Industry leading trade effluent expertise

Trade effluent requirements can be complex, and trade effluent consent is a vital part of wider legislation which protects the environment. It is illegal to discharge trade effluent without consent and doing so carries the risk of prosecution and fines.

Castle Water’s dedicated, expert trade effluent team has the experience and technology required to understand it like no one else – and we make the process simple.

Our experts will provide your organisation with:

  • knowledge and influence to ensure your interests are properly considered
  • full service support for correct consents and licenses and the application process
  • Wholesaler negotiation for bespoke consent limits
  • guidance to meet regulatory obligations
  • support and data reporting to help reach your sustainability and environmental targets
  • tailored solutions for large and multi-site customers
  • consistently accurate trade effluent billing

Get in touch

If you think you're being overcharged for your business water, or under-served in your trade effluent needs, email or call 01250 718718 to speak to our experts.

Trade effluent for industrial and multi-site customers

Businesses producing significant amounts of trade effluent must consider a retailer’s ability to provide as much expertise and support as possible. Between legislation, consents, fees, waste sampling and treatments, trade effluent is a minefield.

Our expertise and technology combine to form an award-winning service

Our specialised account managers make the process simple and have the knowledge and influence to ensure that your interests are properly considered. We will identify the correct consents and licenses, negotiate bespoke consent limits, help you meet regulatory obligations, and support your sustainability and environmental targets. If that wasn’t enough, we're recognised as a market-leader in trade effluent billing, with our unique platform producing consistently reliable trade effluent bills with the highest degree of accuracy.

Consent and negotiation support

Typically, larger industrial customers must negotiate with their wastewater Wholesaler to arrange bespoke consent limits. We have the knowledge and influence to ensure that your interests are properly considered. We'll advise you on these discussions, help to negotiate consent applications, and support you to challenge Wholesalers on a range of issues.

Consistently reliable bills

Our market-leading billing platforms produce consistently reliable invoices with the highest degree of accuracy, and our customer portal, MyAccount, makes it easy to submit monthly meter readings online, so your bills will stay up-to-date and reflect actual consumption. Account balances, bills and transactions can be easily viewed in MyAccount, and with eco-friendly e-billing, you can avoid paper bills.

It pays to have the experts in your corner

When SUEZ switched all its UK sites to Castle Water, we prioritised a data cleanse of the entire portfolio. SUEZ now has confidence in its water, wastewater, and trade effluent charges. Email or call 01250 718718 to speak to our experts.

Read the case study

What is trade effluent?

Trade effluent is any liquid waste (effluent) discharged into the sewers from a business or industrial process. This includes any wastewater produced from washing or cooling activities, as well as process production waste determined to be appropriate for disposal via the sewer network.

Trade effluent does not include waste that is classed as regular sewerage – waste water from kitchens, bathrooms and toilets; therefore, most hotels, restaurants, cafes, pubs, and hairdressers would not require a trade effluent consent.

Typical business types that do require a consent include car washes, launderettes and dry cleaners, transport depots, breweries, dairies and commercial swimming pools. Trade effluent customers can be large or small businesses.

A trade effluent consent does not permit discharge of potentially hazardous chemicals to the sewer – businesses must ensure waste of this nature is disposed of responsibly via a specialist waste contractor.

The links below provide the forms and guidance notes to complete an application for consent. Forms can be completed and sent by email to

Trade Effluent Discharge Application

For premises in England

For premises in Scotland

Application Guidance Notes

For premises in England

For premises in Scotland

Consent and compliance

We'll support you with any compliance challenges to help you meet regulatory obligations, arrange bespoke consent limits, negotiate consent applications, minimise environmental impact, and reduce the risk of unexpected costs. Email or call 01250 718718 to speak to our experts.

Why are consents required for trade effluent?

Unlike domestic sewerage, trade effluent is highly variable in terms of volume and contamination strength. It is therefore necessary to regulate this wastewater to ensure the sewerage network can adequately handle and treat the waste. This is to protect the health and safety of staff and to protect the environment.

To regulate trade effluent, businesses are provided with a licence, or discharge consent. The licence defines the nature of the allowable discharge and establishes any restrictions. Samples of the trade effluent discharge are taken regularly to ensure the customer is complying with the terms of their consent.

It is a criminal offence to discharge trade effluent waste without a consent.

Consistently accurate billing

Castle Water is recognised as a market leader in trade effluent billing. Our unique, state-of-the-art trade effluent invoicing system produces billing with the highest degree of accuracy. Email or call 01250 718718 to speak to our experts.

What charges apply to trade effluent customers?

Unlike sewerage, trade effluent charges relate to the contamination strength. Further information on these rates can be found in our Scheme of Charges. Many customers will find their trade effluent rate to be lower than their sewerage rate.

In addition, there are fixed fees for consent applications, and any additional waste sampling requested by the customer.

Explanation of the trade effluent rate

The volumetric rate (£ / m3) is calculated according to the Mogden formula. This says that the overall charge is the sum of rate components corresponding to different parts of the effluent treatment process. These are:

  • Primary Treatment
  • Reception and Convoy
  • Biological Treatment
  • Solids Treatment
  • Ammonia Treatment

Primary treatment and reception and convoy are independent of the amount of contamination, and the other charges are proportional to the concentration of contaminents. Trade effluent goes through the same treatment processes as sewerage, and subsequently the sewerage rate includes these same charge components, but on a non-variable basis.

FAQs and Glossary

Further information on trade effluent can be found in our FAQs & Glossary

Why am I sent new trade effluent invoices each month, for prior months?

Many customers want to know that their charges are auditable and can be traced back to these Wholesale charges. Unfortunately, if the Wholesaler enters sampling data in the Central Market Operating System after the month in which it is due to be recorded, this gives rise to a change in charges.

I think my business should have a Trade Effluent consent, what steps should I take?

Trade Effluent is any liquid waste discharged into the sewers from a business or industrial process. Trade Effluent is regulated to ensure the sewerage network can adequately handle and treat the waste.

To regulate Trade Effluent, businesses are provided with a license or discharge consent. Samples of the trade effluent discharge are taken regularly to ensure customers are complying with the terms of their consent.  The types of businesses that normally require consent include car washes, launderettes, and dry cleaners, transport depots, breweries, dairies, and commercial swimming pools.

What is Trade Effluent?

The best way to describe trade effluent is to begin with the definition of domestic effluent.

Domestic wastewater is anything disposed of in the sewerage system from toilets, sinks, washing machines and dishwashers. Anything that is not classified as domestic waste, or that is discharged in large volumes or is contaminated.

What is a SPID?

Every business premises has a unique Supply Point Identifier to identify the water and/or sewerage supplies at the property. The Supply Point Identifier number is also known as a SPID number.

Your SPID number is very important as part of your business water charges. It encompasses all of the chargeable data items related to your business premises including full meter details and return to sewer allowance.