WASTEWATER TREATMENT SYSTEMS FOR SMALL SITES IN SARAWAK

The discharge of untreated or inadequately treated wastewater will impose heavy loads on the capacity of the receiving water body, endangering public health and the surrounding environment. For Sarawak, this is crucial as most of its source of water supply comes from rivers. The predominant domestic wastewater treatment system in Sarawak is primary treatment of municipal sewage (blackwater), accomplished with individual septic tanks (ISTs). There are also a handful of small, centralized wastewater treatment facilities for small sites. Effective alternative wastewater treatment systems need to be explored to improve wastewater management. In this study, examples of sustainable wastewater treatment systems from a variety of sites and situations will be presented and discussed. In addition, various existing methods used for both domestic and commercial wastewater treatment in Sarawak are presented. The principle treatment processes for each method are briefly discussed, and benefits for the system are presented. Furthermore, there is a need for a study on centralized wastewater treatment facilities for small, commercial or institutional sites, such as a University, or other institution of higher learning. The wastewater generation patterns for such sites may be different from the expected characteristics for domestic wastewater generation. The Intermittent Decanted Extended Aeration (IDEA) Activated Sludge System used in Curtin University Sarawak Campus, Miri is investigated and the viability and sustainability of the system to be adopted for other institutions of higher learning or campuses in Malaysia is discussed. Furthermore, to characterise wastewater generation for a commercial site, the wastewater production and generation pattern in Curtin University Sarawak Campus is studied. The main finding from this study is that diurnal wastewater generation patterns for commercial sites are different from diurnal domestic generation patterns. The overall wastewater production during the semester break is significantly less than during teaching weeks, and is comparable to wastewater production during the weekends of the teaching weeks. The main factors that influence the wastewater variations in an institution of higher learning is the size of the population and the activities carried out in the institution, including seasonal activities. The data collected from the wastewater quantification study could be used as a useful reference data for other similar institutions of higher learning, in choosing a viable and sustainable wastewater treatment system.