AWWA RSP64397

This paper focuses on the current state of industry knowledge regarding the accumulation and potential release of regulated inorganic and radiological contaminants within drinking water distribution systems. Several limited-focus case studies have shown that certain contaminants, such as arsenic and radium, can accumulate within distribution systems by a variety of mechanisms. Natural and treatment analogs suggest the potential for other contaminants to accumulate as well. These contaminant-rich deposits can then be mobilized into the bulk water by hydraulic disturbances, scale destabilization, and/or re-equilibration due to changing water chemistry. Investigation of this issue has become a high priority for the U.S. Environmental Protection Agency (USEPA) and the industry because of the potential for elevated contaminant concentrations at customer taps and potential public health ramifications. As such, AwwaRF and USEPA have co-funded a research project entitled "Assessment of Inorganics Accumulation in Drinking Water System Scales and Sediments" (AwwaRF 3118) to build upon the water industry's limited understanding of the fate and transport of regulated inorganics and radionuclides within the distribution system. Includes 20 references, tables, figure.