Introduction and Overview

Abstract

There exist many handbooks that offer technical explanations and guidance on fire safety design and on safeguarding the environment, but not the combination. This handbook presents an introduction to fire, its impacts on the environment, and strategies for mitigating both fires and their environmental impacts. It presents examples of significant environmental impacts associated with fire and firefighting, some basics on the chemistry and physics of fire, and means to predict fire and smoke development and spread. The scale considers a range from individual buildings to wildland fires. Means to measure fire effluent and estimate fire impacts on the environment are overviewed, and mitigation strategies across the scale of fires is introduced. This chapter provides a brief introduction to the impact of fire on the environment and to each chapter in the handbook.

1.1 The Problem

Broadly speaking, environmental impacts of fire relate to any fire outcome which affects the physical, chemical, biological, cultural or socioeconomic components of the environment. Impacts can be direct or indirect. In addition to carbon emissions and the associated impact on climate change potential, direct impacts can include non-carbon contamination of the air by products of combustion distributed via the fire plume, contamination of soil and water from the deposition of products of combustion, and contamination from fire suppression agents and firefighting water runoff containing toxic products (Fig. 1.1).

Fig. 1.1

Aerial view of October 23, 2009 fire, Caribbean Petroleum Investigation. (Source: https://www.csb.gov/caribbean-petroleum-investigative-photos. Accessed July 2020)

These in turn can result in harm to ecosystems, wildlife and people, as well as cleanup and recovery costs. The impacts can be local (e.g., associated with a vehicle or small building fire), regional (e.g., as associated with a chemical facility fire or small wildland fire) or even global (e.g., as associated with a large wildland fire), with the magnitude of the impact being a function of the type and quantity of materials burning, size and duration of the fire, contributions from fire suppression and control agents and techniques, weather conditions, and environmental susceptibility in the impacted area (Fig. 1.2).

Fig. 1.2

Source to recipient pathways

When considering environmental impacts of fire, several factors need to be considered, including the pollutants (contaminants) released by the fire and/or suppression material, the exposure pathway (direct impacts), the receptor susceptibility and secondary effects. Contamination of air, soil and water can result from several products of combustion or suppression, including metals, particulates, polycyclic aromatic hydrocarbons (PAHs), chlorinated dioxins and furans, brominated dioxins and furans, polychlorinated biphenyls and polyfluorinated compounds (Fig. 1.3).

Fig. 1.3

Schematic representation of fire and impacts to the environment [1]. (Modified from ©2020, FPRF, permission pending)

The type, quantity and persistence of such substances are important in assessing impacts to various receptors. Some of these substances may not persist long after a fire (e.g., particulate may become diluted in the fire smoke plume as it spreads), while others may remain for some time, such as metals in soil or bioaccumulation of pollutants. In addition, some fire impacts can have long-term effects, other than from release of materials, such as loss of vegetation and subsequent erosion due to wildland fire, which can last from months to years (Table 1.1).

Table 1.1 Connection between recipient, fire exposure and cost of the environmental impact of fires [1]

This handbook on Fire and the Environment: Impacts and Mitigations, aims for the first time to bring together into a single resource a comprehensive overview of the impacts that fire has on the environment, the range of tools available to assess the fire and its impacts, and the approaches that can be taken to reduce or mitigate the impact across the spectrum from individual facility fire to large area wildland fire. The topic of fire impacts on the environment is very broad, has been researched across numerous scientific disciplines, and across all scales. It is not possible to capture the full extent of this research and mitigation guidance in a single document, nor is that practicable for the user. Rather, the aim of this handbook is to present an introduction to the major topic areas and provide reference to in depth treatments of the various issues. It is expected that future editions will expand both in breadth and depth as the need arises and feedback from the users is obtained.

This handbook has been developed by experts in various areas of fire and its impact on the environment. It is structured to provide information on a topical basis along the progress of historical context, fundamentals on fire, dispersion and measurements of fire effluents, building fires, wildland fires, transportation fires, impacts of fire and firefighting in these areas, costs of environmental impact of fires, and physical and regulatory approaches to reduction and mitigation of fire impact.

1.2 Historically Significant Fires

Arguably, the environmental impact of fire only started to gain attention when the broader environmental protection movement began in the 1960s and 1970s. A key event was a fire – the 1969 burning of the Cuyahoga River in Cleveland, Ohio [2], which helped further the public’s understand of the breadth of the damage being done to the environment by industrialization and became one of the events cited as helping to launch the formation of the US Environmental Protection Agency (US EPA).

