Assessment of Industrial Hazard for offsite Emergency Planning and Response – A simulated study on environs of Indane (LPG) Bottling Plant, North Guwahati, Assam, India.

· Articles
Authors

M.S. Singh1* & V. Saikhom2

North Eastern Space Applications Centre (NESAC),Dept. of Space, Shillong, India.

*Corresponding author:M.S. Singh, email:msomorjit69@gmail.com

 Abstract

Industrial disasters however low in frequency may have a great potential to damage the environment. The damage may be either immediate or long term. In present scenario most of the industrial sites are located in densely populated areas. Relocation of either of the industrial sites or important infrastructure e.g. settlement, school, hospital etc. is rarely possible, so the focus on improving the emergency preparedness, response planning, advance safety measures, mock drill etc. is becoming an integral part of the decision makers. A simulated accident scenario have been made and analysis of hazard/threat zonation has been carried out for Indane (Liquefied Petroleum Gas-LPG) Bottling Plant, Abhoyapur , North Guwahati using Areal Locations of Hazardous Atmosphere (ALOHA), Remotely Sensed data and GIS. In the present study, an attempt has been made to generate the maximum probable threat zones of key hazards such as-toxicity, flammability, thermal radiation and over pressure using various parameters. The result of the study may provide a comprehensive idea for emergency planning and response at district level.

Keywords Emergency preparedness, LPG, ALOHA, remotely sensed data, GIS

Introduction

Industrialization is an emerging large scale global phenomenon since it plays a significant key role in the development of a country or region. India is also considered as one of the fastest developing country in terms of industrial and technological sector. These led to the increase in frequency and severity of accidental disasters related to industry. Industries that are processing, manufacturing, refining and storing chemical and petrochemical products as well as transportation of hazardous substances are the major sources of industrial hazard (Sengupta, 2007). There are about 1666 Major Accident Hazard Units (MAH) in India which is handling a large number of chemicals as raw materials, in processing, products, and wastes, with flammable, explosive, toxic properties (NDMA, 2007). Chemical disasters, though low in frequency has a great potential to cause immediate or long term damage. Hazardous installations pose a major source of risk for the human population and the environment. Therefore, it is of great importance to understand the potential hazards involved. It is also vital to keep the information in the form of maps that illustrate the possible consequences of any accident that could happen at an industrial installation (Sales et al., 2007). In today’s scenario most of the industrial sites are in densely populated areas. Relocation of these sites or sensitive neighbourhood like residential areas, important infrastructural setup is rarely possible (Jochum, 2011). It may be noted that time is a critical factor in the first moments of an accident. A mismanaged response due to lack of preplanning can contribute to raise in fatalities and injuries as well as an increase in damage to property and the environment (FEMA, 1987).

The present study is an attempt towards the development of a methodology for industrial hazard / threat zonation analysis. This simulated study is to attempt for providing comprehensive ideas about probable hazardous consequences in terms of spatial coverage. Moreover, the study shall demonstrate the advantages and the utility of remote sensing and Geographic information System (GIS) in various stages of the study.

Study area

The Indane (LPG) Bottling Plant of Abhoyapurgaon is situated on the northern side of Guwahati city separated by the River Brahmaputra. It comes under the marketing division of Indian Oil Corporation Ltd. (IOCL) and deal for domestic and commercial use. The plant was commissioned in 1994 covering an area of 23.30 hectares (approx). Indian Institute of Technology (IIT), Guwahati is the nearest important infrastructure. Guwahati, the district headquarter of Kamrup is the largest city of Assam. It is also considered as one of the fastest growing, a major commercial, educational hub as well as gateway of North East India. It is situated on the bank of the River Brahmaputra covering between 91º30‘E to 91º50‘E longitudes and 26º05‘N to 26º10‘N latitude (Figure 1) with an area of 261.77 sq.km (Guwahati Master Plan Area). The major portion of the city is in the southern bank of the river. The city is well connected with various means of transport systems such as roads, rails, air, water etc. with the rest of the country. The city has attained 9.63 lakhs of population with 91.11% average literacy rate by 2011 census. The climate is humid subtropical by nature. The highest and lowest temperature is recorded in the month of April- May and January of the year.

