What is Effluent?

Effluent is a wastewater which has been discharged from a process.  The process which generates an effluent can be industrial, commercial, municipal or from a treatment plant.

Effluent and the Law

It is a legal requirement that effluent is treated properly to comply with the emission limit values and other conditions of a discharge licence.

A discharge licence is required if you wish to discharge a trade effluent  to surface waters, including lakes, rivers, streams, costal waters or estuaries, ground and groundwater and the public sewer. Discharge of domestic sewage (only) from commercial or industrial premises to municipal sewers may not require a license although it is subject to licensing if it discharged directly into surface water.

Trade Effluent License

Irish Water and local authorities regulate the Trade Effluent Discharge licenses, whilst the EPA regulate the discharge of trade effluents and other emissions from activities which they licence.

You or your business must hold a trade effluent discharge license from one of these regulatory authorities before discharging trade effluent to surface water, ground or municipal sewers. The discharge licence sets out conditions which must be complied with by the licence holder. These conditions include the composition and volume of the effluent, the treatment method, location of discharge, monitoring, procedures and practices to be undertaken and records which must be maintained, as well as other requirements. 

Many industrial processes do not create what many people perceive as a wastewater, including cooling water, boiler blow down water, water treatment plant backwashes, among others. However, all of these are regarded as trade effluent and it is necessary to provide for their discharge in a licence .