Sontel Water Coop, AZ
Lead detected, under the action levels
Latest 90th-percentile lead: 0.33 ppb (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. 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
Sontel Water Coop serves about 80 people through 30 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Maricopa County, Arizona. EPA system ID: AZ0407900; phone on file: 480-773-9632. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Lead results over time
Against the period ending 2020 (0.5 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Sontel Water Coop is 1.1 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0.33 ppb |
| 2020 | 0.5 ppb |
| 2018 | 1.1 ppb |
| 2016 | 0 (not detected) |
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. Sontel Water Coop's 0.33 ppb sits at the 69th percentile in Arizona and the 42nd nationally (higher means more lead).
Neighbouring systems
99 other systems share Maricopa County; 23 of them have a higher latest lead result than Sontel Water Coop. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Phoenix City Of | 1,695,000 | 2.74 ppb |
| Mesa City Of | 466,000 | 5.01 ppb |
| Gilbert, Town Of | 247,600 | 0 (not detected) |
| Chandler City Of | 247,328 | 1.4 ppb |
| Scottsdale City Of | 241,361 | 2.3 ppb |
| Glendale City Of | 234,766 | 2.11 ppb |
| Peoria City Of | 187,676 | 0 (not detected) |
| Tempe City Of | 165,000 | 4.4 ppb |
| Epcor - Agua Fria | 128,040 | 0 (not detected) |
| Avondale City Of | 96,130 | 0 (not detected) |
Next steps for Higley, AZ
Test your own tap with a certified lab first-draw sample; Higley, 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 Sontel Water Coop 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.