Materials and methods

Considering the various environmental constraints pertaining to the study area and the level of information required, very high resolution (VHR) remotely sensed data was used. Specifications of various type of data used is given in Table 1. At the same time in order to meet the objective of the through integrated approach using the strength of remotely sensed data and GIS (NESAC, 2011). Photogrammetric techniques have been used to generate Digital Elevation Model (DEM) from high resolution stereo pair satellite imagery using the Differential Global Positioning System (DGPS) surveyed points collected from the field survey. Ortho-rectification of VHR satellite data has been done using the DEM generated. The quality of the ortho-rectified satellite data are improved using Digital Photometric methods and various Image Enhancement techniques. The satellite data thus prepared was used for pre-field interpretation to identify the hazardous installation locations and extraction of building footprints, preparation of broad landuse and landcover of the surrounding area, field data collection, post-field interpretation etc. The analysis and generation of final hazard/ threat zonation maps was carried out using Areal Locations of Hazardous Atmosphere (ALOHA) software (U.S.E.P.A, 2007). The parameters such as (1) maximum temperature of a particular time of a day of the year; (2) wind speed; (3) wind direction; (4) relative humidity; (5) cloud coverage as well as the chemical properties and the storage properties were considered. The resultant output thus generated was integrated in GIS environment to understand the extent and distribution of hazard/ threat zones spatially. The broad approach is shown in the flowchart (Figure 2).

Table 1 Data used in the present study

Sl. No.

Sensor

Spatial resolution (m)

Date of acquisition

1.

IRS P5 Cartosat-I

2.5

5th Jan. 2009

2.

World View–I Panchromatic

0.5

8th Jan. 2009

3.

World View–II Multispectral

2.4

25th Nov.2010

4.

Others

Existing maps & literature

 

Hazard Addressed

Hazard can be defined as the probability of occurrence of potentially damaging phenomena within a specified period of time in a given area (Westen et al., 2000). Hazards are the situations that have the potential for causing injury to life and/ or damage to property and the environment (U.S.E.P.A, 1987). It can be categorized broadly into natural hazards and technological hazards. Natural hazards are those outcomes which are due to origin of natural processes of endogenic, exogenic as well as climate or land-use change e.g. neotectonics, floods, landslides, jokulhaups, desertification, soil erosion etc. On the other hand, technological hazard refers to the origins of incidents that can arise from human activities such as the manufacture, transportation, storage, and use of hazardous materials (Gilbert Gedeon, P.E, 2003). It is also defined as interaction between technology, society and the environment (Cutter, 1993). Industrial hazard is one of the technological hazards and defined as “accidental failures of design or management relating to large scale structures, transport systems or industrial processes that may cause death, injury, property loss or environmental damage on a community scale” (Smith K, 2013). However, natural processes may sometimes induce technological/ industrial disasters. A lightning strike causing fire at Venezuela’s El Palito Refinery (BBC News, 2012) is a typical example of hazard induced by natural process. Different types of hazard and their degree of severity may be defined depending upon the type of chemical and its sources. Toxicity, flammability, thermal radiation (heat), overpressure (explosion blast force) related to chemical releases that result in toxic gas dispersions, fires and/ or explosion are some of the most common types of industrial hazards (Sengupta, 2007).

Result and Discussion

Hazard analysis is primarily the most important step and overall procedure for evaluating the hazards, consequences, vulnerabilities, probabilities and risk associated with the presence of hazardous material within any given locality or jurisdiction (FEMA, 1987). It will provide as an important input for offsite comprehensive emergency planning. Comprehensive planning requires clear understanding of various types of hazards exist and what risk they pose for various members of the community (U.S.E.P.A, 1987). A simulated study has been carried out for Indane (Liquefied Petroleum Gas-LPG) bottling plant which is located on the northern bank of River Brahmaputra. The plant is identified as one of the Major Accident Hazard (MAH) units by Chief Inspector of Factories, Govt. of Assam (List of MAH units of Assam, 2012). The purpose of this simulated study is to provide probable hazardous consequences in terms of spatial coverage. The information highlighted will be an additional aid to give focus on district level offsite emergency preparedness, response planning (during and after), mock drill, enhanced safety measures etc. Moreover, it also requires having proper information on existing landuse/ landcover of the surrounding plant site. The broad landuse/ landcover map is given in Figure 3.

