What is OSCA and why is it important to Lady Elliot?

At Lady Elliot Island, our impact on the environment is always at the forefront of our minds. We are very proud to utilise several eco-friendly machines and systems on the island and enjoy sharing this information with our guests. If you are interested in the “Behind the Scenes” aspects of the business, we run a tour dedicated to this topic two to three times a week on the island itself. Otherwise, please stay tuned as we break down (excuse the pun) the operation of our compost machine, OSCA!

As Lady Elliot Island is 80km from the mainland there is no weekly garbage truck to remove our waste. Instead, a barge visits the island once every three months which can be a long wait! As the island is leased and falls within the Great Barrier Reef Marine Park, there are guidelines that require us to remove, reuse, or recycle all waste. For the past 46 years this has been done through in-ground composting. Unfortunately, it took two years before this organic matter was able to be dug up and utilised, also taking up space that could have otherwise been used. This was largely due to the composition of the island itself, as a coral cay we don’t have the usual in-ground fauna that the mainland has, such as worms and other bugs to efficiently decompose organic matter.

Then, we had a breakthrough! In 2016, a commercial grade On-Site Composting Apparatus (OSCA) developed by WDU Composting Technologies was installed. OSCA (we call him Oscar) composts all food waste (250kg per day) plus cardboard and garden organic matter. Food waste is collected in the restaurant and cardboard is used as a carbon content to generate the heat required to break down the compost. The pasteurised compost is used in resort gardens, nursery, airstrip, and the re-Greening Program.

The staff spend around three hours a day working with the composting system and feeding OSCA, but in total, it only runs for around five minutes, eight times a day to aerate the compost. The benefits of this machine are incredible, it reduces the volume of waste drastically by about 2/3’s and speeds up the composting process substantially meaning we can mix the compost and use it as soil after only two to three weeks! That is quite a reduction on the previous two years! The end product of OSCA is odourless (wow) and is also tested to ensure there are no pathogens, E-coli or Salmonella.

The OSCA program has not been a small expense for the island, but it has been a fantastic addition and something that we love to show to our guests. Often, guests are so intrigued by the apparatus and the benefits of composting that they set up their own system upon returning to the mainland. Chris from our maintenance team ran us through exactly how it works as seen below.

Step one: Ensure food scraps, cardboard and organic matter are kept separate to other waste products.

Step two: Transport food waste, cardboard, and organic matter to the maintenance yard where it will be put through a shredder and stored in green garbage bins.

Step three: Feed OSCA food waste and organic matter, then tip in cardboard (Follow the recipe of 1 bin of food waste for three bins of cardboard)

Step four: After 10 to 14 days compost is produced and self-ejected from the machine. If you have the opportunity, give it a smell and a feel!

Step five: Each day the 100 litre bins of compost are taken to the compost area and left for two to three weeks. Once removed, the compost is then added to our vegetation compost (leaves, pruning’s, grass clippings, etc.) which is periodically turned with the loader. After around 12 months, this product is used as potting mix, garden, and runway top dressing and we have reached the end of the process!

Thanks for reading!