Stonebridge Mutual Water Co, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 0.6 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.
About Stonebridge Mutual Water Co
Stonebridge Mutual Water Co serves about 38 people through 15 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Santa Clara County, California. EPA system ID: CA4300787; phone on file: 408-515-9205. They can tell you what your service line is made of and whether they pay to replace it.
Stonebridge Mutual Water Co's lead record
The highest 90th-percentile result EPA holds for Stonebridge Mutual Water Co is 0.6 ppb across 1 monitoring period, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0.6 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. Stonebridge Mutual Water Co's 0.6 ppb sits at the 65th percentile in California and the 44th nationally (higher means more lead).
Neighbouring systems
72 other systems share Santa Clara County; 25 of them have a higher latest lead result than Stonebridge Mutual Water Co. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| San Jose Water | 1,039,920 | 0 (not detected) |
| City Of Sunnyvale | 157,566 | 0 (not detected) |
| City Of Santa Clara | 134,587 | 2.7 ppb |
| Great Oaks Wc Inc | 112,582 | 0 (not detected) |
| City Of San Jose - Evg/Edv/Coy | 99,783 | 0 (not detected) |
| City Of Milpitas | 81,915 | 2.5 ppb |
| City Of Mountain View | 81,340 | 0 (not detected) |
| City Of Palo Alto | 67,658 | 0 (not detected) |
| Cwsc Los Altos Suburban | 63,559 | 1.5 ppb |
| City Of Gilroy | 59,426 | 2 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Morgan Hill, 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 Stonebridge Mutual Water Co 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. Size matters more than most people expect: small vs large water systems.