MODELING DRINKING WATER QUALITY VIOLATIONS WITH BAYESIAN NETWORKS1

ABSTRACT: Compliance violations at community water systems are rare but represent significant human health risks. These risks are mediated by the decision schema of human operators at water treatment facilities. However, causal uncertainty among physical and human factors involved in water quality problems complicates assessment of their probability and severity. This study uses a probabilistic Bayesian network modeling approach to explore the causes of compliance violations in a sample of water treatment systems in Pennsylvania. The model presented here is one of several created by treatment system operators during an expert elicitation process. The expert model alone predicts violations poorly, suggesting that experts make inaccurate quantitative estimates. However, Bayesian networks are capable of combining the subjective expertise of treatment system operators with the objective compliance histories of the facilities they manage, and the expert model accurately predicts violations when trained with historical compliance data. Analysis of the trained network reveals those components of the treatment process, including environmental and system characteristics as well as operator decisions, that play the greatest role in determining the likelihood of major violation types. Among operator decisions, coagulant dosing and filter backwash frequency are the most important determinants of violation likelihood.     

Incentive compatible environmental regulation.

Optimal environmental regulations are derived in the presence of asymmetric information about pollution abatement costs. It is recognized that compliance may have to be induced through appropriate monitoring and enforcement measures. The regulator commits to monitoring of compliance with the incentive compatible environmental regulations, and asymmetric information characterizes the interaction between the firm and regulator. The probabilities of monitoring abatement standards and corresponding subsidies are optimally chosen to ensure firm compliance. Enforcement considerations are shown to distort downward the pollution abatement requirements mandated for firms.     

Ecological risk and accessibility analysis to assess the impact of roads under Habitats Directive

We propose a method for the appropriate assessment of adverse effects of roads in compliance with the European Union Habitats Directive. The method incorporates an analysis of ecological risk of edge effects by the proposed roads with the related increase in accessibility. The method was tested on 30 km of planned forest roads inside an 8,000-ha reserve included in two Natura 2000 sites. As a result, the cumulative effect of 19 road segments was judged as not significantly affecting the integrity of the sites, although they made accessible an extra 314 ha. On the basis of the accessibility calculation, 20 ha of land were set aside from forest exploitation as a mandatory mitigation measure. The method objectively determined the cumulative adverse effects, enabled comparison of plan revisions and alternatives and proved to measure direct and indirect significant effects with a realistic effort in terms of field survey and geographic information system processing.     

Intergenerational Impartiality: Replacing Discounting by Probability Weighting

Intergenerational impartiality requires putting the welfare of future generations at par with that of our own. However, rational choice requires weighting all welfare values by the respective probabilities of realization. As the risk of non-survival of mankind is strictly positive for all time periods and as the probability of non-survival is cumulative, the probability weights operate like discount factors, though justified on a morally justifiable and completely different ground. Impartial intertemporal welfare maximization is acceptable, though the welfare of people in the very far future has lower effects as the probabilities of their existence are also lower. However, the effective discount rate on future welfare values (distinct from monetary values) justified on this ground is likely to be less than 0.1 per annum. Such discounting does not compromise environmental protection and sustainability unduly. The finiteness of our universe implies that the sum of our expected welfare to infinity remains finite, solving the paradox of having to compare different infinite values in optimal growth/conservation theories.     

Statistical considerations of progressive value and risk in mineral exploration

Financial markets recognise maximisation of expected value (E), in an essentially risk-neutral context, as the main corporate financial objective of private enterprise. This may be valid for large, integrated mining companies. Yet, most junior and middle-size exploration companies behave in a risk-averse fashion when making decisions about progressively more expensive exploration programs. From their perspective, a potential increase in expected value from either an increase in target value or related probability of discovery, or both, may not be a sufficient incentive to embark in an exploration programme if the resultant increase in expected value is accompanied by a significant increase in possible maximum loss. Risk-averse explorers may be unwilling to bear larger, albeit less probable losses, when the cost of successive exploration programmes is taken into account. The paper provides a practical methodology for such explorers to optimise the decision whether to progress to the next stage of exploration or to farm out a risky project. It uses a decision-tree model incorporating the effectiveness of the proposed exploration programme, the explorer's risk tolerance and related utility values and the probability distribution of the possible value of the exploration target.     

