HAB has downloaded and processed the alum application data from the barge’s guidance and dose control computer system. The coverage and dose map above shows each individual application path that was recorded over the course of the 2019 Cedar Lake application. We are extremely pleased with the precise application and uniform coverage of the two application zones. There are no significant gaps in coverage, which is important to ensure that the sediments received the appropriate alum dose. Gaps in coverage can allow pockets of internal phosphorus loading to the water column and subsequent use by the algae for growth. The comprehensive and complete coverage optimizes the longevity and effectiveness of the lake restoration project.
HAB’s unique application tracking system not only documents the barge’s coverage of the application zones by recording GPS coordinates, but also measures the real-time alum flow rate at each GPS data point. Thus, we are able to document both coverage and the actual alum application rates in various zones. For Cedar, the higher dose rates are shown in green and the lower dose rates are represented in yellow. As intended, the deeper portions of Cedar received a higher dose of alum.