Rancho Pauma Mutual Wc, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 1.3 ppb (monitoring period 2026-2026). 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.
Rancho Pauma Mutual Wc at a glance
Rancho Pauma Mutual Wc serves about 899 people through 387 service connections, which makes it a small system under EPA's size classes. It is privately owned and draws groundwater, in San Diego County, California. EPA system ID: CA3710012; phone on file: 760-615-4050. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Rancho Pauma Mutual Wc's lead record
Against the period ending 2025 (1.6 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Rancho Pauma Mutual Wc is 7.4 ppb across 11 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 1.3 ppb |
| 2025 | 1.6 ppb |
| 2025 | 0 (not detected) |
| 2024 | 1.9 ppb |
| 2024 | 1.2 ppb |
| 2023 | 1.3 ppb |
| 2023 | 2.9 ppb |
| 2022 | 0.75 ppb |
| 2022 | 7.4 ppb |
| 2019 | 0 (not detected) |
| 2018 | 0 (not detected) |
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. Rancho Pauma Mutual Wc's 1.3 ppb sits at the 73rd percentile in California and the 60th nationally (higher means more lead).
Neighbouring systems
80 other systems share San Diego County; 16 of them have a higher latest lead result than Rancho Pauma Mutual Wc. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| San Diego, City Of | 1,408,937 | 0 (not detected) |
| Helix Water District | 277,918 | 0 (not detected) |
| Otay Water District | 242,155 | 0 (not detected) |
| Sweetwater Authority | 184,915 | 0 (not detected) |
| Oceanside, City Of | 174,340 | 0 (not detected) |
| Escondido, City Of | 137,044 | 1.1 ppb |
| Vista Irrigation District | 134,501 | 0 (not detected) |
| Vallecitos Wd | 114,700 | 0 (not detected) |
| Cal-Am Water Coronado | 106,000 | 2 ppb |
| Carlsbad Mwd | 96,371 | 0 (not detected) |
Next steps for Pauma Valley, CA
Test your own tap with a certified lab first-draw sample; Pauma Valley, 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 Rancho Pauma Mutual Wc whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 1600 ppb (copper action level 1,300 ppb).
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.