Success Strategies for On-Site Waste Management
Success Strategies for On-Site Waste Management in Spanish Construction Sites
Abstract There is a wide range of measures that can be implemented in the building construction sites and not all of them are equally effective in reducing construction and demolition (C&D) waste generation or improving its management.
Therefore, this research carries out a survey conducted among the construction stakeholders in order to evaluate the use and effectiveness of 13 measures aiming to promote the minimization and correct management of C&D waste. In addition, this study identifies the most suitable types of building constructions to implement these measures and the advantages and drawbacks of their performance in a building construction project.
Results of this study show that among the highly effective measures are the contract of suppliers managing the waste, the distribution of small containers in the working areas and the periodic checks, although only 50 % of respondents usually implement this measure in their works.
The large-scale construction activities occurred in certain countries of the European Union (EU) have produced a vast amount of construction and demolition (C&D) waste inappropriately managed, as only 50 % of it is actually recycled, not reaching the quantitative target established for 2020 [1–3]. In an attempt to correct the serious consequences, several countries are developing specific legal frames for C&D waste management, to encourage prevention, reuse and recycling.
For the particular case of Spain, the Royal Decree (RD) 105/2008  proposes the inclusion and development of a Waste Management Plan (WMP) for each construction project. This document should necessarily include a description of the best practice measures of reuse, valorisation or final disposal of the waste and the descriptions regarding storage, handling or any other managing operation of the C&D waste to be carried out on the working site.
Although all these measures have been implemented by EU countries, according to de Guzmán Báez et al. study, professionals are still reluctant to implement best practices . There is a wide range of practices that can be implemented, but not all of them are equally effective in reducing C&D waste generation or improving its management. Therefore, the agents involved in taking a decision on the C&D waste management might have difficulties in opting for the more effective ones. For this reason, assessing such practices would help agents in making more effective management decisions.
Moreover, this situation has not only worried EU governments, but it has been of great interest for researchers in the field. According to  special attention to C&D waste management has been developed in recent years. Indeed, specific research within the construction sector has focused in optimizing waste management including quantifying methods of C&D waste generation, as Lu and Yuan claim . Among these studies Solís-Guzmán et al. , Llatas  and Villoria Saez et al.  can be highlighted. Furthermore, specific works on best practices in C&D waste management have also been of interest to many authors [11–13]. Other researchers have focused their analysis on causes influencing C&D waste management on site [14, 15]. Both studies have identified several critical success factors for the C&D waste management; i.e. the limited number of areas in which results—if satisfactory—will ensure successful competitive performance.
Although research on C&D waste management in Asia has been widely conducted, little attention has been paid to best practices of C&D waste management in other geographic areas such as in the EU. The knowledge of C&D waste management developed in one geographical area is not easily adapted and applied to other areas without considering their contextual differences . Therefore, the main goal of this paper has hence been to identify the most commonly used waste management strategies and to assess their efficiency and viability, determining advantages and drawbacks. To this end, a questionnaire has been performed to the stakeholders intervening in the construction process.
The research methodology presented here is used to identify the effectiveness of C&D waste management strategies . Therefore, the steps used for identification of the success measures are: identifying a full set of selected strategies; conducting a survey to investigate each strategy importance; calculating each index value based on the survey data; and analyze the data obtained.
From the body of literature covering C&D waste management [18, 19], a total of 13 strategies for successful on-site C&D waste management were identified:
- Contract providers to manage waste products .
- Planning the number and size of containers needed for each activity .
- Register the quantities and characteristics of the waste that comes from the construction work and control it .
- Carry out periodic checks on the use of containers of C&D waste [21, 22].
- Follow the plans of the project to prevent carrying out unexpected chases or holes .
- Perform an on-site segregation of each waste category [12, 20, 21].
- Respect the instructions of the manufacturer in the collection of material [21, 23].
- Give talks for operators in the field of waste management [12, 16].
- Distribute small containers in the working areas to facilitate the segregation of the different types of waste .
- Reduce excess of ordered material to avoid fracture of it [20, 21].
- Buy materials avoiding unnecessary packaging .
- Planning coordination and review meetings about C&D waste .
- Use shredder machines or compactors in the worksite for the C&D waste .
Moreover, an online questionnaire has been conducted to collect opinions of these best practices. In this sense, respondents were invited to evaluate the previous 13 strategies selected, in terms of their effect and viability. The level of importance was measured on a 5-point scale, where 5 denoted very efficient and 1 insignificant.
The questionnaire was conducted from January to February 2012 and consisted of a total of 82 questionnaires distributed by e-mail to the construction agents in Spain, who were randomly selected from the target population of contractors. During the survey, the following strategies were taken to ensure a high response rate: e-mailing and phoning each construction agent prior to the distribution of the surveys asking for their acceptance in participating and sending reminders every two weeks. A total of 58 valid responses have been obtained, reflecting a response rate of 70.73 %.
Finally, to evaluate the relative effectiveness or importance of the measures analyzed, an index value for each strategy has been calculated using Eq. 1.
y=1NxyVy =_________ (1 , 2 ,………….. ; 1 , 2 , 3 ,4 , 5)
x = n y = (1)
|is the index value of the strategy effectiveness.
is the mean value appointed by the agents of each strategy (S1 = 1,…, S5 = 5). is the number of agents that chose the yth value (Vy) for the xth strategy.
