City Of Grass Valley, CA
Lead detected, under the action levels
Latest 90th-percentile lead: 0.88 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.
Who runs the water here
City Of Grass Valley serves about 4,947 people through 2,733 service connections, which makes it a medium-sized system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Nevada County, California. EPA system ID: CA2910001; phone on file: 530-274-4371. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
City Of Grass Valley's lead record
Against the period ending 2025 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for City Of Grass Valley is 14 ppb across 5 monitoring periods, none of them over 15 ppb (1 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0.88 ppb |
| 2025 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2020 | 0 (not detected) |
| 2018 | 14 ppb over 10 |
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. City Of Grass Valley's 0.88 ppb sits at the 68th percentile in California and the 49th nationally (higher means more lead).
Other water systems in Nevada County
20 other systems share Nevada County; 7 of them have a higher latest lead result than City Of Grass Valley. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Truckee-Donner Pud, Main | 36,730 | 3.9 ppb |
| Nevada Id - E. George, Banner Mountain | 17,154 | 0 (not detected) |
| Nevada Id - Loma Rica | 14,072 | 0.77 ppb |
| Nevada Id - Lake Wildwood | 9,108 | 0 (not detected) |
| Nevada Id - Lake Of Pines | 6,870 | 0 (not detected) |
| City Of Nevada City | 3,148 | 0 (not detected) |
| Washington Water District | 330 | 41.4 ppb |
| Creekside Village | 300 | 0 (not detected) |
| Ananda Village | 226 | 0 (not detected) |
| Rough & Ready Village | 154 | 5.63 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Grass Valley, 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 City Of Grass Valley 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. The lead result guide covers how utilities pick the homes they sample. The action level is dropping - the 10 ppb rule from 2027.