At higher concentrations, causes undesirable tastes in beverages. As with iron, its presence in water may lead to the accumulation of microbial growths in the distribution system. Some copper occurs naturally, however, much of it may come from the plumbing system due to the corrosive tendencies of water with low pH and low alkalinity. High zinc levels can cause undesirable taste and a greasy film on boiling water. Much of the zinc in tap water may come from the plumbing system.
Alkalinity is a measure of the buffered condition of water.
Low alkalinity may cause water to be corrosive. No guidelines have been established for alkalinity. An acceptable pH range for drinking water is from 6.5 to 8.5. Corrosion effects may become significant below 6.5, and the frequency of incrustation and scaling problems may be increased above pH 8.5. High pH levels decrease the efficiency of chlorine disinfection processes.