Forest Lake Alum Treatment

The proposed alum treatment will reduce internal phosphorus loading by 527 lb/yr and ensure Forest Lake remains below the state standard of 40 ?g/L summer average phosphorus concentration. Forest Lake is not listed as impaired for nutrients, but summertime phosphorus readings occasionally exceed state standards, meaning this lake is at great risk of becoming impaired. CLFLWD sets its own goal for Forest Lake to achieve and maintain a summertime average phosphorus concentration of 30 ?g/L (i.e., even lower than the state standard). Out of the 923-lb/yr external/watershed load reduction goal for the lake to achieve this goal, CLFLWD has completed projects achieving 768 lb/yr (83% of external load goal) and has projects in progress to achieve another 128 lb/yr (14% of external load goal). Forest Lake is one of the top recreational lakes in the metro area and the largest lake in Washington County, with a diverse and healthy fishery and 3 public accesses. It is also an important economic asset to the Forest Lake and surrounding communities because of the impact of its tax base and recreational destination for visitors from outside the community. Water quality of Forest Lake impacts downstream waters, particularly Comfort Lake, Sunrise River, and ultimately Lake St. Croix.