Feasibility study into oyster baskets recycling
The EPA identified that a significant volume of decommissioned waste oyster baskets were being stockpiled at land-based depots.
The baskets have proved difficult to recycle due to mixed construction materials and large amounts of marine bio-fouling. Instead of sending the baskets to landfill, many oyster growers have been stockpiling them on their properties until more environmentally sustainable disposal by recycling becomes available.
Approximately 2.5 million baskets are in use across the industry annually, and about 5-10% (150-200 tonnes) of these plastic baskets reach their end of life and must be disposed of each year. It was estimated that it would cost $600,000 per annum across the industry to dispose of these oyster baskets to landfill.
In conjunction with the SA Oyster Growers Association, the EPA was successful in securing $40,000 to organise and co-manage a feasibility study to identify potential solutions for the recycling of waste plastic materials generated by the oyster industry. The funding was provided as part of the Department for Manufacturing, Innovation, Trade, Resources and Energy's Clever Green Eco-innovation Program.
The aim of the feasibility study was to 'identify cost effective oyster basket recycling options that will value add to the efficient operation of the industry as a whole'. Key objectives were:
- to identify the different materials being used in the manufacture of oyster baskets and their effective lifecycle
- where the waste was being stockpiled
- how much was being generated
- technologies that could minimise the space of the waste for transport purposes
- the logistics and coordination of getting the waste to the recycler
- who could receive and recycle the waste
- the conditions that might apply to recycling and by cost-benefit analysis the best possible options for the oyster industry to dispose and recycle oyster basket waste.
A number of outcomes were identified as a result of the investigation:
- Current (2013) stockpiles of waste oyster baskets in SA were estimated to be approximately 1,300-1,500 tonnes, and growing by approximately 150-200 tonnes per year.
- Waste baskets principally consisted of high-density polyethylene (HDPE) and polypropylene (PP), which in individual polymer form has value as a recyclable material.
- To meet the needs of the recycler, the best approach was proposed to involve pre-sorting the waste to separate HDPE and PP and remove contaminants, disposing of residual waste to landfill, shredding plastics onsite to minimise space for transport, and transporting this material to Adelaide, where a rebate would be received from the plastic re-processor.
- The cost of this approach was estimated to range from $300-$600/tonne of waste material, or 40-60 cents/basket depending on where the grower was located and the volume and quality of waste baskets.
An important recommendation was for the industry to collaborate and tender out its disposal requirements to the market in order to obtain the best price for recycling disposal and minimise its potential disposal management risks.
The industry association met to discuss the project recommendations and agreed to seek expressions of interest for a market-based response to identify a suitable and cost-effective way to recycle oyster baskets.
Review of oyster code of practice
The EPA is currently undertaking a review of the Code of Practice for the Environmental management of the South Australian oyster farming industry. It provides a tool to assist industry to meet the requirements of EPA legislation by identifying potential environmental issues associated with oysters farming and providing management strategies to address these issues. It does this by specifying mandatory requirements that must be complied with and best environmental practices that are generally outcome-based to allow growers to continue their own individual methods of farming oysters.
This document was finalised in 2005 and is now being reviewed to ensure it is up to date and relevant to industry, and incorporates any legislative and industry changes. Several stages of consultation will be undertaken with the oyster industry and other relevant parties.