Providing reliable supply of safe drinking water poses challenges

Abstract

Chlorination of drinking water has eradicated most waterborne disease epidemics. However, small water-supply systems struggle to maintain water quality and aging water-distribution systems are prone to contamination. By the year 2025, California's projected population of 48 million will demand between 1 trillion and 5 trillion gallons per year. Municipal demands clearly will exceed the currently available supply of tap water, forcing conservation and reuse. Future regulations are expected to focus on the quality of the water flowing from the user's tap, rather than the quality exiting the water-treatment facility. As little as 16% of the water treated and conforming to drinking-water health standards is likely to come into direct contact with humans, such as for bathing and drinking. Development of dual water-distribution systems would separate water destined for human consumption from that destined for firefighting, toilet flushing and other domestic uses. As industry manufactures new compounds for drugs, antibiotics, household products and so on, water treatment must be modified to remove or neutralize these new contaminants. Monitoring for new and chlorine-resistant pathogens is also needed.