As fire became understood as a source of impact on the environment, so too did impacts of firefighting. A benchmark example here was the 1986 high-profile fire at the Sandoz Ltd. warehouse near Basel, Switzerland [3]. The warehouse contained some 1250 tons of pesticides, solvents, dyes, and various raw and intermediate materials. After fire broke out, the fire service was on site for hours pouring water on the fire to control its spread. However, there was insufficient means to control the firefighting water runoff, and tons of hazardous and toxic materials contaminated the surrounding soil and flowed into the Rhine River. It is estimated that approximately 9 tons of pesticides and 130 kg of organic mercury compounds infiltrated the soil. The chemicals discharged into the Rhine River by the firefighting runoff resulted in large-scale kills of benthic organisms and fish, particularly eels and salmonids, with impacts observed as far away at the Netherlands. Of particular note was the eel kill, which spread from Schweizerhalle some 400 km downstream to Loreley (near Koblenz). In addition, other fish species were also severely affected, including grayling, brown trout, pike, and pikeperch, as well as typical food for the fish.

More recently, the environmental impacts of wildland fire have gained widespread attention. The extensive wildland fires in Australia, Europe and the Americas since 2017 have resulted in widespread damage (Fig. 1.4).

Fig. 1.4

Smoke cloud from the Lac Megantic petroleum fire [4]. (Source: Wikipedia, 2013)

In Chap. 2, a selection of fires that have had a significant immediate and/or lasting impact on the environment, based on their size and scope, are overviewed. These include mainly large-scale events where information is available concerning interaction between the fire and the environment. The scope includes significant facilities, transportation and wildland fires.

1.3 Fire Fundamentals

The use of fire by humans is a major factor in the evolution of human invention and progress. However, uncontrolled fire has also resulted in significant disasters, from the leveling of cities to the devastation of forests. Chapter 3 provides an introduction to fire fundamentals, including combustion, preventing ignition, and extinguishing fires, from the perspective of the physics and chemistry that influence these processes.

The discussion begins with the ‘fire tetrahedron’, the sides of which are fuel, heat, an oxidizing agent, and an uninhibited chemical chain reaction, the components required for fire (combustion). From there, combustion reactions, basics of ignition, fuel properties and phases are presented. The mechanisms of heat transfer – conduction, convection and radiation – are then discussed, followed by fluid mechanics. The chapter rounds out by presenting fundamentals of fire in compartments and fires that burn in the open. Throughout the chapter, a number of references are provided to help those seeking more in-depth treatment of the topics covered (Fig. 1.5).

Fig. 1.5

Fire tetrahedron [5]. (Reprinted by permission of Pearson Education, Inc., New York, New York)

1.4 Fire and Smoke Modelling

Building on the fundamentals of fire, Chapter 4 provides a summary of knowledge and information underpinning the modelling of fires and release of pollutants to the atmosphere. With a focus on fire impacts on the environment, a particular focus is the pivotal role that wind phenomena take in the pollutant dispersion (Fig. 1.6).

Fig. 1.6

Fire and smoke plume from exterior fire. (Source: https://www.csb.gov/barton-solvents-flammable-liquid-explosion-and-fire/, accessed June 2020)

The starting point is a history on computational modelling of fire in compartments, discussing how heat transfer and fluid mechanics drove research into the dynamics of fire in compartments, and how the advent of computer modelling allowed for the ready consolidation of knowledge into practical tools. It traces developments from simple one- and two-zone models into more elaborate computational fluid dynamics approaches. Next comes an overview of computational wind engineering and models developed to assist in that discipline, and how the fire and wind modeling can be coupled together.

From this start, a comprehensive exploration of computational fluid dynamics (CFD) frameworks is provided. How CFD modeling can be applied to fire and smoke modeling, for assessing environmental impacts, and some of the challenges faced are then presented.

1.5 Emission Measurements

An important aspect of evaluating the environmental impact of fire is the ability to measure the emissions from a fire. Chapter 5 begins with an overview of why it is important to measure fire effluents, as well as challenges faced in doing so. The types of effluents emitted, how they might travel to and disperse in air and water, and their duration and persistence is discussed (Fig. 1.7).

Fig. 1.7

Sampling options. (Adapted from ISO 26367-1 and ISO 26367-2)

With this foundation, discussion of sampling requirements, methods and techniques is presented. Sections on emissions to air, water and land overview exposure pathways and sampling opportunities. This is followed by technologies for sampling in each type of environment. Throughout, reference is made to standards, guidelines and related resources which provide more detail on each aspect.

