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City West Water

Trade waste charges explained

Charges cover the cost of transporting, monitoring, administrating and treating liquid waste generated by commercial and industrial businesses.

They are levied to entities who have applied for, or who currently hold, a trade waste agreement or consent with City West Water.

Trade waste charges are separate to water and sewage usage and service charges that are also usually applicable for commercial and industrial properties.

Unless otherwise agreed the Occupier of the land, from which the trade waste is discharged, is the entity who is required to hold the trade waste agreement or consent. Exceptions apply for customers who hold a Trade Waste Owner’s Consent*.

*See the Trade Waste Owner’s Consent section of our Trade Waste customer charter for more information.

What are City West Water’s trade waste charges?

One-off application fee:

When a trade waste agreement is prepared (or renewed) the customer is charged a one-off fee to cover the cost of processing the Trade Waste Application.

More complex applications take more time to process and attract a higher charge.

A customer’s complexity is determined by their risk rank.

Complexity Risk to sewerage system Risk Rank* One-off application fee
Most complex Extreme 1 $2188.98
High 2 $2188.98
Moderate 3 $2188.98
Low 4 $602.39
Minor 5 $313.71
Least complex Minor 5 (restaurants or other food business only) $79.19

Agreement Charge:

The Trade Waste Agreement Charge is an annual charge (paid in either quarterly or monthly instalments) which cover the cost of administering and monitoring Trade Waste Agreements and Consents.

Higher risk customers pay a higher charge than low risk customers as they require an increased level of monitoring and administration.

Administrative effort by CWW Risk Rank* Annual agreement charge
High degree of monitoring and administration by CWW 1 $19,046.57
2 $15,798.50
3 $7,931.62
4 $1,732.28
Low degree of monitoring and administration 5 (includes restaurants and other food business $328.89

Volumetric and quality charges:

Volumetric and quality charges cover both the transport of trade waste through the sewerage system and treatment of trade waste at the waste water treatment plant.

Customers who discharge less than 4 kilolitres per day of trade waste or operate a restaurant or other food business pay a fixed price per kilolitre.

These charges appear on the relevant water and sewage account as non-residential sewage.

Customer who discharge less than 10 kilolitres per day Rate Notes
Volume charge $1.7295 per kilolitre Charged on the applicable water account as non-residential sewage

Customers who discharge 4 or more kilolitres per day of trade waste and do not operate a restaurant or other food business receive charges that are based on the:

  • volume of trade waste discharged to sewer
  • contaminant loads that are contained within the trade waste discharge
Customer who discharge more than 4 kilolitres per day Rate Notes
Volumetric charge $0.8260 per kilolitre Trade waste volumetric charge
Biochemical Oxygen Demand (BOD) $ 1.0085 per kilogram Contaminant load charge for BOD
Total Kjeldahl Nitrogen (TKN) $1.9409 per kilogram Contaminant load charge for TKN
Suspended Solids (SUS) $0.5463 per kilogram Contaminant load charge for SUS
Inorganic Total Dissolved Solids (iTDS) $0.0196 per kilogram Contaminants load charge for iTDS

How is the volume of trade waste determined?

For customers who discharge 10 or more kilolitres per day, trade waste volumes can be determined using one of the following methods:

  • Applying a factor to the site’s water meter
  • Measuring the volume of trade waste with a flow measurement device (a mandatory requirement for customers who discharge more than 25 kilolitres/day)
  • Using an estimated amount that is agreed between CWW and the customer

Examples of trade waste charges being applied

Example 1: A take-away food shop will discharge 7kL of trade waste on average per day.

The trade waste from the site is the dirty water that is generated from the food preparation and wash-up areas.

One-off application fee Justification
$79.19 The customer is a restaurant or other food business. CWW’s risk rank* classifies the customer as a risk rank 5.
Annual agreement charge Justification
$328.89 Risk rank 5 agreement charge
Minimal complexity/risk

Although this site discharges more than 10kL of trade waste per day, it is a restaurant or other food business, which means this customer will not pay any trade waste volumetric or load based contaminant charges on their trade waste account.

Instead the applicable non-residential water and sewage account will cover the costs associated with the transport and treatment the site’s trade waste.

