My father (RIP) was a chemical engineer and very knowledgeable about chlorine safety, having been the safety officer at a chemical plant that made Freon and other industrial chemicals that required chlorine as a feed stock, and authored international shipping regulations re chlorine. He said if you could smell just a hint of chlorine in drinking water, you did not have to be concerned about pathogens in the water and a little bit was not harmful. I know, that is a very general statement and doesn't indicate what a safe level would be in a measurable sense.

Personally, I drink and cook with distilled water to avoid ingesting chlorine and fluoride.