the atypical assessment of risk and disaster management in … · 2014. 5. 19. · efficient...

The atypical assessment of risk and disaster management in municipalities that have Seveso II production and storage sites on their territory

D. Manca & S. Colombo Dipartimento di Chimica, Materiali e Ingegneria Chimica “G. Natta” Politecnico di Milano, Italy

Abstract

The integration of chemical hazards into the analysis of natural risks, for land use planning purposes, imposes changing perspective. Private major plants usually originate chemical hazards. Consequently, the information necessary for the characterization of risks is filtered by the property itself according to company policies. Safety analysts, working for the municipality, have to negotiate with the property the information concerning the actual risks associated with the plant. Another constraint, which further complicates the inclusion of chemical hazards into the risk analysis, is the difficulty of communicating at the multidisciplinary table with the representatives of natural risks. Actually, chemical risk is substantially different from natural risk, at least when it concerns the dynamics of accident scenarios (extremely fast with no pre-alerting signs) and the modalities (hardly confinable). QUATER, a European Community interregional safety project, developed a methodology to enable decision-makers taking pronouncement based on a more solid and risk-oriented ground. This paper, starting from the outcomes of a real case study, describes how chemical hazards can be integrated into the overall risk analysis associated with the municipality territory. It also describes why and how a negotiating figure should be set by the municipality, between council leaders and the plant property, in order to provide safety analysts with the necessary knowledge. A practical tool to perform a rough estimate of the level of chemical risk present on the municipality is also described. Such a tool should be used in the decision making process that brings the definition of the land use. In particular, a nondimensional index, Chemical Hazard Index, is presented and discussed. Finally, we explain how and why this index should be adopted as a driving force to further deepen the safety analysis as well as improving the authority decisions. Keywords: chemical and industrial risk, hazard, emergency preparedness, disaster management, land-use planning.

© 2005 WIT Press WIT Transactions on Ecology and the Environment, Vol 84, www.witpress.com, ISSN 1743-3541 (on-line)

Sustainable Development and Planning II, Vol. 2 1251

1 Political constraints

The assessment of risks and the introduction of a practical procedure, for an efficient disaster management in those territories characterized by Seveso II production sites and warehouses, are all but easy to perform due to their inherent and peculiar nature. As a matter of fact, differently to what happens for natural risks, i.e. seismic, landslide, and hydrogeologic, whose assessment is made easy by the complete sovereignty of the competent authority on land, the appraisal of industrial risk, or rather, the assessment of negative externalities, which a production site may pose on the urban territory, suffers the anomaly of being filtered by the ownership. When a natural risk has the potential of threatening the health of citizens, the local competent authority (usually the mayor) has the power of arranging repeated inspections of the territory. This allows measuring the risk in depth, while searching for the optimal solution so to reduce both the occurrence and the consequences of the identified accident scenarios. Ultimately, the proper countermeasures may be proposed and implemented. Radically different, in terms of time and content, is the approach adopted when the source of hazard is a production site or warehouse. As a matter of fact, being the risk assessment totally left in the hands of the property, for both the internally-confined accident scenarios (i.e. those whose consequences can impact on workers only) and the scenarios that produce negative externalities (i.e. those whose consequences can impact on the external local community) this approach leaves a far less degree of freedom to the local authority, who is responsible for the health of citizens. Actually, according to local Italian laws, the outcomes of risk assessment are either integrally or partially handed over to the competent authorities. For instance, the Italian municipality does not have the right of consulting the whole documentation produced by the company, but it is allowed to use an abstract for land-use and emergency preparedness purposes. Conversely, the Regional authority holds the right of assessing the thoroughness of the risk analysis and is the repository of the whole documentation. In principle, this approach may be efficient but leaves as well gray zones, which are completely uncovered if the person in charge, at the regional level, does not know in depth the real local situation. If the plant ownership is reliable and has a well-established tradition on safety production, the overall procedure of cooperation, at the municipal level, for the creation of an emergency procedure can only suffer of some laggings without significantly affecting the efficiency and quality of the adopted measures. On the contrary, when the ownership does not have a consolidated tradition on safety assessment and even worst perceives safety expenditures as a cost rather than an investment, the contents of the analysis handed over to the competent authorities may not be so much robust and may lack some fundamental principles. In short, it might not reflect realistically the status quo. In these cases, despite of the mayor having the discretion of putting pressure for better efforts and collaboration, by flagging the phantom of stopping the production in name of the health of citizens, practically speaking such a discretion is significantly


1252 Sustainable Development and Planning II, Vol. 2

counterbalanced, and often opposed, by those stakeholders who have strong economic interests and by workers too. This is certainly true when the dimension and impact of the production site is large if compared to that of the municipality. Frequently, the number of employees is significant and cannot be neglected. Based on these remarks, the QUATER project [18] outlined the need of introducing, within the municipality, the figure of a mediator whose task is supporting the municipality team. This person should be devoted to the assessment of risks and should aim at achieving the best interaction with the ownership by means of a constructive approach.

