In 2012 the PLSLWD contracted with Barr Engineering to study the concentration of phosphorus in the sediment of Spring Lake. They took samples all over the lake, looked at the chemistry of phosphorus, and determined how much aluminum sulfate (alum) would be required to reduce about 90% of the internal phosphorus loading in the lake (45% of the total phosphorus loading).
Barr Engineering took multiple sediment samples in summer of 2012 from the bed of Spring Lake.
Alum has been used in a wide variety of lakes across the US, and specifically in the upper Midwest. The Wisconsin DNR has information about alum applications, including how effective and safe they are.
Now the Barr study is wrapping up with a comparison of Spring Lake to other lakes in the upper Midwest that have been dosed with alum. Please join the Prior Lake-Spring Lake Watershed District (PLSLWD) Board of Managers for a public informational meeting at 6:00 PM on April 30, 2013 at the Council Chambers in Prior Lake City Hall. Greg Wilson from Barr will present the results to the public in an open format, and answer questions people may have.
The PLSLWD recently sent out a postcard to the residents of Spring Lake inviting them to the meeting on April 30. Tell all your friends! We hope to see you there.