Management Of Contaminated Sites Research Articles

Relevance of sustainable remediation to contaminated sites manage in developed and developing countries: Case of Brazil

The sustainable remediation emerged as a paradigm shift within contaminated sites management. However, this approach still has difficulties and therefore its application is quite limited. Thus, this paper aims to present and analyze the characteristics and trends of sustainable remediation approach in developed and developing countries, with an emphasis on Brazil case. Firstly, the background to sustainable remediation approach is presented. The discussion is carried out through a contextualization of the main barriers and challenges in sustainable remediation consideration and application in worldwide. The main perspectives and recommendations about the sustainable remediation were contextualized. Finally, approaches of sustainable remediation in developed and developing countries context was presented and analyzed, with emphasis on Brazilian situation. It is concluded that sustainable remediation is of great importance and that many advances have been made; however, the use of the term is still in adaptation process, especially in developing countries. In Brazil, at the same time as it is verified that has the regulatory structure focused on the management of contaminated sites is fairly recent, the sustainability considerations in this context are almost nonexistent.

Contaminated sites investigation. Objectives and methods

The past human activities, mainly that related to industrial development caused in many cases a strong contamination of soil, subsoil environment and of groundwater. This type of pollution is a concern because it poses risks to human health and to the ecosystem. More than this, such areas may not be used for new development, requiring solutions for remediation. The management of these sites consists of three main activities: characterization, remediation and, finally, redevelopment. The paper presents a case study dedicated to the first step of contaminated sites management, respectively characterization. This phase is very important, a good characterization could ensure a performant solution for the second step – remediation. Two new techniques for site characterization are presented, as technical principles, but also as performances obtained for the mentioned case study.

Tracking chlorinated contaminants in the subsurface using compound-specific chlorine isotope analysis: A review of principles, current challenges and applications.

Many chlorinated hydrocarbons have gained notoriety as persistent organic pollutants in the environment. Engineered and natural remediation efforts require a monitoring tool to track the progress of degradation processes. Compound-specific isotope analysis (CSIA) is a robust method to evaluate the origin and fate of contaminants in the environment and does not rely on concentration measurements. While carbon CSIA has established itself in the routine assessment of contaminated sites, studies incorporating chlorine isotopes have only recently become more common. Although some aspects of chlorine isotope analysis are more challenging than carbon isotope analysis, having additional isotopic data yields valuable information for contaminated site management. This review provides an overview of chlorine isotope fractionation of chlorinated contaminants in the subsurface by different processes and presents analytical techniques and unresolved challenges in chlorine isotope analysis. A summary of successful field applications illustrates the potential of using chlorine isotope data. Finally, approaches in modelling chlorine isotope fractionation due to degradation, diffusion, and sorption processes are discussed.

A legislation for the Risk-Based Contaminated Sites Management

A legislation for the Risk-Based Contaminated Sites Management

Debunking myths about sustainable remediation

AbstractSustainable remediation concepts have evolved during the decade 2007–2017. From the establishment of the first Sustainable Remediation forum (SURF) in 2007, to publication of ASTM and ISO standards by 2017. Guidance has been developed around the world to reflect local regulatory systems, and much has been learned in applying sustainability assessment to contaminated site management projects. In the best examples, significant improvements in project sustainability have been delivered, including concurrent reduction of the environmental footprint of the remediation program, improved social performance, and cost savings and/or value creation. The initial advocates for the concept of sustainable remediation were quickly supported by early adopters who saw its potential to improve the remediation industry's performance, but they also had to overcome some inertia and scepticism from other parties. During the debates and discussions that occurred at numerous international conferences and SURF workshops around the world, various opinions were formed and positions stated. Some proved to be correct, others not so. With the recent publication of ISO Standard 18504 and the benefit of a decade's‐worth of hindsight on sustainable remediation programs implementation and project delivery, this paper summarizes a number of myths and misunderstandings that have been stated regarding sustainable remediation and seeks to debunk them. Sustainable remediation assessment shows us how to manage unacceptable risks to human health and the environment in the best, that is to say the most sustainable, way. It provides the contaminated land management industry a framework to incorporate sustainable development principles into remediation projects and deliver significant value for affected parties and society more broadly. In dispelling some myths about sustainable remediation set out in this paper, it is hoped that consistent application of ISO18504/SuRF‐UK (or equivalently robust guidance) will facilitate even wider use of sustainable remediation around the world.

Framework for Assessment of Oil Spill Site Remediation options in Developing Countries a Life Cycle Perspective.

