ENVIRONMENTAL MANAGEMENT OF URBAN CONSTRUCTION PROJECTS IN CHINA
Pollution and hazards caused by urban civil construction projects have become a serious problem in China. Sources of pollution and hazards from construction sites include dust, harmful gases,
noises, blazing lights, solid and liquid wastes, ground movements, messy sites, fallen items, etc.
These types of pollution and hazards can not only annoy residents nearby, but also affect the
health and well-being of people in the entire city. For example, in big cities such as Shanghai
and Beijing, air quality has been deteriorating due to extensive urban redevelopment activities
In order to tackle the problems, the Chinese government has issued a number of laws and acts on
environmental protection since early 1980s. These laws and acts include Oceanic Environment
Act (issued in 1982), Water Pollution Protection Act (issued in 1984), Air Pollution Protection
Act (issued in 1987), and Noise Pollution Protection Act (issued in 1989). In 1998, the Ministry
of Construction also issued the first Construction Law which explicitly includes the liabilities
and responsibilities of contractors in preventing and reducing the emission of pollutants to the
natural environment.
Project management environmental
Sources of pollution and/or hazards from construction activities can be divided into seven major
types: dusts, harmful gases, noises, solid and liquid wastes, fallen objects, ground movements
and others. In order to reduce and prevent the pollution and hazards, it is necessary to identify
the construction operations that generate the sources. In Table 1, construction activities that
generate pollution and hazards, and corresponding methods for prevention are listed. The table is
based on an extensive studies of many construction sites in Shanghai, Beijing and Hong Kong, as
well as numerous discussions with many project managers.
Methods for preventing pollution and hazards can be divided into the following four categories:
Technology
This category recommends a range of advanced construction technologies which can reduce the amount of dust, harmful gases, noise, solid and liquid wastes, fallen objects, ground movements and others. For example, replacing the impact hammer pile driver with the hydraulic piling machine can significantly reduce the level of noise generated by the piling operation.
Managerial
This category recommends the use of modern construction management methods which may help reduce the amount of dusts, noises, solid and liquid wastes, fallen objects and others.
Planning
This category emphasises on revising and re-arranging construction schedules to reduce the aggregation of pollution and hazards. This category has effect on dusts, noises, solid and liquid wastes, fallen objects, ground movements and others.
Building material
Better building material can also help reduce pollution and hazards. This category has effect on harmful gases, fallen objects, ground movements and others. The four categories of preventive methods and their effects are also summarized in table 2.
We believe that by adopting the above preventive methods, it is possible to effectively control
and reduce the amount of pollution and hazards generated from construction activities. In order
to further analyze the effect of pollution and hazards, the next section describes a method to
quantify the amount of pollution and hazards generated by a construction project.
QUANTITATIVE ANALYSIS OF POLLUTION AND HAZARDS IN URBAN
CONSTRUCTION PROJECTS
As a construction project spans over a year or even longer, the methods for quantitative analysis
have to be a continuous monitoring and assessment of the whole project duration. In this section,
we present a method to quantatively measure the amount of pollution and hazards generated by a
construction project within its project duration. The method sets to measure the Construction
Pollution Index (CPI), as shown in formula 1.
Note:
CPI— Construction Pollution Index of a urban construction project.
CPIi— Construction Pollution Index of a specific construction operation i.
hi— hazard magnitude per unit of time generated by a specific construction operation i.
Di — Duration of the construction operation I that generates hazard hi.
n— Number of construction operations that generate pollution and hazards.
In formula 1, parameter hi is a relative value indicating the magnitude of hazard generated by a
particular construction operation in a unit of time.
Its value is limited in the range of [0,1]. If hi=1, it means that the hazard can cause fatal dama
ge or catastropies to people and/or properties nearby. For example, if a construction operati
on can generate some noise and the sound level atthe receiving end exceeds the ‘threshold of pain’, which is 140 dB (McMullan 1993), then the value of hifor this particular construction operation is 1. If hi= 0, then it indicates that no hazardis detectable from a construction operation.
It is possible to identify values ofhifor all types of pollution and hazards generated by commonly used construction operations and methods. For example, according to the information on sound emmision from piling driven machines, as well as the types of piles, we can formulate the content of Table 3 which contains values of hi for some piling operations.
Information and data such as the emision of noise levels, harmful gases and wastes are normally available in the specifications of relevant construction machinery and plant, or can be conveniently measured. These data can then be converted to hi values by normalising them into the range of [0,1]. In case that there is no data available for such conversion, then hi values have to be decided based on user’s experience and expert opinions.
Durations required for completing construction operations are measured in number of days. For example, the Shanghai Maxwell (see Figure 1) construction project involves a piling operation which includes the following activities and durations,
1) driving prefabricated concrete piles using drop-hammer driver, and duration is 31 days.
2) driving sheet steel piles using hydraulic piling driver, and duration is 57 days.
Then, according to formula 1, the value of CPI for the piling operation is, 0.5*31 + 0.3*57 =
32.6. The overall CPI value for the project is 747.2. The value of Construction Pollution Index (CPI) reflects the accumulated amount of pollution and hazards generated by a construction project within its project duration.