In this plant there are two spherical tanks – Horton Sphere 1 and 2 (14m diameter) with capacity of 600 MT each and two Mounded Bullet 1 and 2 (3.35m diameter, 42.42m length) with capacity of 125 MT each. The present study has been carried out for Horton sphere 1 storing 600 MT of Liquefied Petroleum Gas (LPG) and estimated the areas of probable threats of key hazards such as toxicity, flammability, thermal radiation and over pressure by integrating along with prevailing local atmospheric parameters. Moreover, in order to understand the maximum area extends during any incident, it has been considered that the tank is filled to its maximum capacity to create the worst case scenario. Worst case scenario is defined as “the release of the largest quantity of a regulated substance from a single vessel or process line failure that results in the greatest distance to an endpoint” i.e. the distance a toxic vapour cloud, heat from a fire, or blast waves from an explosion will travel before dissipating to the point that serious injuries from short-term exposures will no longer occur (USEPA, 2009). Propane (C3H8) was considered as an alternative in the analysis for Liquefied Petroleum Gas (LPG). For the purpose of analysis 21st May, 2011, 14.30 hours recorded by Automatic Weather Station (AWS) located at Kahikuchi, Borjhar Guwahati has been considered. At this hour the air temperature recorded was 35.65° C and the prevalent wind speed and direction was 1 meters/ second from 358.99° true north. The relative humidity was 46%, cloud cover 3 tenths with atmospheric stability class B.

Each key hazards or threat zones show an overhead view of the regions in the atmosphere with specific Level of Concerned (LOC) i.e. a threshold value of a hazard above which a threat to people may exist. Each hazard/ threat zone is shown in different colours such as red, orange and yellow. The red zone represents the worst hazard and the orange and yellow zones represent areas of decreasing hazards. The origin (0, 0) in each plot represents the centre or release point of the respective hazards. An uncertainty dashed line known as confidence line enclosed each hazard zones if there is a change under atmospheric stability. The type of the LOC is depending on the scenario. For toxic gas dispersion scenarios, an LOC is a threshold concentration of the gas at ground level above which a hazard is believed to exist. Each LOC estimates a threat zone where the hazard is predicted to exceed that LOC at some time after a release begins. Toxic LOC also referred as exposure limits, exposure guidelines, or toxic endpoints. It is also expressed by an exposure guidelines designed to help the emergency responders known as Acute Exposure Guideline Levels (AEGLs). AEGLs estimate the concentrations in terms of ppm or percentage at which most people including sensitive individuals such as old, sick, or very young people will begin to experience health effects if they are exposed to a toxic chemical for a specific length of time (duration). The toxic threat zone modeled by ALOHA superimposed on satellite data and ward boundary is shown in Figure 4.

The colour red, orange and yellow regions represent the respective predicted LOC values (AEGL) that exceeds at some time after the release begins. The worst hazard level i.e. red threat zone (AEGL-3) extends 732 meters in the downwind direction with a concentration greater than 33000 ppm.. The orange (AEGL-2) and yellow (AEGL-1) zones with 995 meters and 1.7 kilometers with a concentration greater than 17000 ppm and 5500 ppm respectively. The wards that are likely to be affected with toxic hazard threat zones of different concentrations are given in Table 2 below

Table 2 Toxic hazard threat zones

Red (7.9 ppm = PAC-3) North Guwahati (small South western part), Shilagrant (S-Eastern Part), Tilingaon (Central & Southern part), Abhoyapurgaon  (southwest portion)
Orange (0.031 ppm =PAC-2) Shilagrant (Central southern Part), Tiligaon (extreme Southern part), North Guwahati (Southern central part)
Yellow (0.0028 ppm =PAC-1) Shilagrant (southern Part), North Guwahati (extreme Southern part), Namalijalah (extreme southern part), Amingaon (extreme SE corner)

