What to do about your plastic construction waste?
Exploring ways to minimize construction and building waste is a passion for Dr. Terri-Ann Berry, Director of the newly formed Environmental Innovation Centre (EIC). Terri-Ann has partnered with experienced Master Builder Nigel Benton to develop practical environmental solutions for the construction industry. The team at the Environmental Innovation Centre (EIC) will write a monthly column in Building Today on practical advice for managing construction waste and other environmental issues builders might come across.
Have you ever wondered what happens to all the plastic waste on-site?
The answer is not pretty, with the majority of construction industry plastic waste ending up in landfills. Currently, construction waste represents 50% of the waste filling up New Zealand's landfills, with plastics as a major contributor. In Auckland alone, approximately 25,000 tons of plastic waste end up in landfills annually. One residential build on average produces waste equivalent to about 634,000 plastic bags.
Construction plastic is detrimental to landfills as with its low density it takes up a lot of space and will not break down for hundreds of years. This occupies valuable land that could be used for more sustainable purposes. When not send to a landfill It often ends up in waterways, contributing to environmental pollution, and posing long-term hazards to ecosystems.
But is there anything you can do about it?
Yes! Essentially, to reuse or recycle plastic, it must be sorted into plastic types—a bit like your domestic waste. Unfortunately, there are a lot of different plastic products in the industry so how could anyone know which ones to sort where? To address this BRANZ has funded a project where Dr. Terri-Ann Berry and her team partnered with six contractors to trial a practical, new plastic sorting system.
An example of one of these trials was with Master Builder Nigel Benton, who was alarmed at sending skip after skip of construction and demolition waste to landfill. Nigel and the EIC team (then still known as the Environmental Solutions Research Centre - ESRC) undertook a trial to reduce waste on-site at a new project to build eight terraced townhouses in West Auckland. They aimed to divert 90% of waste generated on-site from the landfill. Similar developments typically produce approximately 16 tonnes of waste, equivalent to about eight cars!
To prepare staff and subcontractors for this multi-build project, EIC delivered training on the ‘how-to’ of waste sorting. Bins were clearly labelled and included pictures for quick reference. The sorting system meant plastic could either be sent back to the supplier or sorted into the right types for recycling.
The results were excellent! A total of 22.4 tonnes of materials were collected and audited, of which 18.4 tonnes were recycled or repurposed, including 830kgs of plastic waste, a third of which was soft plastic. Most of the soft plastic was recycled by Hamilton-based SaveBOARD. Best of all, the target was exceeded with 91% of waste diverted from the landfill, making Nigel very happy. “We were able to repurpose 91 percent of all construction waste from one site,” Benton said. “There was a mega amount of plastic used.”
Got Plastic Waste? Get it Sorted!
Sorting is the key, so the main plastic waste streams on-site can be either returned to the supplier or recycled, preventing them from going to the landfill. As an example, how this can be done, find below a decision tree EIC has developed for SARNZ Scaffolding, Access, and Rigging NZ to help their members and other participants in the industry. These decision trees will vary between different industry subsectors and regions In new Zealand and EIC are working on making more bespoke material to support the industry.
Here is the process broken down into five steps:
Identify plastic waste streams. Common ones include: Soft plastics, polypropylene, polystyrene, pipes, food, and drink waste.
Return to the supplier? Check if your supplier will take it back.
Find local recyclers/transport options.
Set up a recycling area with signs and bags.
Train your staff to use the signs to identify plastic and sort it in the right condition.
Currently, EIC is developing an education hub for construction companies with a series of resources to make it easier to divert plastic waste from the landfill. This includes training videos, a plastic catalogue, signage, and bags.
EIC will be presenting here a monthly column, and we will keep you updated on progress with construction waste trials focusing on key plastic waste streams, including suppliers with take-back schemes, recycling options, and case studies of companies successfully diverting waste from the landfill.
If you have any questions for the team that you would like answered in this column, please contact us.