Zam Zam Water Supply, TX
Lead detected, under the action levels
Latest 90th-percentile lead: 2 ppb (monitoring period 2025-2025). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. Lead was measured in sampled homes but the 90th percentile is under both action levels. EPA's health goal for lead is zero, so test your own tap if your home was built before 1986 or anyone in it is pregnant or a young child.
Zam Zam Water Supply at a glance
Zam Zam Water Supply serves about 87 people through 28 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Harris County, Texas. EPA system ID: TX1011747; phone on file: 713-870-2855. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Every lead result on file
Against the period ending 2024 (1 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Zam Zam Water Supply is 2 ppb across 2 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 2 ppb |
| 2024 | 1 ppb |
Where this result ranks
Of the 4,447 Texas systems with a lead result, the median latest reading is 0.28 ppb; 15 are over 15 ppb right now and 202 have gone over at some point. Zam Zam Water Supply's 2 ppb sits at the 82nd percentile in Texas and the 70th nationally (higher means more lead).
Nearby utilities
690 other systems share Harris County; 138 of them have a higher latest lead result than Zam Zam Water Supply. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| City Of Houston | 2,970,543 | 5 ppb |
| City Of Pasadena | 152,000 | 3.72 ppb |
| Clear Lake City Water Authority | 89,702 | 0.88 ppb |
| City Of Baytown | 86,004 | 2.1 ppb |
| City Of Houston Ud 5 - Kingwood | 80,073 | 0.51 ppb |
| Harris County Mud 165 | 40,503 | 1.3 ppb |
| City Of La Porte | 36,569 | 2.35 ppb |
| City Of Deer Park | 34,495 | 0 (not detected) |
| Northwest Harris County Mud 5 | 25,425 | 0 (not detected) |
| City Of Katy | 25,253 | 2.7 ppb |
Next steps for Houston, TX
Test your own tap with a certified lab first-draw sample; Houston, TX may offer free or low-cost kits through the utility. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Zam Zam Water Supply whether it covers that cost before hiring anyone - many utilities now do.
These figures describe homes the utility sampled, not your tap. Only your service line record or a test of your own water answers the question for your house. What a 90th-percentile result does and does not tell you: how to read a lead result. The action level is dropping - the 10 ppb rule from 2027.