A flammable Level of Concern (LOC) is a threshold concentration of a fuel in the air above which a flammability hazard may exist. It is the prediction of flammable area i.e. part of a flammable vapour cloud where the concentration is in the flammable range between Lower and Upper Explosive limits (LEL & UEL). This is also known as Lower and Upper Flammability limits and expressed in terms of percentage. The flammability threat zone modeled by ALOHA, superimposed on satellite data and ward boundary is shown in Figure 5. In the figure the red threat zone extends 1.1 km. in the downwind direction with a concentration of 12600 ppm (60% LEL) and yellow threat zones with 2.9 km. with a concentration of 2100 ppm (10% LEL) representing the estimated flammable area where a flash fire or a vapour cloud explosion could occur at some time after the release begins. The wards that are likely to be affected with flammable vapour cloud of different concentration are given in Table 3 below

Table 3 Concentration of flammable vapour clouds in various wards

Red (12600 ppm = 60%lel = Flame Pockets) Abhoyapurgaon (southwest protion), North Guwahati (Southern part), Tiligaon(Central & Southern part), Shilagrant (S-Eastern Part)
Yellow (2100 ppm = 10%lel) Shilagrant (southern Part), Tilnigaon (extreme Southern part), North Guwahati(Extreme southern part), Amingaon (Extreme southwest corner), Namlijalah (extreme southern part), Extreme northern part of Dehangari gaon, Sadilapur,Garhpandukumarpara, Bharalumukh, Ulubari town, Ulubari 25 (western portion)

A thermal radiation Level of Concern (LOC) is a threshold level of thermal radiation (heat) above which a hazard may exist. This radiation may be from pool fire, jet fire, or Boiling Liquid Expanding Vapour Explosion (BLEVE) and expressed in terms of kilowatts per square meter. BLEVE typically occurs in closed storage tanks that contain liquefied gas, usually a gas that has been liquefied under pressure. When it is heated by fire, increasing the pressure within the container until the tank ruptures and fails with an explosion. The thermal radiation threat zone of BLEVE modeled by ALOHA, superimposed on satellite data and ward boundary is shown in Figure 6. The worst hazard level estimated extends 1.0 km. in all directions as well as orange and yellow 1.4 and 2.2 km respectively. The wards that are likely to be affected with different degree of thermal radiation threat zones are given in Table 4 below.

Table 4 Thermal radiation threat zones in different wards

Red (10.0 kW/(sq m) = potentially lethal within 60 sec) North Guwahati (South western part), Shilagrant (Eastern Part), Tilingaon (Central & Southern part), Abhoyapurgaon (South & southwest portion)
Orange ((5.0 kW/(sqm)=2nd degree burns within 60 sec) Shilagrant (Some central portion) N-Guwahti (south western part), Rudreswar, Tilingaon (Eastern Portion), Abhoyapurgaon (Central portion)
Yellow (2.0 kW/(sqm)=pain within 60 sec) Gauripur (Southern Portion), Rudreswar (NW corner), Shilagrant (western part), Ghoralan, Namlijalah (Eastern portion), North Guwahati (Central Portion), Tilingaon (Extreme Eastern portion), Abhoyapurgaon (Northern portion)

An overpressure Level of Concern (LOC) is a threshold level of pressure from a blast wave, usually the pressure above which a hazard may exist and expressed in terms of pounds per square inch (psi). The overpressure (blast wave) threat zone modeled by ALOHA, superimposed on satellite data and ward boundary is shown in Figure 7. The red threat zone was not plotted because the LOC was never exceeded. However, orange and yellow are predicted to extend 1.0 and 1.6 km in the downwind direction. The wards that are likely to be affected with different threat zones of overpressure are given in Table 5 below.

Table 5 Threat zones of different wards

Orange (3.5 psi = serious injury likely) Extreme southwest portion of Abhoyapurgaon, south-easternpart of Tilingaon, small south western part of North Guwahati,north-eastern part of Shilagrant 
Yellow (1.0 psi = shatters glass) Southwest portion of Abhoyapurgaon and North Gwahati, central and southern part of Tilingaon and northeastern part of Shilagrant.

