Environmental issues and risk management

Environmental Issues and Risk Management

Can the construction of hazardous material/waste Contamination storage facilities survive tornadoes at their current protection levels?

Definition of Construction Waste

Construction Waste Generation

Composition of Construction Waste

Motivation

Development of the Research Project

Brief Description of the Research Methodology

Deliverables

Sustainable Development and Construction Waste Management

Sustainability

Sustainable Construction

Construction Waste Management

Waste Management Hierarchy

The increased interest in the construction of hazardous material/waste Contamination storage and rather or not they can survive natural disasters is the recent movement have forced many construction practices to change considerably. Construction waste management, which is one of the most vital respects in all sustainability review systems, also plays a vital role in green building ratings. Current revelations verify that straightforwardly utilizing on-site waste management programs does not provide sustainability when it comes to facility storage of waste and rather or not they can withstand pressure from disasters; as an alternative, waste management curriculums have to be successfully managed and planned to attain sustainability goals.

This investigation interjects to the construction management body of information by emerging a designing tool that is encompassed of two main constituents that guide the waste management decision making development: a) the appraisal of costs/benefits of waste management strategies for better attainability during storms particularly tornadoes (recycling, reuse, and landfill disposal); and, (b)the modeling of construction waste production;

Modelling of construction waste generation is based on the novel concept of the activity-based waste generation principle, which allows the documentation of each activity's contribution to the total waste generation on-site and rather or not the hazardous/waste facilities can endure through tough times. In this project personal observations and data collections at different construction projects, followed by a series of discussions and interviews with industry professionals, were working to acquire an empirical method to forecast construction waste generation that will have secure facilities in a wake of a natural disaster. A statistical model to predict waste generation from the drywall construction activity will be developed in utilizing the empirical approach.

A computer simulation model will be acquired that reports for the dynamic and random nature of construction activities that motivate every construction project. The benefits and cost of the obtainable waste management alternatives to building construction projects have been incorporated and modeled into the simulation model, thereby delivering various analyses for use in decision making of what should be used in order too see what storage facilities need to be used in provin. The integrated planning tool, which incorporates both the simulation model and project activity schedules, provides an opportunity for construction industry professionals to directly benefit from this application.

The presented approach to strategic planning and management of on-site waste management programs and the subsequent implementation of this planning tool in industry will ensure effective planning of waste management and improved sustainability.

CHAPTER ONE: INTRODUCTION

Situation Analysis

Even though the residents of Joplin Missouri have confront a gigantic cleanup following the tornado that savaged Joplin, experts say environmental dangers as far as the hazardous material/waste contamination. Months later, experts say that it could lurk amid the mountains of debris in the southwestern Missouri city and even in the water and air. It is clear that hazardous waste and its proper disposal are becoming a major sociological problem today owed to its ability of contaminating the area in which people live and its capability to be deadly to all living things. Sequentially for the United States and other parts of the world to save itself from a potentially life frightening issue they must fix the causes which lead to the improper or weak storage of hazardous wastes and like materials when it comes to natural disaster like tornadoes. Certain details that hazardous waste has become a problem in Missouri and other parts of the today is because of the breakdown in implementing laws for the proper disposal of certain wastes, a lack of inventiveness on big companies behalf to getting out there in order to spend money on appropriate disposal and storage of the materials, and the ease of getting rid of such wastes illegally. As a society, the miscalculations of the past should not be repeated, for hazardous waste can be contained properly using methods that avert damage to the environment and human health. A lot of these methods have been abandoned in the past mainly since they have a higher price than undifferentiating or careless dumping, and because no law required their use (Kiefer, 1981, p.51).

Background

The difficulty of hazardous waste today basically shoots from the development of the United States business after World War II. Nevertheless, "with the benefits, unescapably, come hazardous wastes (Kiefer, 1981, p.9). Hazardous wastes are the consequences of everyday industry, fluctuating from heavy metals like mercury, lead, copper to more chemicals that are dangerous that includes things like acids, cyanide, and synthetic organic compounds. "The EPA has recognized four features that may be used to regulate whether or not a waste should be categorized as dangerous: Corrosivity, Ignitability, Toxicity and Ractivity, "(Block, 1985, p.44). The majority of these materials and many more are hazardous to wildlife and humans if they are not correctly arranged.

