Studi Tingkat Pencemaran Air Tanah Dangkal Berdasarkan Kontaminan Total Coliform, Ammonia (NH3N), dan Bod Dari Tangki Septik Masyarakat di Kecamatan Medan Helvetia, Kota Medan

Abstract

Water is one of the basic needs because humans carry out the functions of life that depend on water. About three-quarters of our body consists of water, no one can survive without drinking water for more than 4-5 days. The limited availability of clean water that has not been treated has become one of the problems in the implementation of clean water services in Indonesia, especially in rural areas, the distribution of clean water services is uneven, and the utilization of existing clean water sources is not optimal. Even in some areas, the sources of clean water used by PDAMs are polluted by industrial and household waste, thereby increasing the burden of clean-water management. This study aims to (1) determine the level of vulnerability of shallow groundwater (dug wells) using the Modified APLIS method, (2) determine the actual shallow groundwater pollution (dug wells) using the Pollution Index (IP) method, and (3) knowing the factors that influence the occurrence of pollution by using multiple regression method. Groundwater vulnerability mapping was carried out using the Modified APLIS method with overlay analysis using a geographic information system (GIS). (1) The results of multiple linear regression analysis to show how much influence the distance of the septic tank and the depth of the groundwater table have on NH3N which is indicated by the value of R square = 0.06 (6%), BOD which is shown by the value of R square = 0.002, Total Coliform, which is indicated by the value of R square = 0.04 (4%), PH which is indicated by the value of R square = 0.074 (7%). To find out the actual shallow groundwater pollution, laboratory tests were carried out on the parameters of the BOD (biological oxygen demand), Ammonia (NH3N), and Total Coliform bacteria. (2) The results of the calculation of the Pollution Index value of 53% (23 points) are moderately polluted, 30% (12 points) are lightly polluted, and 12% (5 points) meet the quality standards.