Liquid Waste Management in the Construction Projects

The construction industry is increasingly concerned with improving its environmental performance and reducing the environmental impact. Construction projects utilise water and generate wastewater. A considerable volume of water is used for washing and cleaning processes at construction sites which is often unmetered. At the same time, liquid waste/wastewater generated from construction projects is harmful to the environment and human health, pollutes the groundwater and the ground soil and therefore, it is important to manage liquid waste appropriately. This project investigated the current practice of liquid waste management (LWM) and treatment including the legal requirements related to LWM in construction projects. The sources of liquid waste, different methods used for managing liquid waste in construction sites and barriers for implementing sustainable LWM practices have been identified through semi-structured interviews with industry experts. Systems that improve current practice have been studied as comparators. The average of water consumed for tool washing and water-saving per square meter have been estimated for different types of buildings and compared against the use of sustainable LWM systems in construction projects. Moreover, this study compares the total volume of water consumed for tool washing between water mains and sustainable LWM systems. This research summarises the practice of LWM in construction projects through the analysis of expert user views while providing an account of legislation relent. It also summarises the water use and water saving potential when sustainable LWM practices are adopted. It has the potential to add new and under-measured factors to the current LWM systems for the Green Rating of buildings and produce a more sustainable construction industry

A study of liquid waste management practices in construction projects in Australia

The construction industry is increasingly under pressure to improve environmental performance and reduce environmental degradation, which often results from carbon emissions and a high volume of waste generated from unprecedented levels of development associated with urbanisation and industrialisation. Construction projects consume a significant amount of water at the same time; they generate liquid waste (LW) from several wet processes during construction on-site, which is often unmetered. At the same time, LW or wastewater generated from construction projects is detrimental to the environment and human health, adversely polluting the surface and groundwater as well as the ground soil. It is, therefore, indispensable to manage LW appropriately while utilising the water efficiently. Limited studies have paid attention to explore the importance of effective liquid waste management (LWM) practices in construction projects and their implications on environmental sustainability. This study aimed to investigate the current practices of LWM in construction projects through the analysis of expert user views and quantitative data analysis while providing an account of LWM related legislative requirements. Moreover, this study estimated the average volume of water consumed for tool washing and water saving for different types of projects and compared it against the use of sustainable LWM systems, notably a closed-loop washout system employed in construction projects. The outcome of this study has the potential to add new and under-measured factors to the current LWM systems and to promote sustainable LWM practices in construction projects. While it highlights issues related to LWM, it provides criteria that can be considered for the green rating of buildings

A review of construction waste data and reporting systems used in Australia

The construction industry is well recognised for the generation of a significant amount of waste which in turn has led the management of waste data as an important task of waste management. Waste data is essential not only for promoting effective waste management practices but also for the development and implementation of effective waste policies, legislations, and national standards. This paper aims to evaluate and understand the different waste data and reporting systems used in Australia. The outcomes of this study are based on the literature analysis of secondary data. The review revealed that most of the states and territories use a centralised waste data collection and reporting system and the use of such a system varies between states and territories due to the variation in waste definition, classification and estimation practices. This, in turn, hinders the development of effective waste management policies, relevant waste management programmes and as well as the establishment of domestic and international market platforms for recovered waste materials, attracting new circular business models. Consequently, the results inform the unyielding need to develop an efficient waste data management system. Blockchain as a decentralised data management technology could considerably improve the waste data management practices including waste data collection, reporting, and auditing and contribute to driving a shift towards the circular economy through circularity of waste information. Future research is aimed to develop a decentralised waste data management system as part of the development of a blockchaintechnology based waste trading platform

Investigation of waste diversion rates in the construction and demolition sector in Australia