In 1976 the Resource Conservation and Recovery Act was placed into outcome by the Environmental Protection Agency. This policy does require "that hazardous waste be regulated from the time it is produced managed to its ultimate disposal -- from "cradle-to-grave"(Kiefer, 1981,p.11). Nevertheless, "before RCRA went into outcome, about eighty percent of hazardous waste was gotten rid of by procedures that did not defend human health or the setting "(Kiefer, 1981, p.15). "In New Jersey alone 30% (120,000 gallons) of waste is disposed or treated of in 20 licensed New Jersey proficiencies. The outstanding eighty percent (280,000 gallons) goes to out-of-state facilities or is illegitimately unloaded in New Jersey"(Dodd, 1980).

One reason that is behind a lot of these methods was that before 1976 there had been no laws that had required companies to dispose or treat correctly the hazardous wastes that they created. In the capitalist country we live in these companies did not see any motivations to appropriately influencing of hazardous wastes. This would take coming up with new methods, creating new apparatus, and doing a lot of exploration that would in the end just cost these businesses millions of dollars. These type of companies had found it that it was much easier to get rid of these poisonous chemicals in the waterways or into the ground, thus washing their hands of the difficulty. Another technique was to hire out "midnight-haulers." These persons would try loading up their trucks with a lot of hazardous wastes and though driving and let it leak out onto the ground.

Another motive force that is behind the improper disposal of hazardous waste was the Mafia taking advantage of this after a natural disaster. "Organized crime regulated the concrete waste disposal industry across the major trade relations, the applicable Teamster locals, and the involvement of political associates "(Block, 1985, p.102). The Mafia has the capability to purchase public officials with comfort. This and their scare tactics led a lot of EPA officials to do nothing regarding illegal doings that were going on. "Imagine an EPA inspector or state controlling agent straining to deal with firms that are controlled by the members of the most influential crime organizations in the country"(Block, 1985, p.103).

All of these details led up to the unlawful dumping of toxic and/or hazardous wastes into the environment which was sometimes done after taking advantage of a natural disaster. " Maybe the most serious threat to the environment that is caused by unreliable waste disposal practices has been the threatened and actual pollution of groundwater"(Block, 1985, p.51). It is true that well over 150 million Americans are depending on groundwater for their normal lives. The difficulty with this is that right when the groundwater is unclean or contaminated, recuperation or better storage is almost impossible. "A recent government report exposed that public and private water supplies have been dirty in at least twenty-five unreasonable "(Block, 1985, p.51). These poisonous chemicals can accrue underground and stay in the same locations for drawn-out periods of time. These chemicals never breaking down or disappearing or from the sun's rays can perhaps " collect in aquifers for hundreds of thousands of years, throughout which time they may repeatedly spoil the groundwater that flows beyond the area"(Block, 1985, p.53).

One of the major issue that permits these prepares to go on is the letdown of enforcement. Government agencies like the EPA are specified the power to explore hazardous waste dumpers and unlawful landfills. Nevertheless, there are so few guidelines on the appropriate handling of toxic wastes that those dumping toxic waste have almost an open invite to linger their practices.

The enforcement record that was against toxic waste dumpers is not closely as strong as the enforcement record that was going on against bootlegers throughout Prohibition. . . . The failure of enforcement happensfor three reasons -- a controlling policy of minimal obedience. . . political and law enforcement cronyism and corruption. . . And last, an surprising astonishing level of incompetence which symbolizes much of the authorized intelligence- meeting and investigative developments (Block, 1985, p.310).

This lack of enforcement taking part in helping with the waste especially after a natural disaster such as a tornado will possibly allow such practices as illegal dumping to last unchecked.

"The ideal answer to hazardous waste problems is to alter the industrial processes so that hazardous waste materials are not produced any longer"(Kiefer, 1981, p.51). Nevertheless, in all reality this is extremely unlikely. It would basically be almost impracticable to make any large alterations to plants that are already in process. Many believe that part of the solution will lie in how the government will deal with large organizations that are pertaining to hazardous waste. If the government were to provide tax breaks to those businesses who appropriately get rid of their hazardous waste this could possibly inspire companies to do the same. Also, if the government were to give tax breaks for organizations that are seeking a much better or more well-organized ways of dealing with toxic wastes then not only would individuals see an development in the current condition but most likely a step onward in the right direction of taking care of the hazardous waste issues that are afflicting the world today.

