Northwest Hills Water Supply, TX
Lead detected, under the action levels
Latest 90th-percentile lead: 1.7 ppb (monitoring period 2024-2026). 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.
Who runs the water here
Northwest Hills Water Supply serves about 219 people through 73 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Gillespie County, Texas. EPA system ID: TX0860086; phone on file: 512-990-4400. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Every lead result on file
Against the period ending 2023 (1 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Northwest Hills Water Supply is 1.7 ppb across 2 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 1.7 ppb |
| 2023 | 1 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. Northwest Hills Water Supply's 1.7 ppb sits at the 78th percentile in Texas and the 66th nationally (higher means more lead).
Other water systems in Gillespie County
14 other systems share Gillespie County; 2 of them have a higher latest lead result than Northwest Hills 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 Fredericksburg | 12,360 | 0.7 ppb |
| Stonewall Wcid | 726 | 1.61 ppb |
| Lcra Harper Water System | 381 | 0.7 ppb |
| Deerwood Subdivision | 357 | 0 (not detected) |
| Harper Road Estates | 333 | 2 ppb |
| West Oak Heights | 213 | 0 (not detected) |
| Liveoaks Mobile Home Park | 200 | 0 (not detected) |
| Oakview Water System | 195 | 1.3 ppb |
| Whispering Oaks Water Works | 189 | 0 (not detected) |
| Reservation Ranch | 180 | - |
Your move
Test your own tap with a certified lab first-draw sample; Austin, 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 Northwest Hills 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. The lead result guide covers how utilities pick the homes they sample. Size matters more than most people expect: small vs large water systems.