Closing the
Loop on Pipes!
uPVC and HDPE
Exploring ways to minimize construction and building waste is a passion for Dr. Terri-Ann Berry, Co-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) are writing a monthly column in Building Today on practical advice for managing construction waste and other environmental issues builders might come across.
Have you ever noticed just how much room pipe off-cuts take up in your skip?
It’s a big problem and can represent around 20% by weight of total construction plastics coming from a construction site.
Pipes are predominantly made of one of two plastics, HDPE (high-density polyethylene) and uPVC (unplasticised polyvinyl chloride). Both plastics offer versatility, affordability and chemical resistance, while also being durable, strong, and flexible so ideal for use in drainage, irrigation and plumbing. However, they are both derived from fossil fuel, energy intensive to produce, and if disposed of incorrectly can contribute to environmental pollution..
When managed properly, plastic can undergo multiple recycling cycles. However, historically, uPVC recycling has been challenging to recycle in NZ due to sorting and separation requirements and concerns about additives used during uPVC production. By contrast, HDPE is comparatively easier to recycle but still needs on-site sorting and separation.
So, most pipe off-cuts have historically been destined for landfills due to the lack of recycling facilities capable of handling construction waste at scale. The encouraging news is that both uPVC and HDPE plastics can be recycled in New Zealand.
This situation started to change in 2022 when one of New Zealand's main pipe suppliers, global company Aliaxis (Marley NZ) and local company WM New Zealand announced an $11.145 million investment initiative aimed at reducing plastic construction and demolition waste in the country. This project included funding for research into solutions for plastic waste by Unitec Institute of Technology and our team at EIC, Aliaxis secured a Plastic Innovation Fund grant for $4.464m from the Ministry for the Environment to build HDPE and uPVC pipe recycling capacity in New Zealand. This project underscores the importance of collaboration in the sustainability sector, connecting industry, government, scientists, and communities. Since its inception in September 2022, the project is already producing significant results across three key areas:
1. Investing in new plastic recycling facilities across New Zealand to shred, wash, and process uPVC and HDPE plastic from construction, demolition, commercial, and industrial sources. Aliaxis and WM New Zealand formed Plastics Recycling NZ, which acquired recycling expert Compounding Specialists Ltd (Comspec) in Christchurch, handling over 4000 tonnes of plastic resins annually.
2. Establishing a network of metropolitan and regional PVC and HDPE collection services in partnership with WM New Zealand. Currently, there are more than 30 recycling drop-off locations nationwide (see Marley website: https://www.marley.co.nz/find-a-recycling-drop-off/), allowing for free disposal of pipe waste, with the requirement that pipes must be free of rings, tapes, and stickers.
In 2023, Aliaxis successfully recycled an impressive 702 tonnes of plastic, avoiding an estimated 800 tonnes of CO2e emissions. Waste collectors are also starting to collect these pipes with the likes of WM New Zealand and Green Gorilla already on board providing options for sorting pipes on construction sites, and transport sorted pipes to Plastics Recycling NZ and RX Plastics in the South Island for recycling.
3. Conducting research by EIC (formerly ESRC at Unitec) and BRANZ into practical solutions to minimize plastic construction waste and raise awareness of plastic recycling.
A significant aspect of this project is providing scientific research into on-site waste management, with the EIC subcontracted to produce a variety of tools for use in the construction sector. EIC has developed WasteHub to host a range of educational resources to make managing plastic waste more accessible and manageable for the construction industry. This includes signage, instructional videos, and information on recyclers.
Participating is simple: separate your pipes into HDPE and uPVC, ensure they are free of potential contaminants (eg duct tape, concrete and rings), then drop them off at one of the dropoff locations. If working on larger projects you can also separate on site and have the pipe collected by WM New Zealand and other collectors. If you are local to one of the facilities you can also dropoff larger quantities of clean offcuts directly to the recycling plant.
By doing this, you are reducing the waste you send to landfill (saving money) and contribute to the larger goal of closing the loop on pipes to make a tangible difference for our environment and for future generations.
Some common pitfalls to look out for are pipes that are not uPVC or HDPE such as polybutylene and PEX pipes, commonly used in hot and cold water systems, which cannot currently be recycled by Plastics Recycling NZ. These should go into general waste for now.
Have Questions?
If you have any questions for the team that you would like answered in this column, please contact ta@environmental-innovation.nz.
Learn more about the Environmental Innovation Centre at www.environmental-innovation.nz/
Learn more about the Marley take back scheme www.marley.co.nz/sustainability/recycling/
