Paper bags for your green bin

Hobsons Bay City Council and Veolia are trialling the use of paper bags to reduce odour and mess and make it easier to recycle food.

Using only Hobsons Bay-issued bags will ensure consistent results for monitoring and evaluation, and maintain low contamination rates.

Veolia advises that only Hobsons Bay-branded paper bags can be used for the trial to provide a good, solid control while implementing a major change.

‘The heavy (100gsm) paper bags supplied by Council have been tested in our in-vessel composting environment, with good results. Tests to date have been on a relatively small scale. Introducing large quantities of paper bags into the system, through a city-wide trial, is a major change to our systems.

To ensure we continue to achieve the highest possible rate of diversion from landfill, it’s important to maintain consistency in materials and avoid the risk of increased contamination.

Through testing, we know that Council-provided heavy (100gsm) paper bags compost in our in-vessel process at the same rate as other materials and we are confident that the same results will be achieved with the lighter (50gsm) paper bags. Having an easily identifiable Hobsons Bay-branded bag also allows staff on the picking line to quickly recognise an accepted, non-contaminating bag.

All materials that come through Veolia go along a conveyor where staff visually check for potential contamination. Staff have less than a second to identify something as potential contamination and decide whether to pick it off the line. Consistent, easily identifiable paper bags reduces variables and allows staff to focus on genuine contamination.

There is a wide variety of paper bags out there, and it can be confusing for the consumer to know which can be safely composted. Using Council-supplied bags makes it simple for residents. It removes any question of whether the bag is made from materials that won’t completely break down, whether it’s lined or coated, or printed with copper-based inks – all of which constitute contamination.

Using only Hobsons Bay-branded paper bags for the trial gives us the best chance of maintaining low contamination and high diversion rates.’

 Steven Marshall, State Manager, Resource Recovery, Veolia

As you know, compostable green bags are not accepted in the food and garden organics bin. While we would like to allow them, as some other council areas do, our contractor, Veolia, advises they can cause issues with contamination.

Veolia advises that better outcomes for food and garden organics are achieved when these bags are not used, identifying the following challenges:

• There are many different types of ‘green’, ‘compostable’ bags on the market. It’s difficult for consumers and for staff on the sorting line to identify.
• The bags remain intact on the sorting line, and may conceal contamination, which compromises the end product – mulch and compost.
• Different bags break down at different rates, which can disrupt the processing of the material inside.
• If a knot is tied in the bag, the knot will take a long time to break down – sometimes more than a year.