South Mesa Wc, CA
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
About South Mesa Wc
South Mesa Wc serves about 10,348 people through 3,136 service connections, which makes it a large system under EPA's size classes. It is privately owned and draws groundwater, in Riverside County, California. EPA system ID: CA3310017; phone on file: 909-795-2401. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Lead results over time
Against the period ending 2022 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for South Mesa Wc is 0 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2016 | 0 (not detected) |
How South Mesa Wc 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. South Mesa Wc's reported as 0 (not detected) sits at the 53rd percentile in California and the 37th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Neighbouring systems
92 other systems share Riverside County; 33 of them have a higher latest lead result than South Mesa Wc. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Eastern Municipal Wd | 659,923 | 2.8 ppb |
| Riverside, City Of | 302,776 | 1 ppb |
| Coachella Vwd: Cove Community | 270,000 | 0 (not detected) |
| Elsinore Valley Mwd | 169,455 | 1.3 ppb |
| Corona, City Of | 169,380 | 1.8 ppb |
| Rancho California Water District | 146,147 | 0 (not detected) |
| Jurupa Community Sd | 134,638 | 0 (not detected) |
| Indio Water Authority | 89,137 | 0 (not detected) |
| Western Mwd | 87,955 | 1.3 ppb |
| Desert Water Agency | 75,588 | 0 (not detected) |
Next steps for Calimesa, CA
Look up your address in South Mesa Wc's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask South Mesa Wc 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. Small systems behave differently: why small systems go over more often.