2 Technical constraints

The political constraints can become insurmountable and leave both the emergency preparedness and the disaster management in a latent and failing state if, from a technical viewpoint, there is a lack of formally accepted methodologies for risk assessment within complex socio-technical contexts. An awkward situation, like that of lack of a properly defined and working procedure for disaster management, might turn out to be unbearable in terms of life and property losses. Lastly, this situation might also bring to a catastrophe, if the source of hazard is a Seveso II production site like a chemical, petrochemical or nuclear power plant. Indeed, the dynamics of an accident scenario, produced by an industrial source, often evolves in few seconds while leaving no space for “just-in-time” management and very little margin for corrections. Consequently, industrial risks impose, from a technical perspective, the elimination of the alerting phase when laying down the plan for intervention. It is advisable that the implications of this technical constraint drive to a strong and robust coordination of all the stakeholders involved in the disaster management. The achievement of this objective calls for the harmonization of both language and way of thinking, meaning that all the actors should talk the same language and implement the same methodological approach. In this respect, it is important to take into account that, within the process industry arena, the quantification of risks is a consolidated practice. This aspect generates a further technical complexity when assessing the industrial risks for both land-use and emergency preparedness. As a matter of fact, a procedure, aimed at defining the dimension and weight of industrial risks, should be based on a quantitative approach in line with the daily practice of technical staff working in the production site. Due to the inherent and unchangeable peculiarities of lacking a direct access and sovereignty to the industrial source of risk, the efforts made by the QUATER project [18] were oriented towards proposing a procedure to rank each industrial source of risk. In this perspective, particular attention was paid to the creation of a quantitative index, whose estimation helps the local authorities in creating the necessary link between their technical staff (through the envisaged mediator) and the staff of industrial sites for satisfying the information demand. Such an index has the ambition of putting industrial and natural risks on a comparable level inside the municipality, when sitting at the negotiation table.



However, the index is shaped in a way that does not allow “peer comparison” amongst similar or adjacent municipalities. This means that in the context of decision making the indexes, associated with the different risks, will help taking decisions based on a more solid ground. This happens when considering the industrial risk in a more thorough way, as long as it is confined to the same working context, i.e. the same municipality. In the following paragraphs the overall procedure for evaluating the chemical risks and specifically the Chemical Hazard Index are extensively presented and discussed.

3 Assessment of industrial and chemical risks

Given the aforementioned peculiarities of industrial risks, the research work focused its attention on the definition of clear and well-defined procedures to evaluate quantitatively the industrial risk and specifically the chemical one. The call for quantitative methods comes from the necessity of having a detailed knowledge of the municipal territory. The main reasons are: risk assessment, emergency preparedness, disaster management and land-use planning. The appraisal of industrial risk can be divided into three levels of analysis. Depending on the degree of knowledge, the amount of available information, and the qualification of the municipality an increasing and exacting detail may be proposed and implemented. Namely, the QUATER procedure proposes [18]:

• Level 1: preliminary analysis. Identification of sources and risk areas; • Level 2: risk analysis. Identification and classification of dangerous

species; • Level 3: detailed risk analysis. Cartographic identification of both risk and

damage areas. For the sake of simplicity, a short description of the three levels is reported in the following. The municipality may implement any level, while passing from the less demanding to the most expensive if both means and times are available.

3.1 Level 1

This preliminary analysis gathers documents and data in order to identify quantify and classify either companies or warehouses that produce and store dangerous materials. Equally, the research activity identifies the sensitive centres and the distance between them and the sources of risk. Finally, if any, the other sources of risk, hydrogeologic, seismic and landslide are also investigated and mapped, so to outline possible interactions between risks (domino effects). Further details may be found in [3, 7, 12–15].

