Platteville Waterworks, WI
Above the new 10 ppb level coming in 2027
Latest 90th-percentile lead: 10.3 ppb (monitoring period 2025-2025). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. Under the current 15 ppb rule this is not an exceedance, but it is above the 10 ppb action level that takes over in Nov 2027. Test your own tap; filter if your result shows lead.
Who runs the water here
Platteville Waterworks serves about 12,268 people through 3,601 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Grant County, Wisconsin. EPA system ID: WI1220115. Ask the utility on your bill for your address in their service line inventory.
Platteville Waterworks's lead record
That is up 5.65 ppb from 4.65 ppb in the period ending 2024. The highest 90th-percentile result EPA holds for Platteville Waterworks is 12.2 ppb across 5 monitoring periods, none of them over 15 ppb (3 over 10 ppb).
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 10.3 ppb over 10 |
| 2024 | 4.65 ppb |
| 2023 | 12.2 ppb over 10 |
| 2020 | 10.7 ppb over 10 |
| 2017 | 9.1 ppb |
Where this result ranks
Of the 947 Wisconsin systems with a lead result, the median latest reading is 1.33 ppb; 6 are over 15 ppb right now and 71 have gone over at some point. Platteville Waterworks's 10.3 ppb sits at the 97th percentile in Wisconsin and the 97th nationally (higher means more lead).
Nearby utilities
27 other systems share Grant County; 0 of them have a higher latest lead result than Platteville Waterworks. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Lancaster Waterworks | 3,907 | 1.8 ppb |
| Boscobel Waterworks | 3,237 | 1.1 ppb |
| Fennimore Waterworks | 2,507 | 1.61 ppb |
| Cuba City Waterworks | 2,141 | 0 (not detected) |
| Muscoda Waterworks | 1,453 | 2.64 ppb |
| Hazel Green Waterworks | 1,193 | 2.83 ppb |
| Dickeyville Waterworks | 1,069 | 0 (not detected) |
| Cassville Waterworks | 777 | 3.24 ppb |
| Montfort Waterworks | 718 | 1.1 ppb |
| Potosi Waterworks | 718 | 1.72 ppb |
Next steps for Platteville, WI
Test your own tap with a certified lab first-draw sample; Platteville, WI 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 Platteville Waterworks 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. This system is in the band the 2027 10 ppb rule changes.