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Water, sewerage and trade effluent charges

Trade effluent charges

You will be billed trade effluent charges if you are consented to discharge liquid waste, other than surface water and domestic waste, to our sewer.

The charge is determined by:

  • The volume of effluent discharged;
  • The strength of effluent discharged;
  • The level of sewage treatment supplied

Trade effluent bills are calculated using a formula agreed between the water industry and the Confederation of British Industry (the Mogden Formula) with samples taken of the discharge where applicable.

The standard unit costs in the Mogden Formula for 2024/25 are shown in the table below:

Charge £/m³

(R) Reception Charge


(V) Volumetric Charge


(B) Biological Charge


(S) Sludge Charge


Standard Strength Combined Charge


Standard Strengths


Standard Strength Chemical Oxygen Demand


Standard Strength Suspended Solids


Trade Effluent charges are payable in addition to normal non-domestic sewerage charges.

For full information on non-domestic water charges please read our Scheme of Charges 2024/25.

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