Impaired Water - Seven Island Lake (Seven Island Lake)
Lincoln County, Wisconsin
UW30
1490300
134.84
Condition has remained stable; water is not impaired.
Notes
Seven 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.
Listing Details
Pollutant
Mercury
Listed For
Impairments
NA
Current Use
Listing Status
Water Delisted
Attainable Use
Priority
Delisted 2014
Designated Use
303(d) ID
422
Listing Date
4/1/1998
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.
Date
1/16/2014