Construction Waste Management

Abstract

The paper show the conditions and premises due to which the construction materials go to waste and to introduce viable alternatives in order to provide pollution prevention and waste minimization. It also provides guidelines on process and practices to manage construction waste on-site. This paper evaluates the construction waste management planning and strategies that should be implemented in order to prevent pollution. Finally some possible solutions, such as reuse and deconstruction are presented. The scope of the paper was developed based upon the following waste management hierarchy, in order of preference: reduce/minimize waste generation; reuse waste materials for their original intended purpose; recycle waste materials for other use; dispose of remaining materials.

Construction Waste Management

Introduction

The design, construction, demolition, upgrade and maintenance of buildings have a tremendous impact on our environment and our natural resources. The resulting waste materials, their volume minimization and their reuse or recycling have been of concern to the EPA and other legislating bodies for some time now. The demolition of existing structures and the construction of new ones to meet the needs of a growing nation generate an enormous amount of debris, some of it even hazardous in nature. There are more than 76 million residential buildings and nearly 5 million commercial buildings in the U.S. (USEPA, 1998). By the year 2010, another 38 million buildings are expected to be constructed. In the past, waste material produced from the process of construction, renovation, or demolition of structures was landfilled; much in solid wastes sanitary landfills.

Pollution Prevention Problem

The U.S. Environmental Protection Agency (EPA) estimates that construction wastes accounts for approximately 24 percent of the waste disposed of in our nation’s landfills. (USEPA, 1998) Disposing of construction and demolition debris in landfills consumes enormous amounts of difficult to develop space and is both economically and environmentally costly. The challenge has been, as more and more engineers and architects realize, to design and build buildings in a smart way, so they use a minimum of nonrenewable energy, produce a minimum of pollution, and cost a minimum of energy dollars to operate, while maximizing the comfort, health, and safety of the people who live and work in them. (Griffith, 1994)

Additionally, buildings are a major source of the pollution that causes urban air quality problems, and the pollutants that contribute to climate change. They account for 49 percent of sulfur dioxide emissions, 25 percent of nitrous oxide emissions, and 10 percent of particulate emissions, all of which damage urban air quality. Buildings also produce 35 percent of the country’s carbon dioxide emissions—the chief pollutant blamed for the greenhouse effect and climate change (USEPA, 1998). Construction is not limited only to buildings. The urban transportation network, especially bridges, also presents significant challenges in terms of waste production and minimization. The construction, maintenance and operation of the road network consumes large quantities of resources. In 1998 roads represented 3% of the nation’s construction work. Between 20,000 and 60,000 tons of aggregate is used to construct a mile of motorway. Yet every year some 70 million tons of construction products and demolition materials are wasted, that is they are discarded as waste instead of reused or recycled. Some 13 million tones of that is material delivered to the work sites and subsequently thrown away unused. (USEPA, 1998).

A difficult aspect of the construction waste issue is that with some notable exceptions, a coordinated effort to assist the construction industry in developing viable alternatives to landfill disposal of construction waste is lacking. For the most part, federal, state, and local governments are not taking an active role in reducing landfill disposal or in stopping the illegal, or unwise and uneconomical dumping of materials, by encouraging their recycling and/or conversion to other building materials. Traditional building practices often overlook the interrelationships between a building, its components, its surroundings, and its occupants. “Typical” buildings consume more of our resources than necessary, negatively impact the environment and the occupant’s health (sick building syndrome), and generate a large amount of waste. Often, these buildings are costly to operate in terms of energy and water consumption. Their design can also create conditions that result in poor indoor air quality, which can lead to occupants health problems. (Teo and Loosemore, 2001)

Sustainable Development

The construction industry plays a vital role in the development and socio economic growth of any society. However, besides these considerations, construction activities also imply the depletion of limited natural resources. The construction industry is one of the largest and most important industries, being at the same time the main consumer of natural resources and one of the largest polluters (Quinn, 2002). According to the United Nations 2002 World Summit on Sustainable Development (WSSD) in Johannesburg, over 70% of the world’s surface could be affected by the impacts of roads, mining, cities, and other infrastructure in the next 30 years (U.S. Green Building Council, 2002).

