 11,550 people · 2019 | 1/10 | SYR4 |
| Simazine | 0.1450 µg/L 3.6% of the EPA limit 4 µg/L Highest in the ZIP: HARRIS COUNTY WCID 110 · 9,807 people · 2019 | 1/10 | SYR4 |
| Pfba | 0.0080 µg/L No EPA limit set Highest in the ZIP: HARRIS COUNTY WCID 110 · 9,807 people · 2024 | 1/10 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: SOUTHERN MONTGOMERY COUNTY MUD · 13,372 people · 2025
Highest in the ZIP: 0.0034 mg/L — CITY OF OAK RIDGE NORTH · 3,585 people · 2023 | 10/10 | 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 77386
| Supplier | State | Population served |
|---|---|---|
| SOUTHERN MONTGOMERY COUNTY MUD | TX | 13,372 |
| RAYFORD ROAD MUD | TX | 11,550 |
| HARRIS COUNTY WCID 110 | TX | 9,807 |
| SPRING CREEK UTILITY DISTRICT | TX | 8,919 |
| MONTGOMERY COUNTY MUD 119 SPRING TRAILS | TX | 6,621 |
| MONTGOMERY COUNTY MUD 94 | TX | 5,184 |
| HARRIS COUNTY IMPROVEMENT DISTRICT 18 | TX | 5,025 |
| MONTGOMERY COUNTY MUD 89 | TX | 4,761 |
| EL DORADO UTILITY DISTRICT | TX | 3,591 |
| CITY OF OAK RIDGE NORTH | TX | 3,585 |
Frequently asked questions about ZIP 77386 tap water
Is the tap water in ZIP 77386 safe to drink?
EPA testing detected 33 contaminants across the water suppliers serving ZIP 77386. 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 77386?
10 public water suppliers report EPA drinking-water monitoring for ZIP 77386. Each is listed above with its population served.
What contaminants are in ZIP 77386's water?
EPA monitoring detected Fluoride, Nitrate, Nitrate-Nitrite, Copper, Barium, and others across this ZIP's suppliers. The full list with levels and sources is above.