Purpose: Waste diversion rate (WDR) is a key indicator of effective waste management and circular economy. However, it has not yet been widely used in the construction and demolition waste (C&DW) sector. This study aims to promote the application of WDR as an effective measure for waste management through the investigation of the current status of C&DW diversion in the Australian construction industry. Design/methodology/approach: A mixed-method approach, which combines a desk study and a case study of 12 residential projects was used in this study. Data retrieved from the National Waste Database (NWD) were used for the descriptive analysis. Findings: The analysis of the national waste data revealed that the national average WDR in Australia is 64%. WDR varies based on material types and across the states. The analysis facilitated the forecasting of the possible future trend of waste diversion in Australia. The studied projects from two states in Australia presented slightly different results. Most of the waste stream, except mixed waste, presented above 95% of WDR in each project. Research limitations/implications: Although the studied projects showed a higher recycling rate, this study claims that achieving a higher rate of recovery by diverting the waste could not be assured unless accurate estimation is carried out with reliable and verifiable data. Lack of reliable data is considered as the limitation of this study. While the scope of descriptive analysis of waste generation and diversion covers the whole country, the case study analysis is limited to the states of New South Wales and Victoria. Originality/value: The study highlights the significance of WDR in assessing the performance of effective waste management in the C&DW sector. WDR is a comprehensive measure that takes the output of the waste life cycle into account for benchmarking waste management. The results provide a critique of the current practices of waste management and the essence of the consistent, transparent and verifiable waste data to enable accurate WDR estimation in Australia. The outcome is useful for waste managers and policymakers in developing potential waste management strategies and C&DW specific legislation for building a more ecologically sustainable industry

A review of smart technology usage in construction and demolition waste management

The management of construction and demolition (C&D) waste, a major part of solid waste, is increasingly become a critical challenge in the quest of social, environmental, and economic sustainability. Innovative and smart technologies are emerging to provide inevitable benefits because of their capacity to enable digitisation, automation, and integration of Solid Waste Management (SWM) processes. Nevertheless, the application of such technologies in Construction and Demolition Waste Management (CDWM) has not gained the appropriate attention. This study aims to draw insights into the current and potential use of smart technologies in CDWM. A literature review-based approach surveyed both academic and applied publications to analyse the current and potential use of smart technologies in both SWM and CDWM. Altogether, 75 peer-reviewed articles and technical white papers were analysed. It was found that the usage of smart technologies is much advanced in SWM and the adoption is still at the prototype stage in CDWM. The results emphasise that the integration of smart technologies into multiple processes of CDWM would overcome many issues related to waste minimisation and management including waste estimation, waste reporting, and data management and waste diversion. The framework developed in this study contributes to the understanding of the potential role of each category of technologies in improving the waste management processes in the C&D sector. This review is useful to waste management practitioners, regulatory bodies and the government to understand the benefits of emerging technologies and to the development of effective strategies and future training programmes

Drivers for implementing effective waste trading practices in the construction industry

Conserving natural resources and reducing the pressure on the environment has become high in the agenda of sustainability. Though construction and demolition (C&D) waste have a high potential to yield a substantial amount of valuable resources into the economy, resource recovery from the C&D sector has not reached its maximum level yet. Waste trading (WT) has been recognised as a sustainable strategy to improve the exploitation and efficiency of resources through the circulation of waste materials and thus diverting the waste from landfills. The effectiveness of WT is influenced by several aspects related to waste management (WM). Nevertheless, the wider application of this approach has gained less attention among researchers and WM practitioners in the C&D sector. This study identified 34 drivers from six major perspectives through an expert forum followed by a validation process. From an aggregate perspective, technical drivers have been ranked as the most significant drivers followed by the institutional/organisational, legal/political, socio-cultural and economic drivers. The identification of the drivers can assist in determining which aspects need to be considered in stimulating and advancing the C&D WT practices and driving a shift towards the circular economy. The results of this study also provide a better understanding of the collective efforts required to enhance the effectiveness of WT practices and a basis for future research in assessing the efficiency of WT practices in the C&D sector. The findings are useful to WM businesses in enhancing existing market conditions and establishing new circular business models and to government/regulatory bodies to develop specific policies/legislation and strategies required to promote sustainable construction through trading strategies in the C&D sector

