Trade waste consents

If your business drains oil, grease or other liquid waste into the sewer, you may need to apply for a trade waste consent.

Why is trade waste controlled?

Trade waste is controlled by laws to help protect drainage system treatment plants, which are essential city assets.

If your business produces waste water that you wish to dispose of to the sewer, you may need to apply for a trade waste consent.  

Grease inceptor sizing guide

After you apply for your trade waste consent, we will issue formal sizing requirements. The method that we’ll use to determine the appropriate size of a grease trap can be found in this guide .

Download the Grease Inceptor Sizing Guide here.

Grease trap info from Wellington Water

Wellington Water has produced information on how to look after grease traps and avoid fatbergs, with info translated into Chinese and Hindi. You can check it out here [Wellington Water]

Types of trade waste

Trade waste discharges shall be classified as one of the following types:

(a) permitted trade waste - trade waste which does not exceed any individual characteristic or combination of characteristics set out in Schedule 1 of the Trade Waste Bylaw as the minimum requirement for a conditional discharge consent;

(b) conditional trade waste - trade waste that exceeds the requirements for a conditional discharge consent but is not a prohibited trade waste as set out in Schedule 2 of the Trade Waste Bylaw;

(c) prohibited trade waste - trade waste that contains or is likely to contain characteristics that are prohibited or are present in concentrations that are prohibited as set out in Schedule 2 of the Trade Waste Bylaw.

If it sounds like your business needs a trade waste consent, an officer will assess your situation by looking at site plans, and the type and volume of liquid waste. 

Characteristics Limit
Flow 2000 litres per day
pH value 6-10
Biochemical Oxygen Demand (BOD5) 1000 grams per cubic metre
Suspended solids 2000 grams per cubic metre
Oil and grease 2000 grams per cubic metre
Temperature 40 degrees Celsius
Sulphides 1 gram per cubic metre
Sulphates 50 grams per cubic metre
Aluminium 300 grams per cubic metre
Copper 10 grams per cubic metre
Refer to the Trade Waste Bylaw for all other permitted trade water characteristics.

Apply for a consent

You can apply online through the MyPorirua customer portal.

Please note - you will need a verified user account in order to access the online application form. The verification process can take up to 2-3 working days to complete and you will be notified once your account has been activated. In the meantime - any applications you have started will be saved under the Drafts tab on your account.

Credit Card payments are accepted, or you can pay by cash or Eftpos at our Customer Services Centre at 16 Cobham Court, Porirua during normal business hours.

An officer may inspect your premises and trade waste discharge prior to processing the application.

We’ll process your application within approximately 20 working days, and send by email your trade waste consent with any associated consent conditions.

Trade waste fees

An annual trade waste consent fee is charged, these are based on the type of trade waste and the risks associated with the trade waste your business produces.

All fees include GST and apply from 1 August 2023.

Description Fees
Initial application fee 279.00
Trade waste consent fee – high risk 2,780.00
Trade waste consent fee – medium risk 1,386.00
Trade waste consent fee – low risk 465.00
Trade waste consent fee – grit/grease traps 202.00

To help you renew your existing trade waste consent, each year we’ll send you an invoice with confirmation of the type of risk your trade waste has been assessed as.  A trade waste inspection may be required as part of the renewal process.

Trade waste consents are not transferable to any other party.

Please notify our Environmental Health Team if occupation of the premises changes. A new trade waste application will need to be submitted by the new occupiers if trade waste is produced.

Trade Waste Bylaw - extract

Part 20 of the Porirua City Council Bylaw 1991 is made under Section 146(a)(iii) of the Local Government Act 2002 with the purpose of improving:

(a) the control of trade waste discharges into the wastewater system to protect:

(i) sewers, pumping stations, storage tanks, wastewater treatment plants and other related wastewater system structures;

(ii) workers operating in or with the wastewater system; and

(iii) the receiving environment.

(b) the basis for charging persons who use the wastewater system; and

(c) the introduction and implementation of the New Zealand Waste Strategy.

Contact us

For any further advice or information phone our Environmental Health Team on (04) 237-5089 

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