Hi Kumarasamy, The biofilm ...

Hi Kumarasamy, The biofilm might reduce friction losses and even improve water quality but will most probably cause corrosion in pipelines. Three comments: 1. Mechanical cleaning using “pigging” https://en.wikipedia.org/wiki/Pigging is probably the safest and most efficient way of cleaning the existing biofilm. There is always a risk by flushing chemicals down a line. 2. In large distribution systems it is common to top-up the disinfectant (Cl2) at more than one location to keep satisfactory levels at the end of the network without overdosing at the treatment works or reservoir. 3. Most importantly: Minimise biofouling and reduce disinfection by-products by improving the efficiency of the Treatment Works through better operation and maintenance. Only then look at upgrade options and newer or more appropriate technologies. Regards Stephanus