Green Diamond Resource Company - Korbel, CA
Exceeded the action level in the past
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2023-2025). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. The latest result is under the action level, but this system has gone over 15 ppb before. Lead comes from pipes, not the source water, so a home with a lead service line can still be exposed. Test your own tap.
Green Diamond Resource Company - Korbel at a glance
Green Diamond Resource Company - Korbel serves about 250 people through 18 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Humboldt County, California. EPA system ID: CA1200715; phone on file: 707-668-3782. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Green Diamond Resource Company - Korbel's lead record
Against the period ending 2022 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Green Diamond Resource Company - Korbel is 138 ppb across 4 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2016 | 138 ppb over 15 |
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. Green Diamond Resource Company - Korbel's reported as 0 (not detected) sits at the 30th percentile in California and the 17th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in Humboldt County
43 other systems share Humboldt County; 31 of them have a higher latest lead result than Green Diamond Resource Company - Korbel. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Eureka, City Of | 27,078 | 2.3 ppb |
| Humboldt C.S.D. | 19,775 | 2.05 ppb |
| Arcata, City Of | 18,857 | 2.54 ppb |
| Mckinleyville C.S.D. | 16,900 | 1.78 ppb |
| Fortuna, City Of | 12,133 | 1.8 ppb |
| Rio Dell, City Of | 3,300 | 0 (not detected) |
| Garberville Sanitary District | 2,041 | 0 (not detected) |
| Fieldbrook Glendale C.S.D. | 1,845 | 0 (not detected) |
| Willow Creek C.S.D. | 1,720 | 0 (not detected) |
| Del Oro Water Co-Ferndale | 1,662 | 3.5 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Korbel, 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 Green Diamond Resource Company - Korbel 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. More in what a past exceedance means today.