Rock Springs Waterworks, WI
Lead detected, under the action levels
Latest 90th-percentile lead: 0.82 ppb (monitoring period 2024-2024). 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.
Rock Springs Waterworks at a glance
Rock Springs Waterworks serves about 292 people through 108 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Sauk County, Wisconsin. EPA system ID: WI1570104. Ask the utility on your bill for your address in their service line inventory.
Rock Springs Waterworks's lead record
Against the period ending 2024 (0.87 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Rock Springs Waterworks is 4.55 ppb across 7 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2024 | 0.82 ppb |
| 2024 | 0.87 ppb |
| 2020 | 2.45 ppb |
| 2019 | 4.55 ppb |
| 2018 | 3 ppb |
| 2018 | 2.7 ppb |
| 2017 | 3.5 ppb |
How Rock Springs Waterworks compares
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. Rock Springs Waterworks's 0.82 ppb sits at the 35th percentile in Wisconsin and the 48th nationally (higher means more lead).
Nearby utilities
22 other systems share Sauk County; 12 of them have a higher latest lead result than Rock Springs Waterworks. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Baraboo Waterworks | 12,703 | 8.1 ppb |
| Reedsburg Waterworks | 9,984 | 0 (not detected) |
| Prairie Du Sac Waterworks | 4,006 | 5.3 ppb |
| Sauk City Waterworks | 3,518 | 6.4 ppb |
| Lake Delton Waterworks | 2,914 | 1.1 ppb |
| Spring Green Waterworks | 1,626 | 3.7 ppb |
| West Baraboo Waterworks | 1,414 | 0.66 ppb |
| Plain Waterworks | 792 | 2.7 ppb |
| North Freedom Waterworks | 589 | 2.4 ppb |
| Bluffview Sanitary District | 450 | 0.46 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Rock Springs, 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 Rock Springs Waterworks whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 1970 ppb (copper action level 1,300 ppb).
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. Systems that went over once often dip back under; here is what that means.