Treasure Island, CA
Above the federal action level
Latest 90th-percentile lead: 100 ppb (monitoring period 2022-2024). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. In the most recent monitoring period, more than 10% of the sampled homes measured above 15 ppb. Use a filter certified to NSF/ANSI 53 for lead for drinking and cooking now, and test your own tap.
About Treasure Island
Treasure Island serves about 3,864 people through 186 service connections, which makes it a medium-sized system under EPA's size classes. It is federally owned and draws surface water, in San Francisco County, California. EPA system ID: CA3810702; phone on file: 650-652-3100. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Lead results over time
That is up 99.4 ppb from 0.6 ppb in the period ending 2021. The highest 90th-percentile result EPA holds for Treasure Island is 100 ppb across 4 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 100 ppb over 15 |
| 2021 | 0.6 ppb |
| 2021 | 0.6 ppb |
| 2018 | 0 (not detected) |
How Treasure Island compares
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. Treasure Island's 100 ppb sits at the 100th percentile in California and the 100th nationally (higher means more lead).
Other water systems in San Francisco County
4 other systems share San Francisco County; 0 of them have a higher latest lead result than Treasure Island. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Sfpuc City Distribution Division | 848,019 | 0 (not detected) |
| Presidio Of San Francisco | 3,500 | 0 (not detected) |
| San Francisco Regional Water System | 600 | 0 (not detected) |
| Hhw&P Moccasin Compound-Sfpuc | 410 | 0 (not detected) |
What to do in your house
Use a filter certified to NSF/ANSI 53 for lead on the tap you drink and cook from, now, before you test. Then test your own tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Treasure Island 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. The action level is dropping - the 10 ppb rule from 2027.