History has shown that possibly another possible solution is to have the government sponsor new projects on how to perhaps reprocess hazardous or toxic waste in a method that is productive and safe.

One method to recycling is to transport one company's waste to another corporation that can utilize it. One fruitful reuse of a waste material includes "pickle acid,." . . The pickle acid is moved to a power plant that will produce electricity with geothermal steam. The iron sulfate in the pickle acid thean reacts with the hydrogen sulfide which is found in geothermal steam to produce a mire of iron sulfide and sulfur; this sludge is a valued supplement to some soils (Kiefer, 1981, p.52,53).

If a waste can not be reprocessed in some way then there is the likelihood of splitting the hazardous materials it encompasses. These materials can then be separately preserved and perhaps made undamaging. This procedure will also aid to separate the hazardous materials and create them calmer for treatments that are concentrated.

It is imaginable that many could perhaps apply these new plans so that it can reduce the quantity of toxic waste that is discarded into the environment or that is exploited through natural disaster such as tornadoes. The problem with applying these kinds of plans would be the expenditure and cooperation on the behalf of the companies which create these hazardous derivatives. If the EPA would make it more promising for these companies to fall into compliance with ecologically friendly regulations and procedures then we would see a potential instant development that would be in the part of hazardous and toxic wastes.

With that said, it is not really impossible that people can fix societies current difficulties that are dealing with the appropriate disposal of toxic and/or hazardous waste, it is nevertheless very unconvincing. The readiness of large companies to make the costs that are necessary to resolve these difficulties is very low. Without a hand that is a help from the government to provide inducements to these corporations and to apply the current laws which administer toxic waste dumping it could possibly be a long time before we observe any gradual expansions on this setback. As for the areas that we have previously contaminated with our nations hazardous wastes there is little hope of ever revitalizing these places Many believe that as a nation, it must be see that by speaking to the problems with appropriate care and discarding of toxic wastes we are in actual fact in the saving of people's lives. Once the nation comes to this reality, the country can expect much more compression by the people for severer laws and stricter penalties of illegal dumping. With that said, there needs to be further research on what can be done to see a positive change that will affect the future of hazardous material/waste Contamination storage facilities control in case of natural disaster such as tornadoes.

Premise

Tornadoes yearly plagued the state of Missouri and cause significant damage to property and infrastructure. One of the greater concerns is hazardous material/waste contamination due to the destruction to associated storage facilities. The government of Missouri is researching facility sightings and construction practices to increase the survivability of hazardous material/waste storages facilities, to include the use of underground facilities and regulating above ground facilities to F5 level construction standards. These revised standards will greatly increase the survivability of these facilities and reduce the risk of hazardous material/waste contamination from future tornado events.

1.1.1 Definition of Construction Waste

Waste materials that are generated throughout the construction processes are usually mentioned to as construction waste. It has basically been the usual repetition to record the material waste from construction, demolition and renovation projects all together, which is indicated to in the literature as demolition and construction waste (C&D waste) or construction, redecoration and demolition waste (CRD waste). Conferring to Statistics Canada (2000) C&D waste is described as waste materials created in the procedure of construction, renovation or demolition of arrangements, which comprise buildings of all forms (both non-residential and residential) as well as roads and bridges. However, the definitions are different from region to region and from country to country. For example, the United States' Environmental Protection Agency (USEPA) definition of CRD waste includes land clearing debris as well. It is important to identify the dissimilarity that is between construction waste and C&D waste, as both of the waste streams are usually reported to have diverse characteristics, that results in a need for having different management choices for each. Therefore, this study will recognizes the definition of construction waste as "waste materials that are produced in the course of construction of arrangements; the structures comprise both non-residential and residential buildings as well as bridges and roads." More precisely, building construction waste and whether or not the facilities can survive disaster such as tornadoes is of main interest to the study. Normally, building construction waste stream entails of materials, such as brick, concrete, wood, cardboard, rubble, metals, floor tiles, drywall, and roofing materials.

