NEARLY 5000 tonnes of plastic has been kept out of circulation from Woolworths alone 12 months after the plastic bag ban was introduced - that's equal to more than 780 African elephants stampeding to our landfill and waterways.

Despite some controversial backflips and modifications to the environmental policy along the way, both major supermarkets have revealed its massive impact.

Woolworths has issued about three billion fewer plastic bags from its stores over the last year.

It says shoppers have embraced the new habit with one in six transactions now including the purchase of a plastic bag, and that number is decreasing month-on-month.

All retail outlets in Victoria will soon ban plastic bags. Picture: Peter Rae/AAP
All retail outlets in Victoria will soon ban plastic bags. Picture: Peter Rae/AAP

Coles says the sustainable strategy has diverted 1.7 billion single-use bags from landfill, with data claiming seven in 10 of its consumers now remember to bring a reusable bag when they shop and a further two in 10 bringing them on more occasions than not.

Single-use plastic bags have been banned in South Australia, Queensland, the ACT and Western Australia, while Victoria is expected to follow in November.

Woolworths chief executive Brad Banducci said consumers were quick to embrace the change despite some vocal criticism from portions of the country.

"We recognise change is never easy, particularly when it comes to something as habitual as grocery shopping," he said.

"Yet one year after we phased out single-use plastic bags, it's clear Australians have formed new habits and embraced a vastly more sustainable way of shopping with reusable bags.

"We're incredibly grateful to our customers for coming on this journey with us to help clean up Australia's waterways for the benefit of local communities and marine life.

"We also understand there is a lot more we can do to help create a truly circular economy."

Coles chief operating officer Greg Davis said the sale of its reusable "community bags" had allowed the supermarket to raise $2.5 million for charity.

"When we announced in 2017 that we would remove lightweight single-use plastic bags from our stores, we knew we would have to support customers to help them form new shopping habits," he said.

"Our community bags are one way we have helped customers who forget to bring their bags from home."

Landcare Australia chief executive Shane Norrish said its volunteers devote time to cleaning up the coastal, marine and river environments.

"Plastic pollution is a real issue for groups who are involved in clean-up projects," he said.

"However, billions of plastic bags have been taken out of the system by Woolworths and its customers, which is having a positive impact on our waterways and our coasts.

"Together we are making a difference. We need to continue driving progress by engaging the entire community and inspire Australians to be aware, empowered and active in caring for the environment."

Planet Ark deputy chief executive Rebecca Gilling said it was always better to reuse than recycle.

"We hope that over time we'll see an even greater reduction in the number of reusable bags sold at check-outs as shoppers really embed the habit of bringing their reusable bags with them," she said.

"In the meantime, fewer single-use bags will end up as litter or in our oceans, where they cause serious harm to marine life."

The Victorian Government introduced a bill on Wednesday proposing a ban on single-use plastic shopping bags across the state from November.

Included in the ban would be supermarkets, fashion boutiques, fast-food outlets, convenience stores and service stations - effectively closing a loophole that allowed the bags to continue to be used after Coles and Woolworths stopped handing them out 12 months ago.

State Environment Minister Lily D'Ambrosio told reporters the ban is about making an impact environmentally.

"Victorians use more than a billion of these bags each and every year; more than 10 million of these end up as litter in our environment," she said.

"We know that that's not good enough."