Harmful algal blooms create problems for water management partially due to the release of taste and odor compounds associated with the die-off of cyanobacteria blooms. Residents are negatively impacted as the compounds remain in the water after treatment and create a foul odor and taste in drinking water. Because cyanobacteria blooms are associated with higher temperatures, this issue is expected to worsen as climate change advances. Phoenix, Arizona, is located in the southwestern United States. Water from reservoirs and rivers are diverted to treatment plants via a system of canals before reaching residents. The taste and odor compounds MIB and geosmin have been identified in Phoenix canals, and local utility services deal with complaints as a result. We will present a water quality analysis of a 20-yr data set of data comparing cyanobacteria abundance, temperature, and taste and odor compounds at 22 different sites along canals in the Phoenix metro area. These data are collected and made publicly available through the Central Arizona-Phoenix Long-Term Ecological Research Drinking Water Quality Monitoring Program. The mean concentrations of MIB and geosmin were 12.3 ng/L and 4.6 ng/L, respectively, in Phoenix canal waterways where filamentous cyanobacteria can reach up to 1900 particles/ml during hot summer months. Understanding how seasonal changes in temperature can influence the release of taste and odor compounds that result from cyanobacteria blooms is important for future freshwater resource management.