.1.2 Construction Waste Generation

The harshness of the construction waste problem can be recognized from studies that were performed in various parts of the world on building waste material amounts. Skoyles (1976) recognized thirty-seven construction materials that have material wastages from 2 to 15% of the weight of the intended quantity of material. Bossink and Brouwers (1996) acknowledged consumptions of materials that are ranging from 1-10% of weight of the acquired material amounts, grounded on a study in Netherlands. Another study, that was based on the construction projects that was in Australia, signified material wastage to be around 2.5-22% of the whole material bought (Forsythe and Marsden, 1999). Pinto (1989) exposed that material wastes ranged from 1- 102% of its calculated weights, that based on the building construction business in Brazil.

Even though the percentages of waste from construction materials are different from district to district, the significant finding is that the amount of construction waste generation is important, irrespective of the location. Obviously, the kind of construction, construction technology and the regulations and rules that were disturbed by local authorities can have an influence on material wastages. It is unmistakable that the generation of construction waste has been snowballing over the years, generating a series of difficulties in numerous regions of Canada. The construction waste portion was approximately equal to 35% of the total municipal solid waste generation in 2001 (CCA, 2001). Being a part of an industry that is growing and due to high construction activities in Alberta, as the statistics confirm, there is a fast upsurge of demolition and construction waste generation over the time of 2000 to 2006. It is predicted that, in Alberta, 30-40% of C&D waste is emerging from constructions that are new. Nevertheless, the described landfill removal of construction waste materials has somewhat declined over time, stretching around to 22% (Alberta Environment, 2006) from 27% in 2003 (Verduga, 2004).

Figure 1.2 Composition of Construction Waste Residential

Limitations

The study will take place in the state of Missouri which will involve The five largest cities in Missouri are Kansas City, St. Louis, Springfield, Independence, and Columbia and also the town of Joplin. The study can have some limited by the honesty of the citizens responses during the interviews regarding contamination storage facilities and how well they can survive tornadoes at their current protection levels . Other limitations will possibly be limitations that are set forth by the quantity of time available to manage the study, along with the time contributors that will be acknowledged in the study. The study was further limited to the information that will be needed in order to collect the right data. The framework of the study was developed as a means of understanding the Can the construction of hazardous material/waste Contamination storage facilities survive tornadoes at their current protection levels? An additional limitation to the study was that probing questions to prompt elaboration were not used.

Delimitations

The study was confined to gathering qualitative and quantitative data that will be obtained through in-depth interviews with current and former city officials and citizens. The study will focus on data collected from city officials and citizens on their perceptions of rather or not hazardous material/waste contamination storage facilities can survive tornadoes at their current protection levels? Several researcher- controlled delimitations can limit the generalizability of research results. First, interviewing current and post-city officials and citizens in Missouri are Kansas City, St. Louis, Springfield, Independence, and Columbia and also the town of Joplin. Could did not take into account all lived experiences and data concerning the survival of material / waste contamination storage. Second, research limited to one geographical area in Missouri may not be inclusive of all other regions associated with the impact of the outcome of storage facilities that were not able to hold due to tornadoes. Third, as a researcher there could be limited interviews and data with participants in Missouri not throughout the country.

CHAPTER TWO: LITERATURE REVIEW

Literature Review

Exposures within the United States

There are other studies that cover other areas when it comes to hazardous material/waste Contamination but none cover them cover construction of hazardous material/waste Contamination and if the storage facilities can survive tornadoes at their current protection levels. It is clear by the lack if information, that a study is needed. The U.S. Environmental Protection Agency (EPA) basically describes hazardous waste as waste that is combustible, harsh, reactive, or toxic. Facilities that produce hazardous waste or accomplish hazardous waste across treatment, disposal, or storage (TSDs) record with the EPA under the Resource Conservation and Recovery Act (RCRA) and regularly provide mechanisms with quantity statistics throughout shipping records or reliable surveys. Early studies on environmental fairness had expended material that is derived from the EPA's hazardous waste program to make an inspection on how possible risks are allocated throughout demographic groups. In 1987, the Commission on Racial Justice had delivered an account that discovered that when communities with commercial hazardous waste facilities were associated with of the counties around them, the society with the facility had a much higher minority proportion, reduced household salary, more locations polluted by preceding exposure to hazardous waste, lower house values, and higher points of waste produced per person. The study flickered a debate that is still going on in the United States over justice and the environment, an argument which encompasses concepts implicates such as environmental equity, environmental racism, and environmental rightness.

