A Trade Waste Agreement (TWA) is a legal requirement for any Victorian business that discharges trade waste — any wastewater other than normal domestic sewage — into the sewer system. This covers an enormous range of businesses: restaurants, cafes, car washes, dental clinics, laundries, printing shops, laboratories, food manufacturers, breweries, and any operation that produces wastewater with elevated levels of oils, chemicals, solids, or other contaminants.
Operating without a TWA is an offence under the Water Act 1989 and can result in penalties, forced disconnection from the sewer, and clean-up costs. Yet many businesses operate without one — either because they do not realise they need one, or because they assumed their landlord or previous tenant had arranged it.
Who Needs a Trade Waste Agreement?
If your business produces wastewater that differs from standard domestic sewage in composition or volume, you need a TWA. Common examples include:
- Food businesses: Restaurants, cafes, bakeries, butchers, caterers, food manufacturers — any operation that produces wastewater containing fats, oils, grease, or food solids
- Automotive: Car washes, mechanical workshops, panel beaters — wastewater containing oils, detergents, metals
- Healthcare: Dental clinics (amalgam waste), pathology labs, veterinary clinics, hospitals
- Industrial: Manufacturing, printing, metal finishing, chemical processing — wastewater containing chemicals, heavy metals, or industrial byproducts
- Laundry and dry cleaning: Commercial laundries producing wastewater with elevated detergent levels, lint, and potentially chemicals
- Cooling systems: Buildings with cooling towers that discharge blowdown water containing treatment chemicals
How Trade Waste Agreements Work in Melbourne
In metropolitan Melbourne, TWAs are managed by the three retail water companies:
- Yarra Valley Water — covers Melbourne's northern and eastern suburbs
- South East Water — covers Melbourne's south-eastern suburbs and Mornington Peninsula
- Greater Western Water — covers Melbourne's western suburbs and surrounding areas
Your TWA is with your local water retailer (determined by your premises location), not Melbourne Water directly. The application process typically involves:
- Application: Submit a trade waste application form to your water retailer, describing your business activities, wastewater characteristics, and proposed pre-treatment
- Assessment: The water retailer assesses your application, may inspect your premises, and determines the appropriate agreement category and conditions
- Pre-treatment requirements: Based on the assessment, you may need to install pre-treatment equipment (grease traps, oil-water separators, pH correction systems, etc.)
- Agreement execution: Once pre-treatment is in place and approved, the TWA is issued with specific conditions including discharge limits, monitoring requirements, and pump-out schedules
Agreement Categories
Trade waste agreements are typically categorised based on risk and volume:
- Category 1 (Consent): Low-risk trade waste — small food businesses, hairdressers, laundries. Simplified agreement with standard conditions
- Category 2 (Agreement): Medium-risk trade waste — larger food operations, car washes, light manufacturing. More detailed conditions and may require monitoring
- Category 3 (Agreement): High-risk trade waste — chemical manufacturing, metal finishing, large industrial operations. Detailed conditions, regular monitoring, and potentially on-site sampling
The category determines your annual trade waste charges, monitoring requirements, and the level of oversight from your water retailer.
Costs of Trade Waste Agreements
TWA costs vary by water retailer and agreement category, but typically include:
- Annual agreement fee: $200-$2,000+ depending on category and discharge volume
- Volume charges: Per-kilolitre charges for trade waste volume discharged (often higher than standard sewerage rates)
- Quality charges: Additional charges for wastewater that exceeds standard discharge limits for specific parameters (BOD, suspended solids, FOG, etc.)
- Monitoring costs: If your agreement requires regular sampling and analysis, these costs are passed to the business
For a typical restaurant in Melbourne, annual trade waste charges (excluding grease trap pump-outs) run between $500 and $2,500 per year. For industrial operations, costs can be significantly higher depending on discharge volume and quality.
Common Compliance Issues
No Agreement in Place
The most common issue is simply not having a TWA when one is required. This often happens when a business takes over an existing premises and assumes the previous tenant's agreement transfers automatically — it does not. Each new business operator must apply for their own TWA.
Pre-Treatment Failure
Grease traps that are not pumped regularly, oil-water separators that are not maintained, or pH correction systems that have failed can cause discharge limit breaches. Your water retailer can and will test your discharge, and non-compliance can result in additional charges, penalty notices, or agreement cancellation.
Prohibited Discharges
Certain substances must never be discharged to sewer regardless of your TWA conditions: flammable liquids, radioactive waste, prescribed industrial waste, pesticides, and any substance that could damage sewer infrastructure or pose a risk to treatment plant workers.
What Happens If You Breach Your Agreement
Water retailers take trade waste non-compliance seriously. Consequences can include:
- Excess discharge charges: Additional fees for exceeding your discharge limits
- Infringement notices: Formal notices requiring corrective action within a specified timeframe
- Agreement cancellation: In serious or repeated cases, your TWA can be revoked — which means you cannot legally discharge trade waste
- Disconnection: As a last resort, your premises can be disconnected from the sewer system
- EPA referral: Serious breaches may be referred to EPA Victoria for prosecution under environmental legislation
Tips for Managing Your Trade Waste Agreement
- Review annually: Check that your TWA conditions still match your actual operations. If your business has changed, notify your water retailer
- Maintain records: Keep all pump-out certificates, maintenance records, and monitoring results for at least two years
- Train staff: Ensure staff understand what can and cannot go down the drain. Most breaches result from staff behaviour, not equipment failure
- Schedule maintenance: Do not wait for problems. Regular preventive maintenance on pre-treatment equipment is far cheaper than emergency repairs and compliance penalties
- Get help if needed: If you are unsure about your trade waste obligations, contact your water retailer or engage a waste management specialist
How Bundle Waste Can Help
While trade waste agreements are managed by water retailers rather than waste collection providers, they are part of your overall waste management picture. At Bundle Waste, we help businesses understand their trade waste obligations, ensure their liquid waste arrangements support compliance, and identify opportunities to reduce costs across all waste streams. Contact us for a free assessment.
