Ann Arbor, MI
Lead detected, under the action levels
Latest 90th-percentile lead: 2.3 ppb (monitoring period 2021-2023). 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
Ann Arbor serves about 123,851 people through 26,050 service connections, which makes it a very large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Washtenaw County, Michigan. EPA system ID: MI0000220; phone on file: 734-794-6000. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Lead results over time
That is up 1.3 ppb from 1 ppb in the period ending 2020. The highest 90th-percentile result EPA holds for Ann Arbor is 3 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 2.3 ppb |
| 2020 | 1 ppb |
| 2017 | 3 ppb |
Against other Michigan systems
Of the 1,227 Michigan systems with a lead result, the median latest reading is 1 ppb; 31 are over 15 ppb right now and 109 have gone over at some point. Ann Arbor's 2.3 ppb sits at the 70th percentile in Michigan and the 76th nationally (higher means more lead).
Nearby utilities
30 other systems share Washtenaw County; 10 of them have a higher latest lead result than Ann Arbor. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Ypsilanti Community Utility Authority | 53,988 | 4.1 ppb |
| Pittsfield Township | 24,500 | 0 (not detected) |
| Saline | 9,158 | 0 (not detected) |
| Scio Township | 8,500 | 0 (not detected) |
| Milan | 7,363 | 5.1 ppb |
| Superior Township | 6,830 | 0 (not detected) |
| Chelsea | 5,474 | 0 (not detected) |
| Dexter | 4,500 | 0 (not detected) |
| Augusta Township | 3,907 | 0 (not detected) |
| Manchester | 2,150 | 4.9 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Ann Arbor, MI 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 Ann Arbor 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. Why sampled homes are the worst-case ones is in the guide to reading the number. Size matters more than most people expect: small vs large water systems.