Municipal solid waste landfill: Evidence of the effect of applied landfill management on vegetation composition.

Proper management of municipal solid waste (MSW) is crucial to avoid pollution, environmental impacts and threat to public health. The problem of MSW is mainly arising from inadequate landfill site management. The objective of this study was to evaluate the impact of management practices and environmental risks at two landfill sites. The landfills were subject to long-term (10 years) vegetation monitoring. The vegetation was assessed using a floristic survey of identified plant species. The vegetation analysis showed that significant differences existed between the two landfill locations, with neophytes, invasive and expansive species dominating on one of the landfill sites, which may be attributed to climatic and geomorphological differences between the two sites, but also to variations in landfill management. These environmentally problematic species can potentially spread from the landfill into adjacent ecosystems, displace native plants and degrade adjacent farmland areas. The study of vegetation monitoring data suggests that, in addition to other types of monitoring, landfills should be subjected to regular vegetation biomonitoring, too. Landfill management practices should target the regulation of unwanted species, create conditions that are favourable to native plant species and provide as early as possible the restoration of filled cells.

Bayesian Analysis of Air Emission Violations from Waste Incineration and Coincineration Plants.

Waste incineration and coincineration plants in most European countries have frequently updated their flue gas cleaning systems, surpassing in most cases E.U. air emission standards. At the same time, in most developing countries, cement and other coincineration facilities follow less stringent emission regulations and have a mixed record of protecting air quality. The European Union, the United States, and Canada have established penalties for air emission violations that account for the harm done to the environment and to human health and aiming to remove the economic benefit reaped as a result of noncompliance. Despite their legal completeness, these regulations do not adequately address the probabilistic nature of air pollution. This article recasts the issue of air pollution penalties in a Bayesian decision-making framework with the aspiration that the assessment of penalties on a rigorous mathematical framework can assist in alleviating the mistrust by sections of the public on the effectiveness of air pollution regulations. Integration of economic analyses into risk assessments of emission violations can help clarify to policymakers the effect of environmental policies. Our analysis indicates that the penalty structure of the United States appears to favor the update of emission systems more often than the corresponding European Commission's penalties. Our study advances the use of the loss function as a risk analysis tool that can be used as a public policy instrument to promote environmentally friendlier air emission choices. A parabolic, compared to a linear, loss function was seen to justify higher expenses in gas cleaning systems.

The lost value of groundwater and its influence on environmental decision making.

A critical aspect in establishing environmental policies lies in the proper assessment of the value of the resource being affected. Standard risk assessment analyses calculate the cost of pollution as consisting, solely, of the cost to remediate a site. This traditional definition is extended here to include the lost value of groundwater. These concepts and their impact on decision-making analyses are illustrated through the case of municipal waste landfills. Based on data from existing polluting sites, a simple cost-benefit probabilistic analysis is conducted first, which equates, as is the practice, the cost of pollution to that of remediation. This leads rationally to selection of the lowest-protection technology. Using plausible arguments the reduction in value of groundwater from potable high-quality water to irrigation water, which is what is returned after remediation, is argued. The arguments consist of: (a) the ratio of the subsidized prices of drinking to irrigation water reflects the relative value of the use of water; (b) the amount paid for remediation, in each case, represents, at a minimum, the value of the water recovered; and (c) the lost value of groundwater equals the value of drinking water minus the value of irrigation water. Incorporation of this lost value of groundwater is sufficient to drastically alter the conclusions of the decision-making analysis and make the highest level technology the most rational and profitable alternative. The broader point of this article lies in that proper accounting of environmental costs is necessary in order to alter environmental policies and practices.

Stochastic analysis and prioritization of the influence of parameter uncertainty on the predicted pressure profile in heterogeneous, unsaturated soils.

This article utilizes a Monte Carlo stochastic framework to investigate the influence on the mean and variance of the predicted mean pressure head profile of statistical assumptions regarding the parameters that enter the mathematical description of the problem of infiltration in unsaturated, heterogeneous layers. The parameters are treated as random functions with an exponential auto-covariance function expressing their spatial continuity. Four different truncated distributions are taken to describe the parameters according to field observations and various phases of site characterization campaigns. The exponential distribution is seen to produce the largest (in absolute value) mean and variance in the pressure head profile. For all distributions the variance in pressure head increases with increasing mean pressure. A second topic of this article is to investigate, the relative importance of each parameter, in terms of the mean and the variance of the predicted pressure. For uniformly or triangularly distributed parameters the saturated hydraulic conductivity appears to dominate the mean-behavior and the uncertainty in the system's solution. For lognormally or exponentially distributed parameters another parameter, the van Genuchten pore-size distribution index, is the dominant factor.