Ontario Municipal Utilities Company, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 0.6 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. 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.
Ontario Municipal Utilities Company at a glance
Ontario Municipal Utilities Company serves about 185,010 people through 40,399 service connections, which makes it a very large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in San Bernardino County, California. EPA system ID: CA3610034; phone on file: 909-395-2682. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Ontario Municipal Utilities Company's lead record
Against the period ending 2021 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Ontario Municipal Utilities Company is 0.6 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 0.6 ppb |
| 2021 | 0 (not detected) |
| 2018 | 0 (not detected) |
How Ontario Municipal Utilities Company 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. Ontario Municipal Utilities Company's 0.6 ppb sits at the 66th percentile in California and the 45th nationally (higher means more lead).
Nearby utilities
146 other systems share San Bernardino County; 31 of them have a higher latest lead result than Ontario Municipal Utilities Company. 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) |
| 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 |
| Upland, City Of | 78,376 | 1.6 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Ontario, 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 Ontario Municipal Utilities Company 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. Systems that went over once often dip back under; here is what that means.