In this subsection there is a review of different types of studies that were produced by this debate: national studies of commercial TSDs, accounts that center chiefly on hazardous waste sites in a given city, study that utilizes company self-reported pollution statistics from the U.S. Toxics Release Inventory, and material on environmental cleanups in the U.S. Superfund program that resulted from things like disasters.

Atlas (2001a) makes manycontributions to the analysis of national TSD locations. He reviews the evidence on the actual risks posed by current hazardous waste TSDs and concludes (p. 952) that: There is no evidence that TSDFs pose, much less have produced, meaningful harm to surrounding populations. The strict regulations under which they operate, the types and quantities of substances that they manage, the minimal potential exposure paths from them to people, and their compliance records all make the risks that they pose pale in comparison to other environmentally regulated facilities, such as those with air emissions. versus .125 for the white population. The magnitude and distribution of the risk exposure again depends to a great extent on the Westinghouse site. If this extremely hazardous site from California is dropped from the analysis, the gap between mean risks faced by minorities (.108) and whites (.102) nearly disappears. These calculated risk levels are high in part because of the EPA's requirement that analyses use conservative parameter values for variables such as ingestion rate or exposure duration in the calculation of individual risks.

2.1 Sustainable Development and Construction Waste Management

Discussions on making sure that and sustainable built environments are of interest in hazardous / waste contamination in some parts of the world. However, it is an issue that does not have much light shining on it. Yudelson (2008) had recognized this program as a transformation that is part of a paradigm shift that is leaning toward "sustainability."

2.1.1 Sustainability

The Montreal Protocol on Substances that Deplete the Ozone Layer (a protocol under the Vienna Convention), that produced the worlds' notice to t give a limit to chlorinated fluorocarbons in 1980s (UNEP, 2010), was the chief international move that is gearing towards global sustainability. Nevertheless, the first description of sustainability - "expansion that meets the essentials of the present without negotiating the capability of future inventions to meet their own needs" (UNWCED, 1987) - was not made accessible until 1987. This is the most usually utilized description in the literature even today.

From definition mentioned above, it must be comprehended that sustainable development includes the real-time hunt of environmental qualities and economic prosperity which inspire the usage of natural resources carefully while giving protection and, if conceivable, improving the atmosphere and social equity that acknowledges the needs of everyone. (WBCSD, 2010; CIRIA, 2010). This perspective is well illustrated in Figure 2.1. And so, municipalities and governments planning for sustainability should inspire companies to execute not against a solitary financial bottom line, but against the triple bottom line of society, economy and environment.

Figure 2.1: Sustainability Social Equity, Environmental Enhancement and Economic Growth (Courtesy CIRIA)

2.1.2 Sustainable Construction

The concept of sustainability has made an impact on the construction industry as a whole in different ways. Customarily, sustainability was regularly viewed as a measure to attain environmental and social objectives, and the cost-benefits were unnoticed. As a result, owners and other shareholders were unenthusiastic to accept sustainable approaches in construction. However, the construction subdivision does play a key role in progress of the socio-economic organization in any union; consequently, its maintainable creativities are significant to the association as a whole.

Being the foremost customer of natural resources and one of the major contaminators (Horvath, 1999), the construction industry's role in sustainable development is fundamental. The Built Green Alberta, Go Green and LEED advantages are some of the greatest extensively consumed voluntary programs that hearten maintainable buildings in Alberta. These agendas are planned to endorse products, practices, products and practices technologies, that ensure:

Better energy effectiveness and decrease pollution,

Better indoor air,

Lessened water consumption,

Conservation of natural resources, and Enhanced sturdiness and decreased maintenance in buildings.

The Built GreenTM Alberta program is envisioned to benefit the homebuyer, the society and the environment. The key focus parts of the program are efficiency, energy, indoor air worth, resource use (counting waste management) and complete environmental impression. The rating system contains of three accomplishment levels: Bronze, Silver and Gold with 95, 105 and 115 details correspondingly. There is a least obligation of 7 points out of 23+ points from the waste management group to attain any level in the Built Green evaluation system.

