Early Warning Systems for Algae-induced Tastes and Odors

The reservoirs in central Arizona are a major water supply system for the Phoenix metropolitan area. These reservoirs are fed by a combination of the Salt River water shed, the Verde River water shed, and Central Arizona Project water transported by a canal system from the Colorado River.  In addition to water storage and hydropower, the lakes also have a great recreational value, including boating and fishing. But fish mortality has been a recurrent problem in the Salt River Lakes and blooms of algae known to release toxins, such as the chrysophyte Prymnesium parvum (Golden Alga), as well as cyanobacteria (e.g., Cylindrospermopsis) that have been linked to these fish kills are found at high abundances in the AZ reservoirs.  Some of these nuisance algal species, particularly the cyanobacteria, are also known to be responsible for taste and odor issues, which can significantly impact customer satisfaction and reduce customer confidence in the quality of the water supply. Additionally, algal biomass makes a significant contribution to the particle loading of the water column, increasing the total suspended matter (total organic matter + sediments) loading.  These increased particle loadings can prove problematic for city water treatment plants.  Therefore the ability to remotely monitor the reservoirs for the presence of algal biomass, in particular those species known to be responsible for taste and odor problems, has the potential for providing advance warning of both environmental and water processing issues.

This AWWA (American Water Works Association) sponsored project is intended to test the ability of some of the new technology that is now available to identify the presence of taste and odor causing organisms.  We are using a FlowCAM® digital analyzer to process samples collected from the Salt River in order to monitor which species are present during taste and odor events.  We hope to correlate these species types with high levels of measured MIB (Methyl Isoborneol) and Geosmin.

This project ran until the end of 2009. Click here to see the full report.