Napa River Ranch, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 4.4 ppb (monitoring period 2024-2024). 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.
Napa River Ranch at a glance
Napa River Ranch serves about 70 people through 14 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Napa County, California. EPA system ID: CA2800531; phone on file: 707-333-6596. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Every lead result on file
That is up 4.4 ppb from 0 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for Napa River Ranch is 4.4 ppb across 8 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 4.4 ppb |
| 2022 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2021 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2017 | 0 (not detected) |
| 2016 | 0 (not detected) |
| 2016 | 3.3 ppb |
How Napa River Ranch 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. Napa River Ranch's 4.4 ppb sits at the 91st percentile in California and the 89th nationally (higher means more lead).
Other water systems in Napa County
27 other systems share Napa County; 5 of them have a higher latest lead result than Napa River Ranch. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Napa, City Of | 84,804 | 0 (not detected) |
| American Canyon, City Of | 18,423 | 0 (not detected) |
| Calistoga, City Of | 5,610 | 0 (not detected) |
| St. Helena, City Of | 5,386 | 0 (not detected) |
| Town Of Yountville | 2,785 | 0 (not detected) |
| Howell Mountain Mutual Water Company | 1,244 | 0 (not detected) |
| Veterans Home Of California | 1,000 | 0 (not detected) |
| Pacific Union College | 758 | 7.8 ppb |
| Berryessa Highlands | 715 | 0 (not detected) |
| Adventist Health - St. Helena Hospital | 617 | 0 (not detected) |
Next steps for Napa, CA
Test your own tap with a certified lab first-draw sample; Napa, 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 Napa River Ranch whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 1450 ppb (copper action level 1,300 ppb).
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.