The construction industry’s practice of landfilling construction and demolition, debris results in a loss of potentially reusable building materials. Sustainability encompasses all social, environmental and economic activities from clean air and water to preserving and protecting natural systems to advancing educational systems to human equality. Within the outer global shell of sustainability, lies one component that can assist in achieving the goal of sustainability and that is sustainable development. An aspect of sustainable development is to adopt sustainable construction practices. One major concept of the construction industry is the construction and demolition waste produced. Adopting a sustainable method of managing this waste would assist in the movement toward sustainability. (Kibert, 1994)

Historically, industrialized nations have grown and advanced technologically while often disregarding the environment One important component of sustainability is to develop and grow in a sustainable manner, often referred to as sustainable development Sustainable development, in general terms, may be defined as meeting the needs of the present without compromising the ability of future generations to meet their needs. The development that occurs on local, regional, and national levels plays a key role in society’s sustainability. Local or regional developments must occur in a sustainable manner or the ultimate goal of sustainability cannot be achieved. (Teo and Loosemore, 2001)

A subset of the concept of sustainable development is sustainable construction practices. The construction industry, the structures it creates or removes and the products developed to support and supply the industry have significant global impacts. In the United States, buildings represent more than 50% of the nation’s wealth. The construction industry uses 40% of all extracted materials. Thirty percent of all energy used is a result of the construction industry and the built environment (USEPA, 1998).

A subset of the construction process is the practice of managing the waste produced by these activities in a sustainable manner. Over 34% of our nation’s waste is produced by a single sector of the economy, the construction industry. Approximately 7 pounds of waste are produced for every square foot of new construction. Renovation and demolition can produce up to 70 pounds of waste per square foot depending on the structure type and demolition technique. Buildings are constructed and, on average, are demolished twenty-eight years later (USEPA, 1998). Unfortunately traditional mechanical demolition leaves piles of mixed debris that are, in general, ultimately landfilled (Weber et al., 2002). The construction industry lags far behind other industries in efficiency related to materials consumption, reuse, and recycling. (Bossink and Brouwers, 1996).

The total economic and environmental impact of the construction industry begins with raw material extraction and continues on with product manufacturing, product transportation, building design and construction, operations and maintenance, and building reuse or disposal. Each building product has an intrinsic value in the form of energy, the energy used to extract the raw materials, process the materials, create a marketable product, distribute the product, and finally transport the product for use. This intrinsic energy value is often referred to as the materials embodied energy (Bossink and Brouwers, 1996). Extraction of these natural resources, especially through mining and smelting, is one of the most wasteful, energy intensive and polluting industries on earth (Kibert, 1994). Reusing and recycling building materials prevents this pollution by reducing the need for mining virgin natural resources. When considering the combined energy required to transport materials and the labor required to design and construct buildings, demolishing a structure is simply throwing away many valuable resources. Reusing building materials conserves this energy “embodied” in the products. (Faniran and Caban, 1998)

The Need for Waste Management Planning in Construction

Limited landfill capacity is one of the major problems that cities and municipalities across country are continuously facing. Given that disposal fees are continuously rising in most of the American landfills, constructors have begun considering their debris as something to be managed rather than something simply to be dumped. In fact, a realistic Construction Waste Management Plan can provide economic and environmental benefits. Economic benefits can be achieved on a short-term period, reducing costs for waste transportation and landfill taxes. Meanwhile, environmental benefits can be achieved on a long-term period by enhancing good construction practices which will lead to the more efficient use of materials, while at the same time reducing the quantity of construction waste at sites (Townsend et al., 2002). A sustainable approach by the construction industry will mitigate negative impacts on the environment and resource depletion.

The consumption of construction materials, energy, and water as well as the increased land use for buildings and infrastructure, represent a potential impact on the environment. (Kibert, 1994)Environmental damages caused by the depletion of natural resources and the increase of waste have left the experimentation with alternative strategies for waste minimization plans such as reducing, reusing, and recycling. This offers the opportunity to safeguard the environment and to achieve monetary savings when managing construction waste in a proper manner. Reducing construction waste involves an integrated process of designing and constructing new buildings, while making efficient use of materials. (Lingard et al., 2001)

