Use of the Contingent Valuation Method in the assessment of a landfill mining project

Energy Potential Assessment of Excavated Landfill Material: A Case Study of the Perm Region, Russia

The paper presents results of field and laboratory studies of thermal characteristics to excavated landfill waste in Perm region, Russia. The peculiarity of the study includes the following aspects: waste composition with a high share of polymers, the climatic conditions of the territory and the lack of engineering infrastructure at the waste disposal facility. When determining the waste composition and thermal properties of waste, it is proposed to include a stage of removal of contamination from landfilled waste fraction, since their share of contamination can reach up to 33%. This stage will allow researchers to adjust the net calorific value of the excavated waste without overestimation, which may affect decision-making when implementing waste management technology. Among combustible components with the highest moisture content are waste paper (69.1%) and diapers (65.8%), whereas wood (11.2%), PET bottles (3.1%) and other 3D plastics (13.4%) have rather low ash content on a dry basis. Calculation of thermal properties and analysis of the energy potential of the waste samples was conducted based on the obtained data. The calorific value of the individual components and excavated waste depends not only on the moisture and ash content of the individual components, but also on the presence of contaminants. The average net calorific value of the excavated waste is 4.9 MJ/kg, and for the separate mixture of combustible components, it is 7.5 MJ/kg at a moisture content of 44%. Excavated landfill waste can be regarded as a resource for the manufacture of secondary fuel only after pretreatment that includes at least sorting and drying. The results of this study may be useful in developing technologies needed to eliminate old MSW dumps and old landfills, for the development of the concept of circular economy and prevention of environmental degradation problems.

Environmental and economic assessment of Enhanced Landfill Mining in Tehran

Landfilling brings many difficulties such as leaching of hazardous substances, methane gas production, loss of land, and natural resources such as groundwater, soil, and minerals. Enhanced landfill mining (ELFM) gives an opportunity to deal with such related problems. This study aimed to assess the environmental performance of ELFM through the application of life cycle assessment (LCA). SimaPro (v 8.5) was utilized to model the consequential life cycle assessment. Moreover, a comprehensive cost-benefit analysis was applied to assess the economic performance along with the Monte Carlo simulation to address the related uncertainties. In addition, the indicator of net present value (NPV) was adopted to understand the economic feasibility of the project. The case study landfill was the closed 55-hectare dumpsite of the municipality of Tehran in Kahrizak due to the need for further landfilling space in the future. The results of this study indicated that ELFM could lead to remarkable environmental benefits compared with the landfill's current status (the do-nothing scenario). The ELFM project reduced the impact of global warming by 1,759,790 ton CO2 eq, equaling to 134% reduction in comparison with the do-nothing scenario. Moreover, the potential profitability of the project was calculated to be 370 million $. Among the processes, recycling and thermal treatment of waste significantly dominated the environmental results of the project. Although the research was based on a case study landfill, the methodology can be applied to similar projects worldwide.

A Study on the Value of Preserving a Parasitic Volcanic Sieve as a Tourism Good for Sustainable Management: Using the Contingent Valuation Method

The purpose of this study is to estimate the economic value of Geomun Oreum (GO), a parasitic volcanic sieve, for sustainable management by using the dichotomous choice contingent valuation method. To address the exaggeration tendency of willingness to pay (WTP), the contingent valuation method’s (CVM’s) traditional threshold, respondents’ WTP answers were reconfirmed to screen only true responses for our analysis. In addition to estimating the economic value, the causal relationship between the tour guide’s quality of explanation and the respondents’ payment intention is examined in the study. The results reveal that the estimated preservation value of GO is 35,881 KRW (33.28 USD), and the quality of the tour guide’s narrative is statistically related to the respondents’ payment intention.

Characterization of Excavated Waste of Different Ages in View of Multiple Resource Recovery in Landfill Mining

With the aim of examining the forcing factors in postmanagement landfills, in this study, excavation waste from nonhazardous municipal waste landfill in Tuscany was characterized for the first time. The specific objective was to estimate the feasibility of sampling and analyzing the excavated waste in order to define its properties and provide information about possible landfill mining projects. Based on the biochemical methane potential assays, it was shown that the excavated waste had not yet been stabilized (i.e., with a production of 52.2 ± 28.7 NlCH4/kgTS) in the landfill, probably due to the low excavated waste moisture content (36% ± 6% w/w). Furthermore, excavated waste has a high calorific value, i.e., 15.2 ± 4.1 MJ/kg; the quantity of combustibles in the industrial shredder waste (16 MJ/kg) was rather modest compared to that of municipal solid waste (20.8 MJ/Kg). In conclusion, during large scale excavation of the landfill, it was possible to evaluate how a dedicated treatment plant could be designed to treat and select waste which might appear in a different category. For excavated industrial waste, detailed mechanical sorting may be convenient for end-of-waste recovery to improve calorific value.

