Septic tank soakage pit systems have been the common- est form of sewage disposal in urban and suburban Sri Lanka, where only parts of the Capital, Colombo, is served by a central sewer network. Virtually none of the other major cities and towns have any form of central sewer network. Even in Colombo, the coverage remains poor, with an estimated 1.7 million people (approximately 80 per cent of the metropolitan population of Greater Colombo) being dependent on on-site systems for sewage disposal (Fernando, 1994)
COREA, E.J.H. GAMAGE, I.R. WICKRAMANAYAKE, P.N. (1998): Anaerobic Filters for On-Site Sewage Treatment. (= Sanitation and Water for All: Proceedings of the 24th WEDC Conference Islamabad, Pakistan ). Leicestershire: Water, Engineering and Development Centre (WEDC) URL [Accessed: 20.03.2015]