SURVEY OF RESIDUAL ALUMINUM IN FILTERED WATER.

Abstract

This article reports results of a survey of water utilities in the United States that use alum as a coagulant and have measured the concentration of total aluminum (Al) in their filtered water. Survey results suggest that effective removal of particulate matter minimizes residual Al levels, especially when raw water contains elevated concentrations of total Al. Results further indicate that lime used for pH adjustment following filtration may be an important source of residual Al.