Hess Winery, CA
Exceeded the action level in the past
Latest 90th-percentile lead: 7 ppb (monitoring period 2026-2026). 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.
About Hess Winery
Hess Winery serves about 100 people through 5 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: CA2801016; phone on file: 707-320-9155. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
That is up 7 ppb from 0 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Hess Winery is 16 ppb across 5 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 7 ppb |
| 2025 | 0 (not detected) |
| 2024 | 16 ppb over 15 |
| 2021 | 4.9 ppb |
| 2018 | 0 (not detected) |
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. Hess Winery's 7 ppb sits at the 95th percentile in California and the 95th nationally (higher means more lead).
Nearby utilities
27 other systems share Napa County; 4 of them have a higher latest lead result than Hess Winery. 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) |
What to do in your house
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 Hess Winery whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 3450 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. The lead result guide covers how utilities pick the homes they sample. Why an old exceedance still matters: over the limit before, under it now.