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Trade effluent FAQs

See our frequently asked questions about discharging trade effluent.

  • Any existing licence remains valid if the licence has not been reviewed or revoked, or
  • Any existing licence remains valid for a period of three years following cessation of the discharge of trade effluent to sewer

The existing licence is sufficient until such time as a licence review is required.

The current licence is revoked and a new licence application is required.

The current licence requires a review which can be initiated by contacting dischargetosewer@water.ie quoting your current discharge licence number.

The current licence is revoked and a new licence application is required.

A licence review will be required if the following applies:

  • If there is a change to the business/trading name
  • If there is a material change to such an extent that the licensee is no longer able to comply with its existing licence conditions. This includes changes that:
    • may alter the nature or composition of the trade effluent discharged to sewer
    • may alter volume or rate of flow of the trade effluent discharged to sewer
    • may alter abatement, treatment or recovery systems installed in connection with the trade effluent discharged to sewer
    • may alter the range of processes or activities giving rise to the trade effluent
  • There are continuous non-compliances with any conditions of the existing licence
  • There is a change of a discharge to sewer location in an already licensed site

Both Uisce Éireann and the licensee can initiate a licence review. To initiate a review please email dischargetosewer@water.ie quoting your current discharge licence number. Where Uisce Éireann initiates the review the application fee is non-applicable

The Mogden Formula is an internationally accepted formula in wastewater treatment to calculate charges for treating trade effluent. The formula takes into account two main factors:

  • The volume of trade effluent discharged into the Uisce Éireann wastewater network and;
  • The level of pollutants present in the trade effluent.

The formula is typically used by water utility companies to determine the charge to recover trade effluent collection, treatment and disposal costs. It enables utilities charge based not only on the volume of wastewater discharged but also the level of pollution in the wastewater. This incentivises customers to reduce the level of pollutants in their wastewater. 

Image
Modgen formula in mathematical form
ComponentDescriptionUnit
RA fixed charge per cubic metre for reception and conveyance costs m3
VA fixed charge per cubic metre for volumetric and primary or preliminary treatment costsm3
OtThe Chemical Oxygen Demand (COD) of the customer's settled trade effluentmg/l
OsThe average national figure for COD of settled wastewater as determined by UÉ across all its wastewater treatment plantsmg/l
BThe biological oxidation cost per cubic metre of settled wastewater of average strengthm3
StThe total suspended solids content of the customer's trade effluentmg/l 
SsThe average national figure for SS of settled wastewater as determined by UÉ across all its wastewater treatment plantsmg/l
SThe charge per cubic metre for treatment and disposal of primary sludge from a wastewater treatment plantm3

Apply for a Trade Effluent License