Hidden Valley Water System, TX
Above the federal action level
Latest 90th-percentile lead: 39 ppb (monitoring period 2026-2026). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. In the most recent monitoring period, more than 10% of the sampled homes measured above 15 ppb. Use a filter certified to NSF/ANSI 53 for lead for drinking and cooking now, and test your own tap.
About Hidden Valley Water System
Hidden Valley Water System serves about 186 people through 62 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Denton County, Texas. EPA system ID: TX0610099; phone on file: 512-990-4400. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Hidden Valley Water System's lead record
That is up 26.2 ppb from 12.8 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Hidden Valley Water System is 39 ppb across 3 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 39 ppb over 15 |
| 2025 | 12.8 ppb over 10 |
| 2024 | 9.2 ppb |
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. Hidden Valley Water System's 39 ppb sits at the 100th percentile in Texas and the 100th nationally (higher means more lead).
Nearby utilities
73 other systems share Denton County; 0 of them have a higher latest lead result than Hidden Valley Water System. 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 |
| Mustang Sud | 127,911 | 1.33 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) |
Next steps for Austin, TX
Use a filter certified to NSF/ANSI 53 for lead on the tap you drink and cook from, now, before you test. Then test your own tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Hidden Valley Water System 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.