3.2 Level 2

Every production centre is described in terms of dangerous species (inlet, outlet or intermediate). For the Seveso II activities (European directive 96/82/CE and Italian law 334/99) it is possible to base the analysis on the documents that are



prescribed by law. In the other cases, which should not be neglected, it is advisable to obtain the information through an explicit written inquiry. Besides the typology and amount of chemical compounds, it is necessary to specify the flammability and explosivity limits and the toxicity thresholds (TLV, IDLH, LD50, LC50, …). See also [9, 12–15].

3.3 Level 3

A detailed risk analysis represents the most demanding level of investigation and widening. Usually, the municipality has not the skill to manage such an activity. Consequently, a third part expert is involved. This level produces the most quantitative results for the emergency preparedness and accident management. The study generates also a cartographic representation of the risk and damage areas. These areas are reproduced in terms of isoconcentration, isobaric and isoenergetic lines since pollutant emissions, explosions and fires are separately modeled (see Figures 1 and 2).

Figure 1: Georeferenced mapping of both isorisk lines and areas for a QUATER project municipality [1].

The cartographic representation of the quantitative data is usually performed through a georeferenced mapping system (i.e. GPS-GIS devices). For more detail see [1, 4–6, 11–16].

4 Evaluation of CHI , the Chemical Hazard Index

Although the third level of analysis, reported in section 3.3, is highly recommended, it should be stressed that the municipality may achieve dynamically such a degree of knowledge through a learning period watered down in years.



Figure 2: Damage area on a georeferenced mapping for a QUATER project municipality [1].

On the other side, there are several reasons, which will be described in the following that call for a quick and simple identification of the chemical hazard within the municipal territory. The main reasons can be summarized in:

• Identification of the municipal situation in terms of chemical risk due to production, storage and carriage of goods;

• Dynamic tracking of the chemical risk on the territory; • Comparison of the natural and artificial hazards to quantify their relative

weights; • Hierarchical planning of the improvements that should be implemented in

order to decrease the chemical hazard. These elements drove the QUATER project towards the identification of a Chemical Hazard Index, CHI , whose main features are:

• It is a nondimensional index; • It is limited between 0 and 100%; • It can be determined easily and univocally; • If does not require a rocket-science preparation; • It can be evaluated periodically to track any evolution of the system.

The evaluation of CHI requires answering to a set of questions. These questions are clear and the answers can be easily found in the documentation lodged in the municipality or by questioning the production sites and warehouses. Table 1 reports an excerpt of the whole questionnaire required to determine the CHI index value. It can be observed that it comprises both qualitative (yes/no) and quantitative (number of) questions. There are several branches and subunits in the questionnaire. Every point is assigned a score, is . The sum of the scores contributes to the evaluation of CHI :



Table 1: Scheme of the report card for the evaluation of the CHI index.

Section Description Content Purpose Section A Data about the

editor Data about the editor and date of compilation.

Identification of the responsible.

Section B Census of the enterprise

Quantification of the companies subject to the chemical risk (Italian law 334/99). Quantification of the companies that have produced the report as requested by law. Number of the companies whose documentation has been accepted by the Authority.

Evaluation of the degree of risk produced by the presence of either chemical companies or warehouses that produce and store dangerous species. Degree of risk bound to the absence of documentation. Lack of approval of the documentation.

Section C Documentation Check of the presence of requested documentation. Documentation about the emergency management and the relevant risks.

Evaluation of the degree of risk produced by the absence of such documentation.

Section D Carriage of dangerous good

Evaluation of the frequency of goods in transit on the municipal territory.

Evaluation of the degree of risk produced by the carriage of dangerous goods through the municipal territory.

Section E Neighboring counties and territorial data

Check of the presence of neighboring counties where are operating either chemical companies or warehouses. Check of the presence on the territory of catchment basins, landslide and seismic areas.

Evaluation of the degree of risk produced by chemical companies and warehouses on neighboring counties. Evaluation of the pollution of catchment basins. Evaluation of domino effects.



