Big Rock C.S.D., CA
Lead reported as not detected
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 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Who runs the water here
Big Rock C.S.D. serves about 513 people through 117 service connections, which makes it a small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Del Norte County, California. EPA system ID: CA0800532; phone on file: 707-954-5509. They can tell you what your service line is made of and whether they pay to replace it.
Every lead result on file
That is down 1.75 ppb from 1.75 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for Big Rock C.S.D. is 1.75 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2022 | 1.75 ppb |
| 2016 | 1.1 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. Big Rock C.S.D.'s reported as 0 (not detected) sits at the 37th percentile in California and the 23rd nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Nearby utilities
15 other systems share Del Norte County; 11 of them have a higher latest lead result than Big Rock C.S.D.. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| City Of Crescent City | 15,202 | 3.01 ppb |
| Bertsch Ocean View Csd | 2,669 | 0 (not detected) |
| Smith River C.S.D. | 2,568 | 4.05 ppb |
| Gasquet C.S.D. | 657 | 0.74 ppb |
| Northcrest Mobile Home Park | 250 | 1.18 ppb |
| Klamath C.S.D. | 240 | 5.7 ppb |
| Redwood Park C.S.D. | 200 | 4.2 ppb |
| Hrc C.S.D. | 185 | 3.35 ppb |
| Pine Grove Mobile Home Park | 142 | 0 (not detected) |
| Las Palmas Mobile Home Park | 120 | 0 (not detected) |
Next steps for Crescent City, CA
Look up your address in Big Rock C.S.D.'s service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Big Rock C.S.D. 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. Small systems behave differently: why small systems go over more often.