Black Rock Wsc, TX
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Black Rock Wsc at a glance
Black Rock Wsc serves about 1,764 people through 588 service connections, which makes it a small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Denton County, Texas. EPA system ID: TX0610040; phone on file: 940-365-0963. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Black Rock Wsc's lead record
Against the period ending 2022 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Black Rock Wsc is 0 ppb across 2 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2022 | 0 (not detected) |
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. Black Rock Wsc's reported as 0 (not detected) sits at the 32nd percentile in Texas and the 30th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in Denton County
73 other systems share Denton County; 29 of them have a higher latest lead result than Black Rock Wsc. 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) |
What to do in your house
Look up your address in Black Rock Wsc's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Black Rock Wsc 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. Why sampled homes are the worst-case ones is in the guide to reading the number. Small systems behave differently: why small systems go over more often.