Exploring the barriers for implementing waste trading practices in the construction industry in Australia

Purpose: The construction industry is a major generator of waste, which has a high potential to yield a substantial amount of waste into the economy as a valuable resource. Waste trading (WT) is a sustainable strategy for improving resource utilisation and transitioning the construction industry towards the circular economy. However, resource recovery through WT is greatly impeded by several barriers which have not been highlighted in previous research. This paper aims to determine the barriers for implementing effective WT practices in the Australian construction and demolition (C&D) sector. Design/methodology/approach: To achieve the aim of this research, a triangulation approach of quantitative and qualitative methods has been used. This mixed-method approach combines a comprehensive literature review, a questionnaire survey using an expert forum and semi-structured interviews with industry experts. Findings: This study has explored a wide range of barriers to the practices of WT in the C&D sector, which have been categorised based on six perspectives. From a collective perspective, the technical barriers were found to be most important among other categories. The key individual barriers found in this study include the following: the high cost associated with sorting and processing of waste on-site, lack of consistent waste data and reporting system at project, industry and national level, insufficient secured and established market for reusable/recycled waste materials, lack of communication and coordination among stakeholders, lack of user-friendly and active web-based waste exchange systems (with reliable waste information) and lack of incentives from the government to encourage market development. Overcoming these barriers collectively would enable the wide application of WT, which in turn, would have a positive impact on the economy, environment and efficiency of the industry. Research limitations/implications: The outcomes of this study are based on the data collected only in the state of New South Wales (NSW) in Australia which is considered as the limitation of this study. Originality/value: This study contributes to the body of knowledge of C&D waste management (WM) by providing the theoretical and practical implications of closing the loop material cycle by highlighting the importance of economic and environmental benefits of WT. In this study, WT has been recognised as a sustainable strategy to manage waste by identifying the barriers impeding the wider application of effective trading practices in the C&D sector. The findings are useful to WM businesses engaged to establish new circular business models and to government/regulatory bodies in developing initiatives and incentives aiming to promote WT strategies and market platforms. Further research is suggested to test and validate the findings from other jurisdictions of Australia

Assessment of waste generation and diversion rates in residential construction projects in Australia

Construction and Demolition (C&D) waste has received major attention due to its adverse impact to the environment and this has led to the development of waste management as an essential function of construction project management. Zero waste strategy targets to achieve 100% waste diversion rate from landfill and optimize resource recovery from waste. The Australian green star rating tool aims to encourage and reward waste management practices that minimize the amount of construction and demolition waste disposed to landfill. In Australia, C&D waste account for 27% of overall landfill and the resource recovery rate is around 64% which is relatively low compared with other developed nations. The Australian government has set targets to increase the rate of construction to meet ongoing and future residential property demand. Thus, there is a pressing need to avoid and minimize the waste at all stages of construction projects by implementing dynamic waste avoidance measures such as promoting the use of modular and prefabricated systems and the need for reuse/recycling waste into new products and services. The aim of this research is to evaluate the waste generation and diversion rates of residential projects in Australia. Waste generation data of 10 material streams from 10 residential projects were collected and analyzed based on the Waste Generation Rates (WGR) and the New Construction Green Star points. The results revealed that concrete, timber, metal and masonry are the most wasted materials in the residential projects. The WGRs indicated a consistent pattern with ‘good’ performance ranking. In addition, the assessment of green star rating for waste management credit revealed that all the projects are eligible for green star credit point 1 out of 14 as they demonstrated above 92% diversion rate of wasted materials. Although the studied projects showed higher recycling rate, this study claims that achieving a higher rate of recovery could not be assured unless accurate waste estimation is carried out with reliable and verifiable data. Such has to consider as the limitation of this study with the lack of reliable data on non-recyclable waste that is dumped either by the developer or waste processing facilities. Future studies on waste estimation and managing waste through re-use and recycling with the use of smart technologies would provide a holistic solution to improve the waste management practices towards achieving sustainability in construction projects