What chlorine concentration in drinking water would be considered excessive?

Chlorine is commonly used in municipal water systems as a disinfectant to kill harmful bacteria, including E. coli, and to ensure that drinking water remains safe. However, there are established guidelines regarding the acceptable levels of chlorine in drinking water to balance effective disinfection and consumer safety.

When considering what constitutes an excessive chlorine concentration in drinking water, it's important to refer to the Environmental Protection Agency (EPA) regulations. The EPA recommends that the residual chlorine levels in drinking water should not exceed 4.0 mg/L (milligrams per liter) for safety reasons. Concentrations above this level can create a variety of health risks and unpleasant side effects, such as water with a strong chemical taste and possible irritations to skin and mucous membranes.

The correct identification of excessive chlorine aligns with the understanding of these safety parameters. Therefore, a designation of "excessive" refers to any concentration that significantly exceeds this limit, posing a threat to health and making the water less palatable.

This understanding connects to the broader context of water quality management, emphasizing the importance of maintaining appropriate chemical levels to ensure both safety and public confidence in drinking water supplies.