St David Dwid, AZ
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
St David Dwid at a glance
St David Dwid serves about 2,192 people through 548 service connections, which makes it a small system under EPA's size classes. It is privately owned and draws groundwater, in Cochise County, Arizona. EPA system ID: AZ0402039; phone on file: 520-720-4467. 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 2022 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for St David Dwid is 1.1 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2016 | 1.1 ppb |
Where this result ranks
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. St David Dwid's reported as 0 (not detected) sits at the 51st percentile in Arizona and the 31st nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Nearby utilities
49 other systems share Cochise County; 18 of them have a higher latest lead result than St David Dwid. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Bella Vista City Water System | 20,045 | 0 (not detected) |
| Douglas City Of | 16,656 | 0 (not detected) |
| Us Army Fort Huachuca | 15,603 | 0 (not detected) |
| Pueblo Del Sol Water Company | 12,804 | 0 (not detected) |
| Arizona Water Co - Sierra Vista | 9,233 | 0 (not detected) |
| Arizona Water Co - Bisbee | 8,590 | 0 (not detected) |
| Benson, City Of Water System | 5,355 | 0 (not detected) |
| City Of Willcox | 3,236 | 0 (not detected) |
| Bella Vista Water South | 2,178 | 0 (not detected) |
| East Slope Water Company | 2,012 | 0 (not detected) |
Next steps for Saint David, AZ
Look up your address in St David Dwid's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask St David Dwid 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. A zero today does not rule out a jump later - the rules are tightening in 2027.