Improving Public Health Protection

摘要

Even though the switch by a number of utilities from chlorine to chloram-ines seems like a recent phenomenon, chloramination has actually been practiced by water utilities for more than 90 years. As much as 16% of US utilities were using chloramination by the mid-1930s. The main reason for the decline in popularity of this form of disinfection revolved around two key events: (1) the discovery of breakpoint chlorination and (2) a shortage of ammonia supplies during World War II. Some utilities, however-such as Denver Water-never stopped using chloramination. (Denver has been chloraminating its drinking water for more than 90 years.) Recently reduced maximum contaminant levels (MCLs) for disinfection by-products have spurred a resurgence in interest in chloramination, and many utilities have switched or are planning to switch to this form of disinfection.