Arizona State University Researchers Conclude Monitoring Offers Early Warning System
Yarmouth, ME, USA: A new study documents a correlation between cyanobacteria levels in source water and taste and odor events in drinking water. Conducted by a team of researchers from Arizona State University School of Life Sciences, Tempe, Ariz., the study found that the level of blue-green algae affected the concentration of 2-methylisoborneol (MIB), the compound frequently associated with taste and odor events, and concluded that these events may be averted or minimized by monitoring reservoirs, lakes, rivers and other source water bodies for changes in the population density of filamentous cyanobacteria. Funded by the American Water Works Association (AWWA) Technical and Education Council and sponsored by its Water Quality and Technology Division (WQTD) Taste and Odor Committee, the researchers analyzed water sampled from 11 different locations in the Salt River watershed and the Phoenix metropolitan canal system over a two-month period using both the automated FlowCAM® particle imaging and analysis instrumentation and manual, epifluorescence microscopy. Comparing particle counts from both types of instrumentation from each location in a time-series, the study concluded that peak algal bloom conditions can act as a pre-cursor for taste and odor events and determined that the FlowCAM may be used as an early warning system to trigger the implementation of preventative treatment plans.
In comparing the manual and automated technologies, the report stated the FlowCAM produced approximate cell counts in 10-30 minutes depending on the sample volume while permitting identification of multiple algal species vs. at least an hour or more required for microscopy. The FlowCAM's ability to be operated largely unattended by staffers with minimal training and to archive each digital image for further analysis were also cited as key advantages in the report. The FlowCAM automatically takes hi-resolution, digital images of individual particles and microscopic organisms, measures each one based on dozens of measurement parameters and saves the images and data for identification, analysis and collaborative review. The Massachussetts Water Resources Authority (MWRA), U.S. EPA and U.S.
Navy currently rely on the FlowCAM for water quality analysis. The final report may be downloaded free at http://www.awwa.org/files/Resources/TECProjects/TECStudyAlgaeTO2009.pdf