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Trade effluent - businesses
Trade effluent is any liquid waste discharged into our sewers from a business or industrial process on a trade premises.
For non-household customers, your retailers should be your first point of contact. For more information on how you choose your retailer, please visit the Open Water website.
Understanding trade effluent
What is it?
Section 141 of the Water Industry Act 1991 defines trade effluent as: 'any liquid, either with or without particles of matter in suspension in the liquid, which is wholly or partly produced in the course of any trade or industry carried on at a trade premises.
Trade effluent includes any wastewater derived from a production process or from washing down or cooling activities, including wastes from public-funded activities such as municipal landfills.
This can also be described as anything other than domestic sewage (toilet, bath or sink waste) or uncontaminated surface water and roof drainage (rainwater).
Trade effluent includes wastewater from, but not limited to:
- Commercial car washes
- Laundries/launderettes
- Food and drink production
- Chemical manufacturers
Why control it?
We need to control trade effluent to ensure that any matter that may cause harm is not discharged.
Trade effluent is highly variable in strength and volume and may contain substances that are a risk to people, our sewerage network, treatment processes and the environment. Controls are in place to reduce these risks.
Under Section 111 of the Water Industry Act 1991, it is an offence to discharge any matter likely to cause harm, this includes fat, oils and grease (FOG) in food businesses.
What happens to it?
First, any large solids are removed. A settlement process then removes heavy particles of solid waste in a sludge, which is further treated and recycled.
Biological treatment then uses bacteria and microbes to remove organic contaminants from wastewater.
Finally, the almost clean water goes through another settlement stage (clarification) to remove any remaining waste particles. In some cases, further treatment is required to meet stricter limits, where for example, we discharge into nutrient-sensitive watercourses or bathing waters. The treated final effluent is discharged back into the environment, where it is ready to go through the cycle all over again. You can also buy final effluent for industrial or business purposes.