ABSTRACT
This chapter attempts to document the sources and measurements of tastes and odors in drinking water. A flavor threshold number is determined from the greatest dilution of sample with a reference water that yields a definitely perceptible difference. The Flavor Rating Assessment is employed to estimate the acceptability of finished water for daily consumption. The Metropolitan Water District of Southern California adopted a sensory technique—the flavor-profile analysis method—from the food industry. Many tastes and odors in drinking waters arise from various organic compounds reacting as individual molecules or reacting in an additive, synergistic, or antagonistic manner. Surface water supplies, especially those contained in reservoirs, frequently have a taste and odor problem due to such biological sources as actinomycetes and algae. Actinomycetes are filamentous bacteria, and not fungi as their name implies. Their filaments branch as they grow, which serves to distinguish them from other bacteria.
