Oasis Investments, CA
Exceeded the action level in the past
Latest 90th-percentile lead: 3 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. 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.
Oasis Investments at a glance
Oasis Investments serves about 75 people through 31 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Stanislaus County, California. EPA system ID: CA5000263; phone on file: 209-581-2707. 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 up 3 ppb from 0 ppb in the period ending 2023. The highest 90th-percentile result EPA holds for Oasis Investments is 19.7 ppb across 8 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 3 ppb |
| 2023 | 0 (not detected) |
| 2023 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2021 | 0 (not detected) |
| 2019 | 1.2 ppb |
| 2019 | 2.4 ppb |
| 2018 | 19.7 ppb over 15 |
Against other California systems
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. Oasis Investments's 3 ppb sits at the 85th percentile in California and the 81st nationally (higher means more lead).
Neighbouring systems
59 other systems share Stanislaus County; 8 of them have a higher latest lead result than Oasis Investments. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Modesto, City Of | 218,915 | 12 ppb |
| Turlock, City Of | 72,888 | 0.97 ppb |
| Ceres, City Of | 54,513 | 0 (not detected) |
| Riverbank, City Of | 25,625 | 21 ppb |
| Patterson, City Of | 24,977 | 0 (not detected) |
| Oakdale, City Of | 23,235 | 0 (not detected) |
| City Of Modesto - Salida | 14,576 | 0 (not detected) |
| City Of Newman-Water Department | 12,389 | 0 (not detected) |
| City Of Waterford | 8,788 | 0 (not detected) |
| Hughson, City Of | 7,977 | 0 (not detected) |
What to do in your house
Test your own tap with a certified lab first-draw sample; Turlock, 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 Oasis Investments 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. Why an old exceedance still matters: over the limit before, under it now.