The Go Green program, which started in 2005 does recognize buildings where the environmental finest performances have been applied. Go Green certification is presented to buildings with the best environmental customs in the following classes: resource consumption, recycling and waste reduction, building materials, tenant awareness and interior environment.

To guarantee operation and maintenance of the current office buildings in a more environmentally manner that is responsible, the Government of countries like Canada had adopted the Go Green Plus environmental valuation program of the Building Owners and Managers Association of Canada (BOMA Canada) in November 2005. Nevertheless, the Go Green program does not ponder the sustainability of any segment other than operations into explanation in their rating system.

The LEED rating system, that was put into practice in 2004 by LEED Canada, delivers a comparatively complete tool to assess the sustainability of a the storing of waste capability and what it can endure, especially in the Canadian context. It recognizes leading-edge storages that merge proposal, operational and construction practices that also guarantee healthy, high-quality and high- presentation with reduced environmental impacts. Presently, LEED is one of the widely accepted sustainable building rating systems (Syal et al., 2007) and has been adopted by many construction companies in Canada.

LEED measures sustainability of a building using five key areas in which credits are awarded for each recognized sustainable practice. The major categories in the rating system are sustainable sites, water efficiency, energy and atmosphere, materials and resources, and indoor environmental quality. LEED has four performance ratings available as illustrated in Table 2.1.

Table 2.1: LEED Canada Performance Ratings

Level

Points

Certified

26-32

Silver

33-38

Gold

39-51

Platinum 52-70

LEED recognizes the importance of on-site construction waste management within its rating system, allocating a maximum of 6 points dedicated to waste management in the materials and resources category. Further, it is noteworthy that the construction waste management credits are the most commonly obtained by Canadian construction companies in their quest for the desired LEED certification (Da Silva et al., 2009).

2.1.3 Construction Waste Management

It is reality that the construction industry's profit margin is tight and that construction companies have to streamline their processes and activities in such a way to survive in the industry (McGrath, 2001). Because economic benefits are not usually revealed through implementation of waste management programs on-site, contractors seemed to give little consideration to waste management aspects of construction compared to meeting other targets and schedules (Poon et al., 2001). Therefore, the most common solution for waste materials generated during construction was their disposal at landfills.

In the past, construction waste materials were considered harmless for the environment; therefore, social and environmental acceptance for such practices were also evident (Kartam et al., 2004). However, with the evolution of research in the area of solid waste management and with global acceptance on sustainable construction principles, landfill disposal of construction waste materials is now considered the last available option.

2.1.3.1 Waste Management Hierarchy

It is evident that Canada, as well as Norway, Sweden and most European Union countries, including France, Germany, Italy and the United Kingdom, have adapted to a waste hierarchy that includes waste reduction, reuse, material recovery, material recycling, energy recovery and final disposal (landfill disposal). The main objective of the hierarchy is decreasing waste disposal at landfills. The waste management hierarchy, which is presented in Figure 2.2, illustrates the various waste management alternatives that are also available for practice in the construction industry.

As mentioned in Section 1.1.2, the construction industry is a major waste generator that accounts for a high percentage of landfill disposals; therefore, a waste management hierarchy, which would help planning, is important. As presented in the hierarchy, it is believed that the most environmentally friendly alternative is first (at the top), while the most undesirable option is last (at the bottom). However, depending on the material considered and various geographical parameters, such as location of the construction site, the distance to the nearest recycling facility, etc., the most sustainable alternative has to be investigated a case-by-case basis.

Figure 2.2: Waste Management Hierarchy

(Picture Courtesy: Ecorec)

2.1.3.1.1 Minimization of Waste (Reduce)

Avoidance is the ideal result for any material waste; however, this may not be possible or practical in most cases. Source reduction is the next best alternative in regulating the generation of waste in the first place. Source reduction is defined as "the design, manufacture, purchase, or use of materials to reduce their quantity or toxicity before they reach the waste stream," according to the U.S. Environmental Protection Agency (EPA). It includes the reduction of waste generation at the inception of the product as well as during the product usage.

2.1.3.1.2 Reuse

The objects that are discarded as waste materials can sometimes be used again for the same intended purpose or for a different purpose: this is referred to as the reuse of waste materials. It may be necessary to have a certain amount of prior treatments involved with material reuse; however, reuse is preferred to recycling, as it does not require as much energy consumption.