Wetland Mitigation Compliance in the Western Upper Peninsula of Michigan

The Army Corps of Engineers (ACE) is generally responsible for the implementation of federal Clean Water Act wetland regulations. It therefore plays an important role in the protection of wetlands within the United States. Unfortunately, past evaluators of ACEs implementation of these regulations found low rates of regulatory compliance. However, the fact that two states have taken responsibility for the implementation of these regulations within their boundaries provided the opportunity to assess whether one of these states might be doing a better job of enforcement. This paper reports on compliance with some of these regulations within one Michigan region. We evaluated permittee compliance with paperwork filing requirements related to wetland mitigation projects. Sixty-seven percent of county road commission permittees were out of compliance with at least one filing requirement. Forty percent of private and non-county government permittees were out of compliance. Our results therefore suggest that serious problems exist with Michigans implementation of wetland regulations. They do not suggest that compliance in this state is significantly better than in states under ACE administration. We believe that increased agency monitoring and enforcement would improve compliance.     

Enforcement Lessons from the Vienna Übahn

/ This paper combines a review of recent publications on the effectiveness of environmental enforcement in the United States with new data to address the question of what type of enforcement activity is most productive. Using data on 39 state National Pollutant Discharge Elimination System (NPDES) programs, the measures of effort and cost typically applied to environmental enforcement and inspection activities were tested for relationships with compliance outcomes. No statistically significant relationships were found. In the absence of any improving trend in traditional measures of compliance, this lack suggests all enforcement systems presently used by states are failing. To work, an environmental enforcement system needs to include maintenance and restoration of compliance, real deterrence, mobilization of public opinion, minimal obtrusiveness, conformity with legal search requirements, cost-effectiveness for all parties, effective primary role for skilled inspectors, self-monitoring, compatibility with environmental management systems (e.g., ISO 14000), environmental auditing, robustness in the face of changing strategies by permittees, segregation of technical assistance from enforcement, team orientation, adaptability to multimedia, and, most difficult of all, disconnection from today's timely, appropriate, proportionate standard. These goals can be achieved through a proposed new environmental enforcement approach built on infrequent, random, but thorough inspections leading to fully documented enforcement actions resulting in high penalties. The enforcement system used by the Vienna übahn, or subway, can serve as a model for this type of environmental enforcement system. KEY WORDS: Enforcement; Deterrence; Environmental water quality; Discharge elimination systems     

GIS-based Probability Assessment of Natural Hazards in Forested Landscapes of Central and South-Eastern Europe

We assessed the probability of three major natural hazards—windthrow, drought, and forest fire—for Central and South-Eastern European forests which are major threats for the provision of forest goods and ecosystem services. In addition, we analyzed spatial distribution and implications for a future oriented management of forested landscapes. For estimating the probability of windthrow, we used rooting depth and average wind speed. Probabilities of drought and fire were calculated from climatic and total water balance during growing season. As an approximation to climate change scenarios, we used a simplified approach with a general increase of pET by 20%. Monitoring data from the pan-European forests crown condition program and observed burnt areas and hot spots from the European Forest Fire Information System were used to test the plausibility of probability maps. Regions with high probabilities of natural hazard are identified and management strategies to minimize probability of natural hazards are discussed. We suggest future research should focus on (i) estimating probabilities using process based models (including sensitivity analysis), (ii) defining probability in terms of economic loss, (iii) including biotic hazards, (iv) using more detailed data sets on natural hazards, forest inventories and climate change scenarios, and (v) developing a framework of adaptive risk management.     

