A
Delphi Study to Identify Environmental Aspects Associated with Demolition Works
Fatemeh Nateghi, Arham Abdullah*
Journal
of Environmental Treatment Techniques, Vol. 4, No. 3, pp.
88-93, September 2016
Department of Structures and
Materials, Faculty of Civil Engineering, Universiti Teknologi Malaysia, Skudai,
Johor, 81300 Malaysia.
Received: 01/08/2016 Accepted: 24/08/2016 Published: 30/09/2016
Abstract
Construction and demolition projects, adversely impact on environment. Environmental laws, put the responsibility of controlling environmental aspects associated with construction and demolition projects on the shoulder of contractors. Obviously, those that break the law will be heavily fined. While complying with environmental laws is a challenging task for demolition practitioners, Environmental Management System (EMS), a self-regulatory framework aims to improve environmental performance of organizations and their complying with regulations. Demolition contractors are no exception, however, the first step in implementing EMS in demolition companies is, identifying environmental aspects. While very few research works cover demolition environmental aspects, this research aims to identify them with the aid of Delphi study.
Keywords: Environmental aspect evaluation,
aspect identification, Delphi study, environmental management system
1
Introduction to Environmental Concerns
Environmental concern is not a new concept. Probably the first clear
definition of environmental concern was given at the United Nations conference.
The conference was about human environment and held at Sweden in early 70 [1]. Twenty years later this issue was again
highlighted at "Rio Conference" where worlds’ leaders were asked to build
a consensus on how to manage and save planet. The conference closing remarks
highlighted two basic principles which have been agreed by 171 nations;
sustainable development and the protection of environment. This global
agreement gingered governments to take necessary, immediate and sufficient
steps toward achieving sustainable development goal and protection of the
environment by developing relevant environmental performance standard [2].
Government of Malaysia, professional bodies and private sectors, in
conjunction with their global responsibilities and public concerns on environmental
pollutions have also started to enhance awareness among companies and improve
companies’ knowledge about their environmental performance [3]. Construction
industry although is not an exception in this movement, unfortunately, in
Malaysia, controlling environmental impacts associated with construction
process by practitioner is very new concept [4].In addition to
that, setting environmental regulations and raising external pressure such as
community’s concerns encouraged companies to move towards adopting self-regulatory
frameworks that introduces a strategic solution for companies’ environmental
aspects and impacts in early planning stage [5]. Environmental
Management System (EMS) is a framework that like a road map shows how to comply
with regulations and take public concerns into consideration
[6, 7, 8]. Construction industry although is not
an exception in this movement, unfortunately, in Malaysia, controlling
environmental impacts associated with construction process by practitioner is
very new concept [8].
2
Environmental Management System and its Current Status
Compliance
with regulations in particular environmental laws has always been a challenging
task for construction companies. According to [9], regulation and
competitive pressure(go green movement) are two main causes that force
companies to deal with their environmental aspects. In this regard, EMS can be
seen as a tool that brings positive changes into the organizational layers by
defining new management strategies and practices that identify all
opportunities to reduce environmental pollutions and continues improvement in
environmental performance [10]. [11] introduce
EMS as a framework for companies to define and organize their policies and also
the first step for companies to move towards sustainable environment. Hence,
the first environmental management system standard was introduced by British
Standard in 1992 (BS7750). The European Union in 1993 prepared the first
environmental management system which is called ‘Eco-Management Audit Scheme’ EMAS;
and subsequently, International Organization for Standardization (ISO)
introduced the ISO 14000 series which are a road map in order to compliance
with regulations. Since then, countries have developed their localized version
of EMS based on their local environmental regulations (eg. MS ISO 14001: 2015)
A
study conducted by [12] revealed very few
Malaysia construction companies have implemented EMS in their organizations
when it is compared with other countries such as Japan and Hong Kong. In addition to that, from the
environmental-based marketing point of view, construction in contrast with
manufacturing does not struggle with trade barriers; also, environmental
performance has been never considered as a selection criterion in tendering
process. Therefore, practitioners in this industry neglect their environmental
aspects. Besides that, from the regulatory view of point, having voluntary or
self-regulatory attitude towards EMS in construction industry is considered
another reason for such stalling.
The
scope of this research is narrowed down to the planning phase of EMS (ISO
14001) in particular identifying significant environmental aspects in
demolition works. This standard for the first time was introduced in 1996 and
revised on November 2015. Majority of changes between two versions are about
clarification of the clauses [13].
