Empirical Estimation of the Conditional Probability of Natech Events Within the United States

Natural disasters are the cause of a sizeable number of hazmat releases, referred to as “natechs.” An enhanced understanding of natech probability, allowing for predictions of natech occurrence, is an important step in determining how industry and government should mitigate natech risk. This study quantifies the conditional probabilities of natechs at TRI/RMP and SICS 1311 facilities given the occurrence of hurricanes, earthquakes, tornadoes, and floods. During hurricanes, a higher probability of releases was observed due to storm surge (7.3 releases per 100 TRI/RMP facilities exposed vs. 6.2 for SIC 1311) compared to category 1–2 hurricane winds (5.6 TRI, 2.6 SIC 1311). Logistic regression confirms the statistical significance of the greater propensity for releases at RMP/TRI facilities, and during some hurricanes, when controlling for hazard zone. The probability of natechs at TRI/RMP facilities during earthquakes increased from 0.1 releases per 100 facilities at MMI V to 21.4 at MMI IX. The probability of a natech at TRI/RMP facilities within 25 miles of a tornado was small (～0.025 per 100 facilities), reflecting the limited area directly affected by tornadoes. Areas inundated during flood events had a probability of 1.1 releases per 100 facilities but demonstrated widely varying natech occurrence during individual events, indicating that factors not quantified in this study such as flood depth and speed are important for predicting flood natechs. These results can inform natech risk analysis, aid government agencies responsible for planning response and remediation after natural disasters, and should be useful in raising awareness of natech risk within industry.     

Reducing Drinking Water Supply Chemical Contamination: Risks from Underground Storage Tanks

Drinking water supplies are at risk of contamination from a variety of physical, chemical, and biological sources. Ranked among these threats are hazardous material releases from leaking or improperly managed underground storage tanks located at municipal, commercial, and industrial facilities. To reduce human health and environmental risks associated with the subsurface storage of hazardous materials, government agencies have taken a variety of legislative and regulatory actions—which date back more than 25 years and include the establishment of rigorous equipment/technology/operational requirements and facility‐by‐facility inspection and enforcement programs. Given a history of more than 470,000 underground storage tank releases nationwide, the U.S. Environmental Protection Agency continues to report that 7,300 new leaks were found in federal fiscal year 2008, while nearly 103,000 old leaks remain to be cleaned up. In this article, we report on an alternate evidence‐based intervention approach for reducing potential releases from the storage of petroleum products (gasoline, diesel, kerosene, heating/fuel oil, and waste oil) in underground tanks at commercial facilities located in Rhode Island. The objective of this study was to evaluate whether a new regulatory model can be used as a cost‐effective alternative to traditional facility‐by‐facility inspection and enforcement programs for underground storage tanks. We conclude that the alternative model, using an emphasis on technical assistance tools, can produce measurable improvements in compliance performance, is a cost‐effective adjunct to traditional facility‐by‐facility inspection and enforcement programs, and has the potential to allow regulatory agencies to decrease their frequency of inspections among low risk facilities without sacrificing compliance performance or increasing public health risks.     

Accident Epidemiology and the U.S. Chemical Industry: Accident History and Worst-Case Data from RMP*Info

This article reports on the data collected on one of the most ambitious government-sponsored environmental data acquisition projects of all time, the Risk Management Plan (RMP) data collected under section 112(r) of the Clean Air Act Amendments of 1990. This RMP Rule 112(r) was triggered by the Bhopal accident in 1984 and led to the requirement that each qualifying facility develop and file with the U.S. Environmental Protection Agency a Risk Management Plan (RMP) as well as accident history data for the five-year period preceding the filing of the RMP. These data were collected in 1999-2001 on more than 15,000 facilities in the United States that store or use listed toxic or flammable chemicals believed to be a hazard to the environment or to human health of facility employees or off-site residents of host communities. The resulting database, RMP*Info, has become a key resource for regulators and researchers concerned with the frequency and severity of accidents, and the underlying facility-specific factors that are statistically associated with accident and injury rates. This article analyzes which facilities actually filed under the Rule and presents results on accident frequencies and severities available from the RMP*Info database. This article also presents summaries of related results from RMP*Info on Offsite Consequence Analysis (OCA), an analytical estimate of the potential consequences of hypothetical worst-case and alternative accidental releases on the public and environment around the facility. The OCA data have become a key input in the evaluation of site security assessment and mitigation policies for both government planners as well as facility managers and their insurers. Following the survey of the RMP*Info data, we discuss the rich set of policy decisions that may be informed by research based on these data.     

