Golden State Water Co.-Clearlake System, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 4.1 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.
About Golden State Water Co.-Clearlake System
Golden State Water Co.-Clearlake System serves about 4,623 people through 2,118 service connections, which makes it a medium-sized system under EPA's size classes. It is privately owned and draws surface water, in Lake County, California. EPA system ID: CA1710002; phone on file: 916-853-3632. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Golden State Water Co.-Clearlake System's lead record
That is up 4.1 ppb from 0 ppb in the period ending 2023. The highest 90th-percentile result EPA holds for Golden State Water Co.-Clearlake System is 4.1 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 4.1 ppb |
| 2023 | 0 (not detected) |
| 2020 | 3.9 ppb |
| 2017 | 0 (not detected) |
How Golden State Water Co.-Clearlake System 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. Golden State Water Co.-Clearlake System's 4.1 ppb sits at the 90th percentile in California and the 88th nationally (higher means more lead).
Nearby utilities
41 other systems share Lake County; 6 of them have a higher latest lead result than Golden State Water Co.-Clearlake System. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Highlands Mutual Water Company | 7,772 | 0 (not detected) |
| Hidden Valley Lake Csd | 6,235 | 0 (not detected) |
| Konocti County Water District | 5,928 | 0 (not detected) |
| Lakeport, City Of | 4,762 | 0 (not detected) |
| Mt. Konocti Mutual Water Company | 4,360 | 0 (not detected) |
| Kelseyville Co Waterworks District 3 | 4,102 | 5.2 ppb |
| Lake County Csa 21 - North Lakeport | 4,046 | 0 (not detected) |
| Cobb Area County Water District | 3,515 | 0 (not detected) |
| Nice Mutual Water Company | 2,929 | 0 (not detected) |
| Clearlake Oaks County Water District | 2,359 | 0 (not detected) |
Next steps for Rancho Cordova, CA
Test your own tap with a certified lab first-draw sample; Rancho Cordova, 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 Golden State Water Co.-Clearlake System 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. The action level is dropping - the 10 ppb rule from 2027.