One of the main issues faced by the oil and gas industry in developing countries is that of oil spill and its impacts on the social-cultural, economic and environment. The adverse effects of oil spill on the environment as well as the socio-cultural life of the inhabitants in the affected areas make it mandatory for proactive management of oil spills. Oil spill contaminated sites management in developing countries such as; (Venezuela, Libya, Iraq and Nigeria) suffers from a number of limitations: lack of a clear statutory definition for contaminated sites, life cycle assessment-based approach, inexperience, weak policy frameworks and limited funding. From the literature on oil spill contaminated sites management, there are different approaches adopted by developed countries to improve the management process as well as the outcome of such processes. However, context specific approaches are sometimes required for successful management decisions to promote efficient policy transfer. In this study we propose an integrated life cycle assessment (LCA) that monitors and assesses the environmental impacts of oil spill and remediation processes applied on the case study environment (Nigeria) with a view to managing them sustainably. Life cycle thinking approach has been identified as a decision-making tool for remediation of contaminated sites because it presents the opportunity to take into consideration the inputs and outputs to the process of remediation, as well as the activities that take place during the remediation process. This research developed a conceptual framework for oil spill sites remediation in the Nigerian. The framework can also be applied to similar oil spill sites whose methodology is currently underdeveloped.

Contaminated Site Management and Remediation Technologies

Contaminated Site Management and Remediation Technologies

Fuzzy synthetic evaluation of contaminated site management policy from the perspective of stakeholders: A case study from China

Abstract Contaminated sites are receiving increasing policy attention internationally due to the significant threats they pose to eco-environmental and human health. In China, a range of policies for contaminated site management have been developed and implemented with the ambition of reaching “zero contaminated sites” – in particular using a policy-driven approach to remediate or manage site risk while delivering useful synergies between services and opportunities in site reuse. To examine the interaction between policy making, policy implementation, and policy outcome, we designed a three-dimensional conceptual model of policy evaluation, and established an indicator framework of stakeholder perceptions covering policy formulation, policy implementation and policy outcome, which was tested in five cities in China (Chengdu, Beijing, Changsha, Chongqing and Shanghai) through interviews with various stakeholders. A combined method of fuzzy synthetic evaluation and entropy weight was applied for the purpose of quantification and comparability of evaluation results at different levels. The results show that: (1) there is no inevitable causality between policy formulation, policy implementation and policy outcome. Policy formulation, which is the premise of policy implementation and may largely influence policy outcome, does not perform well in all tested cities. Policy implementation is the key step and contributes most to the performance of the whole policy process. (2) In general, Chongqing and Beijing have a less-than-ideal performance compared to the other three study cities in contaminated site management. Due to differences in regional context, the same measure may produce different policy outcomes in different cities, indicating a need to carry out specific, locally contextualized or calibrated policies, based on the local cultural and socioeconomic environment. (3) The fuzzy synthetic evaluation method proved feasible in the quantitative evaluation of environmental policy, and can help to (i) better understand the advantages and challenges of implementing contaminated site management policy in target cities, and (ii) provide evidence for further decision making.

Ambient levels of PFOS and PFOA in multiple environmental media

AbstractMaking remediation and risk management decisions for widely‐distributed chemicals is a challenging aspect of contaminated site management. The objective of this study is to present an initial evaluation of the ubiquitous, ambient environmental distribution of poly‐ and perfluoroalkyl substances (PFAS) within the context of environmental decision‐making at contaminated sites. PFAS are anthropogenic contaminants of emerging concern with a wide variety of consumer and industrial sources and uses that result in multiple exposure routes for humans. The combination of widespread prevalence and low screening levels introduces considerable uncertainty and potential costs in the environmental management of PFAS.PFAS are not naturally‐occurring, but are frequently detected in environmental media independent of site‐specific (i.e., point source) contamination. Information was collected on background and ambient levels of two predominant PFAS, perfluorooctane sulfonate and perfluorooctanoate, in North America in both abiotic media (soil, sediment, surface water, and public drinking water supplies) and selected biotic media (human tissues, fish, and shellfish). The background or ambient information was compiled from multiple published sources, organized by medium and concentration ranges, and evaluated for geographical trends and, when available, also compared to health‐based screening levels. Data coverage and quality varied from wide‐ranging and well‐documented for soil, surface water, and serum data to more localized and less well‐documented for sediment and fish and shellfish tissues and some uncertainties in the data were noted. Widespread ambient soil and sediment concentrations were noted but were well below human health‐protective thresholds for direct contact exposures. Surface water, drinking water supply waters (representing a combination of groundwater and surface water), fish and shellfish tissue, and human serum levels ranged from less than to greater than available health‐based threshold values. This evaluation highlights the need for incorporating literature‐based or site‐specific background into PFAS site evaluation and decision‐making, so that source identification, risk management, and remediation goals are properly focused and to also inform general policy development for PFAS management.

