Assessment of individual septic tank effluent quality in Kota Bharu

Abstract

Wastewater is water whose physical, chemical or biological properties have been changed as a result of the introduction of certain substances which render it unsafe for some purposes such as drinking. . Disposal of domestic sewage and industrial effluents into the environment without proper treatment process is a major contributor to deterioration in water quality. Currently, less than 10 percent of the 1.3 million individual septic tanks in Malaysia were emptied. All tanks should be emptied every two years according to the size of the tank and the size of the household to avoid polluting the environment and water sources.This study is intended to identify the premises that carried out the desludging individual septic tank, to check the quality of water effluent from desludged and non-desludged individual septic tank according to the following parameters Biochemical Oxygen Demand (BOD5), Total Suspended Solids (TSS) and Ammoniacal Nitrogen (NH3), to compare the effluent quality from desludging and non-desludging septic tank and also to discuss sustainability management and sewage treatment systems at Kota Bharu, in addition to discussing problems and related issues. The total number of desludged individual septic tank in Kota Bharu still low compared to total number of septic tank. The percentage in 2017 is 2.1%, 2018 is 2.1% and 2019 is 2.2%. The increment only 0.1% shows that the awareness of Kota Bharu residents is still low. Based on the results of laboratory tests performed, the content of three parameters tested from individual septic tanks that have emptied the tank, which is Biological Oxygen Demand (BOD), Total Suspended Solid (TSS) and Ammoniacal Nitrogen (NH3), it is found that the content of the content is below the standard level A and B stated in environmental quality (sewage) regulation 2009 except Total Suspended Solid (TSS) content. The content of Total Suspended Solid (TSS) for D-2 and D-3 premises is still below standard B, only the content for D-1 premises is quite high at 139 mg / L above standards A (50 mg / L) and B (100 mg / L). The Total Suspended Solid (TSS) content in the D-1 premises is quite high as the owner of the permit combines a sink and shower system with a toilet sewage system. Premises D-2 and D-3 use separate systems. Overall, the effluent quality of desludged individual septic tanks is better and safer for the environment.