Guideline on sanitary landfill at Amphoe Si Racha Changwat Chon Buri

Sanitary landfill area at Amphoe Si Racha include in the study area of ground-water system about 30 km that is lying between the grids 1456N to 1456N and 713E to 718E show the undulated land form and gradually slopes down to the coast, shallow granite basement underlies the sandy soil surface. The ground water level around the project site during the dry season is about 2 m from ground surface and only 0.5 m during the rainy season. The ground water flows in the west and southwest direction past the landfill site then reaching Ban Nong Kham. Currently solid waste is brouhgt from Si Racha and Laem Chabang district municipalities and dumped over this landfill site and it is burnt without proper control or any prevention of environmental quality. It was found that the water quality in those shallow wells of the communities around the site has its BOD, turbidity and total hardness of 2.5-8 mg/l, 2.5-28.5 NTU and 30-204 mg/l respectively, and also acidulous. All these are quite beyond drinking water standard. Currently this site were contaminated by solid waste exposing. The community to be worst affected is Ban Nong Kham. The saturated hydraulic conductivity of sand and clayey sand of weathering granite are 2.58x10** (-6) and 3.22x10** (-4) cm/sec respectively, which are moderately high and high. It can be concluded that the proposed area is not suitable for sanitary landfill site due to the shallow ground water level. In case that no selected site, a guideline to prevent ground water contamination can be done by trenching and dike construction, then compact the floor with clayey sand of weathering granite. The thickness of compacted layers are at least 50 cm with a density of 95 % of maximum dry density. The saturated hydraulic conductivity of compacted soil is approximately 10** (-8) cm/sec or about 0.08 l/m2/day. Control of leachate water in the excavated cells can be done by designing the floor to have a slope of 1-2 % so that the leachate water may infiltrate into the main duct carring it to the wastewater treatment system.