Trade effluent

Trade effluent is a liquid waste discharged into our sewers from a business or industrial process. We need to control discharges entering the public sewer system so that it can be safely handled and treated before returning it to the environment. Non-household customers must have consent of the sewerage undertaker (Thames Water Wholesale) before discharging trade effluent. The process is summarised below and if you’d like more information about our services and tariffs, please see our wholesale service offering and wholesale tariff document.

Consent applications, variations and terminations

You or your customer can contact us to discuss trade effluent and if your customer plans to discharge trade effluent into any public foul sewer within our supply area they will need to apply for consent. You can apply for a consent, a variation to existing consent or a consent termination on their behalf by completing the service request form.  

Consent register

We’re required by law to share a public register of consents and you can use our search tool to view all of our authorised trade effluent consents.

View the register

Monitoring and sampling discharges

Once a trade effluent consent is issued we may carry out sampling and analysis to determine the applicable charging structure. Under the terms of a trade effluent consent your customer must pay for the monitoring and analysis that we carry out and full information can be seen in our wholesale tariff document. If your customer wants to arrange their own trade effluent billing samples to be collected then they can do that via you.

From time to time we’ll visit your customer to monitor compliance against consent conditions and as part of this process we may need to take samples to assess the effluent and any health and safety risks. If any samples taken aren’t compliant with the consent, charges may be applied.

If you’re aware of an illegal discharge please contact our Trade Effluent team immediately by calling 0203 577 9200 or if there is a spillage or incident that needs immediate action please call 0800 009 3931.

If your customer has a private meter installed onsite we’ll ask them to keep us updated of the meter details. Photographs of meters showing reference numbers and meter reads will be required.