Identify Impaired Waters
On 5 and 6 October 2010 sediment cores were collected from lakes Sissabagama, Spirit, and North Spirit with a gravity corer. The diatom communities indicate that phosphorus concentrations in all the lakes are higher now than they were historically.
Monitor Targeted Area
Monitoring will be done to determine if there are controllable TP sources and whether the lake should be added to the 303d list. Monitoring and evaluation includes: 1. Analyze existing in-lake and cranberry bog discharge data. Evaluate the significance of internal TP loading. Develop a TP model for the lake. 2. Examine surficial and pre-development sediment samples to compare current and pre-development conditions. Paul Garrison has said he is willing to collect and analyze the samples. 3. Collect TP samples at 1 watershed stream on 5 dates. Flow estimates, and D.O. , temp. and pH measurements will also be made. 4. Collect TP samples from 10 residential wells to evaluate groundwater TP concentrations.
Monitor or Propose 303(d) Listing
Sissabagama Lake: 2393500, Unnamed stream: 5004138. Sissabagama Lake (Sawyer Co.) has an average total phosphorus concentration of 25 ug/l which exceeds the WisCALM threshold of 20 ug/l for a seepage lake for 303d listing. It is not known whether there are controllable TP sources in the lake's watershed. Monitoring will be done to determine if there are controllable TP sources and whether the lake should be added to the 303d list.