Sierra East Hoa, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 1 ppb (monitoring period 2025-2027). 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 Sierra East Hoa
Sierra East Hoa serves about 84 people through 30 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Mono County, California. EPA system ID: CA2600622; phone on file: 530-208-6408. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
That is down 1.1 ppb from 2.1 ppb in the period ending 2026. The highest 90th-percentile result EPA holds for Sierra East Hoa is 5 ppb across 6 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2027 | 1 ppb |
| 2026 | 2.1 ppb |
| 2020 | 4.4 ppb |
| 2019 | 2 ppb |
| 2018 | 4.6 ppb |
| 2017 | 5 ppb |
Where this result ranks
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. Sierra East Hoa's 1 ppb sits at the 70th percentile in California and the 51st nationally (higher means more lead).
Neighbouring systems
17 other systems share Mono County; 11 of them have a higher latest lead result than Sierra East Hoa. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Mammoth Cwd | 8,234 | 1.5 ppb |
| Mountain Meadows Mwc | 525 | 4.4 ppb |
| Usmc - Housing Coleville | 424 | 1.3 ppb |
| Bridgeport Pud | 374 | 1.9 ppb |
| Lower Rock Creek Mutual Water Co. | 310 | 0 (not detected) |
| June Lake Pud - Down Canyon | 310 | 2 ppb |
| Usmc/Mtn Warfare Trng Ctr - Bridgeport | 300 | 1 ppb |
| June Lake Pud Village | 263 | 2.7 ppb |
| Crowley Lake Trailer Park | 230 | 9.4 ppb |
| Lee Vining Public Utility District | 222 | 8 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Coleville, 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 Sierra East Hoa 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. Size matters more than most people expect: small vs large water systems.