Predicting Reservoir and Riverine Algal Blooms

• Cooper Reilly, Environmental Science, University of Delaware

• Pinki Mondal, Environmental Science, University of Delaware

A local reservoir sought to monitor algae and nutrient concentrations of idle river water in their retention pools being treated for human consumption at a nearby water treatment facility, attempting to reduce the frequency and volume of chemical treatments that maintain potable algae levels. The deployment of two data loggers at the entrance and exit of the retention pools gave an indication of how rapidly algae reproduced and spawned as the river water moved through the retention pool, along with the seasonal impact on this rate. Attached to these data loggers were three sensors that recorded four values: chlorophyll fluorescence, dissolved oxygen concentration, conductivity, and water temperature. These sensors were positioned into the center of the reservoir and suspended approximately twenty centimeters into the water column to sample a mixture of benthic and photic algae, and these sensors were cleaned twice weekly. Along with sensor monitoring and maintenance, grab samples were taken from the entrance, exit, and also directly from the source river every week, and tested for nutrient concentration, in-vivo chlorophyll, alkalinity, and chlorophyll concentration. Chlorophyll fluorescence levels were placed into an exponential growth program in order to predict optimal chemical timing and volume and shared with the water treatment organization in order to maximize effectiveness and efficiency. Findings from this research seek to benefit public health, reduce maintenance costs, and answer questions pertaining to riverine algae accumulation and dispersion through freshwater ecosystems.