Business water
Trade effluent
charges explained
Consent, Mogden & your bill
Bill review · no obligation- Trade effluent is business process wastewater that isn't ordinary sewage — it needs consent to discharge to the sewer.
- It's charged separately from normal water and wastewater, often using the Mogden formula.
- The Mogden formula bases charges on the volume and strength (how dirty) of the effluent.
- Getting your consent terms and measured strength right can make a real difference to the bill.
Most businesses just pay for water in and wastewater out. But if your process produces liquid waste that's stronger or different from normal sewage, you're likely dealing with trade effluent — and it's charged in its own way.
What is trade effluent?
Trade effluent is liquid waste produced by a business process that isn't ordinary domestic sewage or surface water. Common sources include food and drink production, laundries, car washes, print works and manufacturing. Because it can be stronger or contain substances normal sewage doesn't, it's regulated separately.
You need consent to discharge it
You can't simply pour trade effluent down the drain. Discharging it to the public sewer requires trade effluent consent (or a trade effluent agreement) from the relevant sewerage provider, which sets limits on volume and content. Discharging without consent can lead to enforcement action.
How it's charged: the Mogden formula
Trade effluent is usually charged using the industry-standard Mogden formula. In simple terms, it bases the charge on:
- Volume — how much effluent you discharge.
- Strength — how 'dirty' it is, measured by things like chemical oxygen demand (COD) and suspended solids.
- Treatment — the cost of reception, treatment and dealing with the solids.
The dirtier and larger the discharge, the higher the charge — which is why measurement and your consent terms matter.
Where businesses can save
Because charges hinge on volume and strength, there's often room to reduce them: cutting water use, pre-treating effluent to lower its strength, and making sure the sampled strength and consent terms reflect your actual discharge rather than cautious assumptions. Billing errors here aren't unusual — see why your water bill is high and having a water audit.
Think you're paying for trade effluent and want your water and wastewater bills reviewed? Send a recent copy — free, no obligation. Call 0845 862 1947 or get in touch.
Trade effluent is business wastewater that needs its own consent and is charged on volume and strength, usually via the Mogden formula. If your process produces it, it's well worth checking the numbers — small corrections can add up.