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​Trade Waste FAQs

Do I need a trade waste agreement?

This will depend on your trade waste classification. If your waste is classified as conditional trade waste, you must hold a trade waste agreement 

What are the main documents I will require?
The Auckland Trade Waste Bylaw 2013 and Watercare’s list of controlled substances

What if the substance I am looking for is not on the controlled substances list?

Please contact the trade waste department on 09 539 7655 or at tradewasteinfo@water.co.nz 

My current trade waste discharges have changed and the details in the agreement do not match them. What should I do?
You should contact the trade waste department on 09 539 7655 or at tradewasteinfo@water.co.nz immediately to advise us of the changes.  

What can I do with waste that cannot be discharged to the sewer?
This must be removed from site by a suitably qualified contractor for disposal at an industrial treatment facility.  

Discharge limits for controlled substances

Why are there controlled substance standards/disharge limits?
Because controlled substances present specific risks, the discharge limits (listed in our controlled substance standards
are set to protect the wastewater system, processes, people and the environment.

Can I apply for a change to the discharge limit for a substance?
Some of the discharge limits in the agreement may be able to be adjusted. Please contact the trade waste department on 09 539 7655 or at tradewasteinfo@water.co.nz to discuss. 

My agreement does not list all the controlled substance limits. What are these limits?
When a controlled substance is not listed in your agreement, the standard limits in Watercare's controlled substances standards apply.

My agreement has a discharge limit for mass rather than concentration, which applies?
Where only a mass limit for a substance is listed in an agreement then the mass limit must be complied with. Where both a mass limit and a concentration limit for a substance are listed in an agreement then both limits must be complied with.    

How do I calculate the mass of a substance in a trade waste discharge to ensure I comply with the mass limit in the agreement?
The mass of a substance is determined by multiplying the concentration of the substance in the discharge by the volume of the discharge over a 24-hour period. For example, 150 grams per cubic metre of oil and grease multiplied by 100 cubic metres discharged over 24 hours equals 15,000 grams or 15 kilograms.    

Why is it important to discharge within the pH range of 6 to 10.5?
Low pH can be corrosive to the sewer system and sewer workers, generate odours which can cause a public nuisance or release toxic hydrogen sulphide gas which can endanger sewer workers. High pH can be caustic to sewer workers or generate toxic gases or blockages when it is mixed with other discharges.


Can I discharge stormwater to the sewer network?
Watercare’s general policy is to not permit stormwater discharges to the sewer network from trade premises. In some circumstances, contaminated stormwater may be allowed. Please contact the trade waste department on 09 539 7655 or at tradewasteinfo@water.co.nz for further information. 

Testing, monitoring and reporting

Where can I get my trade waste discharge tested?

The IANZ website has a list of accredited laboratories for discharge testing. Search for a testing inspection facility under ‘Laboratory - Chemical Testing’, ‘2.41 Waters’, ‘(d) Effluents and trade wastes’.

It is your responsibility to ensure the correct tests are performed and the laboratory is accredited for that test.

What happens to trade waste once it leaves my site?
It is imperative to the health of our communities and environment that we maintain a healthy and safe wastewater system. 

Our Network and Wastewater Treatment Plant Protection Programme identifies and mitigates any risks posed to our network the environment by monitoring influent at various points before it reaches our wastewater treatment plants, then as it is released into the environment as biosolids. 

We actively investigate all incidents that occur in the network to identify where the issue originated. This process can identify substances that have been inappropriately disposed of and lead us to customers that are operating outside of their discharge limits. In some cases this can lead to prosecution and recovery of costs. 

Working with our customers is essential in order to educate them on how to best manage site processes so their discharge has no downstream impacts on our wastewater systems and, ultimately, the environment. 

What are Watercare’s obligations?
We are required to complete random onsite compliance visits, without advance notice, to ensure our customers are complying with the limits set in their TWA and/or the bylaw, and to verify any self-monitoring data provided.

More information on Watercare's responsibilites. 

If we find that a customer is not meeting compliance, we are required to undertake compliance audit monitoring which involves additional visits and laboratory testing by Watercare, the costs of which will be passed on to the customer. 


What if I have a dispute?
We aim to provide the highest standard of service at all times. However, in the event that you are dissatisfied with a trade waste matter, you can contact us to make a complaint