Grease traps must be serviced frequently enough to prevent fats, oils and grease entering the sewer. Under the Plumbing Code of Australia (NCC Vol.3), AS/NZS 3500.2, Water Corporation Trade Waste approvals and WHS legislation, the grease arrestor (grease trap) must be maintained so it does not create blockages, odour, environmental harm, or health risks.

If a grease trap is already causing blockages to residential apartments, it may mean that it is not being serviced at a compliant frequency.

For a high-oil commercial kitchens such as Asian restaurants, fish & chip shops or commercial prep facilities, industry and trade-waste practice is:

Minimum monthly pump-out (every 4 weeks), and more frequently if required, or whenever grease/solids reach 25–30% of trap capacity.

Tenant must also:

• Have a formal grease trap service contract
• Use a licensed liquid waste contractor
• Keep service dockets/records
• Comply with Water Corporation Trade Waste conditions

If grease is entering the building sewer and affecting apartments, the business is likely in breach of trade waste approval and plumbing/WHS obligations, and the strata company can require immediate rectification and evidence of an ongoing servicing contract.