Mustang Sud, TX
Lead detected, under the action levels
Latest 90th-percentile lead: 1.33 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.
Mustang Sud at a glance
Mustang Sud serves about 127,911 people through 42,637 service connections, which makes it a very large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Denton County, Texas. EPA system ID: TX0610036; phone on file: 940-440-9561. They can tell you what your service line is made of and whether they pay to replace it.
Every lead result on file
Against the period ending 2025 (1.45 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Mustang Sud is 1.69 ppb across 8 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1.33 ppb |
| 2025 | 1.45 ppb |
| 2024 | 1.69 ppb |
| 2024 | 1.6 ppb |
| 2022 | 1.2 ppb |
| 2019 | 0 (not detected) |
| 2019 | 1.1 ppb |
| 2016 | 1.3 ppb |
How Mustang Sud compares
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. Mustang Sud's 1.33 ppb sits at the 72nd percentile in Texas and the 61st nationally (higher means more lead).
Neighbouring systems
73 other systems share Denton County; 16 of them have a higher latest lead result than Mustang Sud. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| City Of Denton | 150,037 | 1.5 ppb |
| City Of Lewisville | 140,880 | 1.48 ppb |
| Town Of Flower Mound | 80,000 | 1.6 ppb |
| City Of The Colony | 45,367 | 0.62 ppb |
| Town Of Little Elm | 43,348 | 2.17 ppb |
| City Of Corinth | 23,213 | 2.3 ppb |
| Lake Cities Municipal Utility Authority | 17,826 | 2.78 ppb |
| City Of Highland Village | 16,500 | 2.62 ppb |
| Trophy Club Mud 1 | 13,649 | 0 (not detected) |
| Denton County Fwsd 7 | 12,837 | 1.24 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Aubrey, 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 Mustang Sud 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. Systems that went over once often dip back under; here is what that means.