The report, released by Boomerang Alliance, found that if just 5 per cent of 1.6 million homes in Sydney neighbourhoods are adversely affected by litter, the potential economic impact on housing in Sydney is $11.8 million.

It based its findings on  a model developed in the US by the National Association of Home Builders, who determined the presence of litter devalued property in that neighbourhood by about 7.4 per cent.

These figures don't surprise the Property Council of Australia.

"It's important in a city such as Sydney where the population is growing and there is additional pressure on the environment that we keep litter in check," said Jane Fitzgerald, Property Council's NSW Executive Director.

According to Jeff Angel, Convenor and Director at Boomerang Alliance: "NSW is stuck like shag on a rock surrounded by plastic bag litter. It's pathetic that the state that took the historic decision to introduce container deposits does not seem to get it when it comes to plastic bags and the enormous damage they do to marine life as full bags and broken down microplastics".    ​

"Some smaller states and territories have acted. But when you understand that of the 1.5 billion bags littered since all state governments announced in 2005 they would take action - over 600million have been in NSW, so there is no excuse for delay."

While litter volume in NSW has dropped by 12 per cent, 185 million plastic bags will be discarded this year.

To reduce impact on future Sydney, Boomerang Alliance, which represents 45 community groups and more than  45,000 individual supporters, has presented the report to  urge the state government to act on  products bans, take-back schemes, advanced disposal fees and mandatory design requirements. "Prevention is better than cleaning up", it says, and costs less too.

The Threat Abatement Plan aims to ensure the impacts of plastic pollution in the Australian marine environment are minimised and echoes the issues raised by the Senate inquiry report into marine plastic pollution made in April, which expressed a disappointment "with the apparent lack of action on marine plastic pollution".

The Boomerang Alliance hopes the plan  will provide momentum for Australia to eliminate 70 per cent of plastic pollution by 2020.

The CSIRO estimate 90 per cent of all seabirds have plastic in their stomachs and over half if the world's population of turtles. But Sydney's plastic isn't just costing the environment, it's costing the economy more than $162.2m each year.

According to Dave West, the co-founder of Boomerang Alliance, significant omissions have been made by the government in calculating the exact cost.

"It seems the word 'ban' frightens the folks in Baird's office ... both states have their head in the sand, and use doctored figures to justify inaction," he said.

Mark Speakman, the NSW Environment Minister, said their priority is in implementing the 10-cent container deposit scheme.

"In this year's National Litter Index, containers made up 49 per cent of the total volume of litter in NSW and bags made up less than 2 per cent. Containers that will be caught in the NSW Container Deposit Scheme made up 43 per cent of the total litter volume.

"I said in February that we are looking at our options with respect to plastic bag litter and we are continuing to do so, including by undertaking research with the CSIRO on the environmental impacts of biodegradable bags."