The implementation of ISO 14001, starts with
identifying environmental aspects associated with the organization’s
activities. In other words, an inventory of aspects should be formed with
respect to the relevant local regulations. This inventory must be later used to
determine interrelationships among organizations activity and environment [2].
3
Demolition Environmental Aspects
[14] defines
environmental aspects as “the most important element of any environmental
management system”. In the meantime, environmental aspect is the most confusing
element of environmental management system. Dilemma of environmental aspect
evaluation is one of the reasons that makes organizations reluctant to adopt
EMS [15].
ISO 14001 defines environmental aspect as “an element of an organization’s
activities, products or services that can interact with the environment”. This
standard also explains significant environmental aspect is the one that has
significant environmental impact. Organizations are responsible to establish,
maintain and implement procedures to identify and determine
"significant" aspects. The word "significant" is probably
the beginning of dilemma. Impact and aspect are two sides of one entity.
However, cause and effect relationship exists between them. Impact is caused by
aspect [16].
The eco-management and audit scheme (EMAS) and also [17] categorize
environmental aspects into nine main categories. This includes emission to air,
release to water, waste generation, emission to land, natural and raw resources
use, local issues, environmental accident and effect on biodiversity. [17 and 18] developed a comprehensive
list of construction aspect (listed in Table 1). This research adopts their
list of aspects duo to similarity between demolition and construction
activities and with the aid of Delphi study verify and validate their aspects.
It is expected to filtrate irrelevant aspects at the
end of this study and major demolition environmental aspects are identified.
4 Research Methodology
Delphi has been selected as main research method of this study [19] believe Delphi should be conducted in three rounds. Analysis technique in their proposed Delphi is based on median and deviation around median (Equation 1). This is justified by the fact that no universally accepted level of standard deviation has been defined for Delphi and researchers selectively define it.
Absolute Deviation (AD) = (Median xj –Xj) (EQ.1)
The first round of study helps facilitator to understand how experts think about the questions. Median of judgments represents aggregated responses to a question. For every single question deviation between group median and responses to that question should be calculated. Average of all absolute deviations (AAD) should not be greater than one unit around median (Equation 2). This is a measure that proves achieving consensus in the round. According to [19] even if panel member reach to a good consensus in the first round, the study should be continued up to the third round.
AAD = │Average ADi │≤ 0.5 (EQ.2)
The
results obtained in the first round should be given to the same panel members in
the second round of study; experts are asked to justify the reason why for
outlaying such responses if their earlier responses are two or more units from
the median. By the way, experts can freely change their earlier responses by
either getting closer to group medians or drifting apart from group medians.
Similar to the first round, median of responses, deviation from responses and
average of all absolute deviations should be calculated. Round three is the
final round; in this round final opportunity is given to experts and they are
asked to respond to the same questions after taking a look at justifications
collected in the second round. If in this round responses shift towards those
who made justifications, it means those who had two or more-unit deviation from
median were correct. Similar to the first and second round of study average of
all deviations around median must be calculated validate consistency of study
and proof consensus forming.
5 Data Collection
and Analysis
November
15th, 2013, the first round of Delphi study was started. Delphi
questionnaire template which was developed in Microsoft Word was sent to 15
experts and they were asked to return the complete files within 30 days. The
questionnaire form incudes 37 environmental aspects and the experts were asked
to express their degree of agreement with all 37 factor
if they think factors are relevant to demolition projects. Answering to the
questions could be on the scale of 1 to 10 however for the sake of simplicity,
experts were asked only choose 1,3,5,7 and 9. Where 1 and 9 respectively denote not relevant at all and extremely
relevant. 37 Environmental aspects along with their coding are shown
here.
