Granular Activated Carbon (GAC) is a type of filtration media that can remove certain types of impurities from water. One of the impurities that GAC can remove is chlorine, which can be used as a disinfectant in water treatment plants. Chlorine can cause taste and odor issues in water, and GAC can effectively remove it.
As for chloroform bacteria, it can be removed by GAC but to a limited extent, as GAC is not a sterilization method and it's not designed to remove microorganisms like bacteria, viruses and cysts. GAC is more effective in removing dissolved organic compounds and chlorine by-products. If the water source is suspected to be contaminated with bacteria or other microorganisms, it's important to use additional methods such as UV sterilization, Reverse Osmosis or Microfiltration along with GAC.
It's important to note that regular maintenance of the GAC filter is necessary to ensure it continues to function properly and to prevent any bacterial growth in the filter.