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THE IMPACT OF CONSTRUCTION AND DEMOLITION (C&D) LANDFILLS: EMERGING PUBLIC AND OCCUPATIONAL HEALTH ISSUES

CHAPTER ONE

INTRODUCTION

BACKGROUND OF THE STUDY

Historically, construction and demolition (C&D) debris landfills have been considered nonhazardous operations, containing relatively inert wastes such as concrete, asphalt, wood, metals, gypsum drywall, and roofing materials.

In recent years, however, it has become increasingly clear that emissions resulting from the decomposition of gypsum drywall and organic debris are a public health issue. Drywall, comprised of gypsum (CaSO4 •2H2 O), breaks down into hydrogen sulfide and other sulfur compounds under anaerobic conditions and in the presence of water.

Overall, the good news is that C&D landfills are not known for being particularly dangerous to human health, though certainly they do come with their risks (Colledge & Wilder 2011). In each of the case studies from New York, Wisconsin and Virginia (mentioned above) where a C&D landfill was identified to pose potential health risks to the community, there were problems with the ENST 698, fall 2011 facilities that could have been prevented or fixed (United States Environmental Protection Agency Office of Solid Waste.

The waste assessment examines the quantity, quality and timing of potential sources of waste which will arise from the construction and operation of the proposed secondary drainage channel KT13. Both construction waste and solid waste are considered. Solid waste includes domestic waste, commercial and industrial waste, chemical waste, special wastes and other wastes, while construction and demolition waste include most wastes arising from the construction. Where unacceptable waste impacts are identified, appropriate mitigation measures are recommended. Disposal options are outlined for each type of waste, and the responsibilities for disposal or recycling discussed.

Over the past few years, sustainability has become a topic that is being marketed by governmental organizations and educational institutions globally. From observation, Trinidad and Tobago, a Caribbean Small Island Developing State (SIDS), is lagging behind in efforts to become more sustainable, as wastage continues and landfill use increases. Currently, landfilling is the primary method of final waste disposal in Trinidad and Tobago. Approximately one thousand (1000) tonnes of waste is disposed of per day, divided among nine (9) operating disposal sites in Trinidad and Tobago; the four (4) main landfill sites being the Beetham site, the Forres Park site, the Guanapo site, and the Guapo site [1]. Solid waste management in Trinidad and Tobago has become an issue of growing concern over the past few years, due to a rapid increase in the overall quantity of waste being generated due to industrialization and residential and commercial development. This increase in solid waste generation has resulted in a rapid decrease in the capacity of the four (4) aforementioned primary landfills [1]. The Trinidad and Tobago Solid Waste Management Company Limited (SWMCOL) was created in 1980 for “management, control, collection, treatment and disposal of all waste, either alone or jointly with other companies, statutory authorities, or persons” [2]. SWMCOL has produced records indicating that large quantities of recyclable and reusable materials (paper, plastics, metals, and organics) are being deposited at landfills for final disposal. Elimination of these recyclable/reusable materials could thus lead to an extension of existing landfill lifespans and improved efficiency in waste collection systems. Landfills are usually the final disposal facility of construction and demolition (C&D) waste; the Australian construction industry accounts for approximately 15% per annum of all solid waste being disposed of in landfills, and similar quantities have been recorded in other countries. In an effort to reduce the amount of waste being deposited into landfills, an Australian branch of an international construction company decided to implement C&D waste management policies on their sites. The results of the policy trial yielded cost savings, 15% less waste being generated on site before recycling, and 43% less waste going to landfills [3]. C&D waste management plans therefore have the potential to help reduce landfill usage as well as promote sustainability due to reuse and recycling [4]. Reuse and recycling increase the longevity of materials and reduces the amount of raw material extracted from the earth, and decreases the energy demand to process and manufacture new materials

PROBLEM STATEMENT

“Construction by nature is not environmentally friendly; it generates tremendous C&D waste resulting from various construction activities” [5]. Trinidad’s dependency on the use of non-renewable energy has led to the 2012 Environmental Performance Index rating the country poorly in relation to the environment and sustainability. At present, Trinidad and Tobago is faced with challenges in waste management, and some landfills that have been past their maximum capacity since 1980 are still in use; furthermore, two (2) sectors which have been identified as key areas for development of a green economy are waste management and construction [6]. In 2017, the Planning and Development Commission mandated Solid Waste Management Company Limited (SWMCOL) to undertake the functions of a Waste Recycling Authority as the government strives to alleviate the burden on landfills and modernize local waste disposal [2]. It is believed that this new system and functions of SWMCOL will promote and encourage waste recovery via recycling and reuse, the creation and implementation of financial incentives to encourage recovery, and promotion of business opportunities that may arise from creating a culture of waste minimization [2]. In light of this, the construction industry of Trinidad and Tobago should also begin implementation of sound waste management practices to aid in the development of a green economy.

The main objectives of the waste assessment are to:

(i) identify the sources, volumes, quality and timing of wastes arising from the construction activities;

(ii) recommend construction waste management strategies and control measures/routings (including final disposal sites) in accordance with the current legal and administrative requirements for the disposal of construction waste, including waste reduction, re-use and recycling for inclusion into contract documents; and

(iii) recommend measures for the disposal of inert materials and wastes.

LIMITATIONS OF THE STUDY

A limitation of this study is the use of survey research. There may be surveys returned that were not filled out truthfully or with responses that do not reflect true intentions. The results will not be generalizable beyond the population or sample used.