Barton Flats Water System, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 2.8 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.
Who runs the water here
Barton Flats Water System serves about 11 people through 16 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws surface water, in San Bernardino County, California. EPA system ID: CA3601048; phone on file: 909-794-2824. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
Against the period ending 2025 (2.8 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Barton Flats Water System is 11 ppb across 6 monitoring periods, none of them over 15 ppb (2 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 2.8 ppb |
| 2025 | 2.8 ppb |
| 2022 | 11 ppb over 10 |
| 2022 | 11 ppb over 10 |
| 2019 | 0 (not detected) |
| 2019 | 5 ppb |
How Barton Flats Water System 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. Barton Flats Water System's 2.8 ppb sits at the 83rd percentile in California and the 79th nationally (higher means more lead).
Other water systems in San Bernardino County
146 other systems share San Bernardino County; 18 of them have a higher latest lead result than Barton Flats Water System. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| San Gabriel Valley Wc - Fontana | 228,270 | 0 (not detected) |
| San Bernardino City | 214,665 | 0 (not detected) |
| Cucamonga Valley Water District | 213,375 | 0 (not detected) |
| Ontario Municipal Utilities Company | 185,010 | 0.6 ppb |
| Victorville Water District | 140,721 | 0 (not detected) |
| San Bernardino Valley Wd | 109,608 | - |
| East Valley Water District | 108,600 | 0 (not detected) |
| Hesperia Wd | 101,836 | 0 (not detected) |
| West Valley Water District | 96,123 | 0 (not detected) |
| Chino, City Of | 90,187 | 1 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Angelus Oaks, 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 Barton Flats Water System 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.