Twin Boulders Subdivision, VA
Lead detected, under the action levels
Latest 90th-percentile lead: 1.8 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.
About Twin Boulders Subdivision
Twin Boulders Subdivision serves about 90 people through 29 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Montgomery County, Virginia. EPA system ID: VA1121755. Ask the utility on your bill for your address in their service line inventory.
Lead results over time
That is down 8.3 ppb from 10.1 ppb in the period ending 2023. The highest 90th-percentile result EPA holds for Twin Boulders Subdivision is 10.1 ppb across 5 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1.8 ppb |
| 2023 | 10.1 ppb over 10 |
| 2022 | 3 ppb |
| 2019 | 6.1 ppb |
| 2019 | 2.1 ppb |
How Twin Boulders Subdivision compares
Of the 996 Virginia systems with a lead result, the median latest reading is 0 ppb; 3 are over 15 ppb right now and 59 have gone over at some point. Twin Boulders Subdivision's 1.8 ppb sits at the 70th percentile in Virginia and the 67th nationally (higher means more lead).
Neighbouring systems
14 other systems share Montgomery County; 3 of them have a higher latest lead result than Twin Boulders Subdivision. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Blacksburg, Town Of | 34,578 | 0 (not detected) |
| Christiansburg Town Of | 22,000 | 0 (not detected) |
| Prices Fork/Merrimac | 4,541 | 0.51 ppb |
| Christiansburg Elliston Waterline | 3,626 | 2.91 ppb |
| Plum Creek | 1,740 | 0 (not detected) |
| Radford Army Ammunition Plant | 1,602 | 4.37 ppb |
| Bethel Area | 1,247 | 1.2 ppb |
| Riner Community | 1,161 | 2.7 ppb |
| Belview | 1,034 | 0 (not detected) |
| Mudpike Road Waterline | 353 | 0.33 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Christiansburg, VA 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 Twin Boulders Subdivision 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. Systems that went over once often dip back under; here is what that means.