The U.S. EPA Geographic Information System for Mapping Environmental Releases of Toxic Chemical Release Inventory (TRI) Chemicals

This study characterizes the environmental releases of toxic chemicals of the Toxic Chemical Release Inventory (TRI) in the southeastern United States by using the U.S. Environmental Protection Agency (EPA) Geographic Information System (GIS) to map them. These maps show that the largest quantities of TRI releases in the Southeast are usually near densely populated areas. This GIS mapping approach takes the first steps in defining those areas in the region which may be potential exposure zones and which could be strategic targets for future risk screening efforts in this geographic area.     

Hurricane Isaac: A Longitudinal Analysis of Storm Characteristics and Power Outage Risk

In August 2012, Hurricane Isaac, a Category 1 hurricane at landfall, caused extensive power outages in Louisiana. The storm brought high winds, storm surge, and flooding to Louisiana, and power outages were widespread and prolonged. Hourly power outage data for the state of Louisiana were collected during the storm and analyzed. This analysis included correlation of hourly power outage figures by zip code with storm conditions including wind, rainfall, and storm surge using a nonparametric ensemble data mining approach. Results were analyzed to understand how correlation of power outages with storm conditions differed geographically within the state. This analysis provided insight on how rainfall and storm surge, along with wind, contribute to power outages in hurricanes. By conducting a longitudinal study of outages at the zip code level, we were able to gain insight into the causal drivers of power outages during hurricanes. Our analysis showed that the statistical importance of storm characteristic covariates to power outages varies geographically. For Hurricane Isaac, wind speed, precipitation, and previous outages generally had high importance, whereas storm surge had lower importance, even in zip codes that experienced significant surge. The results of this analysis can inform the development of power outage forecasting models, which often focus strictly on wind‐related covariates. Our study of Hurricane Isaac indicates that inclusion of other covariates, particularly precipitation, may improve model accuracy and robustness across a range of storm conditions and geography.     

The Role of Geographic Scale in Monitoring Environmental Justice

Utilizing the concept of environmental justice, this paper examines the differential burdens of toxic and hazardous waste facilities locations in low income minority communities. The association between the presence of facilities and socioeconomic characteristics of places are examined for the state of South Carolina at three different spatial scales: counties, census tracts, and census block groups. Three different types of hazardous waste/toxic facilities are also examined: Toxic Release Inventory (TRI) sites, Treatment, Storage, and Disposal sites (TSD), and inactive hazardous waste sites. At the county level, there was some association between the presence of toxic/hazardous waste facilities and race and income. In South Carolina, this translates to a disproportionate burden on White, more affluent communities in metropolitan areas, rather than low income minority communities. At both the census tract and block group levels, there is no association between race and the location of toxic/hazardous waste facilities. There are slight differences in the income levels between tracts and block groups with facilities and those without. This localized ecology of hazard sources must be expanded to include emission/discharge data in order to adequately address environmental justice issues on who bears the burdens of environmental contamination.     

The Role of the Community in the Implementation of the EPA's Rule on Risk Management Programs for Chemical Accidental Release Prevention

Regulations under the 1990 Clean Air Act Amendments (CAAA) include requirements for preventing accidental chemical releases. Section 112(r) of the CAAA, the Accidental Release Provisions, requires the U.S. Environmental Protection Agency (EPA) to develop and implement regulations for preventing accidental releases to the air of regulated substances and to minimize the consequences of releases that do occur. The regulations require regulated facilities to have in place the structural elements of a sound process safety program, and to practice, document, and communicate the elements of their program. The rule requires also that registered facilities calculate and make available worst case accidental chemical release information. The rule does not set a level of risk that a facility must achieve after it takes the required compliance steps, the level of risk a community must accept, the limit of consequences the community might suffer from a worst case chemical release, nor the specific actions a community must take in its response plan. These are issues that local communities and local officials must decide. Because the regulation involves the community in many unsettled risk issues the Wharton School initiated a project within the City Philadelphia to evaluate the proposition that productive dialogue on the implementation of the Rule and resolution of unsettled risk issues can take place in advance of a crisis occasioned by a major accidental release. This paper describes the steps taken by Wharton to bring together various stakeholders in the community to explore the implementation of the rule and the reaction of those stakeholders to be involved in such a process. It outlines some principal choices communities will have to make in order to implement 112(r) and explains some of the dilemmas associated with these choices. It describes the stakeholder-based implementation effort being undertaken in Philadelphia in the hope that others may benefit from what has been learned there.     

