Sonoita Valley (South) Water Company, AZ
Lead detected, under the action levels
Latest 90th-percentile lead: 8 ppb (monitoring period 2022-2024). 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.
About Sonoita Valley (South) Water Company
Sonoita Valley (South) Water Company serves about 172 people through 62 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Santa Cruz County, Arizona. EPA system ID: AZ0412005; phone on file: 520-624-1460. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Sonoita Valley (South) Water Company's lead record
That is up 8 ppb from 0 ppb in the period ending 2021. The highest 90th-percentile result EPA holds for Sonoita Valley (South) Water Company is 8 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 8 ppb |
| 2021 | 0 (not detected) |
| 2018 | 2.4 ppb |
Against other Arizona systems
Of the 730 Arizona systems with a lead result, the median latest reading is 0 ppb; 9 are over 15 ppb right now and 58 have gone over at some point. Sonoita Valley (South) Water Company's 8 ppb sits at the 95th percentile in Arizona and the 96th nationally (higher means more lead).
Nearby utilities
15 other systems share Santa Cruz County; 0 of them have a higher latest lead result than Sonoita Valley (South) Water Company. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Nogales City Of | 22,000 | 0 (not detected) |
| Liberty Water Rio Rico | 17,960 | 0 (not detected) |
| Valle Verde Water Company - East | 2,397 | 0 (not detected) |
| Epcor - Tubac | 2,076 | 0 (not detected) |
| Baca Float Water Company | 1,162 | 0 (not detected) |
| Patagonia Water Department | 819 | 0 (not detected) |
| Town & Country - Preston | 430 | 0 (not detected) |
| Kino Ranch 2 | 173 | 0 (not detected) |
| The Grand Acres | 153 | 0 (not detected) |
| Avalon Gardens Water System | 100 | 0 (not detected) |
Your move
Test your own tap with a certified lab first-draw sample; Laveen, AZ 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 Sonoita Valley (South) Water Company 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. Systems that went over once often dip back under; here is what that means.