2.1.3.1.3 Recycle

Recycling is an important waste management process that replaces the production of virgin material. Therefore, recycling is considered as a solution to the depletion of landfill space, which also saves energy and natural resources by providing useful products and economic benefits.

2.1.3.1.4 Recovery of Energy and Materials

Energy production through the incineration of waste materials, which is also referred to as "waste to energy," as a means of energy recovery is practiced most in European countries. For instance, Denmark effectively utilizes energy recovery techniques to produce 20% of its heat demand over about 400 districts (Fruergaard et al., 2010). This method could be applied to construction waste materials, such as wood waste, and is one of the alternatives preferred to landfill disposal (Kartam et al., 2004). However, incineration, which involves sintering that generates ash, residuals, non-combustibles and other elements, necessitates the disposal in landfills of those materials that may contain toxic constituents (IJC-IAQAB, 1996).

2.1.3.1.5 Incineration

Incineration is one of the solid waste management options that helps to reduce the quantity of material waste at landfills. However, ash, a by-product of the process, needs to be disposed of landfills in most cases. Incineration has a great waste reduction potential in the range of 80-95% by volume (Rand et al., 2000). However, the high start-up cost of an incineration plant and its maintenance costs make this option unattractive to most low-income countries (Rand et al., 2000). In fact, many cities across the globe had been forced to close their operations because of soaring costs and environmental concerns. Buenos Aires, Mexico City, Sao Paolo and New Delhi are some of these cities (UNEP 1996).

For countries that have no land spaces for landfills, this technology is preferred. The critiques of adverse environmental impacts are mainly focussed on the air pollution associated with these operations, even with the use of high-cost equipment, such as scrubbers, to control the emissions.

2.1.3.1.6 Landfill Disposal

Currently landfill disposal (landfilling) of waste materials is considered as the last option of the waste management hierarchy, as uncontrolled dumping is no longer acceptable due to environmental concerns. Although sanitary landfills solve the groundwater contamination problem, which was a major concern in uncontrolled dumping, further improvements are required to make landfilling an environmentally friendly option. For instance, problems related to landfill gas emissions, as well as those related to leachate generation, still exist with sanitary landfill technology.

2.1.5 Planning and Management of Construction Waste

To achieve economic benefits while receiving environmental and societal advantages from an on-site waste management program, it is necessary to begin planning even before the start of the program (Osmani et al., 2008; Ruwanpura et al., 2003; Urio et al., 2006; Wimalasena et al., 2007). Planning and management of waste can be very different from one type of project to another where the type of the project can vary from construction project to construction renovation and demolition project. In fact, the characteristics of waste depend on the type of the structure, size and the type of activity being performed (i.e. construction, renovation or demolition) in the project (MVC, 1992; Boileau et al., 1996; Hettiaratchi et al., 1997).

Waste characteristics can also be very different from one type of structure to the other (building, bridge, etc.), which suggests that the structure type can be a factor that may have an effect on the waste management strategy. Even if the same type of structure is considered, e.g. A building construction, the size of the building (low-rise, or high rise), its intended purpose (residential, commercial, or industrial building), the materials used in construction, the locality, the schedule (whether it is fast track or not) and the contractor's housekeeping practices are other factors that affect the waste generation (MVC, 1992; McGregor et al., 1993) and, therefore, must be considered in the planning and management of on-site waste management program.

2.2 Quantification and Prediction - Models and Tools

To facilitate front-end planning of the waste management process for a given construction project, it is necessary to predict the waste quantities. To the astonishment of the author, the studies that focus on construction waste management and cost effectiveness of waste management programs do not include predictions. Kofoworola et al. (2009) claims that waste prediction has become a challenging task due to the unavailability of construction waste quantity and quality related data in the industry. The lack of data may be considered as a result of many reasons, which have been identified by previous researchers (Boileau et al., 1996; Kofoworola et al., 2009; Yost et al., 1996) and can be listed as follows:

Not keeping construction waste records for reasons such as not having or not adapting to regulatory requirements,

Not motivated to keep records or manage waste in any form, because it has been considered as a non-value added task, and Considered as potential trouble for the progress of other activities.

However, the few available research works on construction waste prediction are described in the following section.