Recovered glass sand

November 7, 2019

Could glass bottles, jars and containers support local jobs, reduce waste to landfill, and lessen the depletion of local natural resources? All while saving Icon Water money?

It’s a cutting edge question. 

A number of successful trials and recent approvals suggests they can. 

First things first. What is recovered glass sand? 

Glass is made from sand. Happily, in the case of glass containers, it can be returned to sand. The recovered glass sand produced is much the same as quarried or river sands. And not to worry – the particles are small and don’t cause cuts or abrasion. 

So why is Icon Water talking about it? 

Most of our 3000+ kilometres of sewer pipes are embedded in specialised quarried or river sands. This means that whenever Icon Water and our contractors install new pipe assets, they use plenty of sand. 
Recovered glass sand has been used widely as a replacement for natural sand. Other water utilities including Melbourne Water, and Yarra Valley Water have all approved and actively use recovered glass sand products for pipe embedment on their sewer pipe assets.  
Icon Water have been working with local producers and potential suppliers of recovered glass sand to ensure it is fit-for-purpose. We are currently waiting on the installation of processing infrastructure at the ACT Government’s recycling facility and the final product classification to be approved. Thanks to the advice of our engineering team the product is on its way to meeting Icon Water requirements in the near future.   

Why are Icon Water interested in the product?

There are a number of benefits for Icon Water, environmentally, financially, and in terms of safety.

  • Recovered glass sand can be 50 per cent or more cheaper than quarried natural sands. 
  • Recycling creates three times as many local jobs than disposing of waste to landfill.
  • Recovered glass sand adds another fit-for-purpose product from recycling, helping support the local industry to diversify and sustain itself.
  • Natural resources are conserved, reducing extraction activities and loss of natural ecosystems and biodiversity.
  • Recovered glass sand typically produces less dust than quarried sand and has significantly less crystalline silicon.
  • Recovered glass sand does not decompose, is durable and inert.

Does recovered glass sand undermine recycled glass manufacturing? 

Generally, glass packaging is either recycled back into glass packaging, recycled into recovered glass sand products or, at its lowest value, used as a capping material for landfills. 

In the ACT the tyranny of distance means that sending recycled ACT glass to manufacturers is not always cost-effective. Glass manufacturers are mostly overseas and require whole or only partly damaged bottles. This is not always possible, so instead recycled ACT glass undergoes multiple processes including crushing, imploding, screening to a range of size fractions, and drying. A number of recovered glass sand products are then formed and used in the construction industry to replace natural sand in making road base, asphalt, concrete, pipe bedding, drainage material and other engineering uses. If there is no local use of the recovered glass sand products, the glass is used as landfill capping, its lowest value. 

Is Icon Water using it yet?

Not yet. With any engineering product it is essential that it be fit-for-purpose. The product must meet defined levels for parameters such as wet and dry strength compactability, particle size distribution and contaminant freedom before the business accepts it for use.  
The product must also prove it will not harm human health and the environment. The material must be 99 per cent inert glass and have been shown to have negligible impact on the environment. 

In terms of safety it should not cut or cause abrasions when handled. Testing has proven it to ha Recovered glass sand has dramatically less silicosis-causing dust than quarried or river sand. It has an odour, as does river sand, but the odour tends to be stronger and more acidic due to fermenting inert contaminants. The odour will not harm health and can be mitigated by a masking agent applied during production or use. 

Recovered glass sand should be managed like any sand product, with face mask, gloves and safety glasses worn at a minimum. 

What next? 

Icon Water are continuing to analyse each recovered glass sand product. This is likely to include a trial to gauge how the product performs in the field and how it is viewed by our field services crew who install it. It is the product supplier’s responsibility to prove the efficacy of any recovered glass sand product.