Eliciting stakeholder needs - An anticipatory approach assessing enhanced landfill mining

Landfill owners, governmental institutions, technology providers, academia and local communities are important stakeholders involved in Enhanced Landfill Mining (ELFM). This concept of excavating and processing historical waste streams to higher added values can be seen as a continuation of traditional landfill mining (LFM) and seems to be an innovative and promising idea for potential environmental and societal benefits. However, ELFM's profitability is still under debate, and environmental as well as societal impacts have to be further investigated. This study provides a first step towards an anticipatory approach, assessing ELFM through stakeholder integration. In the study, semi-structured interviews were conducted with various stakeholders, involved in a case study in Flanders, Belgium. Participants were selected across a quadruple helix (QH) framework, i.e. industrial, governmental, scientific, and local community actors. The research comprises 13 interviews conducted with an aim to elicit stakeholder needs for ELFM implementation using a general inductive approach. In total 18 different stakeholder needs were identified. The paper explains how the stakeholder needs refer to the different dimensions of sustainability, which groups of stakeholders they primarily affect, and what types of uncertainty could be influenced by their implementation. The stakeholder needs are structured into societal, environmental, regulatory and techno-economic needs. Results show additional economic, environmental, and societal aspects of ELFM to be integrated into ELFM research, as well as a need for the dynamic modeling of impacts.

Contaminants in landfill soils - Reliability of prefeasibility studies

Recent landfill mining studies have researched the potential for resource recovery using samples from core drilling or grab cranes. However, most studies used small sample numbers, which may not represent the heterogeneous landfill composition. As a consequence, there exists a high risk of an incorrect economic and/or ecological evaluation. The main objective of this work is to investigate the possibilities and limitations of preliminary investigations concerning the crucial soil composition. The preliminary samples of landfill investigations were compared to the excavation samples from three completely excavated landfills in Germany. In addition, the research compared the reliability of prediction of the two investigation methods, core drilling and grab crane. Sampling using a grab crane led to better results, even for smaller investigations of 10 samples. Analyses of both methods showed sufficiently accurate results to make predictions (standard error 5%, level of confidence 95%) for most heavy metals, cyanide and PAH in the dry substance and for sulphate, barium, Benzo[a]pyrene, pH and the electrical conductivity in leachate analyses of soil type waste. While chrome and nickel showed less accurate results, the concentrations of hydrocarbons, TOC, DOC, PCB and fluorine (leachate) were not predictable even for sample numbers of up to 59. Overestimations of pollutant concentrations were more frequently apparent in drilling, and underestimations when using a grab crane. The dispersion of the element and elemental composition had no direct impact on the reliability of prediction. Thus, an individual consideration of the particular element or elemental composition for dry substance and leachate analyses is recommended to adapt the sample strategy and calculate an optimum sample number.

Monetizing the social benefits of landfill mining: Evidence from a Contingent Valuation survey in a rural area in Greece

Despite the emerging global attention towards promoting waste management policies that reduce environmental impacts and conserve natural resources, landfilling still remains the dominant waste management practice in many parts of the world. Owing to this situation, environmental burdens are bequeathed to and large amounts of potentially valuable materials are lost for future generations. As a means to undo these adverse effects a process known as landfill mining (LFM) could be implemented provided that economic feasibility is ensured. So far, only a few studies have focused on the economic feasibility of LFM from a private point of view and even less studies have attempted to economically justify the need for LMF projects from a social point of view. This paper, aiming to add to the limited literature in the field, presents the results of a survey conducted in a rural district in Greece, by means of the Contingent Valuation method (CVM) in order to estimate society's willingness to pay for LFM programs. According to the empirical survey, more than 95% of the respondents recognize the need for LFM programs. Nevertheless, only one-fourth of the respondents are willing to pay through increased taxes for LFM, owing mainly to economic depression and unemployment. Those who accept the increased tax are willing to pay about €50 per household per year, on average, which results in a mean willingness to pay (WTP) for the entire population under investigation of around €12 per household per year. The findings of this research work provide useful insights about the 'dollar-based' benefits of LFM in the context of social cost-benefit analysis of LFM projects. Yet, it is evident that further research is necessary.

Landfill aeration for emission control before and during landfill mining

The landfill of Modena, in northern Italy, is now crossed by the new high velocity railway line connecting Milan and Bologna. Waste was completely removed from a part of the landfill and a trench for the train line was built. With the aim of facilitating excavation and further disposal of the material extracted, suitable measures were defined. In order to prevent undesired emissions into the excavation area, the aerobic in situ stabilisation by means of the Airflow technology took place before and during the Landfill Mining. Specific project features involved the pneumatic leachate extraction from the aeration wells (to keep the leachate table low inside the landfill and increase the volume of waste available for air migration) and the controlled moisture addition into a limited zone, for a preliminary evaluation of the effects on process enhancement. Waste and leachate were periodically sampled in the landfill during the aeration before the excavation, for quality assessment over time; the evolution of biogas composition in the landfill body and in the extraction system for different plant set-ups during the project was monitored, with specific focus on uncontrolled migration into the excavation area. Waste biological stability significantly increased during the aeration (waste respiration index dropped to 33% of the initial value after six months). Leachate head decreased from 4 to 1.5m; leachate recirculation tests proved the beneficial effects of moisture addition on temperature control, without hampering waste aerobization. Proper management of the aeration plant enabled the minimization of uncontrolled biogas emissions into the excavation area.

