ABSTRACT
This is probably one of the easiest to sample in that spigots and faucets on the distribution lines can be used to collect the samples. However, drinking water distribution lines have residual chlorine present within the system. It is important that this disinfectant residual be removed especially when virus sampling is conducted. Sodium thiosulfate is often used to remove residual chlorine. Faucets and spigots within the distribution system (as well as in groundwater wells) may harbor microbial populations within them as biofilms. Even though it is impossible to remove the biofilm within distribution lines, attention must be paid to remove as many indigenous microbial populations from the sampling spigot (faucet) as possible. Heat surface sterilization (using flame or torch) or chemical disinfections can be used. It is critical that the water is allowed to run for at least 10-15min after these treatments.
