CHENNAI: Nearly 7.5 crore litres of sewage and sullage are flowing every day through 65 open drains in 18 urban local bodies around Chennai, with most of the wa. Kancheepuram has five drains carrying 13.4 MLD and Avadi has four drains carrying 11.7 MLD discharging in the Cooum.Together, Tambaram, Kancheepuram and Avadi account for 60.1 MLD, or more than 80% of the total sewage and sullage carried through the identified drains.