Final answer:
Monitoring of the distribution of free and total halogen from a biocide involves determining the chlorine residuals in the water supply by adding greater amounts of chlorine and measuring the remaining compounds.
Step-by-step explanation:
Monitoring of the distribution of free and total halogen from a biocide should be done by adding greater amounts of chlorine to a set of samples taken from the water supply and determining the chlorine residuals. This process helps to understand if the biocide is effectively disinfecting the water by measuring the chlorine that remains after a reaction with the organic matter and microorganisms in the water. To ensure the efficacy and safety of the disinfecting process, it's crucial to monitor not only the total halogens but also the free halogens that are available to react with and neutralize potential pathogens.