Trade waste is the commercial and industrial liquid waste that is disposed of through the Christchurch City Council sewerage system.

This includes discharge from restaurants, takeaway outlets, food processors, metal finishers, service stations, and chemical manufacturers. Trade waste does not include wastewater from toilets or bathrooms. 

The increasing number of commercial and industrial operations results in a significant increase in the amount of trade waste discharged through the sewer network. Currently, about 10% (15,000 m3) of the wastewater treated at the Christchurch Wastewater Treatment Plant comes from industry.

Trade waste is not necessarily toxic but can be harmful if discharged directly into the sewer without first having the problem substances removed.

Such substances can:

  • harm people's health and safety as well as the environment
  • corrode or block sewer pipes
  • create odours
  • put extra demands on treatment at the wastewater treatment plant.

Trade waste schedule of rates and charges


Any business found discharging hazardous material into the sewerage system must cease the discharge immediately and will be requested to rectify the problem.

Businesses whose Trade Waste discharge (discharged without agreement from the Council) exceeds maximum acceptable discharge characteristics as outlined in Schedule 1A of the Trade Waste Bylaw 2015 must also stop this action immediately.

Businesses will be asked to co-operate to resolve a discharge issue and prevent a non-complying, potentially damaging discharge from reoccurring. Christchurch City Council may provide advice on requirements and collect evidence of non-complying discharges such as wastewater samples and photographs.

If any Christchurch City Council infrastructure (such as the sewerage system) has been damaged as a result of malpractice, Council may recover all costs incurred in repairing the damage, including administration costs.

If the business is reluctant to co-operate, it will be subject to a tighter timeframe for compliance and if an improvement has not been achieved within a reasonable timeframe, access to the city sewerage system will be denied or only granted on a batch discharge basis i.e. after an independent laboratory analysis has shown compliance of the batch to be discharged.

Under section 242 (5) of the Local Government Act, a person who is convicted of an offence against a trade waste bylaw and has not made any reasonable attempt to resolve the problem is liable for a fine not exceeding $200,000.

Consent and registration to discharge

All businesses that produce liquid trade waste and discharge it to the sewer system must apply for consent or registration to discharge.

Trade waste consent

A trade waste consent is an agreement between the Christchurch City Council and the industrial and commercial customers authorising them to discharge trade wastewater to the sewer system.

A trade waste consent is required by all businesses which fall into the small business (permitted use) or large business (conditional use) categories under the Trade Waste Bylaw 2015.

A trade waste consent may specify:

  • the type of pre-treatment required
  • how often the system needs to be serviced
  • the substances that are allowed to be discharged
  • the volume and/or rate of discharge.

Consents are usually issued for between 1 and 5 years depending on the type of consent and involve annual or quarterly trade waste charges. It may be necessary to monitor trade waste discharged into the sewer.

Registration to discharge

A business that discharges trade waste of less than 1,245m³ per annum, and is within the limits set out in Schedule 1A of the Trade Waste Bylaw 2015, must register. A permitted consent may be required and this will be looked at on a case-by-case basis.

Transferring ownership

Trade waste consents are non-transferable. The existing owner should inform the trade waste team of their intention to sell the business so consent can be cancelled. The new owner will need to apply via the normal process.


Apply for a trade waste consent or registration to discharge by completing the relevant form below:

Email your completed form to: or post to:

Water Services, Three Waters
Christchurch City Council
53 Hereford Street
PO Box 73014
Christchurch 8154

Wastewater pre-treatment

Businesses must comply with wastewater quality standards set in the Trade Waste Bylaw. Preliminary treatment of trade waste to remove or reduce harmful substances may need to occur before discharging into the public sewer.

Maintenance and cleaning is required for pre-treatment facilities such as grease traps, settling and balance tanks and petrol/oil interceptors. Failure to maintain pre-treatment equipment may result in the owner being liable for any costs of damages to the sewer and the trade waste consent may be withdrawn.

All pre-treatment facilities accumulate residual waste, which is to be removed by an approved operator for treatment for disposal at an authorised waste processing plant.

Pre-treatment Website Brochure Technical drawing
Grease and oil traps Website Brochure [PDF, 959 KB]  
Hair traps Website    
Petrol-oil interceptor   Brochure [PDF, 97 KB]  Technical Drawing [PDF, 48 KB]
Washdown areas smaller than 250m²   Brochure [PDF, 1.2 MB]   

If your washdown areas / heavy-duty washdown areas are greater than 250m², please email us or call 03 941 8999 for more information.

Monitoring trade waste

Sampling is normally carried out for businesses with discharge volumes of more than 1,245m³ per annum. This is to monitor trade waste compliance and to ensure trade waste fees are charged accordingly.

Routine sampling usually takes place once every quarter and the costs of sampling are passed on to the customer.

Depending on the type of business and wastewater characteristics, Council will specify the sampling criteria and organise the relevant sample containers.

Sampling is carried out either automatically or manually to suit the characteristics under review.

An appropriate sampling point and means of flow recording must be provided. Once the Trade Waste Consent has been issued for your business the Council will contact you to discuss the sampling procedure.

Automatic sampling

This sampling is the most representative method and involves collecting individual samples and then combining them into one composite sample.

Individual samples are taken at a set frequency. Automatic sampling is the usual method for routine sampling and these samples are used for the standard Trade Waste Consent monitoring parameters:

  • pH
  • Suspended Solids
  • Biochemical Oxygen Demand (BOD5).

Other parameters such as heavy metals may also be analysed on these samples depending on the nature of the business and where the time taken to sample and/or the sample container do not affect the reliability of the test result.

Manual sampling

This sample is collected at a particular instance and represents conditions existing at that moment. Typically, this type of sample is used where only a small number of samples (e.g. two or three) are taken manually over a working day.