The alum treatment on Spring Lake was completed at the end of last week on May 14. There were a few wind delays, but the project went smoothly was completed over the course of 11 days. With the help of their barge and the computerized application system, HAB applied 249,000 gallons of alum precisely and uniformly on Spring Lake.

This was the third part of three doses planned for Spring Lake; the previous alum treatments were completed in 2013 and 2018.  Phosphorus in Spring Lake has decreased by 48% since the first treatment in 2013.

We’re looking forward to enjoying a cleaner lake!

Find more information on the alum treatments in the District on the project page of our website and the Spring Lake alum treatment website.

Over the weekend the alum treatment on Spring Lake moved past the halfway mark. Several windy days did slow progress over the weekend but the treatment is still on track!

Check out the full project update and learn more about the treatment’s precise alum dosing on the alum project website. 

The alum is applied using precise dosing with the help of computer aboard the barge which tell the pumps how much alum to dispense where on the lake. The alum is injected into the lake 2-3 feet under the surface of the water to maximize treatment effectiveness and the GPS on the barge ensures that there are no gaps in coverage on the lake.

Miss the first project update? Check out the summary of mobilization and the first three days of treatment here. This included assembly of the barge’s application boom, launching the barge into the lake, setting up on-shore storage tanks, confirming the delivery plan for the alum and calibrating the barge computer system for application.

For more information on the alum treatment project for Spring Lake and Upper Prior Lake, visit the alum page on the District’s website here.