Assessment of landfill final covers employing contaminated soils

被污染的土壤再利用的选择有限，注定要被填埋。目前的法规允许轻度污染的土壤在最终覆盖物中的任何地方重新用于填埋，而中度污染的土壤的使用受到更多限制。虽然在以前的研究中，我们已经发现，径流从实验最终覆盖含有中度污染不构成直接的环境问题，长期污染物的垂直和水平运输这些土壤周围的环境需要进行调查，如果中度污染的土壤被列入最终覆盖。 该研究项目建议将2018年在St-Nicephore垃圾填埋场建造的五个全仪器化实验盖退役。该项目提供了一个独特的机会，以系统的方法挖掘土壤，以便：（1）在整个实验覆盖层中建立污染物分布图;（2）确定现场土壤特性，用于通过垃圾填埋场覆盖层进行渗漏的计算机模拟。将进行实验室实验，以便：（1）确定非饱和土壤的特性，评估实验覆盖层的变化，并将数值与最初的施工数值进行比较;（2）评估污染物的长期迁移模式。这些实验室和现场结果将用于渗流和污染物迁移的计算机模拟。 该项目的预期成果是重新评估关于再利用受污染土壤作为垃圾填埋场最终覆盖物的现行规定。预期的好处是：（1）减少填埋的土壤;（2）减少开采清洁土壤用于填埋场。 该项目是与WM魁北克合作的成果。污染土壤的使用为公司提供了一个独特的商业机会，也很可能为残留物行业可持续管理的所有利益相关者提供了机会。因此，这对加拿大来说是一个不可否认的环境和经济收益。

Contaminated soils have limited options for re-use and are destined to be landfilled. Current regulations allow for lightly contaminated soils to be reused anywhere in final cover for landfills, with the use of moderately contaminated soils being more restricted. Although in a previous study we have found that run-off from experimental final covers containing moderately contaminated do not pose an immediate environmental concern, long-term contaminant vertical and horizontal transport of these soils to the surrounding environment needs to be investigated if moderately contaminated soils are to be included in final covers. This research project proposes to decommission five fully instrumented experimental covers that were constructed at the St-Nicephore landfill in 2018. This project provides the unique opportunity to exhume soil in a methodical approach to: (1) develop a contaminant profile throughout the experimental covers; and (2) establish the soil characteristics in-situ to be used in computer modelling of seepage through landfill covers. Laboratory experiments will be performed to: (1) develop unsaturated soil characteristics and assess changes in the experimental cover and compare values to initial construction values; and (2) assess long-term contaminant transport patterns. These laboratory and field results will be used in computer modelling of seepage and contaminant transport. The expected outcomes of the project are to re-evaluate the existing regulations for re-utilisation of contaminated soils for final cover in landfills. Expected benefits are: (1) reduction of soil landfilled; and (2) decrease of quarrying clean soil for use at landfill sites. This project is a collaborative effort with WM Quebec. The use of contaminated soils constitutes a unique business opportunity for the company and most likely for all stakeholders in the sustainable management of residual materials industry. As a result, it is an undeniable environmental and economic gain for Canada.