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Chapter 2: Construction and Demolition Wastes


2.4. QUANTIFYING WASTE
      The amount of C&D waste produced depends on several variables. The amount of C&D waste generated at the national level depends on:
The extent of growth and overall economic development that drives the level of construction, renovation, and demolition
Periodic special projects, such as urban renewal, road construction and bridge repair, and unplanned events, such as natural disasters
Availability and cost of hauling and disposal options
local, State and Federal regulations concerning separation, reuse, and recycling of C&D waste
Availability of recycling facilities and the extent of end-use markets.

          There are few comprehensive estimates of C&D waste generation rates at the national level. It has been either historically aggregated into the municipal solid waste data, or not accounted for since there are so many non-regulated disposal options. It is estimated that the quantity of C&D waste generated in India is over 10-20 million tons per year. This equates to almost 35 to 40 percent of the total amount of municipal solid waste.
At the local level, the difficulty in quantifying the amount of waste being landfilled is due to the difficulty of measuring specific quantity of the waste. C&D debris is handled by a myriad of individual contractors, waste haulers, and landfill operators. The amount of materials handled by each one of these handlers would have to be measured to accurately determine generation rates. Many studies have found that landfill operators either keep no records, or keep records that are inadequate to determine waste generation rates of the original producer. Another difficulty in quantifying the waste is its highly variable and heterogeneous nature. The amount of waste produced by one contractor may differ significantly that produced by another, due primarily to the level of expertise or training of employees. Finally, estimating C&D waste by State may not be very accurate because many States allow inter-state disposal of these wastes.

2.5. IMPACTS OF CDW GENERATION
     The Construction of any infrastructure make a considerable environmental impact through extraction of raw materials, the use of energy in production processes and transport, production of masses by byproduct waste, and the damage to environment and health in all phases of the life cycle of hazardous components.
     The disposal of C and D wastes has become a major concern in recent year. Some building owners, waste haulers and demolition contractors are disposing of this waste improperly and illegally in order to avoid transportation costs and tipping fees at waste disposal facilities. Illegal disposal sites have been discovered in gravel pits and ground water recharge areas, on farm land, and prime residential property, and in borrow pits and low lying areas. The land disposal of C and D waste presents a threat of ground water contamination because of trace amounts of hazardous constituents, which are sometimes encountered. The potential for ground water contamination results from small amounts of hazardous materials, such has organic compounds or heavy metals that may be present in substances that have been applied to construction materials, or by the improper disposal of residues or bulk chemicals in the waste stream. Degradation of ground water quality may also results from larger amount of generally non-toxic chemicals, such as Chloride, Sodium, Sulphate, and Ammonia that may be present in leachate generated from C and D waste materials (Ex: wood, concrete, metal, drywall, asphalt) when land filled. Therefore the improper disposal of C and D waste does pose a threat to ground water quality.
      An illegal disposal site may also attract the illegal disposal of other types of waste, including conventional municipal waste, industrial waste and hazardous waste this would further impact the site and increase the future cost for cleaning up an impacted or contaminated site. The open burning of demolition material is a major concern and is prohibited. Plastic material, insulation foam, painted or treated wood, etc. will give of toxic fumes when burnt. Demolition material from ware housing buildings, industrial and agricultural facilities may be contaminated with chemicals some spillage or from their normal operation. Leachate from the ashes may impact the ground water. Health Canada advises that “burning any form of treated wood represents a health hazard and should be avoided”.
   The impacts of huge amount of the construction and demolition waste generated and which are increasing due to urbanization and industrialization in construction industry can be summarized below in different environmental, economical and social aspects: -

2.5.1. ENVIRONMENTAL IMPACTS
      The generation of the huge amount of the CDW materials cause major impacts on the environment as the disposal of these waste materials are very difficult.
Environmental pollutions
Contamination of the underground water due to leachate in landfills
Contamination with surface water causes many problems as well, etc.

2.5.2. ECONOMICAL IMPACTS
      The generation of the huge amount of the construction and demolition waste cause wastage of money too.
Landfilling needs space and money
Disposal of the huge amount of the CDW need money for disposal of these       waste
Loss of Resources, Municipal wellbeing, Recycling revenue
Increased production of construction materials (mining) will be needed.

2.5.3. SOCIAL IMPACTS
     The social impacts caused by the generation of the construction and demolition waste are Health Hazards, employments, etc.
(This Chapter is Continue.....)

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