Which of the following is NOT a typical chlorine byproduct?

Hydrochloric acid is not a typical chlorine byproduct formed during water chlorination processes. Chlorine is commonly used in water treatment for disinfection, and while it can react with organic compounds and other substances in water, leading to various byproducts, hydrochloric acid is not among those commonly associated with chlorination.

Chloroform and dichloroacetic acid are both part of a group of disinfection byproducts known as trihalomethanes (THMs), which occur when chlorine reacts with natural organic matter in water. Bromates are another disinfection byproduct that can form when ozone, another disinfectant, is combined with bromide present in the source water. Hydrochloric acid, on the other hand, is produced as a product of the reaction between chlorine and inorganic materials but is not identified as a disinfection byproduct resulting from the treatment process involving organic compounds. Thus, it stands apart from the other options listed, making it the correct answer.