Transformation of heavy metal fractionation under changing environments: a case study of a drainage system in an e-waste dismantling community.

The change in environmental conditions during the transportation of contaminated soil and sediment was expected to affect the transformation of heavy metal fractionation. This study disclosed the serious contamination of copper (Cu), lead (Pb), and zinc (Zn) in the sewer sediment of an e-waste dismantling community in Thailand which may be caused by flushed contaminated soil and e-waste fragments. Two environmental conditions were simulated to observe the transformation of heavy metal fractionation. The anoxic sewer condition was induced using high substrate and sulfate in a closed container. The aeration of anoxic contaminated sediment was applied to simulate the transformation to an oxidative environment. The BCR sequential extraction was applied for heavy metal fractionation in this study. The study results exhibited that when heavy metal contaminated soil was transferred into this induced anoxic condition, fractionation was redistributed based on the chemical change of system that tends to be associated into F3 (oxidizable fraction) > F2 (reducible fraction) > F1 (acid soluble/exchangeable fraction). Cu exhibited the outstanding capability association to F3. The iron sulfide was not observed as usual due to its lower capability than Cu, Pb, and Zn. When contaminated sediment was transported to a more oxidative environment, the heavy metals fractionation would be redistributed again among those new environment media. It is noteworthy that F3 of Cu was stable even in oxic conditions. F2 of Fe was not developed by this oxic condition, possibly because its dehydration process was limited. The redistribution under an oxic environment became F1 > F2 > F3 indicating their more available form. This transformation was imperative and should be taken into account in heavy metal contaminated site management and control.

Analysis of influencing factors on public perception in contaminated site management: Simulation by structural equation modeling at four sites in China

Public perception towards contaminated site management, a not readily quantifiable latent parameter, was linked through structural equation modeling in this paper to 22 measurable/observable manifest variables associated with the extent of information dissemination and public knowledge of soil pollution, attitude towards remediation policies, and participation in risk mitigation processes. Data obtained through a survey of 412 community residents at four remediation sites in China were employed in the model validation. The outcomes showed that public perception towards contaminated site management might be explained through selected measurable parameters in five categories, namely information disclosure, knowledge of soil pollution, expectations of remediation and redevelopment outcomes, public participation, and site policy, along with their interactions. Among these, information dissemination and attitude towards management policies exhibited significant influence in promoting positive public perception. Based on these examples, responsible agencies therefore should focus on public accessibility to reliable information, and encourage public inputs into policies for contaminated site management, in order to gain public confidence during remediation and regeneration projects.

Management of petroleum hydrocarbon contaminated sites in Nigeria: Current challenges and future direction

Sites affected by petroleum hydrocarbons from oil exploitation activities have been identified as a major environmental and socio-economic problem in the Niger Delta region of Nigeria. The current Nigerian regulatory instruments to manage these contaminated sites are fragmented and the roles and responsibilities of government agencies, such as the Department for Petroleum Resources (DPR), and the National Oil Spill Detection and Response Agency (NOSDRA), are not well defined. This lack of coordination has led to ineffective land contamination policy and poor enforcement more generally. Appropriate, risk-based policy instruments are needed to improve regulatory capacity, and to enhance the regulator's ability to manage new and existing petroleum hydrocarbons contaminated sites. Lessons can be learned from countries like the United Kingdom (UK) and the United States America (USA) that have experience with the management and clean up of historically contaminated land. In this paper, we review the status of petroleum hydrocarbon contaminated sites management in Nigeria and identify the gaps in existing policy and regulation. We review the contaminated land policies and regulation from the UK and the USA, and identify lessons that could be transferred to the Nigerian system. Finally, we provide a series of recommendations (e.g. source – pathway-receptor approach, soil screening criteria, clean-up funding, liability) that could enhance contaminated land legislation in Nigeria.

Contaminated sites in China: Countermeasures of provincial governments

Contaminated sites have caused worldwide attention and been dealt with through a variety of policies and practices both nationally and regionally. Unlike the US, Canada, Japan, and Europe, which have accumulated rich experiences in contaminated site management, China, facing serious contaminated site issues, still lacks effective strategies on issues such as remediation standards, funding resources, accountability, and stakeholders coordination. This paper collected policies for contaminated site management from 31 regions in China. A comprehensive analysis was conducted of current policies, including policy framework, number of policies and instruments, policy types, and spatial and temporal variation. We find that most regions in China, such as Beijing and Chongqing, have taken positive measures to manage contaminated sites, and that there are similarities as well as differences in policy responses and mechanisms in different regions. A multi-level objective system, combined with diverse instruments, cooperation between different stakeholders, and a multi-sectoral joint supervision mechanism emphasized by all 31 regions, are extremely important to promote sustainable site management. Specialized policies, site-specific standards, information disclosure, public participation, remediation priority and groundwater protection are urgently needed to strengthen the local framework of contaminated site management and to promote remediation projects.