It is also very useful to create a CPI bar chart. A CPI bar chart is very similar to the ordinary bar charts used in construction scheduling, except that the thickness of the bars represents the hi value for the corresponding construction operation. By integrating the concept of CPI into MS Project, which is a commonly used tool for construction project management, we can develop a system to neatly combine environmental management with project management, as shown in Figure 1. In Figure 1, hi values are listed beside their corresponding construction operations. As the height of a bar represents the hi value, the area of the bar represents the CPI value of the construction operation. The aggregation of the thicknesses of bars, as indicated at the bottom of the bar chart, represents the distribution of the CPI value along the whole project duration. This distribution is particularly useful for project managers to identify the periods when the project will generate the highest amount of pollution and hazards. Therefore, preventive methods such as those listed in Table 1 can be used to reduce the amount of pollution and hazards during those periods. In this example, it can be seen, from the distribution diagram of Figure 1, that during Nov. to Dec. 1998 the project generated the highest poillution and hazards, mainly because of the large amount of on-site mixing of concrete and masonry works. The project manager forsaw the problem, and decided to reduce the amount of on-site mixing concrete in those months by using 25% ready-mixed concrete. The use of ready-mixed concrete reduced the amount of noise generated from the on-site concrete mixing. This reduced the hi value in Nov. and Dec. 1998 from 3.3 to 2.5, a 25% reduction in the value of hi. It also indicates that the amount of pollution and hazards has been reduced.
Durations required for completing construction operations are measured in number of days. For example, the Shanghai Maxwell (see Figure 1) construction project involves a piling operation which includes the following activities and durations,
1) driving prefabricated concrete piles using drop-hammer driver, and duration is 31 days.
2) driving sheet steel piles using hydraulic piling driver, and duration is 57 days.
Then, according to formula 1, the value of CPI for the piling operation is, 0.5*31 + 0.3*57 =
32.6. The overall CPI value for the project is 747.2. The value of Construction Pollution Index (CPI) reflects the accumulated amount of pollution and hazards generated by a construction project within its project duration.
It is also very useful to create a CPI bar chart. A CPI bar chart is very similar to the ordinary bar charts used in construction scheduling, except that the thickness of the bars represents the hi value for the corresponding construction operation. By integrating the concept of CPI into MS Project, which is a commonly used tool for construction project management, we can develop a system to neatly combine environmental management with project management, as shown in Figure 1. In Figure 1, hi values are listed beside their corresponding construction operations. As the height of a bar represents the hi value, the area of the bar represents the CPI value of the construction operation. The aggregation of the thicknesses of bars, as indicated at the bottom of the bar chart, represents the distribution of the CPI value along the whole project duration. This distribution is particularly useful for project managers to identify the periods when the project will generate the highest amount of pollution and hazards. Therefore, preventive methods such as those listed in Table 1 can be used to reduce the amount of pollution and hazards during those periods. In this example, it can be seen, from the distribution diagram of Figure 1, that during Nov. to Dec. 1998 the project generated the highest poillution and hazards, mainly because of the large amount of on-site mixing of concrete and masonry works. The project manager forsaw the problem, and decided to reduce the amount of on-site mixing concrete in those months by using 25% ready-mixed concrete. The use of ready-mixed concrete reduced the amount of noise generated from the on-site concrete mixing. This reduced the hi value in Nov. and Dec. 1998 from 3.3 to 2.5, a 25% reduction in the value of hi. It also indicates that the amount of pollution and hazards has been reduced.
So far, a quantitative method for analysing the magnitude of construction pollution and hazards has been presented. In order to ensure that the concept of environmental management is embedded into the daily practice of construction project management, we propose that major construction companies should obtain ISO 14001 Environmental Management System (EMS) certifications. Discussions on the ISO 14000 stnadards and ways of integrating the standards into construction project management are given in the next section.
INTEGRATING ENVIRONMENTAL MANAGEMENT WITH CONSTRUCTION MANAGEMENT
This section presents the series of international standards on environmental management, ISO
14000, and the need for integrating environmental management into construction management. ISO 14000 is a series of international standards for environmental management. The ISO14000 standards address the following aspects of environmental management (Quality network 1999, Peglau1999, ISO 1999, Kloepfer 1997), as shown in Table 4.
As a subset of ISO 14000, the EMS is a systematic approach to dealing with issues related to environmental management. It is a 'tool' that enables a company of any size or type to control the impact of its activities, products or services on the natural environment. Although many companies in other businesses have already obtained ISO14001 EMS (Environmental Management System) certifications, none of the construction companies (contractors) in China has such a certification. In order to build the concept of environmental management into construction management, we propose that it is fundamentally important for major construction companies in China to make necessary efforts to obtain certifications on ISO 14001 EMS.
In the ISO 14001 EMS, environmental management is maintained through five stages (see Figure 2): issuing environmental policies, planning, implementation and operation, checking and corrective action, and management review.