Table 1: Initial List of Aspects
|
NO. |
Aspect Name |
||
|
As1: |
Generation of GHG (CO2, N2O,)
and metal emission to air by machinery and power generator |
|
|
|
As2: |
VOC and CFC (Synthetic paint,
damaged refrigerant, cleaning and liquefying agents in fuels, …) |
|
|
|
As3: |
Dumping of water resulting from
dust control process to water |
|
|
|
As4: |
Dumping of sanitary water to
water |
|
|
|
As5: |
Dumping due to cleaning process
of machinery and tools to water |
|
|
|
As6: |
Generation of inert waste
(debris, rubble, earth and concrete…) |
|
|
|
As7: |
Generation of ordinary waste
(wood, plastic, metal, paper, cardboard, glass, …) |
|
|
|
As8: |
Generation of special waste
(potentially dangerous such as: asbestos, lead…) |
|
|
|
As9: |
Generation of municipal waste
by on-site demolition workers |
|
|
|
As10: |
Land occupancy (occupancy of
public through fares by on site facilities, storage, …) |
|
|
|
As11: |
Dumping derived from the use
and maintenance of demolition machinery to soil |
|
|
|
As12: |
Dumping of water resulting from
the dust control to soil |
|
|
|
As13: |
Dumping of sanitary water
resulting from on-site sanitary conveniences to soil |
|
|
|
As14: |
Water consumption during the
demolition process |
|
|
|
As15: |
Electricity consumption |
|
|
|
As16: |
Fuel consumption |
|
|
|
As17: |
Material consumption |
|
|
|
As18: |
Dust and Particles generation |
|
|
|
As19: |
Dirtiness at the on-site
entrances |
|
|
|
As20: |
Generation of noise and
vibrations due to site activities |
|
|
|
As21: |
Odor generation |
|
|
|
As22: |
Landscape alteration such as
existing visual and lighting alteration |
|
|
|
As23: |
Increase in external road
traffic due to demolition site |
|
|
|
As24: |
Interference in external road
traffic due to the demolition site. |
|
|
|
As25: |
Vegetation removal (inside and
outside of site) and emission to flora habitat |
|
|
|
As26: |
Emission to fauna habitat |
|
|
|
As27: |
Create barrier to migration of
animals & fish |
|
|
|
As28: |
Cause migration of animals
& birds |
|
|
|
As29: |
Soil compaction and changing in
absorption rate, drainage pattern and amount of surface water run off |
|
|
|
As30: |
Soil erosion and Removal of top
soil |
|
|
|
As31: |
Water channelling and stream
water cut off and changing river banks |
|
|
|
As32: |
Alter in national park, rivers,
national forest land, … |
|
|
|
As33: |
Fires at areas for storing
flammable and combustible substances |
|
|
|
As34: |
Fires due to breakage of
underground liquid or gaseous hydrocarbon pipes |
|
|
|
As35: |
Breakage of receptacles with
harmful substances or storage of dangerous product and wastage |
|
|
|
As36: |
Breakage of electric power
cables, telephone lines, water pipes |
|
|
|
As37: |
Accidental spills and leaks of
oils, furls, chemicals, herbicides… |
|
|
In
the first round, it was expected to collect 555 answers (15 experts * 37 questions=
555). However, one expert did not answer to several questions and ultimately
549 answers were received; although it had no negative impact on quality of
data. Responses to each question in Microsoft Excel was
sorted in ascending order. Median of their responses were
obtained. This value represents how group of 15 experts think about importance
of environmental aspects. For example, generation of GHG (CO2, N2O…)
and metal emission to air by machinery and power generator that represented by
AS1 is considered important (relevant to demolition) because the group median
for this aspect is equal to seven. Grey columns in Table 2 shows those answers
that captured in the first round of study. For instance, three experts believe
AS1 is extremely important; seven believe this environmental aspect is just
important and the rest of respondents had neutral opinion about this factor.
Apparently, initial results show that six environmental aspects including AS21,
AS25, AS27, AS30, AS31 and AS32 can be excluded from the list of demolition
environmental aspects (marked with yellow). However, this is not the final
conclusion and study must be continued.
To
determine consensus in the first round for every single response absolute deviation
around median was calculated (shown in appendix). For instance, (-2) indicates
that group median is two units smaller than what this expert believes about the
importance of AS1. In the first round average of all absolute deviations is
equal to 0.32<0.5 which proves achieving consensus in the first round.
