Cover Image

Not for Sale

View/Hide Left Panel
Click for next page ( 8

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement

Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 7
Overview of the Approach 7 Table 1. Risk portfolio. Hazard [H] Vulner- Consequence [C] Capability Response Risk Metric (Chapters 1, 4) ability (Chapters 1, 5) [ERC] Time [RTF] (Equation 1) [V] Facility or Route Description Pop. Env. (Chapters 1, 6) (Chapter 1) (Chapters 1, 7) (Chapter 1) narios are areas where improvements may be beneficial. Clearly, scenarios with high risk esti- mates would be valuable to address as well. These decisions are the responsibility of the asses- sor or the assessment team. The goal is to make the process more rigorous, not to make it needlessly complicated. Developing a Hazmat Portfolio This Guide recommends using a relative risk-based approach to support hazmat emergency response planning decisions. A risk portfolio (column headings shown in Table 1) is used to manage the results of this process. Each column in Table 1 represents one of the elements used to compute the relative risk metric, and each row represents a particular scenario for which the planning agency needs to consider the appropriate emergency response. A scenario is a unique combination of hazardous material and location, and can also include the specific quantities involved and the frequency with which the material in those quantities is present at that location. Subsequent chapters of this Guide will address specific elements of the risk equation and will build on prior sections, resulting in a complete hazmat portfolio. Defining the Risk Metric While a planning agency may be able to qualitatively determine broad relationships regard- ing the risk of certain materials and the ability of existing emergency response teams to miti- gate the consequences of releases, using a defined process with as many quantitative elements as possible helps to establish a sound basis for policy decisions related to response coverage. The approach outlined in this Guide uses a relative risk metric to capture and integrate all of the ele- ments that contribute to the community's risk and to inform those policy decisions. This Guide uses the term "metric" to emphasize that the approach does not determine an absolute value of risk, but only a measure that is suitable for supporting planning activities. Calculating the risk metric allows you to determine the response capability that would offset expected consequences from hazmat incidents. In this section, the measure of risk is defined and the overall method- ology is presented. The risk metric is given in Equation 1 and follows the standard three-term representation of risk commonly used in many industries: Risk Metric = H V C (1) where H = hazard, V = vulnerability, and C = consequence.