铅酸电池行业环保专项行动的环境与经济影响研究

"十五"以来,我国涉重行业高速发展,造成了严重的重金属污染和多起群体性污染事故。从2009年起,环保部等九部委连续四年对重金属排放企业违法排污行为进行环保专项行动。本文以2011年铅蓄电池行业环保专项行动为例,分析重金属污染治理的环境影响、经济影响和社会影响。专项行动对行业短期赢利能力和中小企业就业有一定负面影响,但是显著改善了行业产能利用率,提升了行业整体技术水平,提高了产业集中度,促进了空间布局向工业园区、向东部地区集中。总体来看,铅蓄电池行业环保专项行动达到了预期的环境和经济目标,行业发展从高增长、高代价的"非常态"模式进入相对可持续的中高速、低代价的"新常态"。"十三五"期间,要实现经济中高速增长和环境质量总体改善的双重目标,必须加强对高污染行业的环境管理。将行政执法与刑事执法紧密衔接,通过提高企业违法成本从源头遏制违法排污行为;根据污染企业的空间布局建设相应的环保机构,加强农村地区的环保能力;在欠发达地区要保持经济规划、城镇规划和环境规划的一致性,在区域协调发展过程中实现绿色发展。     

Forest law compliance and enforcement: the case of on-farm timber extraction in Ghana

The paper investigates law compliance in case of on-farm timber extraction in Ghana. It empirically investigates compliance with rules that (i) require timber operators to obtain prior and informed consent from the farmers, (ii) require timber operators to pay appropriate and timely compensation for crop damage caused by timber extraction and (iii) ban chainsaw lumbering. The study documents a low level of compliance in all three domains. Subsequently, the paper discusses the underlying causes for the observed low compliance. The low compliance level is attributed to a legislation, and enforcement, that provides huge financial incentives for non-compliance for both farmers and timber operators, and in the latter case both with and without legal permits. At the same time the regulation is perceived to violate their moral values. The paper underlines the interests of the political elite as decisive in shaping the current regulation and the way it is implemented on the ground. It asserts that eliciting compliance requires consideration of both the instrumental and normative perspectives; else it becomes illusive. The study thus challenges the typical response of governments in developing countries, who, supported by donor agencies, attempt to elicit compliance through enhanced law enforcement efforts. The results presented on the Ghana case suggest that such an approach is unlikely to elicit compliance.     

Learning-by-catching: uncertain invasive-species populations and the value of information

This paper develops a model of invasive species control when the species’ population size is unknown. In the face of an uncertain population size, a resource manager's species-control efforts provide two potential benefits: (1) a direct benefit of possibly reducing the population of invasive species, and (2) an indirect benefit of information acquisition (due to learning about the population size, which reduces uncertainty). We provide a methodology that takes into account both of these benefits, and show how optimal management decisions are altered in the presence of the indirect benefit of learning. We then apply this methodology to the case of controlling the Brown Treesnake (Boiga irregularis) on the island of Saipan. We find that the indirect benefit—the value of information to reduce uncertainty—is likely to be quite large.     

NATIONAL FLOOD INSURANCE AND THE COASTAL ZONE: A CASE STUDY OF HURRICANE ELOISE1

ABSTRACT: This paper presents evidence that currently published flood insurance premiums may be insufficient to cover expected losses in coastal areas subject to hurricane. The problems of developing flood premiums in coastal zones are discussed and Federal Insurance Administration (FIA) reaction to these problems analyzed. Flood losses in the coastal zone of Bay County, Florida due to hurricane Eloise are compared with losses which would be predicted by the FIA. This comparison raises important questions concerning the adequacy of flood premiums in coastal zones and the undesirable indirect effects that underpricing flood risk will have on location decisions in the coastal floodplain.     