The
second round of Delphi study immediately stared after analysing the first
round’s data. 10th Jan 2014, the second series of Delphi questions
were sent to the same panel of experts. In the second round the median of their
earlier responses were given to the panel members. They were asked to highlight
the importance of given 37 environmental aspects once again. In addition to
that, experts in the second round were asked to justify the reason for
outlaying a judgment with more than 2-unit distances from median. Appendix 1
was also sent to experts along with questionnaire forms. It remarks which
expert’s judgment has more than two-unit distance from median. Green line
represents group median values while orange and blue bars represent expert’s
responses. This figure shows that 13 judgments had 2 or more unit distances
from group median. For example, in the first round of study group of experts
believe that accidental spillage of oil is an important environmental aspect of
demolition works since its median is equal to seven. However, expert one
believes this environmental aspect is neither important nor unimportant. In the
second round experts are expected to react in two ways; sticking to their earlier
judgment and justifying the reason why for outlaying such judgments or changing
their previous responses and getting closer to the group median.
Orange columns in Table 2 shows how experts responded to the
second round’s questions. Interestingly, in the second round of study, only one
median value changed (AS30, median changed from 6 to 5). This value change
however, did not change first round’s initial assumption that says six
environmental aspects should be removed from the list.
Average of all absolute deviations
around median in the second round is equal to 0.24. This value indicates that
in the second round experts reach to a better consensus as this value is
smaller than 0.32 (measure of consensus in the first round).
Considering AS1, in the second
round, similar to the first round of study three experts believe this
environmental aspect is extremely important. However, in contrast to the first
round that seven experts believed this environmental aspect is important; in
the second round one expert joined changed his earlier judgment and came closer
to the first round’s group median. In this round of study, eight experts
believe that AS1 is only important and the rest of them (3 experts) voted
neutrally.
Table 2: Delphi Study
|
NO. |
Agreement Level |
Med |
Med |
Med |
||||||||||||||
|
9 |
7 |
5 |
3 |
1 |
||||||||||||||
|
1st |
2nd |
3rd |
1st |
2nd |
3rd |
1st |
2nd |
3rd |
1st |
2nd |
3rd |
1st |
2nd |
3rd |
1st |
2nd |
3rd |
|
|
As1 |
3 |
3 |
3 |
7 |
8 |
12 |
4 |
4 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As2 |
4 |
4 |
4 |
5 |
5 |
6 |
4 |
6 |
5 |
1 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As3 |
3 |
3 |
3 |
6 |
6 |
7 |
5 |
6 |
5 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As4 |
3 |
3 |
3 |
5 |
6 |
6 |
6 |
6 |
6 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As5 |
1 |
1 |
1 |
7 |
7 |
9 |
6 |
7 |
5 |
1 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As6 |
2 |
2 |
2 |
8 |
9 |
12 |
4 |
4 |
1 |
1 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As7 |
0 |
0 |
0 |
9 |
9 |
12 |
6 |
6 |
3 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As8 |
5 |
5 |
5 |
7 |
7 |
9 |
3 |
3 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As9 |
1 |
1 |
0 |
7 |
7 |
10 |
6 |
6 |
4 |
1 |
1 |
1 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As10 |
3 |
3 |
3 |
7 |
7 |
7 |
4 |
5 |
5 |
1 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As11 |
1 |
1 |
1 |
7 |
7 |
11 |
7 |
7 |
3 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As12 |
2 |
2 |
2 |
9 |
9 |
11 |
4 |
4 |
2 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As13 |
3 |
3 |
3 |
5 |
7 |
9 |
7 |
5 |
3 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As14 |
4 |
4 |
3 |
6 |
6 |
7 |
4 |
4 |
4 |
1 |
1 |
1 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As15 |
1 |
1 |
1 |
8 |
8 |
8 |
5 |
5 |
5 |
1 |
1 |
1 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As16 |
2 |
2 |
2 |
9 |
9 |
13 |
4 |
4 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As17 |
1 |
1 |
1 |
7 |
7 |
8 |
7 |
7 |
6 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As18 |
3 |
3 |
3 |
8 |
9 |
12 |
4 |
3 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As19 |
2 |
2 |
2 |
6 |
6 |
6 |
6 |
7 |
7 |
1 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As20 |
3 |
3 |