Equation 1 has been widely adopted to identify the relative importance of factors/ variables by calculating their importance index values and it has been used to calculate the index value of each strategy in this paper [12, 15, 24]. The strategy measures selected were then ranked according to their index value score. This analysis has led to part of the conclusions which have given rise to the conclusions of this paper.
Table 1 Percentage of stakeholders which usually implement the strategies studied
On site strategiesa %
- Contract suppliers which manage their products waste 64
- Planning the number and size of containers needed for each activity 57
- Register the quantities of C&D waste and control them 50
- Carry out periodic checks on C&D waste containers 50
- Follow the plans of the project to prevent carrying out unexpected changes 46
- Perform an on-site segregation of each waste category 43
- Respect the instructions of the manufacturer in the collection of material 39
- Give talks for operators in the field of waste management 36
- Distribute small containers in the working areas 36
- Reduce excess of ordered material to avoid fracture of it 32
- Buy materials avoiding unnecessary packaging (bulk) 29
- Planning coordination and review meetings about C&D waste 29
- Use shredder machines in the worksite for the C&D waste 18
a Respondents can select more than one strategy, and therefore, percentages can exceed 100 %
3 Results and Discussion
Identifying all the measures determined by the agents in the WMP it is not only essential, but also, it is important indicating the degree of effectiveness and feasibility of them. Table 1 show the results of the common on site strategies according to the surveyed stakeholders, which refers mainly to recruiting suppliers to manage waste products (64 %) and to plan the number of containers and size needed for each activity (57 %).
From the results, it is necessary to remark that only 50 % of respondents claim to have carried out checks on the use of C&D waste containers or registering and controlling the quantities of waste leaving the work site. In addition, all agents surveyed were asked to value the strategy from 1 to 5. Table 2 shows the ranking of the assessment performed by the surveyed agents and the index value obtained for each strategy valued using Eq. 1.
In general, respondents highlighted, with Ix greater than 4.0, the contracting of suppliers to manage their products waste. This means that it tends to be a high effective measure. In addition, strategies such as: on site segregation of each waste category, the distribution of small containers in working areas, periodic checks and planning the number of containers required, are valued as medium-high effective measures (Ix ≥ 3.0).
In particular, the distribution of small containers in the working areas is a well valued measure; however, only 36 % of respondents implemented this measure in their works habitually (Table 1).
Furthermore, among the results, the stakeholders positively valued—Ix greater than 3.0—periodic controls of waste containers and of the generated C&D waste quantities, although only 50 % of those surveyed usually perform these checks (Table 1).
|Success Strategies for On-Site Waste Management in Spanish Construction Sites Table 2 Index value calculation for each on-site strategy analyzed||
|1. Contract suppliers which manage their products waste||4.00||4.138||1|
|6. Perform an on-site segregation of each waste category||4.00||3.638||2|
|9. Distribute small containers in the working areas||4.00||3.466||3|
|4. Carry out periodic checks on C&D waste containers||3.50||3.414||4|
|11. Buy materials avoiding unnecessary packaging (bulk)||3.00||3.397||5|
|2. Planning the number and size of containers needed for each activity||4.00||3.397||6|
|3. Register the quantities of C&D waste and control them||3.50||3.276||7|
|12. Planning coordination and review meetings about C&D waste||3.00||3.190||8|
|8. Give talks for operators in the field of waste management||3.00||3.121||9|
|7. Respect the instructions of the manufacturer in the collection of material||3.00||3.103||10|
|13. Use shredder machines in the worksite for the C&D waste||3.00||3.103||11|
|5. Follow the plans of the project to prevent carrying out unexpected changes||2.75||2.759||12|
|10. Reduce excess of ordered material to avoid fracture of it||3.00||2.741||13|
Moreover, the agents were invited to point out the possible advantages of implementing on site strategies. Surveyed stakeholders showed that the main advantages are: improving the image of the company committed with the environment and enhancing the on-site C&D waste management, the saving of raw materials and raising staff awareness. In addition, respondents determined that the application of these strategies contributes to some extent, to reduce the economic cost, to obtain greater advantages in bids and reduce legal sanctions. On the other hand, when they were asked to provide their opinion on the major drawbacks all the answers obtained could be classified into the following factors:
- Economic: The extra costs for a greater vigilance and control for its implementation due to lack of awareness of agents that intervene in the process. Ultimately, the need of a person just dedicated to it.
- Time: More time devoted to sorting out waste, which conditions the work plan schedule.
- On site space: Lack of space to locate the different types and varieties of containers.
- Increase of red tape.
The assessment performed in this paper implies a detailed knowledge of the effectiveness and viability of each of the strategy studied. Through a series of analytical processes, this research identified 3 effective on site strategies: (1) Contracting suppliers to manage their waste, (2) on-site sorting out waste categories, (3) distributing small containers in the working areas. Indeed, the distribution of small containers in the work areas is the third best valued measure (Ix = 3.466), while only 36 % of respondents implemented this measure commonly in their works.
The success strategy assessment developed in this paper, highlighting their effectiveness as well as their advantages and drawbacks, can help construction stakeholders to make a decision between the wide range of possible C&D waste measures, ensuring a sustainable waste management procedure throughout the construction process and promoting zero waste generation buildings.
Acknowledgements This paper is part of the research project entitled “C&D waste minimization in building construction works” supported by two Spanish construction companies: ARPADA and Construcciones MS. We are grateful to these contractors and their staff for their cooperation in the development of this research.