What Is the Safe Level of Chlorine in Drinking Water?

Up to 98 percent of water treatment facilities in the United States use some form of chlorination process to clean their drinking water supply. Chlorine was first used in Jersey City, New Jersey in 1908 in an effort to reduce waterborne infectious disease.

Acceptable Chlorine to Water Ratio

• The United States Environmental Protection Agency (EPA) sets the regulation standard for drinking water throughout the country. According to the EPA, the acceptable ratio of chlorine to water is four parts chlorine per million of water.

Concerns About Chlorine

• Concerns regarding chlorine levels in drinking water surround long-term exposure to the chemical and its potential to cause cancer. The EPA claims that the risk associated with exposure to regulation amounts of chlorine present in drinking water are minute and that the benefits outweigh the risk.

What It Does

• Chlorine is a chemical disinfectant that is added to the drinking water supply to kill bacteria, germs, parasites and viruses that can make people sick. It is administered either in liquid or tablet form.