What is the standard and acceptable percentage of chlorine in drinking water?

The standard and acceptable percentage of chlorine in drinking water is typically around 0.2 to 4.0 milligrams per liter (mg/L), which corresponds to 0.00002% to 0.0004%. The U.S. Environmental Protection Agency (EPA) sets a maximum residual disinfectant level (MRDL) of 4.0 mg/L for chlorine to ensure safety while maintaining effective disinfection. It's important to monitor chlorine levels to balance safety and taste in drinking water.