1.6 Fires in Enclosures

To understand the environmental impact of fire from facilities, one needs to understand something about fires in enclosures and fire spread within buildings, as well as how fires in enclosures can be controlled. Chapter 6 provides an overview of important factors, several which are reflected in Fig. 1.8.

Fig. 1.8

Factors influencing environmental impact from enclosure fires

In any enclosure (single compartment to building of many compartments), the type and amount of fuel influences the amount of combustion product, which influences size and spread of the fire (see Chaps. 3 and 4) and the damage caused. Enclosure factors which influence the fire include the volume of compartment and size and number of ventilation openings. Factors such as fuel type, load and distribution, rate of heat release and smoke production, and effluents associated with enclosure fires are discussed.

There are also significant factors not directly related to the combustion process. Means to mitigate the fire (see also Chap. 10) include compartment construction and fire safety systems, including response time and tactics during fire suppression. When manual firefighting is needed, the time and tactics also result in contaminated runoff water, which may or may not have firefighting chemical additives (see Chap. 10), that can potentially pollute the ground water, soil and the community water handling system. The demolition of the building and its restoration, and in some cases restoration of the soil around the enclosure, have environmental effects as well, as does the environmental cost of rebuilding and replacement of the contents of the building.

1.7 Wildland Fires

Wildfires, and their associated management activities, can have complex social, economic, and environmental impacts. Chapter 7 highlights some of the key impacts of wildfires, focusing on communities, biodiversity, water and soil and air quality. It then highlights the role of dynamic fire behaviors that lead to the most severe impacts.

A single wildfire can have wide-ranging effects on biodiversity. The effects of a single fire will depend on properties of the fire event such as fire behavior,

intensity and extent. This chapter discusses properties of wildfires, including how they are impacted by fuels, climate and weather conditions, and impacts to flora and fauna, water, soil and air quality that result (Fig. 1.9).

Fig. 1.9

California fires from space. (Source: NASA Goddard Photo and Video reproduced under license CC BY 2.0)

A discussion is also provided on the growing magnitude of wildfires and how climate change is influencing this. The chapter presents a case study from the 2009 fires in the Australian state of Victoria, and closes by describing the impacts of the 2019/20 fire season in south-eastern Australia as example of the extreme impact of wildland fire on people and the environment.

1.8 Firefighting Chemicals

In Chap. 8, firefighting chemicals (FFCs) are discussed, including chemical properties of classes of FFCs and potential impacts on the environment. A brief overview of the taxonomy of FFCs and a historical perspective on their development is provided. The mechanisms by which FFC function as fire suppressants is overviewed along with typical methods of application, with a focus on wildland fire suppression (Fig. 1.10).

Fig. 1.10

FFC release at Grand Canyon National Park, Arizona, 2006. (Source: https://www.nps.gov/Media/photo/view.htm?id=03BA34D8-1DD8-B71B-0B485B3AFF136A6A)

A discussion on different types FFCs, based on short-term and long-term persistence is provided. The environmental impacts are then discussed, including aquatic and terrestrial. A brief discussion on human health impacts is also presented. This chapter closes by introducing trends towards more eco-friendly FFCs, which have become available in recent years.

1.9 Tools and Techniques for Impact Analysis

There exists a variety of methods that can be used to assess the environmental impacts of fire. Chapter 9 considers the types of environmental impacts that result from fire emissions, models for assessing the impact of these emissions and mitigation efforts to minimize these impacts (Fig. 1.11).

Fig. 1.11

Schematic overview of water cycle and access to it from a fire

The discussion begins with emissions and the pathways to environmental exposure – air, water and soil. Methods to represent the risk associated with the emissions is presented, followed by means to assess impacts.

Impact assessment methods that are addressed include benefit-cost analysis (BCA), life-cycle cost analysis (LCCA), life cycle assessment (LCA), and a selection of hybrid models.

1.10 Mitigation Strategies for Buildings

There are many fire protection systems and features that can be implemented as part of building fire mitigation strategies. These can be largely grouped into (1) means to prevent fire ignition, (2) means to manage the development and spread of fire and fire effluents, and (3) means to manage impacts to that which is exposed to the fire and its effects. These approaches are outlined in Chap. 10. These three approaches are reflected well in the Fire Safety Concepts Tree (FSCT) published by the National Fire Protection Association in the USA [6]. However, the focus of the FSCT is largely on people and property, and not the environment. As used in the context of environmental impacts, a modified structure is introduced in Chap. 10, called the Environmental Impact of Fires Management Tree (EIFMT), which places consideration of fire mitigation in buildings into an environmental protection context (Fig. 1.12).

