AWWA JAW60865

Concern has been growing in recent years about the quality and reliability of water treatment chemicals. These uncertainties have been perpetuated by contamination incidents that received significant public attention, and they continue as emerging contamination issues arise. This article describes a comprehensive national investigation of trace contaminants in water treatment chemicals. Before this research was conducted, it was not known if problems associated with contaminants in water treatment chemicals were widespread or limited to isolated events. This project was intended to answer this basic question using the best available information across the United States and beyond and to develop practical recommendations for utilities and the industry as a whole about how to identify, limit, and prevent contamination of treatment chemicals to improve plant operations, lower treatment costs, and protect public health. In general, no pervasive problems with trace contaminants in US water treatment chemicals were found in this research, but when incidents do occur, the most commonly identified problems were transport-related, typically the result of improperly cleaned or maintained delivery vehicles and transfer hoses. Treatment chemicals were found to be of high quality, and trace contaminant composition was lower than indicated in the few previous studies that are available. This study showed that contamination incidents may be largely averted when utilities develop and implement inspection and evaluation programs for incoming chemical deliveries at their facilities. These programs result in more opportunities to identify, reject, and arrange replacement shipment for contaminated treatment chemicals before they are used at a facility and before they can affect finished water or residuals quality. Includes 20 references, tables, figures.