Site-specific aftercare completion criteria for sustainable landfilling in the Netherlands : Geochemical modelling and sensitivity analysis
Dijkstra, Joris J. ; Zomeren, André van; Brand, Ellen ; Comans, Rob N.J. - \ 2018
Waste Management 75 (2018). - ISSN 0956-053X - p. 407 - 414.
Aftercare completion - Environmental protection criteria - Geochemical modelling - Risk assessment - Sensitivity analysis - Sustainable landfill management
A novel, regulatory accepted approach is developed that enables competent authorities to decide whether landfill aftercare can be reduced or terminated. Our previous paper (Brand et al., Waste Management 2016, 56, 255–261, https://doi.org//10.1016/j.wasman.2016.07.038) outlines the general approach, that consists of a 10-year treatment phase (e.g., aeration, leachate recirculation), in combination with site-specific Environmental Protection Criteria (EPC) for contaminant concentrations in the landfill leachate after treatment. The current paper presents the unique modelling approach by which the site-specific EPC are derived. The modelling approach is based on the use of mechanistic multi-surface geochemical models covering the main sorption processes in soils underneath the landfills, and is composed of widely-accepted surface complexation models in combination with published “generic” parameter sets. This approach enables the consideration of the main site-specific soil properties that influence the attenuation of emitted contaminants. In addition, the sensitivity of the EPC is shown for variation of the main physicochemical-assumptions and policy-based decisions. Site-specific soil properties have been found to substantially determine the EPC and include soil-pH, dissolved organic matter, and iron-(hydr)oxide content. Apart from the sorption capacity of the local soil, EPC also depend strongly on the assumed dilution with local groundwater in the saturated zone. An important policy-related decision that influences the calculated EPC is the assessment period during which the groundwater is protected. The transparent setup of the approach using geochemical modelling, the explicit consideration of site-specific properties and the achieved regulatory acceptance may also stimulate application to landfills in other countries.
A novel approach in calculating site-specific aftercare completion criteria for landfills in The Netherlands : Policy developments
Brand, Ellen ; Nijs, Ton C.M. de; Dijkstra, Joris J. ; Comans, Rob N.J. - \ 2016
Waste Management 56 (2016). - ISSN 0956-053X - p. 255 - 261.
Aftercare completion - Environmental protection criteria - MSW landfills - Point of compliance - Risk assessment - Sustainable landfill management
As part of a more circular economy, current attention on waste is shifting from landfilling towards the prevention, re-use and recycling of waste materials. Although the need for landfills is decreasing, there are many landfills around the world that are still operational or at the point of starting the aftercare period. With traditional aftercare management, these landfills require perpetual aftercare at considerable cost due to monitoring and regular maintenance of liners. In an attempt to lower these aftercare costs, and to prevent that future generations become responsible for finding a sustainable solution of present day waste, the Dutch government takes action to explore the possibilities of sustainable landfill management. A project was started to investigate whether the use of source-oriented treatment techniques (so-called active treatment) of landfills can result in a sustainable emission reduction to soil and groundwater. During the next decade, sustainable landfill management is tested at three selected pilot landfills in the Netherlands. To enable this pilot testing and to determine its success after the experimental treatment period, a new methodology and conceptual framework was developed. The aim of this paper is to describe the development of the new methodology, and in particular the policy decisions, needed to determine whether the pilot experiments will be successful. The pilot projects are considered successful when the concentrations in the leachate of the pilot landfills have sufficiently been reduced and for longer periods of time and comply with the derived site-specific Environmental Protection Criteria (EPC). In that case, aftercare can be reduced, and it can be determined whether sustainable landfill management is economically feasible for further implementation.