Oakhill Correctional Inst, WI
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2023-2023). 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.
Who runs the water here
Oakhill Correctional Inst serves about 1,096 people through 405 service connections, which makes it a small system under EPA's size classes. It is owned by the state and draws groundwater, in Dane County, Wisconsin. EPA system ID: WI1130250. Ask the utility on your bill for your address in their service line inventory.
Every lead result on file
That is down 6 ppb from 6 ppb in the period ending 2020. The highest 90th-percentile result EPA holds for Oakhill Correctional Inst is 6 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 0 (not detected) |
| 2020 | 6 ppb |
| 2017 | 1.45 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. Oakhill Correctional Inst's reported as 0 (not detected) sits at the 14th percentile in Wisconsin and the 27th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in Dane County
42 other systems share Dane County; 39 of them have a higher latest lead result than Oakhill Correctional Inst. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Madison Water Utility | 272,000 | 1.8 ppb |
| Sun Prairie Utilities | 39,300 | 2.8 ppb |
| Fitchburg Utility Dist 1 | 29,900 | 2.3 ppb |
| Middleton Waterworks | 23,868 | 4 ppb |
| Waunakee Waterworks | 14,879 | 1.7 ppb |
| Verona Waterworks | 14,030 | 2.86 ppb |
| Stoughton Waterworks | 13,078 | 4.2 ppb |
| Oregon Waterworks | 11,200 | 4.97 ppb |
| Deforest Waterworks | 10,500 | 5.95 ppb |
| Mcfarland Waterworks | 9,676 | 2.1 ppb |
What to do in your house
Look up your address in Oakhill Correctional Inst'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 Oakhill Correctional Inst 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. Small systems behave differently: why small systems go over more often.