However, the inability to identify and predict the quantity of materials that are wasted during the construction process is a major culprit in the generation of construction waste. Construction activities demand the use of several resources; the lack of detailed planning and communication of progress within the construction process being one of the main reasons for waste generation (Touart, 1998). Constructors are constantly experimenting with the efficient use of construction materials in order to reduce the quantity of construction waste generated at site. Some research projects and investigations have been carried out in order to find the methods for minimizing the generation of construction waste. (Lingard et al., 2001)

However, most of the research projects have focused their objectives on waste characterization, or have merely evaluated the potential for recycling main types of construction materials through construction guidelines and best practices when dealing with waste on-site. These projects have been limited to give an insight on the benefits, advantages, or disadvantages faced by constructors when implementing on-site recycling activities for different types of construction waste, instead of providing with a methodology which can be used to identify and predict the quantity of waste generated based on the type of waste that a specific construction activity could generate. (Griffith, 1994) The use of the construction schedule as a reference for a waste management plan will assist site managers to anticipate the type of waste that could be generated from week to week. This strategy will help them in the decision-making process when having to implement on-site activities such as reduce, reuse, and recycle. (Touart, 1998)

Waste Management Hierarchy

In looking at the waste management hierarchy (Figure 1) one of the highest waste management levels is reuse (Coventry et al, 2001). However, the majority of the current practices fall in the lower two levels, landfilling and burning. The most common practice on construction and demolition sites is to simply toss “waste” into the dumpster and send to a landfill. This practice often occurs because it is fast and seemingly inexpensive regardless of the potential value of the materials. Unfortunately, disposal costs or tipping fees do not accurately account for the long-term environmental ramifications of throwing away potentially reusable materials. Less developed areas often bum debris on site – commonly without permits or authorization.

Deconstruction assists in moving the construction industry further up the sustainability “food chain”. Moving up the food chain from burning and landfilling is composting. This process is not commonly implemented on a larger scale. The next step is recycling. Most individuals are aware of curbside recycling programs that target newspaper, glass, metal and plastics. Recycling construction materials is becoming more prominent as regional struggle to reach their recycling goals and as landfills near capacity. Reuse is the most environmentally beneficial option for materials currently in circulation. By deconstructing versus demolishing it is possible to reclaim materials for reuse. At the top of the hierarchy is the most important step toward a more sustainable industry, reduce. This step is the foundation of designing for the environment. Reduction requires careful planning, rethinking current practices, and implementing sustainable alternatives. (Coventry et al, 2001).

Construction Waste Management Planning and Strategies

Waste Management is the cornerstone for successful pollution prevention. Building construction, disaster cleanup, and demolition projects pose unique challenges in the area of waste management and pollution prevention. Since each project is different, generating its own unique combination of wastes, flexible and creative measures have to be implemented in order to find ways to reduce, reuse, recycle or dispose of, in an environmentally responsible way, the various types of waste generated. (Griffith, 1994)

Contractors and owners can realize high levels of construction waste diversion and cost savings through careful planning throughout the project, establishment of construction goals, and provisions for the generation minimization, separation, salvage, reuse, recycling and disposal of waste. The ultimate goal is to reduce the amount of construction waste destined for landfilling to an absolute minimum. This also helps the contractor to identify opportunities from waste as a resource rather than having to deal with it as a problem and extra cost of operation on site. With the advent of the concept of sustainable development, construction industries around the world have embarked on strategies to deliver environmentally responsible construction.  (Kibert, 1994)

The strategies may include: the redirection of construction waste from landfill sites to extended use applications (i.e., reuse and recycling); innovations in the building waste removal process to ensure the recovery of good quality secondary materials; innovations in construction site practices to prioritize waste generation prevention and management; instruments to stimulate secondary construction markets. (Lambert and Domizio, 1997) Other factors that are desirable in a waste management plan include: a waste audit; waste disposal options; waste handling requirements; transportation requirements. (Griffith, 1994)

A functioning Waste Management Plan includes the following phases, as shown in Table 1.

