Comparison of Groundwater Quality Status at Active and Inactive Landfill in Selangor, Malaysia
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International Journal of Civil Engineering and Technology (IJCIET) Volume 9, Issue 7, July 2018, pp. 1896–1902, Article ID: IJCIET_09_07_200 Available online at http://iaeme.com/Home/issue/IJCIET?Volume=9&Issue=7 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 © IAEME Publication Scopus Indexed COMPARISON OF GROUNDWATER QUALITY STATUS AT ACTIVE AND INACTIVE LANDFILL IN SELANGOR, MALAYSIA M.H. Ahmad Faculty of Civil Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia J. Jani Faculty of Civil Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia ABSTRACT Landfills and dumping are one of the method for managing solid waste disposal activities in Malaysia and frequently shown as potential sources of groundwater pollution. However, groundwater pollution in the past has not been identified as key environmental issue in Malaysia since only a few cases of environmental and human health incidences have been reported. In our country, there are a lot of landfills which already in-active and active. Both active and in-active landfills still generate leachate. The most significant pollutant that need to be consider in both landfills are leachate contaminants. The objective of this study is to compare the groundwater quality status between active and inactive landfill sites. Tanjung Dua Belas Sanitary Landfill (TDBSL) is an active landfill, whereas Air Hitam Landfill Park (AHLP) is inactive landfill. The groundwater flow direction at TDBSL was from North East to the South West, whereas the groundwater in AHLP is flowing from East to West South West. The groundwater at TDBSL have exceeded the provided benchmark of Raw Drinking Water Quality Guideline in terms of high in NH3-N, TDS, COD, DO, BOD5, TSS, NO2ˉ and NO3ˉ. The heavy metals concentration (descending concentration) at TDBSL landfill are Zn > Pb > Mn > Cu > Fe > Cd > Ni. The sample had been contaminated by Fe, Mn, Pb and Cd. In contrast to the sample at AHLP, the heavy metals concentration in the groundwater sample are Fe > Zn > Mn > Cd > Pb > Ni. The groundwater sample at AHLP had been contaminated by Fe, Mn, Pb and also Cd but the contamination is not due to the leachate in the landfill. Key words: landfill, groundwater quality, leachate, groundwater flow direction. Cite this Article: M.H. Ahmad and J. Jani, Comparison of Groundwater Quality Status at Active and Inactive Landfill in Selangor, Malaysia. International Journal of Civil Engineering and Technology, 9(7), 2018, pp. 1896-1902. http://iaeme.com/Home/issue/IJCIET?Volume=9&Issue=7 http://iaeme.com/Home/journal/IJCIET 1896 [email protected] M.H. Ahmad and J. Jani 1. INTRODUCTION Landfills and dumping are one of the method for managing solid waste disposal activities in Malaysia. Groundwater contamination is one of the most serious environmental risks, especially around areas with an industrial history. However, landfills are frequently shown as potential sources of groundwater pollution. Therefore, landfill needs continuous monitoring of the area and surroundings, even after closure of landfills. Sanitary landfilling is presently well-known and being worldwide used due to its low budget and economic advantage. However, leachate from the sanitary landfill can be main cause of pollution to both surface and ground water system. Leachate is an origin of contamination as it can leave the landfill site if it is unlined or if the lining fails and have leakage. Leachate is a highly contaminated liquid that produced in the landfill, it generates during the decaying or biodegradation process, when precipitation (rain water) percolates or leached through the ground surface and subsurface and flows out of the landfill. A large amount of hazardous compounds facing an environmental risk have previously been identified in the landfill leachates. According to [7], landfills can be classified into five levels, which is known as: Level 0 , where there is just an open dumping without any controlled tipping, Level 1, where there is controlled tipping of the open dump, Level 2, where there is a sanitary landfill with a bund and daily soil cover, Level 3, where sanitary landfill with leachate recirculation system only, and lastly, Level 4, where it is a fully engineered sanitary landfill with full leachate treatment facilities and gas monitoring. As most of the landfills were built after year 1989, it also subjected to the Environmental Impact Assessment requirements. Hence, it must be fairly managed and were convenient and excellently sited. In this study, there are two different category of landfill which are operated and non-operated landfills will be investigated on the current groundwater quality study. Legislation is one of the ground rules which are significant in managing groundwater and surface water contamination. These standard and regulations are mandatory to all of the Environmental Practitioner and Environmental Organisation to ensure surface water and groundwater quality in a good condition and safe to be consumed by public. In details, this study focused on comparing groundwater quality status between active and in-active landfills which involved the physical-chemical parameters and heavy metals with respect to the standard and regulation provided by Malaysian Government agencies (i.e., Ministry of Health and Department of Environment). 