What is trade waste?
Trade waste is the liquid waste produced by commercial, industrial, and business activities that enters the wastewater system. Unlike normal household wastewater, it can contain substances such as chemicals, fats, or by-products that may harm pipes, treatment systems, or the environment if not properly managed. Trade waste may also include domestic sewage generated at the premises.
Why it matters
Poor trade waste management can lead to:
- Sewer blockages or overflows
- Damage to the wastewater network
- Health risks for workers and the public
- Harm to the environment
Trade waste is not always hazardous, but it can cause significant issues if discharged without appropriate treatment.
Who needs a consent?
Any business that discharges, or intends to discharge, trade waste into the public wastewater network must apply for a Trade Waste Consent. No plumbing or drainage work connected to the wastewater system should begin without approval.
All businesses are assessed based on the volume and composition of their wastewater.
Following assessment, discharges are classified as:
- Permitted
Low-risk discharges that meet standard requirements and can be managed with minimal controls. - Conditional
Discharges that require specific conditions, such as pre-treatment (e.g. grease traps) or monitoring, to ensure they do not harm the system. - Prohibited
Discharges that are not allowed because they pose a significant risk to the wastewater network, treatment processes, public health, or the environment.
In some cases, additional information may be required, such as wastewater sampling or laboratory analysis, to determine the appropriate classification.
Who typically needs a Trade Waste Consent
Examples of businesses that may require a Trade Waste Consent include:
- Restaurants and food manufacturers
- Hairdressers and laundromats
- Car washes
- Meat processing plants
- Metal finishers and chemical plants
- Hospitals and healthcare facilities
Selwyn Water must manage trade waste in line with Selwyn District Council's Trade Waste Bylaw 2021 which sets out rules and controls to prevent harmful discharges into the wastewater system.
How we support you
We work with businesses to:
- Understand their level of risk
- Explain their obligations under the Trade Waste Bylaw
- Identify practical and cost-effective ways to comply
Apply for a Trade Waste Consent
If your business is discharging without a consent or plans to discharge trade waste into Selwyn Water’s public wastewater system, you’ll need to follow the steps below.
1. Get in touch with us
We recommend contacting us as early as possible, especially if you’re planning a new build, fit-out, or change in business activity.
Email our team at tradewaste@selwynwater.co.nz to discuss your situation or to arrange a pre-application meeting.
2. Prepare and submit your application
Complete the Trade Waste Consent application form below, provide all required supporting information and email it to us at tradewaste@selwynwater.co.nz
Application for Consent (including renewal) to Discharge Trade Waste
Depending on your business, this may include:
- Details of your processes and water use
- Site and plumbing plans
- Information on any pre-treatment systems
- Wastewater test results (if required)
3. Application review
Once we’ve received your application and payment, we will:
- Acknowledge receipt within 10 working days
- Assess your discharge against the Trade Waste Bylaw 2021
- Determine whether your discharge is permitted, conditional, or prohibited
- We may contact you if further information is needed.
4. Consent decision
If approved, your Trade Waste Consent will outline:
- What you can discharge
- Any treatment or system requirements
- Monitoring, sampling, or maintenance expectations
- Applicable charges
Fees and charges
Trade waste charges vary depending on your discharge type and volume using the calculation set out in the Trade Waste Bylaw 2021.
Please also see our Fees and Charges Schedule for a full list of other trade waste fees.
Fees may apply for:
- Trade Waste discharge consent application (required for most non-residential premises with conditional discharges)
- Temporary Trade Waste discharge consent
- Uniform annual charge (permitted discharges)
- Trade Waste re-inspection
- Disconnection – at estimated cost
- Uniform annual charge (conditional discharges) – calculated per discharge (as per Bylaw)
Please note: A Development Contribution fee may also apply under Selwyn Water’s Development Contribution Policy.