Blue Lake to Receive Alum Treatment this September 2022
The dates have been selected for the Alum Treatment on Blue Lake! The Isanti SWCD has been working to protect the health of Blue Lake. An alum treatment has been selected as the next most logical and cost-effective way to protect it.
The alum treatment will take place from September 12th to the 16th. Both Blue Lake Public Boat Launches will be shut down during the application on the 13th, 14th, and 15th to ensure the application will work as effectively as possible. Residents are also advised to avoid boating on Blue Lake during these dates. Parking will be limited at the Stanford Public Boat Launch on the 12th and the 16th due to the alum equipment set up. If you are planning to use the boat accesses on these days, please consider making other plans. As soon as the application is over, people may resume using the lake as normal!
Diagnostics taken on Blue Lake indicate it is at risk of becoming an impaired water body due to an excess of phosphorus in the lake, which fuels algae blooms. The Isanti SWCD is taking steps to reduce the amount of phosphorus in Blue Lake and assure it does not become impaired. Multiple conservation projects in the area surrounding the lake have already been completed by the Isanti SWCD however, these projects are not enough. Studies on Blue Lake indicate an alum treatment is the best next step to protect the lake.
Alum is a safe and widely studied option for lake treatments to reduce the amount of phosphorus present in the water. It works by forming a fluffy aluminum hydroxide solid called a floc when applied to water. As the floc settles, it removes phosphorus and particulates (including algae) from the water column. Therefore, after the treatment, the water should be noticeably clearer! The floc settles on the sediment where it forms a layer that acts as a blanket for phosphorus, so phosphorus released from the sediments cannot enter the water. The alum treatment will achieve 164% of the phosphorus reduction goal the Isanti SWCD set to keep Blue Lake Healthy!
The Isanti SWCD secured a Clean Water Fund Grant to pay for the alum treatment. The treatment also would not be possible without the Blue Lake Improvement District, which is providing a necessary 25% grant match and has been working with the Isanti SWCD to make this a reality. The first treatment is happening this September and a second treatment will be done in 2024. Regular updates are available on www.isantiswcd.org as well as answers to frequently asked questions.