• 50-75% goal recommended for most projects
  Preliminary or Schematic design
  Review potential building systems to consider:
• Waste management potential
• Modular design to reduce waste and labor
  Value Engineering
• Design Development
  Commission Construction Management Feasibility
• Consider feasibility of salvaged materials use
  Working drawings
  Specify recyclable materials
• Also materials with recycled content
• Focus on design and details that reduce waste
  Demolition
  Require contractor to submit Construction plan including list of permitted construction facilities prior to demolition
  Construction
  Project waste coordinator coordinates activities
• Conducts progress meetings, solicits feedback
• Continuously monitors Construction activities
  Building Close Out
  Project waste coordinator summarizes and documents the results of construction waste management efforts
• Submits required contractual documentation

Possible Solutions

Construction waste consists mostly of inert non-hazardous waste, which can be landfilled with municipal solid waste. However, various management options are available to divert construction waste from landfills, such as volume reduction, waste minimization, reuse, and recycling. Landfilling should only be considered as a last option when all other avenues have been exhausted, since processes and markets exist to recover most construction waste. (Weber et al., 2002)

Construction and renovation activities can implement source reduction procedures and save resources by selecting environmentally friendly products, utilizing products containing or made from recycled material, reusing excess material on site, and in developing sustainable designs. Deconstruction minimizes contamination of debris, and also increases the potential value of material diverted for reuse or recycling. For several decades now, specialized salvage companies purchase and remove for resale parts of a building such as doors, windows, metal staircases, fireplaces, architectural exterior details, and other parts prior to demolition activities. (Coventry et al., 2001)

In the movement toward sustainability there are several changes occurring in the construction industry. For example, using “green” materials, designing and constructing more energy efficient structures, managing construction waste, and implementing reuse and deconstruction. As in most industries, the construction industry is driven by cost. (Johnston & Mincks, 1995)  The practices are well established and therefore the industry is resistant to change. In addition to resisting change in construction methods and disposal alternatives there is also a resistance to the concept of reuse. The common perceptions are that used materials are sub standard. These are some of the perceptions that must be changed – there are more sustainable waste management options, sources of materials, and construction techniques. (Touart, 1998)

Deconstruction encompasses a thorough and comprehensive approach to whole building disassembly (versus cherry picking specialty items) allowing the majority of the materials to be salvaged for reuse (Lambert and Domizio, 1997). The deconstruction process is simply the construction in reverse order. The deconstruction process has many steps and considerations that differ from traditional demolition. . Although only the main categories of benefits are listed here, each benefit tends to have a spider web effect branching off to intersect and affect other areas.

• Environmental Benefits
• Regional Benefits
• Decrease site disturbance
• Preserve land
• Conserve Landfill Space
• Create jobs
• Save Energy (Reuse Materials)
• Spur regional growth
• Decrease Airborne lead, asbestos, and dust
• Provide jobs to low skilled workers
• Decrease deforestation
• Provide a supply of low cost building supplies
• Reduce greenhouse gases
• Promote infill
• Reach recycling and waste diversion goals
• Sustainability
• Reduce land consumption

For example, although the benefit of saving energy is only listed once, energy savings occurs in many instances when materials are reused. Energy is saved from mining and processing fewer materials, therefore fewer materials to transport and market reducing energy expenditure for transportation and distribution, the embodied energy of the material is conserved during reuse, and the energy to dispose of the materials is save. (Faniran and Caban, 1998)

Conclusion

Construction sites are often the cause of local environmental impacts such as dust, noise, vibration and pollution of soil, watercourses, and groundwater. Environmentally friendly practices are needed on all sites, not just to reduce the risk of prosecution, but also to reduce costs associated with construction waste management and to mitigate environmental impacts, The benefits of adopting a sustainable approach include reductions in waste management costs, improved efficiency and productivity, compliance with present and future environmental rules and regulations, and improvement of corporate image. Sustainable construction can minimize the environmental impacts of construction through specifications and continue monitoring of construction activities. Most of these impacts can be predetermined during the design and planning phase. However, on-site solid waste management can significantly reduce the impacts of construction activities. The efficient use of construction materials represents money-savings, reduction of solid waste, reduction of energy consumption, as well as pollution prevention from different construction processes.

It can be said that in its broadest sense, construction is responsible for the built environment that dominates the inhabited land. Nevertheless, if construction is not implemented correctly it can have serious impacts to the environment, which nowadays is quite fragile. More and more people and more importantly government, are becoming conscious of the criticality of the situation and move towards more effective and sustainable policies in order to conserve the environment. Many organizations have developed an environmental management system and have tried to implement an effective waste minimization scheme; that does not only benefit their organization, but the environment as well.  However, it can achieve minimization of waste, conservation of the natural resources, and provide hope for the future – a thing that is actually priceless.

References

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