Provision is made for the construction of a secondary sewerage network of 11178 m length 10396 m gravitational network 782 m network of twin depressive ducts of 2 pumping stations as well as 250 external branches of private connections with it in order to drain the area of Kallithea of the Municipality of Penteli, which currently lacks a sewerage network. 6 internal network and 7 in the transmission network and 2480 external branches in the areas of Kapandriti Afidnon Polydendri and Mikrochori of the Municipality of Oropos