Retail Trade effluent

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.'

What is trade effluent?

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

This 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 be best described as anything other than domestic sewage (toilet, bath or sink waste) or uncontaminated surface water and roof drainage (rainwater).

How do I submit a Trade Effluent Customer Application form for the customer?

You will need to submit the application on the Bilateral Hub as a G2A or G2B process.

The completed form must be signed by the authorised signatory of the applying company and be attached the service request in the bilateral hub.

How do we find out about trade effluent charges?

Southern Water will charge your customer directly for the following non-standard charges: please refer to our current Wholesale statement of principles and charges.

Trade effluent is covered in sections:

  • Section 2, Part 5 for primary charges
  • Section 3, Part 4 for non-primary charges

Alternatively please contact us for any queries, details below.

What does Southern Water charge the customer for?

Recovery of incurred costs


  • the recovery of extraordinary costs incurred by Southern Water due to an event caused by your customer. This includes, but is not limited to, damage to our assets or increased operational costs
  • the recovery of costs incurred by Southern Water in respect of pre-emptive measures undertaken by us to minimise the impact on our assets in anticipation of a breach or breaches of your trade effluent consent.

Formal sampling charge

The recovery of costs incurred by Southern Water in respect of formal sampling undertaken in accordance with our policies and procedures, due to the failure to comply with your customers consent.




Recovery of incurred costs


Determined on an individual incident basis

Formal sampling charge (7am - 6pm)


£255.00 per sample

Formal sampling charge (6pm - 7am)


£480.00 per sample

How do retailers view customers' trade effluent sample results?

As per the G4 process, when all sample analysis is completed and verified the results are sent to the trade effluent customer by email and the results are made available to their retailer through our retailer portal.

Retailers will be sent an email notifying them when results are added.

You can find the results under Section 5: Trade Effluent - G Forms – TE monitoring and search by SPID.

What is flow measurement (private meters)?

Consent conditions may require flow measuring equipment such as a private trade effluent meter to be provided, maintained and records kept. The cost of installing and maintaining such equipment will be the responsibility of the discharger.

Assessment of flow by other means such as private water meters or process meters may also be used by trade effluent dischargers to aid calculation and accuracy of billing, as well as providing improved monitoring of their processes.

Any flow measuring equipment and installation used for trade effluent billing should be to MCERTS standard.

Does a private meter used to calculate trade effluent bills need to be registered in the market?

Yes. Any private meter used to calculate trade effluent bills should be registered in the market.

To notify us that your customer has installed, exchanged or has an issue with a private meter please submit a BO1 form. Please refer to the Market Operational Codes (Schedule 1

Part 3) under B12, B13 and B14 to view the processes that may need to be followed.

Contact us

Please complete the G1 process on the Bilateral Hub for any query relating to:

  • a site visit or communication we have had with your customer
  • an enquiry from the customer
  • the details or processing of a Trade Effluent Consent
  • quality and analytical or monitoring information
  • CMOS data / trade effluent account set up
  • consent compliance or enforcement being carried out by Southern Water.

For anything else please contact: [email protected]


Regulatory Position Statement - Heating and flushing

Trade Effluent Briefing - Wholesale Statement of Principles and Charges 2023 - 24

Regulatory Position Statement - Pet Washing and Grooming