Lincoln County, Wisconsin
Condition has remained stable; water is not impaired.
NotesSeven Island Lake was on the impaired waters list for mercury in fish tissue from 1998 to 2014. New fish tissue data showed mercury levels were below the statewide general consumption advisory. This lake was assessed every two years between 2014 and 2018, and again in 2022; total phosphorus, algae, and aquatic plants showed a healthy system. The lake?s aquatic plant community was evaluated every year from 2011 to 2019 and was consistently in very good condition. This lake is on the Healthy Waters List.
Impaired Water Notes
Correction - should have been delisted in 2012. New data confirms that the statewide advisory is sufficient because mercury concentrations fall in the range of the general advisory so this lake is proposed for delisting.