Trade waste | Selwyn Water 2026

Trade waste

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, chemicals, fats or by-products that may harm pipes, treatment systems or the environment if not managed properly.

Why it matters

Poor trade waste management can cause:

  • Sewer blockages or spills
  • Damage to the wastewater network
  • Health hazards for workers and the public
  • Harm to the environment

Trade waste isn't necessarily toxic – but it can cause problems if it's discharged into the sewer without treatment.

Who needs a consent?

Any business that discharges – or wants to discharge – trade waste into our wastewater network must apply for a trade waste discharge consent. No plumbing or drainage work connected to the wastewater network can start without our agreement.

Examples of businesses that typically need a consent:

  • Meat processing plants
  • Food manufacturers
  • Metal finishers
  • Car washes
  • Hospitals
  • Laundries
  • Chemical plants

The Trade Waste Bylaw 2021 sets certain controls on the discharge of potentially harmful trade waste.

Contact us

We work with business customers to understand their level of risk, explain their obligations, and help them comply at the lowest possible cost. We recommend getting in touch with us early to discuss your project.

You can request a pre-application meeting with one of our trade waste engineers at tradewaste@selwynwater.co.nz