Shallow Long Lake (273 ac surface area) has exhibited excessive summer cyanobacterial blooms and poor water quality (WQ) conditions (high phosphorus and chlorophyll concentrations and low water clarity) linked to internal phosphorus (P) recycling from sediments (James & Clemens 2017). A total aluminum sulfate (alum) dosage of ~ 105 g/m2 split into lower concentrations and spread out over 2-3-year intervals was recommended to control internal P loading. The first alum dosage of 60 g/m2 was applied to sediments located within the 15-ft depth contour of the lake on 11-13 June 2018.

CHLOROPHYLL A, FLUORESCENCE (WELSCHMAYER 1994) (99717), PHOSPHATE ORTHO AS PO4 (660), and PHOSPHORUS TOTAL (665) data

The Long Lake P&R District is sponsoring an alum treatment monitoring project for Long Lake. The final deliverables include all data collected and a final report. Specific project tasks include: 1) In-Lake water quality monitoring; 2) Collection of sediment cores; 3) Lab analyses of sediments to determine phosphorus release and alum-phosphorus binding effectiveness.