If your business discharges anything other than domestic sewage into the public foul sewer — process water, wash-down water, chemical residues, or compressor condensate — you almost certainly need a trade effluent discharge consent from your local water company. Discharging without one is a criminal offence under the Water Industry Act 1991, regardless of whether the breach was intentional.
Our consultants confirm whether your activities need consent, prepare and submit your application, and liaise with your water company throughout — including any treatment or site works needed to get the application over the line.
Who needs a trade effluent discharge consent?
You’re likely to need consent if your site carries out any of the following:
- Vehicle washing
- Process water discharge from manufacturing or production
- Chemical or pharmaceutical manufacturing
- Food and drink production
- Engineering or metal finishing, including degreasing and treatment baths
- Condensate discharge from compressors or refrigeration plant
This isn’t an exhaustive list. If your site produces any liquid waste other than ordinary domestic sewage — anything that isn’t from toilets, kitchens or washrooms — it’s worth checking whether consent applies to you.
What is a trade effluent discharge consent?
Trade effluent is defined under Section 141 of the Water Industry Act 1991 as any liquid, with or without matter in suspension, produced wholly or partly in the course of a trade or industry at trade premises. Discharge to a foul sewer is controlled by your local water company (your sewerage undertaker) to protect the sewer network, treatment works and the environment.
Discharging trade effluent without consent is an offence under Section 118 of the Act — punishable by a fine on summary conviction, or an unlimited fine on conviction on indictment. Breaching the conditions of a consent you already hold is a separate offence under Section 121.
Once granted, a consent sets out the parameters your discharge must meet — commonly including pH, chemical oxygen demand (COD), suspended solids, temperature, and limits on volume and rate of discharge — along with any substances you’re prohibited from releasing. You’ll usually need to carry out periodic sampling to demonstrate ongoing compliance and report any exceedance.
Permanent and temporary consents
Most consents are ongoing and apply for as long as the discharging activity continues. But if your discharge is short-term — heating system flushing or groundwater remediation, for example — most water companies offer a separate temporary consent route, which is typically quicker to obtain than a permanent one. We can advise which route fits your situation.
What’s excluded
Trade effluent consent covers discharge to the foul sewer only. It does not cover surface water (rainwater run-off), which is regulated separately, or ordinary domestic sewage from toilets, kitchens and washrooms. If your site discharges to a watercourse, soakaway or via a surface water sewer instead of the foul network, you’re likely to need a different permit — such as a water discharge activity permit from the Environment Agency — rather than trade effluent consent.
Key benefits of our Trade Effluent Discharge Consent service
- Confirm whether your activities require consent before you apply
- Prepare and submit a complete application, reducing the risk of delays from missing information
- Expert liaison with your water company throughout the process
- Support with variations to an existing consent as your operations change
- Advice on any treatment or site works needed to bring your discharge within consent parameters
- Avoid the disruption and legal exposure of operating without the correct consent
What to expect from our Trade Effluent Discharge Consent service
Our team of environmental experts will liaise with your water company to confirm whether you need a trade effluent discharge consent, and either prepare a new application or manage a variation to an existing one. We handle:
- Confirming the correct consent route (permanent or temporary) for your discharge.
- Preparing and submitting the application, including details of discharge volume, rate, and composition.
- Liaising with your water company on assessment queries and consultation.
- Advising on any treatment or process changes needed to meet consent parameters.
- Supporting ongoing compliance once your consent is granted, including sampling and reporting.
Timescales vary by water company, but most applications are assessed within around two months of submission, provided the information supplied is complete. Applications with gaps or missing technical detail take longer — which is exactly where a well-prepared submission makes the difference.
Understanding the strength and volume of your effluent before you apply also puts you in a stronger position, both for the application itself and for managing costs once you’re consented (trade effluent charges are calculated using the Mogden formula). If you’re not yet sure what your effluent looks like, our Flow and Load Surveys service can establish this before you submit.
Further information
- Flow and Load Surveys — understand your effluent strength and volume, including the Mogden formula, before you apply
- Trade Effluent Monitoring Service — ongoing compliance monitoring once your consent is granted
- Environmental Permit Applications
- H1 Risk Assessments — if you’re discharging to ground or a watercourse rather than the foul sewer
