Malaysia's most common form of sewerage system is the invidual septic tank (IST). There are an estimated 1.2 million premise with individual septic tanks in the country. An IST comprises two chambers connected in series. In the first chamber, solids from the incoming sewage settle forming a "sludge", while greases and oils float to the surface forming a "scum" layer. Effluent from between the scum and sludge layers then passes into the second chamber where further sedimentation occurs. Presently, prefabricated ISTs are made from fibreglass, a mixture of glass fibre and unsaturated polYester. Currently the production cost is about RM800 with the price increasing with the increase in oil palm industry are produced in large quantities in Malaysia, approximately more than 10 millions tonnes per annum. Subtituting the glass fibres with natural fibres reduces the cost to RM400.