Mercer Sanitary District, WI
Lead detected, under the action levels
Latest 90th-percentile lead: 3.6 ppb (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. 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.
About Mercer Sanitary District
Mercer Sanitary District serves about 760 people through 384 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 groundwater, in Iron County, Wisconsin. EPA system ID: WI8260120. Ask the utility on your bill for your address in their service line inventory.
Lead results over time
Against the period ending 2020 (3.2 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Mercer Sanitary District is 4.1 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 3.6 ppb |
| 2020 | 3.2 ppb |
| 2017 | 4.1 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. Mercer Sanitary District's 3.6 ppb sits at the 81st percentile in Wisconsin and the 86th nationally (higher means more lead).
Other water systems in Iron County
4 other systems share Iron County; 1 of them has a higher latest lead result than Mercer Sanitary District. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Hurley Waterworks | 1,515 | 0.31 ppb |
| Montreal Waterworks | 887 | 2.2 ppb |
| Iron Belt Waterworks | 211 | 2.8 ppb |
| Pence Waterworks | 191 | 4.25 ppb |
Next steps for Mercer, WI
Test your own tap with a certified lab first-draw sample; Mercer, 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 Mercer Sanitary District 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. Size matters more than most people expect: small vs large water systems.