Uso combinado de traçadores ideais e reativos para verificação do desempenho de poços multiníveis

A caracterização de plumas de contaminação é uma etapa crucial para o gerenciamento de áreas contaminadas, mas, por serem heterogêneas, há a necessidade de investigação de alta resolução. Nesse trabalho buscou-se desenvolver um poço multínivel pré-montado e selecionar traçadores para verificação do isolamento hidráulico entre os níveis. Testes de coluna foram feitos para avaliar o comportamento dos traçadores e protótipos foram montados e testados em laboratório. Um poço multinível foi instalado numa área experimental, e seu desempenho avaliado por teste com os traçadores. A fluoresceína foi selecionada como traçador reativo e o brometo como traçador ideal. As melhores configurações para o selo do poço multinível foram papel pardo com bentonita em pellets quebrada e granulada, e tela plástica com bentonita em pellets quebrada. No teste em campo, o protótipo instalado funcionou satisfatoriamente e verificou-se que o uso de traçadores ideal e reativo permite avaliar a instalação do poço e também a conectividade entre os níveis.

Environmental behaviors and potential ecological risks of heavy metals (Cd, Cr, Cu, Pb, and Zn) in multimedia in an oilfield in China.

The environmental behaviors of five heavy metals (Cd, Cr, Cu, Pb, and Zn) in a Chinese oilfield were investigated using a steady-state multimedia aquivalence (SMA) model. The modeling results showed good agreement with the actual measured values, with average residual errors of 0.69, 0.83, 0.35, 0.16, and 0.54 logarithmic units for air, water, soil, sediment, and vegetation compartments, respectively. Model results indicated that most heavy metals were buried in sediment, and that transfers between adjacent compartments were mainly deposition from the water to the sediment compartment (48.59%) and from the air to the soil compartment (47.74%) via atmospheric dry/wet deposition. Sediment and soil were the dominant sinks, accounting for 68.80 and 25.26% of all the heavy metals in the multimedia system, respectively. The potential ecological risks from the five heavy metals in the sediment and soil compartments were assessed by the potential ecological risk index (PERI). The assessment results demonstrate that the heavy metals presented low levels of ecological risk in the sediment compartment, and that Cd was the most significant contributor to the integrated potential ecological risk in the oilfield. The SMA model provided useful simulations of the transport and fate of heavy metals and is a useful tool for ecological risk assessment and contaminated site management.

Legal Framework Modifications for Contaminated Sites Management in Peru

Legal Framework Modifications for Contaminated Sites Management in Peru

Panorama do gerenciamento de áreas contaminadas no Brasil após a resolução CONAMA 420/09

<p class="Default">Nos países industrializados, a descoberta da dimensão do problema da contaminação dos solos e das águas subterrâneas levou à sistematização do gerenciamento de áreas contaminadas. Cerca de cinco anos após a publicação da Resolução CONAMA 420/09, que estabeleceu diretrizes para o gerenciamento de áreas contaminadas no Brasil, foi levantado neste estudo o panorama do país em relacão ao tema. Foram obtidas informações junto aos órgãos ambientais de cada Estado através de consultas aos seus sítios eletrônicos, contatos telefônicos e aplicação de um questionário. Os Estados das regiões sudeste e sul avançaram significativamente no gerenciamento da contaminação do solo. Por outro lado, nas demais regiões do Brasil o gerenciamento de áreas contaminadas ainda é incipiente, e a Resolução CONAMA 420/09 ainda está por ser atendida. Foi realizada uma análise qualitativa do risco causado pela contaminação de solo e água subterrânea em cada unidade da federação, que levou em consideração o nível de gerenciamento praticado e o potencial poluidor existente. Foi encontrado nível de risco alto no Paraná, Santa Catarina, Rio Grande do Sul, Espírito Santo, Distrito Federal, Ceará, Pernambuco e Bahia. Os Estados da região nordeste em acelerado processo de industrialização encontram-se em situação mais crítica, sendo preciso avançar rapidamente no gerenciamento de áreas contaminadas, sob pena de repetirem-se os injustificáveis danos ao meio ambiente e à saúde pública ocorridos nas regiões industrializadas do país em décadas passadas. O avanço do gerenciamento nos Estados brasileiros pode ser alcançado com a criação de leis estaduais específicas e com a evolução do nível técnico dos profissionais que atuam nessa área.</p>

Effect of NAPL Source Morphology on Mass Transfer in the Vadose Zone.

