Trade effluent

We monitor and control all discharges of trade effluent into the public sewer from commercial or industrial processes.

What is trade effluent?

Trade effluent is any liquid waste (effluent) discharged into our sewers from a business or industrial process.

Trade effluent is any liquid waste (effluent) discharged into our sewers from a business or industrial process. This includes any waste water derived from a production process or from washing down or cooling activities including wastes from public funded activities such as municipal landfills. This can be best described as anything other than domestic sewage (toilet, bath or sink waste) or uncontaminated surface water and roof drainage (rainwater).

The table below shows examples of commercial and industrial properties that produce wastewater and whether the wastewater is classed as trade effluent or not.


Examples of trade effluent

Yes No
Commercial car wash Kitchens and toilets at commercial premises
Laundrettes Restaurants, pubs and hotels
Food and drink production Hairdressers
Chemical manufacturers Dentists
Metal finishers Care homes
Engineering Swimming pools (domestic)
Swimming pools (commercial)

Examples of temporary trade effluent discharges:

  • Heating system flushing
  • Groundwater remediation


Why we control trade effluent

Unlike domestic sewage, trade effluent is highly variable in terms of strength and volume and may contain substances that present the risk of harm to people, our sewerage network, treatment processes and the environment.

Trade effluent controls are in place to reduce these risks to acceptable levels and ensure that our network and treatment processes are not overloaded. Trade effluent cannot be discharged without a consent, doing so constitutes a criminal offence.


Controlling trade effluent

We're under no obligations to accept trade effluent as we must ensure that any discharge to the public sewer is controlled in order to:

  • Protect the environment
  • Prevent damage to our sewers, pumping stations and wastewater treatment processes
  • Protect the health and safety of the public and our staff.


Discharges that we do not normally consent

In common with other sewerage wholesalers we do not issue consents for low risk discharges that are similar to domestic sewage in nature, although we reserve the right to consent if we deem it necessary. Instead we will normally control illegal discharges and damage to our infrastructure under clause 111 of the Water Industry act (1991).

We do not require a consent to discharge from offices and any non-household premises that only discharge domestic sewage.

We do not require a consent to discharge from food service establishments such as restaurants, takeaways, canteens, and healthcare sector meal services. We do expect these activities to have suitable grease management procedures in place as well as measures to prevent food waste from entering the public sewer.

We do not require a consent to discharge from hospitals, nursing/care homes, GP surgeries, dental practices and veterinary practices however there are some substances that cannot be discharged or require a consent.

Examples of discharges requiring a consent are laundry effluent and boiler blow-downs from larger premises as well as X Ray effluents from conventional film processes. We follow detailed guidance on healthcare discharges that have been published by Water UK.

Other low risk activities that we do not normally consent are listed below. The list is indicative and not exclusive;

  • Hairdressers
  • Butchers & fishmongers
  • Other food retail businesses such as grocers and florists
  • Stables
  • Kennels
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