1 100

NQ

ii

MAX

sCHI

s== ⋅∑

where NQ is the total number of questions and MAXs is the maximum theoretical score (achieved in the worst case). Since the questionnaire comprises a section about the carriage of goods and a section on risks exerted by neighboring counties, it may happen that a municipality gets a positive CHI score also if neither chemical companies nor warehouses are present in its territory. It is worth underlining that the CHI index does not allow, at all, any comparison between municipalities. Since any municipality is characterized by a peculiar profile it is impracticable to compare CHI values from different counties. Conversely, as mentioned before, it is possible to compare CHI values of the same municipality measured at different times to quantify the improvement in terms of chemical hazard. As a matter of fact, there is a portion of the questionnaire that cannot be modified by human intervention, since it is intrinsic and peculiar of the territory. Conversely, there is a complementary portion of the questionnaire that can be piloted by the major to increase the safety and efficiency of the county. Moreover, the CHI index allows the major keeping the county at an optimal value. In this sense the CHI value may be considered as a gauging device that measures the quality of a county in the viewpoint of certifying its safety. Once again, the quantitative improvement of the CHI index, achieved by the major, through specifically tailored projects, cannot be compared to that of another municipality. Conversely, the CHI index outlines the road for improving the safety of citizens while keeping the operating units and warehouses on the territory. Another quite important feature of the CHI index is the possibility of informing the major quantitatively about the natural and artificial risks that are present in the territory. Actually, QUATER project has introduced [2, 8, 10, 17, 18] three more indexes that quantify the following natural hazards: seismic, landslide and hydrogeologic (respectively SHI , LHI and HHI indexes). These indexes, being nondimensional and limited between 0 and 100%, may be compared quantitatively to the CHI index in order to identify a hazard hierarchy. Through a rather simple procedure, the major can evaluate and compare the degree of natural and artificial risks that characterize the territory, while intervening accordingly on the most compelling one.

The authors wish to thank Giovanni Squassabia for his technical contribution to the QUATER project.



Acknowledgement

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[3] Drogaris G., Major accident reporting system: lessons learned from accidents notified, Elsevier Science Publishers, The Netherlands, 1993.

[4] Fullwood R., Probabilistic Safety Assessment in the Chemical and Nuclear Industries, Butterworth-Heinemann, 2000.

[5] Gifford F. A., Atmospheric dispersion calculations using generalized Garrison plume model, Nuclear Safety, 2, 56, 1961a.

[6] Gifford F. A., Use of routine meteorological observations for estimating atmospheric dispersion, Nuclear Safety, 2, 56, 1961b.

[7] Khan F. I., Abbasi S. A., Models for domino effect analysis in chemical process industries, Process Safety Progress, 17, 2, 107 – 123, 2004.

[8] Larcan E., La valutazione dell'indice di pericolosità alluvionale come guida alla localizzazione ed al contenimento del processo insediativo in “La misura dello spreco - Esercizi di valutazione ambientale strategica delle risorse fisiche”, Editor Pier Luigi Paolillo, Franco Angeli DIAP, 2004.

[9] Lees F. P., Loss Prevention in the Process Industries, Vol. 1-2-3, Butterworth-Heinemann, Oxford, 2004.

[10] Luzi L., Pergalani F., A correlation between slope failures and accelerometric parameters: the 26 September 1997 earthquake (Umbria-Marche, Italy), Soil Dynamic and Earthquake Engineering, Elsevier Science, vol. 20, pp. 301-313, 2000.

[11] Manca D., Rovaglio M., Cycom Link: Monitoraggio remoto di un impianto di incenerimento, La Termotecnica, pp. 75-80, Aprile, 1998.

[12] Marsili, G., Dal concetto teorico all’analisi del rischio – 1, IPSOA, Milano, 1996a.

[13] Marsili, G., Identificazione delle sorgenti di pericolo – 2, IPSOA, Milano, 1996b.

[14] Marsili, G., Stima delle probabilità di accadimento degli eventi incidentali – 3, IPSOA, Milano, 1996c.

[15] Marsili, G. Stima delle conseguenze per l’uomo e l’ambiente – 4, Milano, IPSOA, 1996d.

[16] Pasquill, F. The estimation of the dispersion of windborne materials, Metallurgical Magazine, 90, 33, 1961.

[17] Pergalani F., Compagnoni M., Petrini V., Evaluation of site effects in some localities of “Alta Val Tiberina Umbra” (Italy) by numerical analysis, Soil Dynamic and Earthquake Engineering, Elsevier Science, 23, 2, pp 85-105, 2003.

[18] Treu M. C. (coordinator), QUATER PROJECT, Territorial Risk Management Systems of Municipality, INTERREG IIIB MEDOC, Research group of Politecnico di Milano, 2004.



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