The generation of vapor-phase contaminant plumes within the vadose zone is of interest for contaminated site management. Therefore, it is important to understand vapor sources such as non-aqueous-phase liquids (NAPLs) and processes that govern their volatilization. The distribution of NAPL, gas, and water phases within a source zone is expected to influence the rate of volatilization. However, the effect of this distribution morphology on volatilization has not been thoroughly quantified. Because field quantification of NAPL volatilization is often infeasible, a controlled laboratory experiment was conducted in a two-dimensional tank (28 cm × 15.5 cm × 2.5 cm) with water-wet sandy media and an emplaced trichloroethylene (TCE) source. The source was emplaced in two configurations to represent morphologies encountered in field settings: (1) NAPL pools directly exposed to the air phase and (2) NAPLs trapped in water-saturated zones that were occluded from the air phase. Airflow was passed through the tank and effluent concentrations of TCE were quantified. Models were used to analyze results, which indicated that mass transfer from directly exposed NAPL was fast and controlled by advective-dispersive-diffusive transport in the gas phase. However, sources occluded by pore water showed strong rate limitations and slower effective mass transfer. This difference is explained by diffusional resistance within the aqueous phase. Results demonstrate that vapor generation rates from a NAPL source will be influenced by the soil water content distribution within the source. The implications of the NAPL morphology on volatilization in the context of a dynamic water table or climate are discussed.

A three-dimensional numerical model for linking community-wide vapour risks

A three-dimensional (3D) numerical model that couples contaminant transport in the saturated zone to vapour transport in the vadose zone and vapour intrusion into buildings was developed. Coupling these processes allows the simulation of vapour intrusion, arising from volatilization at the water table, associated with temporally and spatially variable groundwater plumes. In particular, the model was designed to permit, for the first time, 3D simulations of risk at receptors located in the wider community (i.e., kilometre scale) surrounding a contaminated site. The model can account for heterogeneous distributions of permeability, fraction organic carbon, sorption and biodegradation in the vadose and saturated zones. The model formulation, based upon integration of a number of widely accepted models, is presented along with verification and benchmarking tests. In addition, a number of exploratory simulations of benzene and naphthalene transport in a 1000 m long domain (aquifer cross-section: 500 m×14 m) are presented, which employed conservative assumptions consistent with the development of regulatory guidance. Under these conservative conditions, these simulations demonstrated, for example, that whether houses in the community were predicted to be impacted by groundwater and indoor air concentrations exceeding regulatory standards strongly depended on their distance downgradient from the source and lateral distance from the plume centreline. In addition, this study reveals that the degree of reduction in source concentration (i.e., remediation) required to achieve compliance with standards is less if the risk receptor is in the wider community than at the site boundary. However, these example scenarios suggest that, even considering community receptors, sources with initially high concentrations still required substantial remediation (i.e., >99% reductions in source concentration). Overall, this work provides insights and a new tool for considering the relationships between contaminated site source zones and community-wide risk assessment that allows for development of policies and technical approaches for contaminated site management. It is anticipated that this coupled model not only will allow significant convenience, for example in running suites of Monte Carlo simulations for complex scenarios, but will also allow the investigation of vapour intrusion under conditions where soil gas concentrations may change over the same timescale as an evolving plume.

The role of stakeholder attitudes in managing contaminated sites: survey of Romanian stakeholder awareness

The past decade has seen substantial policy effort directed at promoting the reclamation and reuse of urban brownfield or potentially contaminated land. This paper is based on the results of a survey regarding the role of stakeholder attitudes in managing contaminated sites at the Romanian level. Findings indicate that effective policies and programmes need to be framed within an understanding of the different needs of national development. While different perceptions were identified in regard to the meanings of several concepts and terms used in this field, important aspects related to the need for developing a correctly ranked and coordinated decision-making process were also identified. Additional findings indicate gaps in the legal mechanisms intended to promote brownfield rehabilitation in the course of redevelopment. At the same time, the survey respondents suggested several recommendations such as the necessity of developing a risk assessment to establish the level and extent of contamination that can endanger human health and the environmental integrity on a site and also the need for greater compatibility between land-use planning processes and environmental legislation related to contaminated site management. The paper presents general conclusions engaging all the recommendations drawn from the survey questionnaire as well as from the general current situation in Romania.