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Any wastewater discharge from business or industry other than staff amenities or office facilities is generally classified as trade waste.

When do I need a trade waste permit?

Not all trade wastes (or industrial wastes) are compatible with our sewer system. This is why, any industry or business in WA that wishes to discharge trade waste to Water Corporation sewers is required by law to apply to us for approval. Approval is given in the form of a trade waste permit.

What does a trade waste permit do?

Your permit is your approval to discharge your wastewater to sewer and any pre-treatment arrangements or limitations necessary to ensure the safe handling of your wastewater are specified in the conditions associated with your permit.

We use this permit licensing system to help us keep track of all non-domestic wastes that are entering our wastewater system and to provide a mechanism for us to check each new applicant’s proposed discharge to make sure we can handle it properly.

Why are there conditions associated with my permit?

Your application to discharge trade waste is assessed for compatibility with our wastewater system and disposal methods before approval is given to ensure that any risks to the public or the environment are properly managed.

Not all types of wastewater are compatible with our system, and others are only compatible after being partially treated on site. In such circumstances, we will attach conditions to your permit. These will specify any operational arrangements that you will need to have in place to ensure the safe disposal of your wastewater via our sewer, or any other restrictions that we may need to apply to your discharges.

By following these conditions, you can rest assured that your waste will be handled in a way that is safe for the environment and your local community.

What should I do with my permit?

You should make sure that all of your relevant employees are made familiar with the permit, the associated conditions, and any operational arrangements and restrictions that have been put in place. It should then be kept in a safe place at the discharge property.Your permit gives you permission to discharge wastewater to sewer. It should be available for viewing (if requested) by an officer of Water Corporation, Department of Environment Regulation, or local government.

How do changes in my business affect my permit?

Your permit is specific to the particular business owner, business name, location, and operations or processes identified on your permit. You must notify us at least 14 days in advance of any change in:

  • Any operation or process that in turn causes a change in the nature or volume of wastewater discharging to sewer
  • Ownership of the business
  • Business name
  • Location of the business to another site

In the event that such a change occurs, you will be required to complete a new application, or an application to transfer your permit, depending on the situation.

What other obligations do I have?

You must ensure that any pre-treatment fixture you have is kept in good condition, is well maintained, and is cleaned or emptied as required for its proper operation. Poorly maintained fixtures become ineffective, resulting in non-compliant sewer discharges which can pose a threat to our staff, our wastewater system, the public or the environment.

What can happen if I breach my permit conditions?

You must comply with all the conditions associated with your permit. They are based on an individual assessment of your business, and are specific to the particular characteristics of your wastewater.

Breaching your conditions could result in:

  • Threat to the health and safety of workers within the wastewater system
  • Damage to the physical infrastructure or operation of our wastewater system, or poisoning the biological processes at our treatment plants
  • Threat to public health directly from your discharge, or from any sewer failures which might be caused by your discharge
  • Inability to reclaim and re-use our treated wastewater, or our ‘Biosolids’ treatment byproducts, in industry or agriculture
  • Threat to the environment from any failure of the sewer system which your discharge might cause, or by contaminants which cannot be removed by our treatment processes


Penalties for breaches of your permit conditions do exist, and we can disconnect your service if breaches are not rectified. We are bound by our own legal duties to protect against unauthorised sewer discharges.

These provisions are only used as a last resort. We prefer to work with you to meet our shared responsibilities to the community and environment, for the safe and effective handling and disposal of your trade wastes.

Acceptance criteria

Before applying for a permit, please read our acceptance criteria which explains the limitations on how your waste can be disposed to the wastewater system.