Drink containers end up in the ocean at a truly alarming rate. Simply paying people a small amount to return them cuts that rate by nearly half.

Read more:
Eight million tonnes of plastic are going into the ocean each year

One possible solution – paying a small amount for returned drink containers – has been consistently opposed by the beverage industry for many years. But for the first time our research, published in Marine Policy, has found that container deposits reduce the amount of beverage containers on the coasts of both the United States and Australia by 40%.

What’s more, the reduction is even more pronounced in areas of lower socio-economic status, where plastic waste is most common.

Plastic not so fantastic

There have been many suggestions for how to reduce marine debris. Some promote reducing plastic packaging, re-purposing plastic debris], or cleaning beaches. There has been a push to get rid of plastic straws, and even Queen Elizabeth II has banned single use plastics from Royal Estates! All of these contribute to the reduction of plastics, and are important options to consider.

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Pristine paradise to rubbish dump: the same Pacific island, 23 years apart

Legislation and policy are another way to address the problems of plastic pollution. Recent legislation includes plastic bag bans and microbead bans. Economic incentives, such as container deposits, have attracted substantial attention in countries around the world.

Several Australian jusrisdictions, including South Australia, the Northern Territory, and New South Wales), already have container deposit laws, with Western Australia and Queensland set to start in 2019. In the United States, 10 states have implemented container deposit schemes.

But how effective is a cash for containers program? While there is evidence to suggest that container deposits increase return rates and decrease litter, until now there has been no study asking whether they also reduce the sources of debris entering the oceans.

In Australia, we analysed data from litter surveys by Keep South Australia Beautiful, and Keep Australia Beautiful. In the US, we accessed data from the Ocean Conservancy’s International Coastal Cleanup.

Read more:
The future of plastics: reusing the bad and encouraging the good

We compared coastline surveys in states with a container deposit scheme to those without. In both Australia and the US, the proportion of beverage containers in states without a deposit scheme was about 1.6 times higher than their neighbours. Based on estimates of debris loading on US beaches that we conducted previously, if all coastal states in the United States implemented deposit schemes, there would be 6.6 million fewer containers on the shoreline each year.

Keep your lid on

But how do we know that this difference is caused by the deposit scheme? Maybe people in states with container deposit schemes simply drink fewer bottled beverages than people states without them, and so there are fewer containers in the litter stream?

To answer that question, we measured the ratio of lids to containers from the same surveys. Lids are manufactured in equal proportion to containers, and arrive to the consumer on the containers, but do not attract a deposit in either country.

If deposit schemes cause a decrease in containers in the environment, it is unlikely to cause a similar decrease in littered lids. So, if a cashback incentive is responsible for the significantly lower containers on the shorelines, we would expect to see a higher ratio of lids to containers in states with these programs, as compared to states without.

That’s exactly what we found.

We were also interested in whether other factors also influenced the amount of containers in the environment. We tested whether the socio-economic status of the area (as defined by data from the Australian census) was related to more containers in the environment. Generally, we found fewer containers in the environment in wealthier communities. However, the presence of a container deposit reduced the container load more in poorer communities.

This is possibly because a relatively small reward of 10 cents per bottle may make a bigger difference to less affluent people than to more wealthy consumers. This pattern is very positive, as it means that cashback programs have a stronger impact in areas of lower economic advantage, which are also the places with the biggest litter problems.

Read more:
Sustainable shopping: take the ‘litter’ out of glitter

Ultimately, our best hope of addressing the plastic pollution problem will be through a range of approaches. These will include bottom-up grassroots governance, state and federal legislation, and both hard and soft law.

The ConversationAlong with these strategies, we must see a shift in the type of we products use and their design. Both consumers and manufacturers are responsibility for shifting from a make, use, dispose culture to a make, reuse, repurpose, and recycle culture, also known as a circular economy.

Qamar Schuyler, Research Scientist, Oceans and Atmospheres, CSIRO; Britta Denise Hardesty, Principal Research Scientist, Oceans and Atmosphere Flagship, CSIRO, and Chris Wilcox, Senior Research Scientist, CSIRO

This article was originally published on The Conversation. Read the original article.


  1. Similar to Ian. I was in favour of a deposit scheme (we do not have one in Victoria) until a holiday in South Australia. No mention in any tourist literature. Crates near the office of tourist parks “Bottles & cans”. Lunch in a café, full price and they clear the table. Looked but never saw a return depot. Of course that’s the universal tourist law – foreigners pay more.

  2. Of course, the genuinely sensible answer to our plastic problem is to burn it at high temperature in a Waste to Energy plant, producing the equivalent of green electricity and reducing landfill by 90% with no sorting of domestic waste needed.

  3. I’ve seen data that shows the cost of a CDS is about $500 million per annum for a state like South Australia where it’s been in operation for many years. To be honest, is a 40% reduction in marine pollution the best we can do for $500 million? It’s actually a very inefficient way to fix up a problem which, in a developed country like Australia, is honestly not a serious marine pollution issue. If we wanted to spend this much money well, we would go to the developing countries where 10 of their rivers contribute something like 90% of the world’s marine plastic pollution.

  4. Perhaps scientists should come up with a product which is durable to hold the product but destructible to end easily, i believe that is possible. The answer lies with us. dont buy products which are indistructible.go natural vegetables meat fish, and all of those food items which are naturally available. did we nor survive in the past without all this plastic you hold the answer.

  5. It’s a lovely idea but in country NSW it’s completely stuffed in the implementation. Domestic users store their deposit containers at home until there’s enough to offset the fuel used in driving to the reclaiming station, but there are NO depots/machines/return points for these recyclables in many country areas. However that hasn’t stopped the beverage makers from putting up the prices across the board. So as usual country folks pay more, for zero return, thanks to a government that seemingly cannot tie its own shoelaces. We have two choices: drive 50+ kms to a nearby town to recycle (in which case the deposits barely cover the fuel used and the carbon burnt) or continue to put the containers in the yellow bin. This second solution allows the recycling contractor to extract all those eligible containers at the central sorting depot, and claim the deposits! So we pay more at the shop, but cannot realistically get a refund, when we recycle responsibly, the recyclers reap the benefits. Sounds like taxation by stealth, to me. Never mind, I’m sure the National Party at State level has the interests of the country consumer at heart. (sarc font enabled).

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