Williams City Of, AZ
Lead detected, under the action levels
Latest 90th-percentile lead: 8.6 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. 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.
Williams City Of at a glance
Williams City Of serves about 3,145 people through 1,883 service connections, which makes it a small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Coconino County, Arizona. EPA system ID: AZ0403026; phone on file: 928-635-4451. They can tell you what your service line is made of and whether they pay to replace it.
Every lead result on file
That is up 8.6 ppb from 0 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Williams City Of is 8.6 ppb across 7 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 8.6 ppb |
| 2025 | 0 (not detected) |
| 2024 | 0 (not detected) |
| 2023 | 0 (not detected) |
| 2022 | 8.5 ppb |
| 2019 | 2.85 ppb |
| 2016 | 1.3 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. Williams City Of's 8.6 ppb sits at the 96th percentile in Arizona and the 96th nationally (higher means more lead).
Nearby utilities
32 other systems share Coconino County; 0 of them have a higher latest lead result than Williams City Of. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Flagstaff City Of | 79,796 | 3.6 ppb |
| Grand Canyon National Park | 16,590 | 0 (not detected) |
| Arizona Water Co - Sedona | 12,104 | 6 ppb |
| Doney Park Water | 9,222 | 0 (not detected) |
| Arizona Water Co - Pinewood | 8,115 | 0 (not detected) |
| Page City Of | 7,445 | 0 (not detected) |
| Kachina Village Dwid | 3,500 | 0 (not detected) |
| Blue Ridge Dwid | 1,920 | 0 (not detected) |
| Forest Lakes Water Improvement District | 1,746 | 5.9 ppb |
| Utility Source Llc | 1,710 | 0 (not detected) |
Your move
Test your own tap with a certified lab first-draw sample; Williams, 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 Williams City Of 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. The action level is dropping - the 10 ppb rule from 2027.