Environmental Policy Analysis, Peer Reviewed: A Risk-Based Approach to Soil Remediation Modeling

Davis, Andy; Kamp, Susan; Fennemore, G.G.; Schmidt, R. E.; Keating, Michael; Hoenke, K. A.

doi:10.1021/es9725662

Cited by 13 publications

(5 citation statements)

References 5 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The FSDA approach is illustrated here using a twodimensional spatial domain with one contaminant. Future uses of floating domain averaging and the linear program-ming model for environmental applications may include other dimensional domains, such as three-dimensional land applications (16), a spatial domain that includes multiple contaminants as additional variables or a temporal domain such as those associated with discharge permits.…”

Section: Resultsmentioning

confidence: 99%

Floating Spatial Domain Averaging in Surface Soil Remediation

Brakewood

Grasso

2000

Environ. Sci. Technol.

View full text Add to dashboard Cite

Cleanup plans for contaminated surface soil are frequently developed with the goal of ensuring that regulatory criteria for risk exposure are met after remediation. Currently, some of the plans for Superfund sites are based on the premise that a concentration equal to the average goal or based on a confidence level expression of the concentration measurements is not to be exceeded (NTE). However, in cases of widespread low-level contamination, the NTE constraint may result in lowering risk well below the regulatory criteria and substantially increasing remediation costs. Alternative methods based on spatial averaging are developed and explored in this paper. Floating spatial domain averaging (FSDA) is a multi-criteria decisionmaking tool in which concentrations or risk factors are averaged over domains that represent exposure areas. The domains are variable in space. The averaging domain floats over the surface in increments representative of the sample or cells spatially interpolated raster units. This allows for the incorporation of domain-wide topological information into the averaging operation around each cell. Floating domain averaging can be done manually or with the aid of geographical information systems (GIS). Additional marginal cost or cleanup objectives can be incorporated into the model and linear programming solutions used as a multi-objective decision-making tool. IntroductionThe Environmental Protection Agency (EPA) is responsible for the development of cleanup goals and remediation plans at waste sites in the United States (1). These plans are intended to ensure that regulatory criteria that protect public health and the environment are met at the sites after remediation.Remediation plans are commonly based upon the premise that a certain concentration is not to be exceeded anywhere at the site, which is referred to as the "not to exceed" (NTE) approach. However, soil screening levels (SSLs) developed by the EPA for screening potential surface soil remediation areas are based on an areal or spatial domain averaged risk (2). Consequently, alternative cleanup plans that are based on spatial averaging may be appropriate.Spatial domain averaging techniques are of particular interest in areas of widespread low level contamination, where full-site remediation based on the NTE approach might reduce average risk well below the EPA SSL criteria with associated significant increases in costs (3). If contamination at a site is not randomly distributed, then spatial interactions and relationships are important considerations in spatial domain averaging techniques. The floating spatial domain method in surface soil remediation planning, which is introduced here, is a multi-criteria decision-making tool by which some spatial topology and interactions are considered over exposure areas for future land uses. This method is evaluated herein for a site where one contaminant or risk factor is being targeted for remediation. The contamination is not distributed randomly over the site, and its levels are within an ...

show abstract

Section: Resultsmentioning

confidence: 99%

Floating Spatial Domain Averaging in Surface Soil Remediation

Brakewood

Grasso

2000

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…also known as interaction effect between parameter i and j, and subsequently for other terms in Eqn. (10).The equation is exclusive for all input parameters that are independent, i.e. orthogonal, from each other.…”

Section: Sobol' Methodsmentioning

confidence: 99%

“…Negligible sensitivity response could be resulted by too small perturbation size, and inaccuracy in sensitivity response could be due to too large perturbation size (Poeter and Hill 1998). The input parametervalues were subjected to a perturbation size between -5% and 5% as suggested by Zheng and Bennett (2002).Some other perturbation sizes used by researchers, for example, 90 % in Vereecken et al (1990), 20% in De Roo and Offermans (1995), and 10% in Davis et al (1997). In considering the simulation time, we limit the sensitivity analysis to a simulation time of 10 5 s. The sensitivity analysis study was based on a single perturbation size of increment or decrement in each simulation.…”

Section: Local Sensitivity Analysismentioning

confidence: 99%

Morris method with improved sampling strategy and Sobol’ variance-based method, as validation tool on numerical model of Richard’s equation