The overall scenario of various possible hazards (LPG) of Horton Sphere no. 1 is given in Table 6

Table 6 Overall Scenario of Horton Sphere no. 1 – Liquefied Petroleum Gas (LPG)

Scenario

Threat/Hazard

Modeled

Red Zone

Orange Zone

Yellow Zone

Toxic Dispersion

Toxicity

732 m

995 m

1.7 Km

Flammable Area

Thermal Radiation if a flash fire occurs

1.1 Km

No LOC selected

2.9 Km

BLEVE (Boiling liquid expanding vapour explosion)

Thermal Radiation

1.0 Km

1.4 Km

2.2 Km

Vapour Cloud Explosion

Overpressure

LOC never exceeded

1.0 Km

1.6 Km

Conclusion

In the entire process of the study, an attempt has been made to estimate the areas near a short-duration of chemical release and their probable threats of various key hazards such as-toxicity, flammability, thermal radiation, over pressure. The information may provide first hand ideas for emergency responders in planning the direction of evacuation plan of general public during emergency as well as further assessment of vulnerability and associated risk. In addition, it may be used as an important input in carrying out of environmental impact assessment. The generation of entire hazard/ threat zones of various scenarios has been carried out by setting a constant time of a particular day of a month of the year and its local atmospheric condition to have the maximum extent in terms of spatial coverage. In addition, very high resolution remotely sensed data has played a significant role in the identification of various storage facilities and individual tanks. It also helped to interpret the various existing natural and man-made features. It may be noted that if any accident happened in any of the storage tanks, the extent of the hazard/ threat zones from the adjacent one may not be same as analyzed above, due to various reasons.

Acknowledgement

The authors conveyed deep gratitude to the Assam State Disaster Management Authority, under Revenue and Disaster Management Department, Govt. of Assam, India for giving an opportunity to carry out the study.

References

BBC, News. 20 Sept., 2012. Last updated 08.43 GMT Latin America. Retrieved April 12, 2013 from http://www.bbc.com/news/world-latin-america

Chief Inspector of Factories, 2012. List of Major Accident Hazard (MAH) Industries (Chemical) in the state of Assam.

Cutter, S. L., 1993. Living with Risk: The Geography of  Technological Hazards. Hodder Education Publishers, Pub. Date: 01/28/1993 ISBN: 0340529873

Federal Emergency Management Agency, U.S. Department of Transportation, U. S. Environmental Protection Agency, 1987. Handbook of Chemical Hazard Analysis Procedures. Washington, D. C.: Federal Emergency Management Agency Publication Office.

Gilbert Gedeon, P.E. 2003. Integrating Manmade Hazards into Mitigation Planning course no. 505-003 Credit: 5 PDH.

Jochum, C. 2011. Approach to Land-use planning at Major Hazard Sites in Germany. In: Gupta, A. K, Nair, S. S. (Ed.) Environmental Knowledge for Disaster Risk Management, Abstracts 10-11 May, 2011, Vigyan Bhavan, New Delhi, India, pp. 16.

National Disaster Management Authority (NDMA). 2007. National Disaster Management Guidelines – Chemical Disasters (Industrial).

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Sales, J., Wood, M., Jelinek, R. 2007. Risk Mapping in Industrial Hazards in New Member States. Joint Research Centre (JRC) Scientific and Technical Reports, European Commission.

Sengupta, A. 2007. Industrial Hazard, Vulnerability and Risk Assessment for Landuse Planning: A Case Study of Haldia Town, West Bengal.

Smith, K. 2013. Environmental Hazards. Routledge Publications, Sixth Edition. ISBN: 9780415681063 (pbk).

U.S. Environmental Protection Agency, Federal Emergency Management Agency, U. S. Department of Transportation. 1987. Technical Guidance for Hazards Analysis-Emergency Planning for Extremely Hazardous Substances.

U.S. Environmental Protection Agency, NOAA, 2007. Aerial Location of Hazardous Atmosphere (ALOHA). User Manual.

U.S. Environmental Protection Agency. 2009. Risk Management Program Guidance for Offsite Consequence Analysis. EPA 550-B-99- 009.

Van Westen, C.J., Soeters, R. 2000. Remote Sensing and GIS for Natural Disaster Management. In: Roy P.S, van Westen C.J, Jha V. K, Lakhera R.C, Champaty P.K (Ed.) Natural Disaster and their Mitigation-A Remote Sensing and GIS Perspective.

Sl. No.

Sensor

Spatial resolution (m)

Date of acquisition

1.

IRS P5 Cartosat-I

2.5

5th Jan. 2009

2.

World View–I Panchromatic

0.5

8th Jan. 2009

3.

World View–II Multispectral

2.4

25th Nov.2010

4.

Others

Existing maps & literature

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