Risk,Media, and Stigma at Rocky Flats

Public responses to nuclear technologies are often strongly negative. Events, such as accidents or evidence of unsafe conditions at nuclear facilities, receive extensive and dramatic coverage by the news media. These news stories affect public perceptions of nuclear risks and the geographic areas near nuclear facilities. One result of these perceptions, avoidance behavior, is a form of "technological stigma" that leads to losses in property values near nuclear facilities. The social amplification of risk is a conceptual framework that attempts to explain how stigma is created through media transmission of information about hazardous places and public perceptions and decisions. This paper examines stigma associated with the U.S. Department of Energy's Rocky Flats facility, a major production plant in the nation's nuclear weapons complex, located near Denver, Colorado. This study, based upon newspaper analyses and a survey of Denver area residents, finds that the social amplification theory provides a reasonable framework for understanding the events and public responses that took place in regard to Rocky Flats during a 6-year period, beginning with an FBI raid of the facility in 1989.     

Analysis of the Effects of Communication and Surveillance Facility Service Outages on Traffic Separations

This study examines air traffic separations in the service volumes of communication and surveillance facilities that experienced service outages. The data sample consists of 338 unscheduled service outages that happened in 2010 and 2011 at facilities located in the vicinity of 15 major traffic hubs. For each outage, radar track data were collected and used to calculate traffic separations during the period of 30 minutes before to 30 minutes after an outage. Then, the separation index, which indicates the percentage of horizontal separation retained between two aircraft at the same altitude, was estimated. The separation index and loss of separation events were analyzed using lognormal and negative binomial regression models. The results suggest that the count of separation events peaks during the 15 minutes after an outage. In addition, traffic collision avoidance system resolution advisory (TCAS RA) encounters and Category A separation events are 1.31 times more likely during the 30 minutes following the beginning of a service outage, as compared to the 30 minutes before the outage, for both types of facilities. Also, the separation index values are 19% lower following a surveillance facility outage and 4% lower following a communication facility service loss. This study provides evidence that unscheduled service outages of air traffic management facilities are associated with lost or reduced traffic separations and thus can be considered precursors to hazardous loss of separation events.     

Adaptive Management: A Paradigm for Remediation of Public Facilities Following a Terrorist Attack

Terrorist actions are aimed at maximizing harm (health, psychological, economical, and political) through the combined physical impacts of the act and fear. Immediate and effective response to a terrorist act is critical to limit human and environmental harm, effectively restore facility function, and maintain public confidence. Though there have been terrorist attacks in public facilities that we have learned from, overall our experiences in restoration of public facilities following a terrorist attack are limited. Restoration of public facilities following a release of a hazardous material is inherently far more complex than in industrial settings and has many unique technical, economic, social, and political challenges. For example, there may be a great need to quickly restore the facility to full operation and allow public access even though it was not designed for easy or rapid restoration, and critical information is needed for quantitative risk assessment and effective restoration must be anticipated to be incomplete and uncertain. Whereas present planning documents have substantial linearity in their organization, the “adaptive management” paradigm provides a constructive parallel paradigm for restoration of public facilities that anticipates and plans for uncertainty, inefficiencies, and stakeholder participation. Adaptive management grew out of the need to manage and restore natural resources in highly complex and changing environments with limited knowledge about causal relationships and responses to restoration actions. Similarities between natural resource management and restoration of a public facility after a terrorist attack suggest that integration of adaptive management principles explicitly into restoration processes will result in substantially enhanced and flexible responses necessary to meet the uncertainties of potential terrorist attacks.     