3 |
5 |
6 |
10 |
7 |
6 |
2 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As21 |
1 |
1 |
1 |
4 |
4 |
8 |
8 |
8 |
6 |
2 |
2 |
0 |
0 |
0 |
0 |
5 |
5 |
7 |
|
As22 |
4 |
4 |
4 |
5 |
5 |
6 |
5 |
6 |
5 |
1 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As23 |
1 |
1 |
1 |
7 |
7 |
7 |
6 |
7 |
7 |
1 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As24 |
1 |
1 |
1 |
12 |
12 |
12 |
2 |
2 |
2 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As25 |
1 |
1 |
3 |
5 |
5 |
6 |
8 |
9 |
6 |
1 |
0 |
0 |
0 |
0 |
0 |
5 |
5 |
7 |
|
As26 |
2 |
2 |
1 |
6 |
7 |
10 |
6 |
6 |
4 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As27 |
2 |
0 |
0 |
3 |
5 |
5 |
10 |
10 |
10 |
0 |
0 |
0 |
0 |
0 |
0 |
5 |
5 |
5 |
|
As28 |
2 |
2 |
2 |
6 |
6 |
5 |
6 |
6 |
7 |
1 |
1 |
1 |
0 |
0 |
0 |
7 |
7 |
5 |
|
As29 |
3 |
3 |
3 |
5 |
5 |
5 |
4 |
6 |
6 |
3 |
1 |
1 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As30 |
2 |
2 |
2 |
5 |
5 |
6 |
5 |
7 |
6 |
2 |
1 |
1 |
0 |
0 |
0 |
6 |
5 |
7 |
|
As31 |
1 |
1 |
1 |
6 |
6 |
6 |
5 |
5 |
6 |
3 |
3 |
2 |
0 |
0 |
0 |
5 |
5 |
5 |
|
As32 |
1 |
0 |
0 |
3 |
4 |
4 |
6 |
6 |
6 |
5 |
5 |
5 |
0 |
0 |
0 |
5 |
5 |
5 |
|
As33 |
5 |
5 |
3 |
7 |
7 |
9 |
3 |
3 |
3 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As34 |
3 |
3 |
3 |
6 |
6 |
8 |
6 |
6 |
4 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As35 |
1 |
1 |
1 |
11 |
11 |
11 |
3 |
3 |
3 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As36 |
1 |
0 |
0 |
8 |
10 |
11 |
6 |
5 |
4 |
0 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
As37 |
4 |
4 |
4 |
8 |
8 |
8 |
2 |
3 |
3 |
1 |
0 |
0 |
0 |
0 |
0 |
7 |
7 |
7 |
|
Consensus Measure (Median Absolute Deviations) |
0.32 |
0.24 |
0.17 |
|||||||||||||||
Round three is the final round of study. In this round the
pattern through which experts make their final decision is developed. In 15th
March 2014, the final questions sent to the panel members. In contrast to the
second round that 1st round’s group medians were given to the
experts, in the final round, 2nd round’s group medians were sent to
the experts together with all justifications that were made by experts. In the
first two rounds, the analysis revealed that six environmental aspects should
be excluded from the list. However, in the final round this number reduced to
only found environmental aspects. All irrelevant environmental aspect to
demolition projects were remarked with yellow color (whose median falls below
seven). The measure of consensus in the final round is lower than the second
round’s measure and as this measures (0.17) is lower than 0.5, Delphi study can
be stopped at this round.
6 Discussion and Finding
The first objective of this research was set to identify major
demolition related environmental aspects. In response to this objective with
the aid of extensive review of literature initial pool of 37
environmental aspects developed. Three-round Delphi study conducted on these
aspects to verify and identify major demolition relate ones. It was found
"Create barrier to migration of animals & fish", "Cause
migration of animals & birds", "Water channeling and stream water
cut off and changing river banks" and "Alter in national park,
rivers, national forest land, …" can be removed from the initial developed
pool of aspects (whose median in the third round is equal or lower than 5).
While responsibility of identifying environmental aspects is
given to those creating them, no demolition or construction guideline directly
suggests comprehensive list of environmental aspects; and usually suggestions
limit to controlling nuisance (dust, noise and vibration). This objective, however,
identified 33 demolition relevant environmental aspects. Something far broader
than controlling only dust, noise and vibration. In other words, this objective
highlights the responsibility of demolition practitioner in protecting
environment by introducing major aspects that have to be always considered
during the execution of demolition projects.
7 Conclusion
The aim of
this study was to identify major environmental aspects associated with
demolition projects. Therefore, a comprehensive list of environmental aspects
with the aid of reviewing literature has been developed. Delphi which is a
consensus forming strategy was selected and with the aid of 15 demolition
experts the initial list of aspects was verified and validated. In three rounds
of Delphi study, finally major demolition environmental aspects were
identified.
References
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