Example 2: A new mechanics workshop will discharge 3kL of trade waste on average per day.

The trade waste is the dirty water that results from the cleaning of parts and washing of vehicles on site.

One-off application fee Justification
$313.71 The customer is not a restaurant or other food business.
CWW’s risk rank* classifies the customer as a risk rank 5.
Annual agreement charge Justification
$328.89 Risk rank 5 agreement charge
Minimal complexity/risk

Because the site discharges less than 10kL of trade waste per day this customer will not pay any trade waste volumetric or load based contaminant charges on their trade waste account.

Instead the applicable non-residential water and sewage account will cover the costs associated with the transport and treatment the site’s trade waste.

Example 3: An Industrial Laundry will discharge 18kL of trade waste per day.

The trade waste is the dirty water that gets discharged from the washing machines.

One-off application fee Justification
$602.39 The customer is not a restaurant or other food business. CWW’s risk rank* classifies the customer as a risk rank 4.
Annual agreement charge

Justification

$1,732.28 Risk rank 4 agreement charge
Low complexity/risk

Because the site is expected to discharge more than 10kL of trade waste per day this customer will be required to pay trade waste volumetric and load based contaminant charges on their trade waste account.

The quality of the site’s trade waste may either be determined by:

  • Analysing samples of trade waste taken from the site; or
  • Apply qualities determined from samples taken from similar businesses.

Typical laundry qualities are:

Biochemical Oxygen Demand (BOD) 322 mg/L
Total Kjeldahl Nitrogen (TKN) 13 mg/L
Suspended Solids (SUS) 97 mg/L
Inorganics Total Dissolved Solids (iTDS) 448 mg/L

This means every kilolitre of trade waste discharge will be charged at the following rate:

Component Rate Quantity per kilolitre (1000 litres) Charge per kilolitre (1000 litres)
Volumetric charge $0.8260/kL 1 kL $0.8260
BOD charge $1.0085/kg 0.322 kg $0.3247
TKN Charge $1.9409/kg 0.013 kg $0.0252
SUS Charges $0.5463/kg 0.097 kg $0.0530
iTDS Charge $0.0196/kg 0.448 kg $0.0088
TOTAL per kilolitre $1.2377/kL

Because the customer discharges is less than 25 kilolitres per day the volume of trade waste to be billed will be determined by a factor applied to the site’s water meter.

The factor will be derived by performing a water balance over the site using information provided by the customer.

Example 4: A Chemical Plant will discharge 400kL of trade waste per day.

The trade waste is the waste water that gets discharged from the site’s boilers, cooling towers and from the cleaning of the site’s vessels and reactors.

One-off application fee Justification
$2188.98 CWW’s risk rank* classifies the customer as a risk rank 1
The customer is not a restaurant or other food business
Annual agreement charge Justification
$19,046.57 Risk rank 1 agreement charge
Extreme complexity/risk

Because the site is expected to discharge more than 10kL per day of trade waste this customer will be required to pay trade waste volumetric and load based contaminant charges on their trade waste account.

The quality of the site’s trade waste will be assessed by sampling programs. Alternatively City West Water will apply qualities determined from samples taken from similar businesses.

Sample data taken by both CWW and the customer determines the trade waste qualities to be:

Biochemical Oxygen Demand (BOD) 1792 mg/L
Total Kjeldahl Nitrogen (TKN) 7 mg/L
Suspended Solids (SUS) 182 mg/L
Inorganics Total Dissolved Solids (iTDS) 350 mg/L

This means every kilolitre of trade waste discharge will be charged at the following rate:

Component Rate Quantity per kilolitre (1000 litres) Charge per kilolitre (1000 litres)
Volumetric charge $0.8260/kL 1 kL $0.8260
BOD charge $1.0085/kg 1.792 kg $1.8072
TKN Charge $1.9409/kg 0.007 kg $0.0136
SUS Charges $0.5463/kg 0.182 kg $0.0994
iTDS Charge $0.0196/kg 0.350 kg $0.0069
TOTAL per kilolitre $2.7531/kL

*For more information on how your risk rank is determined see the Customer risk classification section of our Trade Waste customer charter and the Trade Waste section of our Pricing handbook both available on our website.

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