trade effluent

Trade effluent is contaminated liquid that is produced in a process carried out at a trade premises. 

Lots of businesses produce trade effluent. Some of the most common include chemical manufacturing plants, car washes, swimming pools, and companies involved in food production.  

Trade effluent doesn’t include domestic sewage, such as normal kitchen and toilet waste. 

As you can imagine, trade effluent discharges vary a lot, both in volume and composition; a launderette will produce a relatively low volume of liquid contaminated with detergents, whilst a manufacturing plant may produce thousands of litres of wastewater contaminated with toxic substances.  

This makes it quite complex and means that trade effluent discharges need to be properly assessed and regulated. Since all water is recycled and must flow back to the environment, it is crucial that trade effluent disposal is controlled well, in order to protect both public health and the environment.  


Under section 118 of the 1991 Water Industry Act, it is an offence to discharge trade effluent without consent from the water wholesaler, so it’s really important you obtain consent before disposing.  

How do I get consent? 

Fill in the relevant form below,  and email it to us at

The forms can be complicated, so we would recommend using a guide alongside to help you out.

We will contact your wholesaler who will process your application, and we’ll keep you in the loop with updates from them.  

If the wholesaler deems the trade effluent unsuitable for discharge into the sewer, they will not issue consent.  

You can find out more about wholesaler’s individual policies and enforcement by visiting your wholesaler’s website.  

If there’s a change to your process which might affect your trade effluent, contact us as soon as you can so that, if we need to, we can apply for a new consent for you.  

How is it charged? 

We calculate trade effluent charges by multiplying the volume of discharge by the unit rate. 

Your unit rate is calculated using something called the Mogden Formula. It sounds and looks a bit confusing, but it’s basically just adding the different components of the wastewater treatment process together. 

Your volume will then either be calculated using meter reads, calculated discharge, or allowances.