ISO 14001 EMS requires construction management to establish systematic policies and methods to deal with problems related to environmental management. Specifically, the certification requires a construction company to establish objectives, targets and programs for environmental management. A thorough analysis of all processes and methods used in construction operations is necessary in order to identify sources and magnitude of pollution and hazards. Once the sources are identified, the construction company needs to make all necessary efforts to reduce the amount of pollution and hazards generated from a particular operation. Also, it is important to have a regular management review to ensure the suitability and sustainable implementation of the established policies and methods.
The establishment and implementation of ISO 14001 EMS requires a total commitement and cooperation of all parties involved in the supply chain, including construction contractors, supervisors, designers, manufacturers, investors (Cysewski 1995). However, in developing countries such as China, there are many difficulties and challenges ahead for implementing ISO 14001 EMS in the construction industry. The most formidable one is that, efforts spent in environmental protection do not necessarily result in lower project cost and/or shorter durations. In fact, introducing environmental management into construction management increases the project direct costs, as at present, contractors do not need to pay for the pollution and hazards generated by their projects, if they can get away with current environment and construction laws. Another difficulty is that the awareness of environmental protection among general public is low compared to many developed countries. People seem to be too busy accumulating personal wealth to worry about the natural environment. As a consequence, the public pressure on the construction industry for improving its environmental management is not very high.
With these difficulties and challenges in mind, we believe that it is important for the government to further reinforce relevant environmental protection laws on one hand, and promote the general education of importance in protecting the natural environment on the other.
14000, and the need for integrating environmental management into construction management. ISO 14000 is a series of international standards for environmental management. The ISO14000 standards address the following aspects of environmental management (Quality network 1999, Peglau1999, ISO 1999, Kloepfer 1997), as shown in Table 4.
As a subset of ISO 14000, the EMS is a systematic approach to dealing with issues related to environmental management. It is a 'tool' that enables a company of any size or type to control the impact of its activities, products or services on the natural environment. Although many companies in other businesses have already obtained ISO14001 EMS (Environmental Management System) certifications, none of the construction companies (contractors) in China has such a certification. In order to build the concept of environmental management into construction management, we propose that it is fundamentally important for major construction companies in China to make necessary efforts to obtain certifications on ISO 14001 EMS.
In the ISO 14001 EMS, environmental management is maintained through five stages (see Figure 2): issuing environmental policies, planning, implementation and operation, checking and corrective action, and management review.
ISO 14001 EMS requires construction management to establish systematic policies and methods to deal with problems related to environmental management. Specifically, the certification requires a construction company to establish objectives, targets and programs for environmental management. A thorough analysis of all processes and methods used in construction operations is necessary in order to identify sources and magnitude of pollution and hazards. Once the sources are identified, the construction company needs to make all necessary efforts to reduce the amount of pollution and hazards generated from a particular operation. Also, it is important to have a regular management review to ensure the suitability and sustainable implementation of the established policies and methods.
The establishment and implementation of ISO 14001 EMS requires a total commitement and cooperation of all parties involved in the supply chain, including construction contractors, supervisors, designers, manufacturers, investors (Cysewski 1995). However, in developing countries such as China, there are many difficulties and challenges ahead for implementing ISO 14001 EMS in the construction industry. The most formidable one is that, efforts spent in environmental protection do not necessarily result in lower project cost and/or shorter durations. In fact, introducing environmental management into construction management increases the project direct costs, as at present, contractors do not need to pay for the pollution and hazards generated by their projects, if they can get away with current environment and construction laws. Another difficulty is that the awareness of environmental protection among general public is low compared to many developed countries. People seem to be too busy accumulating personal wealth to worry about the natural environment. As a consequence, the public pressure on the construction industry for improving its environmental management is not very high.
With these difficulties and challenges in mind, we believe that it is important for the government to further reinforce relevant environmental protection laws on one hand, and promote the general education of importance in protecting the natural environment on the other.
CONCLUSIONS
In order to tackle pollution and hazards generated by urban construction projects in China, we first presented a qualitative system to identify and to categorise sources of pollution and hazards on construction sites. Methods for preventing or reducing the amount of pollution and hazards at the sources are provided. Then, a method is presented to quantitatively measure the construction pollution index (CPI) which indicates the accumulated pollution and hazards generated from a construction site. Integrated with MS Project, a popular scheduling software used by construction professionals in China, we developed a computer tool which can automatically generate the pollution and hazards distribution diagram over the project duration. The distribution diagram can assist project managers to identify worst periods in terms of emision of pollution, and to take necessary preventive measures to reduce the amount of pollution and hazards. The computer tool is being tested on different projects, and detailed descriptions of the computer tool and its test results will be reported in the future.
As the concept of environmental management is relatively new in China, we recommended that it is vital for major construction companies in China to obtain ISO 14001 EMS certifications. By doing so, construction companies will establish comprehensive policies and regulations and self- guard the implementation of enviromental management within the context of construction management.
As the concept of environmental management is relatively new in China, we recommended that it is vital for major construction companies in China to obtain ISO 14001 EMS certifications. By doing so, construction companies will establish comprehensive policies and regulations and self- guard the implementation of enviromental management within the context of construction management.
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