1.1. Leachate as a Source of Pollution Municipal solid waste (MSW) has also been considered as one of the most serious environmental challenges in many cities in the world [7]. Sanitary landfills have been constructed to manage solid wastes in most countries [6]. Although solid waste management provides benefits, this approach also produces leachates [1]. Leachate is the liquid that leaches from a landfill that is piled with solid wastes. It varies widely in composition depending on the age of the landfill and the type of waste that being dumped in the landfill. It usually contains both dissolved and suspended material. In fact, the term “leachate” is so often applied to landfill leachate, both within the waste management industry and outside, that it is easy to forget that leachate is the term used for any liquid produced by the action of leaching. Leaching occurs when water percolates through any permeable material. Chemicals can leach into the groundwater by means of precipitation and surface runoff over the landfill. New landfills are required to equip with clay or synthetic liners and proper leachate collection systems to shield groundwater from any contamination. However, the most older landfills do not have this kind of safety features. Old landfills were often constructed http://iaeme.com/Home/journal/IJCIET 1897 [email protected] Comparison of Groundwater Quality Status at Active and Inactive Landfill in Selangor, Malaysia over aquifers or closed to surface waters and in permeable soils with shallow water tables, which will encourage the potential for leachate to contaminate ground water. Inactive landfills can continue to face a groundwater pollution threat if they are not capped with an impermeable material before closure to prohibit the percolation of contaminants by precipitation [4]. Based on the study made by [3], leachate is one of the main root cause of groundwater and surface water contamination if it is not properly collected, rehabilitated and safely disposed as it may leached through soil reaching the aquifers below the ground. Furthermore, [2] had reported that the subsequent migration of leachate away from landfill boundaries and the release to the adjacent environment is a serious environmental concern and a threat to public health and safety. Leachate often contains high concentrations of various pollutants namely organic matter and inorganic ions including heavy metals. Therefore, this study was conducted to evaluate and compare the groundwater quality between active and in- active landfill sites 2. STUDY AREA: ACTIVE AND INACTIVE LANDFILL The study area for groundwater sampling consist of active and inactive landfill site in Selangor. Tanjung Dua Belas Sanitary Landfill (TDBSL) is located at Lot 12194, 12195 and 12196 Mukim Tg. Dua Belas, Kuala Langat which is 9km to the west of Kuala Lumpur International Airport (Figure 1). This active sanitary landfill had been operated by Worldwide Holdings Berhad (WHB) Environment since 2010 and it operated to take over the end of concession period of Sungai Sedu Sanitary Landfill. This landfill had been active for almost 9 years since it first commencement on 1st January 2010 and the landfill have a concession of 25 years under the State Government of Selangor. The area of the sanitary landfill is about 160 acres equipped with full level 4 sanitary landfill facilities. Figure 1 Location of the landfill sites. The second landfill site is Air Hitam Worldwide Landfill Park (AHLP). AHLP is located at Air Hitam Forest Reserve in Mukim Petaling, Daerah Petaling, Puchong, Selangor (Figure1). Under the same operator, this sanitary landfill had already being closed for almost 12 years but still undergoing Landfill Closure and Post Closure Maintenance Activity. It is also considered as the first level 4 sanitary landfill where the facilities such as Waste Reception Area (Site office, Weighbridge office, Weighbridge), Leachate Treatment Plant, Waste Cell and 2MW Landfill Gas Power Plant equipped). It has been operated for almost 11 http://iaeme.com/Home/journal/IJCIET 1898 [email protected] M.H. Ahmad and J. Jani years since 1st of April 1995 until 31st December 2006. The contract is actually for 20 years design lifespan. However, there are rapid human settlement around the area force it to close 9 years earlier. 2.1. Hydrogeological Description The TDBSL landfill is located on top of the peaty alluvial deposit consisting mainly of peat and clayey-silt (<20%), clayey-silt (50 – 70%) and sands (<20%). This site is more peaty to clayey-silt near the ground surface but more clayey-silt below 5 m depth to sandy in the deeper layers (>21 m), representing the shallow confined aquifer. Based on the borehole logging data, a clayey-silt layer forms the top 5 m to 21 m of the alluvium.