Containment of Polioviruses After Eradication and OPV Cessation: Characterizing Risks to Improve Management

The goal of the World Health Organization is to stop routine use of oral poliovirus vaccine shortly after interruption of wild poliovirus transmission. A key component of this goal is to minimize the risk of reintroduction by destruction of polioviruses except in an absolute minimum number of facilities that serve essential functions and implement effective containment. Effective containment begins with a complete facility risk assessment. This article focuses on characterizing the risks of exposure to polioviruses from the essential vaccine production, quality control, and international reference and research facilities that remain. We consider the potential exposure pathways that might lead to a poliovirus reintroduction, including para-occupational exposures and releases to the environment, and review the literature to provide available estimates and a qualitative assessment of containment risks. Minimizing the risk of poliovirus transmission from a poliovirus facility to increasingly susceptible communities is a crucial and ongoing effort requiring understanding and actively managing the potential exposure pathways.     

Hazardous Materials Releases in the Northridge Earthquake: Implications for Seismic Risk Assessment

In recent years, increasing attention has been given to the problem of earthquake-initiated hazardous materials releases (EIHRs). While the evidence indicates that EHIRs are an important part of the earthquake hazard profile, little attention has been given to documenting them in a way that could form the basis for more systematic estimates of their probability and consequences. Data from the January 17, 1994 Northridge earthquake document the range and nature of hazardous materials events in the impact area, including those at fixed-site facilities and in transportation systems. Proportional estimates of hazmat incidence are provided, and the implications of these data for developing risk assessments and earthquake hazard management are discussed.     

How Close Is Close Enough: Public Perceptions of the Risks of Industrial Facilities

Public opinion poll data have consistently shown that the proportion of respondents who are willing to have a nuclear power plant in their own community is smaller than the proportion who agree that more nuclear plants should be built in this country. Respondents' judgments of the minimum safe distance from each of eight hazardous facilities confirmed that this finding results from perceived risk gradients that differ by facility (e.g., nuclear vs. natural gas power plants) and social group (e.g., chemical engineers vs. environmentalists) but are relatively stable over time. Ratings of the facilities on thirteen perceived risk dimensions were used to determine whether any of the dimensions could explain the distance data. Because the rank order of the facilities with respect to acceptable distance was very similar to the rank order on a number of the perceived risk dimensions, it is difficult to determine which of the latter is the critical determinant of acceptable distance if, indeed, there is only one. There were, however, a number of reversals of rank order that indicate that the respondents had a differentiated view of technological risk. Finally, data from this and other studies were interpreted as suggesting that perceived lack of any other form of personal control over risk exposure may be an important factor in stimulating public opposition to the siting of hazardous facilities.     

Risk based facility location by using fault tree analysis in disaster management

Determining the locations of facilities for prepositioning supplies to be used during a disaster is a strategic decision that directly affects the success of disaster response operations. Locating such facilities close to the disaster-prone areas is of utmost importance to minimize response time. However, this is also risky because the facility may be disrupted and hence may not support the demand point(s). In this study, we develop an optimization model that minimizes the risk that a demand point may be exposed to because it is not supported by the located facilities. The purpose is to choose the locations such that a reliable facility network to support the demand points is constructed. The risk for a demand point is calculated as the multiplication of the (probability of the) threat (e.g., earthquake), the vulnerability of the demand point (the probability that it is not supported by the facilities), and consequence (value or possible loss at the demand point due to threat). The vulnerability of a demand point is computed by using fault tree analysis and incorporated into the optimization model innovatively. To our knowledge, this paper is the first to use such an approach. The resulting non-linear integer program is linearized and solved as a linear integer program. The locations produced by the proposed model are compared to those produced by the p-center model with respect to risk value, coverage distance, and covered population by using several test problems. The model is also applied in a real problem. The results indicate that taking the risk into account explicitly may create significant differences in the risk levels.     

Perceived Risk, Stigma, and Potential Economic Impacts of a High-Level Nuclear Waste Repository in Nevada

This study investigates the potential impacts of the proposed nuclear waste repository at Yucca Mountain, Nevada, upon tourism, retirement and job-related migration, and business development in Las Vegas and the state. Adverse impacts may be expected to result from perceptions of risk, stigmatization, and socially amplified reactions to "unfortunate events" associated with the repository (major and minor accidents, discoveries of radiation releases, evidence of mismanagement, attempts to sabotage or disrupt the facility, etc.). The conceptual underpinnings of risk perception, stigmatization, and social amplification are discussed and empirical data are presented to demonstrate how nuclear images associated with Las Vegas and the State of Nevada might trigger adverse economic effects. The possibility that intense negative imagery associated with the repository may cause significant harm to Nevada's economy can no longer be ignored by serious attempts to assess the risks and impacts of this unique facility. The behavioral processes described here appear relevant as well to the social impact assessment of any proposed facility that produces, uses, transports, or disposes of hazardous materials.     

