Diagnosis of contaminated areas by final disposal of solid waste in the municipality of Paço do Lumiar (MA), Brazil

ABSTRACT The final disposal of solid waste is considered a potential source of contamination and has been highlighted due to the environmental problems and socioeconomic factors that it can generate. The municipality of Paço do Lumiar, Maranhão, uses a garbage dump as a way of disposing urban solid waste, even after the deadline for the end of dumps in Brazil, as established by the National Solid Waste Policy, Federal Law No. 12,305, dated August 2, 2010. As a result, the objective of this study was to detect areas contaminated by disposal of solid waste in Paço do Lumiar, based on the Workshop Management of Contaminated Areas’ methodology, a part of the project CETESB/GTZ (1999), using the environmental compartments soil and surface water as objects of analysis. Thus, it was found that the garbage dump has contributed to the contamination of soil with heavy metals in the place of provision and 200m to its downstream, which can mean potential contamination of ground water due to the local geology and the fact that sandy soil facilitates the process of transporting contaminants. The analysis of the surface water revealed that the disposal of solid waste can contribute less than other sources of contamination, highlighting in this context those generated by the communities that occupy the basin. Therefore, as the verified contamination compromises some land uses (residential and agricultural), further studies may contemplate the remediation process of these contaminated areas according to the CTESB/GTZ (1999) material for stablishing measures to minimize this region’s environmental impacts.

摘要 固体废物最终处置被视为潜在污染源，其引发的环境问题与社会经济因素使其备受关注。巴西马拉尼昂州（Maranhão）的卢米亚尔帕苏市（Paço do Lumiar）虽已依据2010年8月2日颁布的《国家固体废物政策》（National Solid Waste Policy，联邦法律第12305号（Federal Law No. 12,305））设定了垃圾填埋场的关停时限，但仍采用露天垃圾场处置城市固体废物。有鉴于此，本研究以受污染场地管理工作坊（Workshop Management of Contaminated Areas）方法——该方法为CETESB/GTZ（1999）项目的组成部分——为依托，以土壤与地表水两类环境介质为分析对象，旨在检测卢米亚尔帕苏市内因固体废物处置造成污染的区域。研究结果显示，该垃圾场已对其处置场地及下游200米范围内的土壤造成重金属污染；结合当地地质条件与砂土易迁移污染物的特性，该区域存在地下水受潜在污染的风险。地表水分析结果表明，固体废物处置对地表水的污染贡献低于其他污染源，本研究重点关注流域内居住社区产生的污染。综上，经证实的污染已对住宅与农业等部分土地利用类型造成损害，后续研究可参照CETESB/GTZ（1999）的相关指南开展污染场地修复工作，制定措施以最大限度降低该区域的环境影响。