From management point of view, no single management strategy is suitable for managing all the construction waste steam in all circumstances. A sustainable construction waste management strategy includes a range of comprehensive strategies such as reduce, reuse and recycle. Effective waste management strategies require source segregation of all wastes generated during the construction. Construction contractors can form a dedicated team to deal with all aspects of waste management starting from source segregation to housekeeping, waste collection and recycling. A waste inventory or log should be maintained to keep records of waste manifest invoices from the vendors or waste contractors.
Construction and Demolition Waste Management Plan (CDWMP)
Develop a CDWMP prior to the start of construction and demolition activities. It will help to identify to identify each type of waste that will be generated including but not limited to the materials that are considered as hazardous, non-hazardous materials to be diverted to landfill, materials to be salvages and refurbished and reused. It will also indicate whether the materials will require on-site segregation or not. All hazardous wastes must be disposed off in an appropriate and safe manner as required by local regulatory authorities.
To manage the wastes effectively, it is important to classify them in two broad categories such as hazardous and non-hazardous waste. Again, all non-hazardous wastes can be categorised into of three types as recyclable, reusable and non-usable or non-recyclable wastes.
Hazardous wastes are those that have a characteristic that make those toxic, corrosive, flammable, and reactive. These include discarded and old chemicals, glues, oil and lubricants, paints, chemical containers, unused and discarded paints, adhesives, sealants, paint soaked brush, oily rags etc. with HAZMAT contents. These wastes cannot be recycled due to the risk factors attached to them. The legal and sustainable way of handling those is to store them in different colour coded leak proof container and then get them collected by an approved contractor for storage, treatment and disposal purposes.
These are generated in large quantities during demolition or removal of existing road surfaces. These can be recycled by sending them to a contractor for further processing or for using in their manufacturing processes.
Paints, Coatings and Adhesives
The leftover materials can be utilised in small projects and empty containers can be disposed off through an approved contractor.
Non-hazardous Reusable and Recyclable Wastes
The best of way of managing them is to separate them at the source by storing them separately from non-hazardous non-recyclable wastes and then reuse or recycle them in situ depending upon their potential use. Selling or donating them to others can be considered as an option if they cannot be reused or recycled onsite. The materials than can be used for such purposes include scrap metals, excess concrete, ceramic products, concrete blocks, pavers, wood and wood products, cardboard boxes, gypsum board, glass etc. can be either reused directly or recycled depending upon the condition and usage requirements.
Metals sheets from a demolition site can be used to make fences. Metals recovered from demolition sites can be used as metal frames in the building. The rejected scrap metals during the construction should be kept separately and then be sold to local scrap metal dealers who can utilise those for variety of uses.
The excess concrete from the concrete work and pile cutting and trimming should be collected and crushed to required sizes to be reused for reclaiming work with approval from relevant regulatory authorities. The left over concrete from the concrete mixer can be utilised to make concrete blocks, road posts for signs, road barriers or other structures that can be used for temporary works during construction.
Leftover bricks can be utilised for other temporary construction or for landscaping purposes or can be sold to other people or organisation.
Wood and Timber Materials
Door frames or old doors from a demolition site can be refurbished and reused or recycled onsite or sent to be used in another project or can be sold to a vendor to make other wood products. Other wood products such as ply wood, composite wood, agri-fibre products should be collected and stored separately in a designated place, which later on can be reused onsite depending upon their use or sold to wood recycler.
Cardboards can be sold to a vender for reuse and recycling purpose.
Depending upon the reuse and recycling option, plastic wastes can be sold or donated to recycler.
Concrete Masonry Blocks
The rejected and damaged concrete blocks can be used in landscaping designs or can be collected along with other concrete wastes to be used for reclamation works.
Tiles and Ceramics
The leftover tiles and ceramics can be used in garden landscaping designs or can be collected separately to be used in reclamation work.
Excavated materials such as soil, sand, gravels can be reused on the site or sent to another site for reuse or reclamation work. These materials can be sold to local vendors or can be donated to other organisation or people who have the need for those.
Non-recyclable Non-hazardous Waste Materials
These include trash and organic wastes such as trees and plants. Green materials can be composted and used as fertiliser or soil conditioner. Trash materials can be send to landfill for disposal.