Goh

2019

JGC

View full text Add to dashboard Cite

Richard’s equation was approximated by finite-difference numerical scheme to model water infiltration profile in variably unsaturated soil. The published data of Philip’s semi-analytical solution was used to validate the simulated results from the numerical scheme. A discrepancy was found between the simulated and the published semi-analytical results. Morris method as a global sensitivity tool was used as an alternative to local sensitivity analysis to assess the results discrepancy. Morris method with different sampling strategies were tested, of which Manhattan distance method have resulted a better sensitivity measures and also a better scan of input space than Euclidean method. Moreover, Morris method at and Manhattan distance sampling strategy, with only 2 extra simulation runs than local sensitivity analysis, was able to produce reliable sensitivity measures ( , ). The sensitivity analysis results were cross-validated by Sobol’ variance-based method with 150,000 simulation runs. The global sensitivity tool has identified three important parameters, of which spatial discretization size was the sole reason of the discrepancy observed. In addition, a high proportion of total output variance contributed by parameters and is suggesting a greater significant digits is required to reduce its input uncertainty range.

show abstract

“…Adopt risk-based approaches to set remediation goals. Setting the remediation endpoints for contaminated sites based on fixed soil quality standards (i.e., making the soil cleanup at all contaminated sites meet the same pollutant concentration thresholds) often results in over-remediation and unnecessary expenditures (Davis et al 1997;USEPA 2004;CCME 2007). In China, the need to set the level of soil remediation by risk assessment (Zhang et al 2011) as well as background values of target pollutants in regional soil and threshold values specified in national standards has been recognized.…”

Section: Challenges Of the Site Management Policies In Chinamentioning

confidence: 99%

Soil pollution and site remediation policies in China: A review

Jiao

Xiao

et al. 2015

Environ. Rev.

View full text Add to dashboard Cite

It was not until the 1980s that China's policy makers became aware of the detrimental impacts on urban health from soil pollution as a result of industrial waste emissions. For the past three decades, the Chinese government has strived to prevent and control industrial pollution. Setting appropriate environmental policies is the key to mitigating the legacy of industrial waste emissions accumulated for three decades. In this paper, we review the development process by outlining the evolution of the policies and the resulting legal infrastructure in terms of acts, regulations, ordinances, and standards. Deficiencies of the existing policies are identified. In the early stages, environmental policies were fragmented, consisting of single-purpose laws that are narrowly focused. With time, these policies gradually evolved to become better integrated and comprehensive management plans. However, the laws emphasize contaminated site restoration instead of preventing soil pollution. The legal framework shows that the policies that are in place often lack clear mandates because the authorizations are piggybacked on environmental acts and regulations that do not directly address issues of soil pollution. Furthermore, implementation plans are impractical due to outdated soil quality standards, unclear soil cleanup goals, unenforceable liability and supervision mechanisms, limited funding, lack of transparency and public outreach, and the unreliable financial and technical capabilities of the remediation industries.Résumé : Il a fallu attendre les années 1980 avant que les décideurs politiques chinois prennent conscience des impacts néfastes sur la santé urbaine exercés par la pollution des sols provenant des émissions de rejets industriels. Au cours des trois dernières décades, le gouvernement chinois s'est efforcé de prévenir et de contrôler la pollution industrielle. La mise en place de politiques environnementales appropriées constitue la clé pour mitiger l'héritage des émissions de rejets industriels accumulés depuis pendant trois décades. Les auteurs passent en revue le processus de développement, en soulignant l'évolution des politiques et les infrastructures légales qui en résultent en termes d'actions, de règlements, d'ordonnances et de standards. On identifie de plus les faiblesses des politiques existantes. Aux premières étapes, les politiques étaient fragmentées, consistant en législations à finalités uniques étroitement ciblées. Avec le temps, ces politiques ont graduellement évolué pour se traduire en plans d'aménagement mieux intégrés et plus complets. Cependant, les lois insistent sur la restauration des sites contaminés plutôt que sur la prévention de la pollution du sol. Le cadre légal montre que les politiques en place manquent souvent de mandats clairs par ce que les autorisations s'empilent sur des actes et règlements ne s'adressant pas directement aux problèmes de la pollution des sols. De plus, la réalisation des plans n'est pas possible dû à des standards désuets sur la qualité des sols, des objectifs...

show abstract

Environmental Policy Analysis, Peer Reviewed: A Risk-Based Approach to Soil Remediation Modeling

Cited by 13 publications

References 5 publications

Floating Spatial Domain Averaging in Surface Soil Remediation

Floating Spatial Domain Averaging in Surface Soil Remediation

Morris method with improved sampling strategy and Sobol’ variance-based method, as validation tool on numerical model of Richard’s equation

Soil pollution and site remediation policies in China: A review

Contact Info

Product

Resources

About