Twin Valley Inc, CA
Exceeded the action level in the past
Latest 90th-percentile lead: 3.9 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. The latest result is under the action level, but this system has gone over 15 ppb before. Lead comes from pipes, not the source water, so a home with a lead service line can still be exposed. Test your own tap.
About Twin Valley Inc
Twin Valley Inc serves about 317 people through 96 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Santa Clara County, California. EPA system ID: CA4300575; phone on file: 831-920-6796. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Every lead result on file
That is down 1.5 ppb from 5.4 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for Twin Valley Inc is 28.6 ppb across 4 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 3.9 ppb |
| 2022 | 5.4 ppb |
| 2019 | 9 ppb |
| 2018 | 28.6 ppb over 15 |
Where this result ranks
Of the 2,884 California systems with a lead result, the median latest reading is 0 ppb; 30 are over 15 ppb right now and 215 have gone over at some point. Twin Valley Inc's 3.9 ppb sits at the 89th percentile in California and the 87th nationally (higher means more lead).
Other water systems in Santa Clara County
72 other systems share Santa Clara County; 6 of them have a higher latest lead result than Twin Valley Inc. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| San Jose Water | 1,039,920 | 0 (not detected) |
| City Of Sunnyvale | 157,566 | 0 (not detected) |
| City Of Santa Clara | 134,587 | 2.7 ppb |
| Great Oaks Wc Inc | 112,582 | 0 (not detected) |
| City Of San Jose - Evg/Edv/Coy | 99,783 | 0 (not detected) |
| City Of Milpitas | 81,915 | 2.5 ppb |
| City Of Mountain View | 81,340 | 0 (not detected) |
| City Of Palo Alto | 67,658 | 0 (not detected) |
| Cwsc Los Altos Suburban | 63,559 | 1.5 ppb |
| City Of Gilroy | 59,426 | 2 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Castroville, CA 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 Valley Inc 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. More in what a past exceedance means today.