Publisher's Synopsis
Manganese in drinking water is an aesthetic problem, characterized by so-called "black water", laundry spotting, and similar issues. The control of manganese in a water distribution system relates more to reducing consumer complaints than to protecting health. However, consumers often judge drinking water based on its appearance, odor, and color at the tap even if it is safe to consume. The control of manganese is complicated by its complex chemistry. The objective of this project was first to evaluate the occurrence, chemistry, and treatment methods associated with manganese (Mn) in ground and surface waters.
Building upon these findings, a further goal was to study problems associated with manganese in water distribution systems and measure Mn in specific distribution systems. Another objective was to estimate achievable, cost-effective target levels for manganese below the current drinking water advisory standard of 0.05 mg/L. The research team conducted a comprehensive literature review. This review dealt with the regulatory history, health effects, chemistry, and technology associated with Mn. A survey was used to determine the industry's knowledge base as well as obtaining certain occurrence data. This data was a focused set. Certain utilities participated in distribution system sample analysis. These samples were taken along the length of the distribution system, including the near, middle, and far ends. The concentration of Mn was determined and speciation was conducted via filtration. Case studies were performed to test the limits of certain Mn control technology. Finally, a cost model was proposed to help quantify the cost of increased Mn control as compared to the benefit realized by consumer.
