Water Quality & Health Council - Facts About Chlorine and Drinking Water

If left untreated, drinking water supplies (primarily from surface water sources) will cause waterborne diseases such as cholera, typhoid and dysentery. The cholera epidemic in Latin America presents a clear example of the constant threat from waterborne disease.

"The cholera epidemic in Latin America was fostered, at least in part, by the misconception that DBPs pose a greater risk to public health than pathogens. The epidemic which began in January 1991 and has now spread to all but one Latin American country, has caused 1.3 million illnesses and almost 12,000 deaths." Horst Otterstetter, Pan American Health Organization and Gunther Craun, Journal AWWA Sept. 1997

In developing countries, where nearly half the population drinks contaminated water, diarrheal diseases kill over 3 million children annually.

Chlorination has played a critical role in protecting America's drinking water supply from waterborne diseases for nearly a century. According to the World Health Organization, the adoption of drinking water chlorination has been one of the most significant advances in public health protection.

Over 98 percent of U.S. water supply systems that disinfect drinking water use chlorine. In the US we have depended on chlorine as our drinking water disinfectant for nearly a century. Public health officials heralded water chlorination as one of the greatest public health achievements of this century.

Chlorine-based disinfectants are the only disinfectants that provide lasting residual protection to protect the water from waterborne disease throughout the distribution system from treatment plant to the consumer's tap. Alternatives to chlorination for primary disinfection such as ozone or ultraviolet light can not provide this residual protection. All chemical disinfectants produce byproducts. Chlorination byproducts have been well studied compared to the byproducts of alternatives which are just beginning to be studied.

According to the World Health Organization "disinfection by chlorine is still the best guarantee of microbiologically safe water."

New Regulations Will Reduce Disinfection Byproducts Without Compromising Microbial Protection

The US Environmental Protection Agency (EPA) is in the final stages of adding regulations that will reduce disinfection byproducts without causing waterborne diseases such as cholera [Stage I of the Disinfectants and Disinfection Byproducts Rule]. This rule was developed by the EPA with the broad support of environmentalists, water utilities, and chlorine producers. It will be finalized in November 1998.

The new rule will require water utilities to use a process called enhanced coagulation to remove organic material from the water. Organic matter, in combination with any disinfectants, produces disinfection byproducts. This rule will significantly reduce disinfection byproduct levels while allowing utilities to continue to use disinfectants, such as chlorine, to kill bacteria and other disease causing microbes.