Value of information analysis for adequate monitoring of carbon dioxide storage in geological reservoirs under uncertainty

As monitoring is essential for the proper management of geological storage of carbon dioxide (CO₂), the ability to value information from monitoring is indispensable to adequately design a monitoring program. It is necessary to judge whether the expected improvement in management is worth the cost of monitoring. The value of information (VOI) is closely related to the possible increase in expected utility gained by gathering the information, the concept of which can be applied to such judgement. Although VOI analysis has been extensively studied in the context of decision analysis, its application to the management of carbon dioxide capture and storage (CCS) operations is rare. This paper introduces and discusses the methodology of VOI analyses in the context of monitoring CO₂ storage. A motivating problem with discrete probabilities is used to illustrate the concept of VOI. It is demonstrated that information is not always of value; for information to be worthwhile, monitoring under uncertainty must satisfy certain conditions. This concept is then extended to continuous probability distributions. The effects of prior uncertainty and information reliability on the VOI are examined. It is shown that an excessive improvement in information accuracy yields little value and that the optimal level of reliability can be inferred. VOI analyses provide quantitative insights into the value of information-gathering activities and therefore can be an objective means to adequately design and impartially justify a monitoring program.     

Violation analysis for solid waste management systems: an interval fuzzy programming approach

This paper introduces a violation analysis approach for the planning of regional solid waste management systems under uncertainty, based on an interval-parameter fuzzy integer programming (IPFIP) model. In this approach, several given levels of tolerable violation for system constraints are permitted. This is realized through a relaxation of the critical constraints using violation variables, such that the model's decision space can be expanded. Thus, solutions from the violation analysis will not necessarily satisfy all of the model's original constraints. Application of the developed methodology to the planning of a waste management system indicates that reasonable solutions can be generated through this approach. Considerable information regarding decisions of facility expansion and waste flow allocation within the waste management system were generated. The modeling results help to generate a number of decision alternatives under various system conditions, allowing for more in-depth analyses of tradeoffs between environmental and economic objectives as well as those between system optimality and reliability.     

A study of compliance with environmental regulations of ISO 14001 certified companies in Korea

This article investigates the impact of ISO 14001 certification on the compliance with environmental regulations by Korean companies. The impact of ISO 14001 certification on the industry was studied through a questionnaire survey and the compliance of environmental regulations were investigated using government-released data. The motivation for an environment management system was a result of the current international situation and the need to maintain fair competition. ISO 14001 certification has been recognized as an essential strategy for industrial competition and to improve company/product recognition. The certified and non-certified companies' environmental regulation violation (ERV) rates were 3.5% and 11.6%, respectively, in 1997. In 1998, the ERV rate had an eight-time difference with 1.0% and 8.5% for certified and non-certified companies, respectively. Annual regulation violation rates were reduced from 3.5% in 1997 to 1.0% in 1998 with certified companies and from 11.6% in 1997 to 8.5% in 1998 with their non-certified counterparts, respectively. ISO 14001 certified companies showed more improvement than non-certified companies in regards to environmental performance.     

Building and managing new compliance delivery systems

Companies today are continuously improving their efforts to incorporate an environmental management system (EMS) in their everyday operations and work practices, with an emphasis on identifying and reducing risks. Risks may include the cost of enforcement penalties, potential workplace dangers to employees, or cleanup liabilities due to past or present practices. Environmental auditing is an effective tool commonly used to enhance an EMS. Typically, there are two levels of auditing: (1) a review of management systems and (2) a review of compliance with regulatory requirements. There is yet another intermediate level of auditing that is more focused than management systems or compliance audits—compliance delivery systems (CDS) audits. This article examines the elements making up these systems for improving compliance performance and provides a ?ready to use”? checklist of items for managers to begin implementation.     

