Designated substances include asbestos, lead, mercury-filled bulbs, mercury switches, PCBs (ballasts, capacitors, and transformers), refrigerant, as well as any underground storage tanks that may be present on site. These substances must be disposed of at licensed receiving facilities.  

Following the removal of these substances, demolition and simultaneous segregation can begin. Clean wood, metal and concrete are all separated into bins, which can be sent to recycling facilities. Interior wood components are usually clean.  

Any useable equipment or fixtures such as chairs and tables is usually donated to schools or charities or other institutions and organizations. Other metals such as aluminum, copper and stainless steel are also recyclable. Concrete is crushed on-site and recycled as Granular A or B.    

Challenges abound

Apart from the benefits of diverting demolition waste, there are a few challenges, particularly when dealing with small-scale demolition work. The majority of the buildings that are demolished are older and hence so is the technology of the materials within that building. Items such as light fixtures and windows are outdated and few places are willing to accept such items.  

Another challenge is the feasibility of recycling small amounts of waste generated from smaller demolition jobs. Metal-framed windows for example, can be separated into metal and glass, but again, it is difficult to find a facility that will accept one pail of glass and even if they will, the transportation costs might not make that a feasible option.

Painted and treated wood is also a challenge. This cannot be recycled because it is contaminated and the labour required to strip the wood of its paint would outweigh the cost savings.

Despite these challenges, the fact remains that it is feasible to recycle up to 80 per cent of the waste generated from a demolition site.  

Apart from waste diversion during the demolition process, there are also ways to reduce the amount of contaminated soil taken to landfills. It is common practice to excavate contaminated soil and dispose of it at a landfill.

However, emerging technologies in recent years have shown that there are other, viable remedial options. Some of these include in-situ treatment options such as chemical oxidation, bioremediation, stabilization, etc.

These technologies treat soil in place and remove contamination, thereby alleviating the increasing burden on landfills. However, as with any remedial option, there are factors to consider as limitations apply to all.  

Considering factors such as contaminant of concern, time restrictions, soil composition, cost implications, availability of space, etc. is key to choosing the best possible solution.

Agnes Miczynska is the Business Development Manager at Tri-Phase Environmental Inc.  Contact Agnes at Agnes@triphasegroup.com.