AWWA JAW69266

Changes in water treatment processes not only affect primary objectives but also bring about secondary benefits or detriments. This article examines the types of secondary (and possibly unintended) effects that can be triggered by implementation of various column treatment technologies for arsenic removal. To meet the new arsenic standards, many small utilities may select strong-base anion exchange, activated alumina, or granular ferric hydroxide/granular ferric oxide media because of their lower capital cost. However, these technologies can result in lead dissolution from brass fittings and solder, higher levels of iron corrosion, and an increase in copper pitting of plumbing. When making their decisions about which process to implement for arsenic removal, water providers should consider the secondary effects of implementing certain treatment processes. For those utilities that already have these treatment processes in place, this study will enable them to be proactive in checking for possible corrosion problems in the distribution system or in consumers' homes. Includes 95 references, tables, figures.