Analysis of residents' willingness to pay to reduce air pollution to improve children's health in community and hospital settings in Shanghai, China

BACKGROUND

Shanghai, along with many major cities in China, faces deterioration of air quality and increases in air pollution-related respiratory diseases (RDs) in children due to rapid industrialization and urbanization. The Contingent Valuation Method (CVM) was used to qualitatively and quantitatively measure the willingness to pay (WTP) for reducing children's RDs through air quality improvement.

METHODS

Between April and May, 2014, 975 face-to-face interviews were collected from parents in a community-based and a hospital-setting in Shanghai. Multiple imputation and the Probit model were used to determine the relationship between the WTP and the related environmental factors, child health factors and the socio-economic status.

RESULTS

Most respondents reported being willing to make a financial contribution to improve air quality in both the community (52.6%) and hospital (70.2%) samples. Those in the hospital setting were willing to pay significantly more ¥504 (USD$80.7) compared to the community sample ¥428 ($68.5) as expected. Reasons for those not being willing to pay included lack of disposable income and believing that responsibility of the air quality was a community issue. These did not differ by sample. Annual household income and education were related to WTP.

CONCLUSION

This study indicated that parents in Shanghai would be willing to pay for improved air quality. Children's health can be the incentive for the citizens' participation and support in the air quality improvement, therefore, hospital settings may present unique places to improve education about air quality and enhance advocacy efforts. This study also suggested that future environmental policies be addressed more rigorously for targeted populations.

Assessment of environmental and economic feasibility of Enhanced Landfill Mining

This paper addresses the environmental and economic performance of Enhanced Landfill Mining (ELFM). Based on life cycle assessment and life cycle costing, a detailed model is developed and is applied to a case study, i.e. the first ELFM project in Belgium. The environmental and economic analysis is performed in order to study the valorisation of different waste types in the landfill, such as municipal solid waste, industrial waste and total waste. We found that ELFM is promising for the case study landfill as greater environmental benefits are foreseen in several impact categories compared to the landfill's current situation (the 'Do-nothing' scenario). Among the considered processes, the thermal treatment process dominates both the environmental and economic performances of ELFM. Improvements in the electrical efficiency of thermal treatment process, the calorific value of refuse derived fuel and recovery efficiencies of different waste fractions lead the performance of ELFM towards an environmentally sustainable and economically feasible direction. Although the environmental and economic profiles of ELFM will differ from case to case, the results of this analysis can be used as a benchmark for future ELFM projects.

Integrating remediation and resource recovery: On the economic conditions of landfill mining

This article analyzes the economic potential of integrating material separation and resource recovery into a landfill remediation project, and discusses the result and the largest impact factors. The analysis is done using a direct costs/revenues approach and the stochastic uncertainties are handled using Monte Carlo simulation. Two remediation scenarios are applied to a hypothetical landfill. One scenario includes only remediation, while the second scenario adds resource recovery to the remediation project. Moreover, the second scenario is divided into two cases, case A and B. In case A, the landfill tax needs to be paid for re-deposited material and the landfill holder does not own a combined heat and power plant (CHP), which leads to disposal costs in the form of gate fees. In case B, the landfill tax is waived on the re-deposited material and the landfill holder owns its own CHP. Results show that the remediation project in the first scenario costs about €23/ton. Adding resource recovery as in case A worsens the result to -€36/ton, while for case B the result improves to -€14/ton. This shows the importance of landfill tax and the access to a CHP. Other important factors for the result are the material composition in the landfill, the efficiency of the separation technology used, and the price of the saleable material.

A cost-benefit analysis of landfill mining and material recycling in China

Landfill mining is an environmentally-friendly technology that combines the concepts of material recycling and sustainable waste management, and it has received a great deal of worldwide attention because of its significant environmental and economic potential in material recycling, energy recovery, land reclamation and pollution prevention. This work applied a cost-benefit analysis model for assessing the economic feasibility, which is important for promoting landfill mining. The model includes eight indicators of costs and nine indicators of benefits. Four landfill mining scenarios were designed and analyzed based on field data. The economic feasibility of landfill mining was then evaluated by the indicator of net present value (NPV). According to our case study of a typical old landfill mining project in China (Yingchun landfill), rental of excavation and hauling equipment, waste processing and material transportation were the top three costs of landfill mining, accounting for 88.2% of the total cost, and the average cost per unit of stored waste was 12.7USDton(-1). The top three benefits of landfill mining were electricity generation by incineration, land reclamation and recycling soil-like materials. The NPV analysis of the four different scenarios indicated that the Yingchun landfill mining project could obtain a net positive benefit varying from 1.92 million USD to 16.63 million USD. However, the NPV was sensitive to the mode of land reuse, the availability of energy recovery facilities and the possibility of obtaining financial support by avoiding post-closure care.