Fig. 1.12

Top branch of EIFMT.

Following the EIFMT structure, various approaches for mitigating fires and their effects are presented. This discussion is provided at an introductory level, for those who may not be expert in fire protection design. It is placed within a context of common approaches identified within building and regulations, and provides overviews of various systems and technologies and how they can help mitigate fire’s impact on the environment. The chapter also discusses the potential impacts of firefighting additives (see also Chap. 8) and runoff water, and strategies for addressing these issues (Fig. 1.13).

Fig. 1.13

Structural firefighter training. (Photo: https://www.nps.gov/Media/photo/view.htm?id=A6CA1057-1DD8-B71B-0B8C1FF56E656EEA)

This chapter closes with a representative sampling of where one can find guidance in regulatory instruments (e.g., building and fire regulations, environmental regulations, and occupational health and safety regulations), consensus standards, standards and guidelines from the insurance industry, guidelines and codes of practice from professional associations and societies, and textbooks.

1.11 Mitigation Strategies for Waste Fires

Waste fires can ignite spontaneously, may be very long-lasting and difficult to extinguish, with potentially large emissions of smoke and water runoff. Large storage volumes, combined with a wide range of chemical components present, makes waste fires a potential environmental disaster. There are reports of landfill fires burning for days, months and even years.

Chapter 11 discusses large-scale waste handling and storage, focusing on four types of waste storage: (1) outdoor waste deposits or landfills without solid cover under the waste, (2) more controlled forms of waste storage at waste facilities, (3) indoor storage without collection of run-off water, and (4) indoor storage with collection of run-off water. This is illustrated graphically in Fig. 1.14.

Fig. 1.14

Four forms of waste storage. (Based on [7], used with permission)

Emissions from waster fires is then discussed, followed by fire mitigation strategies. This includes measures to limit the risk of large size fires and fire spread, including limiting the quantities of stored waste, providing separation, and monitoring the condition of the stored waste. Means of fire detection and different fire suppression strategies are also highlighted. The importance of addressing firefighting runoff water is also addressed.

1.12 Mitigation Strategies for Wildland Fires and WUI

Climate change portends an increase in wildfire activity, including potential increases in terms of fire extent, severity and/or frequency. It is becoming increasingly important to consider ways to manage, and where possible, mitigate the impacts of wildland fire, in particular the wildland urban interface (WUI). At present, fuel management is the primary means for land and fire managers to reduce the risk from future fires, and there are multiple strategies of varying levels of effectiveness.

Chapter 12 reviews mitigation strategies for wildfire in the context of fuel management, with a primary focus on reducing the impacts to people and property. The range of fuel management strategies considered includes prescribed fire, mechanical treatments, grazing and landscaping. Fuel management is commonly broken down into three distinct but overlapping spatial scales: landscape treatments (i.e. broadscale fuel treatments); interface treatments (i.e. finer scale fuel treatments, predominantly undertaken at the wildland-urban interface, WUI); or home-owner/community scale actions (i.e. localised defendable space around individual properties. The known evidence-base for the efficacy of each strategy is discussed in terms of their influence on three key elements of wildfire risk: the likelihood of ignition; spread to the Wildland-Urban Interface, and impacts at the Wildland-Urban Interface (Fig. 1.15).

Fig. 1.15

Spatial scales of fuel management

Finally, Chap. 12 discusses fire risk mitigation strategies under the umbrella of a changing climate. It is noted that there is no single solution for addressing all stated objectives: fire managers need to consider where and when it is appropriate to apply the various fuel management actions in order to achieve the greatest risk reduction across a range of values, and whether the risk reduction benefit is outweighed by the harm it may do to human health or the conservation of biodiversity.

1.13 Sustainable and Fire Resilient Built Environment (SAFR-BE)

Sustainability and resilience are terms one often hears in discussions about the built environment at all levels – buildings, infrastructure and communities. While some use the terms interchangeably, they embody different concepts, which sometimes align, but in other cases, can result in competing objectives. Good building design should address both sustainability and resiliency concepts as part of a holistic approach. This is also true for planning of communities and critical infrastructure for all hazards.

To guide such integrated thinking and planning, it is important to develop a philosophy which embodies both sustainability and resiliency. In the context of fire, the need is for a sustainable and fire resilient (SAFR) approach (Fig. 1.16).

Fig. 1.16

Sustainable and Fire Resilient Built Environment (SAFR-BE) Concept

Chapter 13 provides a framing for sustainability and resiliency, and how it applies to buildings, infrastructure and communities, and what constitutes a sustainable and fire resilience built environment (SAFR-BE).