Los Madrones Mwc, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 5.4 ppb (monitoring period 2024-2026). 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.
Los Madrones Mwc at a glance
Los Madrones Mwc serves about 39 people through 14 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in San Benito County, California. EPA system ID: CA3500578; phone on file: 408-483-0857. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Los Madrones Mwc's lead record
That is down 7.2 ppb from 12.6 ppb in the period ending 2023. The highest 90th-percentile result EPA holds for Los Madrones Mwc is 12.6 ppb across 4 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 5.4 ppb |
| 2023 | 12.6 ppb over 10 |
| 2020 | 5.1 ppb |
| 2017 | 5 ppb |
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. Los Madrones Mwc's 5.4 ppb sits at the 92nd percentile in California and the 92nd nationally (higher means more lead).
Nearby utilities
30 other systems share San Benito County; 2 of them have a higher latest lead result than Los Madrones Mwc. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Hollister, City Of | 26,598 | 1.4 ppb |
| Sunnyslope County Water Dist | 25,486 | 0 (not detected) |
| Aromas Water District | 2,988 | 1.4 ppb |
| San Juan Bautista, City Of | 2,335 | 0 (not detected) |
| Mission Oaks Mobile Home Park | 550 | 0 (not detected) |
| Tres Pinos Cwd | 350 | 0 (not detected) |
| Golden State Water Co - San Juan Oaks | 260 | 0 (not detected) |
| Csa No. 31 Stonegate Ws | 230 | 0.7 ppb |
| San Justo Mutual Water Company | 166 | 0 (not detected) |
| Hollister Ranch Estates | 150 | 0 (not detected) |
What to do in your house
Test your own tap with a certified lab first-draw sample; San Juan Bautista, 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 Los Madrones Mwc 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.