Harris County Mud 501, TX
Lead detected, under the action levels
Latest 90th-percentile lead: 1.17 ppb (monitoring period 2023-2025). 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.
Harris County Mud 501 at a glance
Harris County Mud 501 serves about 4,740 people through 1,580 service connections, which makes it a medium-sized system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Harris County, Texas. EPA system ID: TX1013403; phone on file: 713-860-6400. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Harris County Mud 501's lead record
Against the period ending 2022 (0.5 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Harris County Mud 501 is 1.17 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1.17 ppb |
| 2022 | 0.5 ppb |
| 2019 | 1.16 ppb |
| 2016 | 0 (not detected) |
Against other Texas systems
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. Harris County Mud 501's 1.17 ppb sits at the 68th percentile in Texas and the 58th nationally (higher means more lead).
Neighbouring systems
690 other systems share Harris County; 238 of them have a higher latest lead result than Harris County Mud 501. 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 |
What to do in your house
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 Harris County Mud 501 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. The lead result guide covers how utilities pick the homes they sample. The action level is dropping - the 10 ppb rule from 2027.