Trade waste charges are calculated based on the volume and the quality of the waste and take into account certain risk factors.
The trade waste charge may consist of three components:
- application fees for new customers
- management fees, to cover the costs of site inspections, monitoring, administering and reviewing Trade Waste Agreements
- volume and quality charges, based upon the customers' risk rating, to cover the cost of collecting, transporting, treating and disposing of trade waste as well as managing environmental impacts.
Risk and category types
Trade waste customers are divided into the following categories, based on the volume and quality of their trade waste;
- Category A customers are those discharging less than 1000 litres of trade waste per day. They are also considered Risk 1 customers. These customers pay the minimum management charge and will not be charged for volume or quality of their waste. The majority of Western Water customers fall in this category and typical customers include take-away food shops, bakeries, fast-food shops etc.
- Category B customers are those discharging 1,000 litres to 10,000 litres of trade waste per day with less than 400 milligrams of organic content or solids per litre. Due to the volume of discharge, customers in this category are considered Risk 2 customers. Category B customers will be charged a management charge and volumetric charge. Typical Category B customers include swimming pools, hospitals, car washes etc.
- Category C customers are those discharging 1,000 litres to 10,000 litres of trade waste per day with more then 400 milligrams of organic content or solids per litre. Due to the volume of discharge, they are considered Risk 2 customers. Category C customers will be charged a management charge, a volumetric charge and a quality charge. Typical Category C customers include aged care facilities, large restaurants etc.
Category B customers will pay a higher unit charge for volume than Category C customers. This principle was adopted to provide Category B customers incentive to reuse relatively clean water within the business.
Application and management fees
Application and management fees - 2020/21:
|Quantity||Risk rating||Category||Application fee||Management fee|
|Less than 1000 L/day||1||A||$143.33||$278.52 per year|
|1000 - 10,000 L/day||2||B & C||$225.30||$584.26 per year|
Increased charges apply for larger industries with higher risks. Please contact us for more information.
Western Water generally does not meter the trade waste discharges to sewer, except for major customers, so the potable water consumption (rolling three year average) has been used with an industry adjustment factor to estimate the trade waste discharge.
In most instances Western Water has used a factor of 0.6 (for example, every 1000 litres of water consumed, 600 litres is estimated to go to sewer as trade waste), whereas other authorities use factors of up to 0.9 resulting in higher charges. The factor will be adjusted depending on site-specific use.
If a customer wishes Western Water to review the use of the discharge factor they either need to install a flow meter to measure actual trade waste discharges to sewer or provide satisfactory alternative discharge volume evidence.
Volumetric charges - 2020/21:
|Category B (low strength waste)||$1.7383 per 1000 litres|
|Category C (high strength waste)||$1.2169 per 1000 litres|
Trade waste quality is determined by the use of industry averages for similar businesses or, in some cases, by sampling undertaken directly at the business.
Western Water randomly selected a number of customers to cover a wide range of industry types and, based on the waste quality results and from results obtained from other water authorities, has built a database for typical quality for various industry types. Western Water will continue to refine the data as more information is collected.
A revision of the charges is possible if the customer provides satisfactory evidence of discharge quality that differs from Western Water’s information.
Quality charges - 2020/21:
|Parameter||Charge per Kg|
|Biological Oxygen Demand >400 mg/L||$0.3514|
|Suspended Solids >400mg/L||$0.2239|
|Total Phosphorus >30mg/L||$0.5232|
|Total Combined Nitrogen >60mg/L||$0.6729|
|Total Oxidisable Sulphur >100mg/L||$0.9723|
|Heavy Metals - Cadmium >0.4g/day||$0.2238|
|Heavy Metals - Chromium (III & VI) >100g/day||$0.2238|
|Heavy Metals - Copper >100g/day||$0.2238|
|Heavy Metals - Lead >100g/day||$0.2238|
|Heavy Metals - Mercury >0.2 g/day||$0.2238|
|Heavy Metals - Nickel >10g/day||$0.2238|
|Heavy Metals - Selenium >10g/day||$0.2238|
|Heavy Metals - Zinc >100g/day||$0.2238|