Industry Response to SARA Title III: Pollution Prevention, Risk Reduction, and Risk Communication

This paper reports results from a survey designed to: (1) evaluate changes in industrial pollution prevention practices since the passage of the landmark environmental legislation, the Emergency Planning and Community Right-to-Know Act of 1986, also known as SARA Title III, and (2) identify those factors that may contribute to an industrial facility engaging in pollution prevention and risk communication activities. The survey was conducted under a Cooperative Agreement between the U.S. Environmental Protection Agency and the Columbia University Center for Risk Communication. Evidence from the survey indicates that a wide variety of waste and pollution reduction activities have been undertaken since passage of the Act. Virtually all facilities surveyed in the pulp and paper, chemical, and petroleum and refining industries reported that they had reduced pollutants or wastes on at least one often measures, including reducing toxic air emissions. Most facilities indicated paying more attention to pollution prevention activities as a result of SARA Title III and half reported that their communication activities have also increased.     

The Tradeoffs Associated with Rerouting Highway Shipments of Hazardous Materials to Minimize Risk

Recent legislative and regulatory activities at the federal level have focused attention on the highway routing of hazardous materials. The question is whether routes that minimize the risk of release accidents (i.e., the expected number of persons impacted by releases of hazardous materials) should be used in lieu of the routes that have the lowest operating costs. This policy issue is addressed for interstate shipments by using a national network model to determine the practical route and minimum risk route between each of 100 different origin-destination pairs (state capitals). The resulting cost-risk tradeoffs are then used to estimate the average cost of rerouting per fatality averted, the value of which turns out to be within the range of values for a number of familiar existing regulations.     

Acute Exposure to Extremely Hazardous Substances: An Analysis of Environmental Equity

Although environmental equity research has focused primarily on chronic pollution sources, recent advances in environmental modeling and geographic information systems (GIS) provide a foundation for developing measures that can be used to evaluate differential exposure to acute pollution events. This article describes a methodology that uses facility-specific information to develop a risk surface representing the spatial distribution of accidental exposure to hazardous substances in a study area. Environmental pollution models recommended by the U.S. Environmental Protection Agency were used in conjunction with GIS software to achieve this objective. The methodology was implemented in a large metropolitan region (Hillsborough County, Florida) to examine disproportionate exposure to worst-case releases of extremely hazardous substances. The environmental inequity hypothesis was investigated by directly comparing the distribution of potential exposures within each racial (non-White versus White) and income (below poverty versus above poverty) subgroup. The results indicate that a significantly large proportion of both non-White and impoverished individuals resided in areas potentially exposed to multiple accidental releases.     

Safe and Sorry: Risk, Environmental Equity, and Hazardous Waste Management Facilities

Many empirical environmental equity analyses have attempted to determine if hazardous waste treatment, storage, or disposal facilities (TSDFs) are in disproportionately minority or low-income areas. These prior analyses did not explain the extent of the risks posed by TSDFs, nor did they weight the distribution of those risks by the individual characteristics of the TSDFs. This study evaluated the risks posed by TSDFs in general and then examined whether any such risks were distributed inequitably when each TSDF was weighted by the amount of hazardous waste that it managed. Based on an assessment of the nature of the hazardous wastes that TSDFs manage, the possible exposure paths to risk from TSDFs, the laws designed to minimize the risks that TSDFs pose, and TSDFs' safety records, the attention devoted to TSDFs by environmental equity researchers is greatly exaggerated. Furthermore, based on this study's analyses, there was no pattern of the TSDFs or the risks that they posed being inequitably concentrated in disproportionately minority or low-income areas. Most of the TSDFs and the hazardous waste that they manage are in areas that are either unpopulated or have fewer minority or low-income people than the national average. There are, however, some TSDFs that are in highly populated, heavily minority or low-income areas, which results in such people being more likely overall to be in close proximity to these facilities.