固定源排污许可合规制度研究

固定源合规制度是确保固定源企业将排污许可证中载明的要求得以实施的具体措施和规定,也是将排污许可制度打造为固定源环境管理核心制度的重要环节。本文基于美国固定源合规监管经验和当前国内排污许可实施基础,构建了固定源排污许可合规管理制度。所构建的制度基于整体性治理理论,以固定源企业需提交的排污许可合规报告为主要合规监管环节,将政府部门对于固定源企业的合规监管分为以合规报告为主的书面核查和企业现场核查两个环节,并在整个合规监管过程中贯彻数据管理,设计了企业合规报告、政府核查报告、核查类型及任务、核查评估方法、合规信息公开及违规处罚方式等关键内容,以节省对于固定源企业污染排放合规监管过程的环境执法资源和提升监管效率。     

ARSENIC IN THE SHALLOW GROUND WATERS OF CONTERMINOUS UNITED STATES: ASSESSMENT,HEALTH RISKS,AND COSTS FOR MCL COMPLIANCE1

A methodology consisting of ordinal logistic regression (OLR) is used to predict the probability of occurrence of arsenic concentrations in different threshold limits in shallow ground waters of the conterminous United States (CONUS) subject to a set of influencing variables. The analysis considered a number of maximum contaminant level (MCL) options as threshold values to estimate the probabilities of occurrence of arsenic in ranges defined by a given MCL of 3, 5, 10, 20, and 50 μg/l and a detection limit of 1 μg/l. The fit between the observed and predicted probability of occurrence was around 83 percent for all MCL options. The estimated probabilities were used to estimate the median background concentration of arsenic in the CONUS. The shallow ground water of the western United States is more vulnerable than the eastern United States. Arizona, Utah, Nevada, and California in particular are hotspots for arsenic contamination. The risk assessment showed that counties in southern California, Arizona, Florida, and Washington and a few others scattered throughout the CONUS face a high risk from arsenic exposure through untreated ground water consumption. A simple cost effectiveness analysis was performed to understand the household costs for MCL compliance in using arsenic contaminated ground water. The results showed that the current MCL of 10 μg/l is a good compromise based on existing treatment technologies.     

Optimal hardwood tree planting and forest reclamation policy on reclaimed surface mine lands in the Appalachian coal region

We study the optimal hardwood tree planting decision on reclaimed surface coal mines in the Appalachian region using a mine operator-focused, expected cost model that recognizes costs of preparing the site for tree planting, unit costs of planting seedlings, and opportunity costs of reforestation treatments and the performance bond. We also consider the possibility of failed initial attempts by incorporating the probability of reforestation success, based on empirical seedling ,survival rates and regulated tree survival standards, as well as fixed and unit costs of returning for additional planting. Optimal planting levels from 319 to 780 trees per acre and expected costs from $1049 to $2338 were found using simulations over a range of unit planting costs, fixed costs of replanting, tree survival standards, and interest rates. Further simulations compared optimal planting across un-weathered gray sandstone and weathered brown sandstone substrate materials, finding gray sandstone to be associated with lower expected costs. We conclude that optimal planting density and expected reforestation cost are sensitive to economic parameters, regulations, and planting substrate materials; and those policies influencing these factors may have substantial impact on reforestation outcomes and the choice of post-mining land use by mine operators. Our study provides a framework for understanding forest reclamation decisions that incorporates incentives faced by the mine operators who develop and implement the plans for mine reclamation, including forestry.     

A TREATISE ON THE USE OF EXPECTED VALUES IN WATER RESOURCE PROJECT EVALUATION1

This paper focuses on two factors that influence the acceptability of the expected value criterion as a method of handling risk or uncertainty in decision-making where damages from unusual physical occurrences such as hurricanes or floods must be considered. These are the length of time of project existence and the problem of obtaining accurate estimates of the probability of occurrence for different sizes of natural disasters. The problem of estimating accurate probabilities of occurrence for different sizes of natural disasters is not as great as it might appear and in most situations will not defeat the usefulness of the method. The time span during which the project is expected to exist has greater implications for the usefulness of the expected value approach appears highly applicable. However, it becomes less applicable for projects that are short-term in nature. The basis for distinguishing between short- and long-term projects is presented.