Strategy 3: Recycle/Treat food waste
Food waste that cannot be avoided should be recycled where possible. To support successful food waste recycling, food waste must be separated from non-food waste items, such as disposable cutlery, as they may disrupt the recycling process. Segregation of food waste is best done at the source (i.e. at the point of generation) as it is less efficient to separate it once it is mixed with general waste.
Some households have started composting food waste, such as raw fruit and vegetable scraps, using worms or making their own composting bins at home. The National Parks Board has provided some guidelines on how the public can begin their DIY composting at home.
Homogeneous food waste recycling
Currently, majority of the food waste that is recycled is mainly homogeneous food waste from food manufacturers. These include spent yeast/grains from beer brewing, soya bean waste and bread waste, which are segregated at the source and sold to recyclers for conversion into animal feed.
Click here for the list of food waste recycling facilities and the types of food waste that they can accept.
On-site food waste treatment
In addition, several owners/operators of premises, including hotels, shopping malls and schools, are segregating their food waste and using on-site food waste treatment systems to convert the food waste into compost for landscaping purposes or water for non-potable use.
Click here for a list of suppliers of on-site food waste treatment systems.
Owners and operators of premises who wish to implement on-site food waste treatment may refer to the process flow below:
1. Conduct a food waste audit or estimate the amount of food waste generated (Refer to S/N 1)
2. Decide on the type of system (i.e. wet system with non-potable water as the end-product, dry system with compost as the end product) (Refer to S/N 2)
3. Decide location of food waste treatment system (Refer to S/N 3)
|S/N||Description of initiatives|
|1. Determine the capacity of food waste treatment system ||Prior to selecting the food waste treatment system, we recommend premises owners/operators to conduct a food waste audit to determine the amount of food waste generated. This provides an indication on a suitable capacity for the food waste treatment system.|
To conduct a food waste audit, you may refer to the Food Waste Minimisation Guidebooks which provides a simple food waste audit template. Alternatively, premises who wish to conduct an in-depth audit can refer to SS 633 - Singapore Standards on Food Waste Management for Food Manufacturing/Processing Establishments and SS 640 - Singapore Standards on Food Waste Management for Food Retail, Wholesale and Distribution Establishments.
Premises can also work with suppliers of on-site treatment systems to estimate the amount of food waste generated and the recommended capacity of the system.
| 2. Consider the type of food waste treatment system ||When selecting the type of food waste treatment system, consider the following:|
- Type of food waste that can be treated
Consider the types of food waste that the system can and cannot treat. Some systems may require a grinder to crush big or hard bones before they can be treated. Generally, hard shells (e.g. lobster/oyster shells, coconut/durian husks) or fibrous items like sugarcane bagasse cannot be deposited into the treatment system.
Types and uses of end-products
Consider the uses of end-product(s) (e.g. non-potable water, compost, fertiliser and liquid nutrient) that are generated from the food waste treatment system. In general, there are 2 types of end-product.
i. Non-potable water: They may be used to backwash the treatment system or washing of floors.
ii. Compost/fertiliser/liquid nutrient: They may be used for landscaping purposes. Please refer to the SS 628 – Singapore Standards on Specifications for Compost for the use of compost in agriculture and horticulture.
Provisions shall be made for the effluent from the food waste treatment system to be discharged into the sewer through a grease trap.
|3. Location of food waste treatment system||Premises should cater space to house the food waste treatment system. In general, the space required for a 1-tonne food waste treatment system is approximately the size of 2 carpark lots. For new developments, this space could be set aside during planning or renovation. Premises are also recommended to check with suppliers on the exact space requirements for the specific systems. |
For hygiene purpose, the food waste treatment system should be sited away from the food preparation area. Some possible areas for siting of food waste treatment system include the bin centre or dishwashing area. Please ensure that proper refuse, odour and pest management are in place with the installation of the food waste treatment system. There should also be a power supply available for the treatment system.
Besides on-site food waste treatment systems, there are systems that remove moisture from food waste through dehydration or heating. While these systems reduce the weight and volume of food waste, they do not involve biological processes to decompose food waste. The residue is dewatered food waste and may cause odour or pest issues when it becomes wet. Thus, it is unsuitable for landscaping use.
Off-site food waste treatment
NEA has conducted a pilot project to assess the viability of collecting and transporting source-segregated food waste to an off-site treatment facility where the food waste is co-digested with used water sludge. Source-segregated food waste collected from various premises is transported to a demonstration facility located at Ulu Pandan.
The demonstration facility is designed to treat up to 40 tonnes of combined food waste and used water sludge daily. The co-digestion process yields more biogas compared to the treatment of used water sludge alone, thereby enhancing energy recovery. As the pilot has demonstrated that it is feasible to collect food waste from various premises for transportation to an off-site facility for treatment and conversion into biogas, the process will be implemented at the upcoming Tuas Nexus.
Implementing food waste segregation
To guide owners/operators and occupiers of premises on implementing proper food waste segregation and adopting food waste recycling/treatment, NEA has also developed a food waste segregation guidebook.
Food Waste Segregation and Treatment Guidebook [PDF, 2.2 Mb]