Markesan Waterworks, WI
Lead detected, under the action levels
Latest 90th-percentile lead: 7.1 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.
Markesan Waterworks at a glance
Markesan Waterworks serves about 1,365 people through 505 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 Green Lake County, Wisconsin. EPA system ID: WI4240218. Ask the utility on your bill for your address in their service line inventory.
Markesan Waterworks's lead record
That is up 3.8 ppb from 3.3 ppb in the period ending 2020. The highest 90th-percentile result EPA holds for Markesan Waterworks is 7.1 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 7.1 ppb |
| 2020 | 3.3 ppb |
| 2017 | 2.3 ppb |
How Markesan 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. Markesan Waterworks's 7.1 ppb sits at the 94th percentile in Wisconsin and the 95th nationally (higher means more lead).
Neighbouring systems
4 other systems share Green Lake County; 0 of them have a higher latest lead result than Markesan Waterworks. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Berlin Waterworks | 5,524 | 0.55 ppb |
| Princeton Waterworks | 1,166 | 1.1 ppb |
| Green Lake Waterworks | 1,002 | 1.1 ppb |
| Lamplighter Mhc Llc | 80 | 1.75 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Markesan, 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 Markesan 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. Systems that went over once often dip back under; here is what that means.