Current status2015
Short term status2011 - 2015
Long term status

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Chart E.1.v._1 Level of compliance with the Urban Waste Water Treatment DirectiveChart E.1.v._2 Level of compliance with the Urban Waste Water Treatment Directive

The EU Urban Waste Water Treatment Directive (91/271/EEC) has requirements for sewerage systems (or waste water collection systems) to be provided and sets deadlines for the provision of sewage treatment. The main requirements of the UWWTD are as follows:

  • Scheduled provision of waste water collecting systems and treatment plants based on the size of the agglomeration and the type of water body to which the waste water is discharged (freshwater, estuarine or coastal, sensitive or non-sensitive).
  • Monitoring by water services authorities (including frequency of monitoring) of discharges from waste water treatment plants.

In Ireland the Urban Waste Water Treatment Regulations, 2001 (S.I. No. 254 of 2001), as amended, give effect to the UWWTD.  The UWWTD also sets out criteria for identification of sensitive areas, such as freshwater bodies, estuaries and coastal waters which have received, or at risk of receiving, high concentrations of nutrients from waste water if action is not taken. Fifty-one water bodies are now designated as sensitive in Ireland.

The Environmental Protection Agency (EPA) is the environmental regulator responsible for the authorisation and enforcement of waste water discharges from water services authority waste water works. The purpose of the authorisation system is to prevent and reduce pollution by waste water discharges. All waste water discharge authorisations transferred from the local authorities to Irish Water on 1st January 2014 and Irish Water is now responsible for ensuring compliance with the requirements of the authorisations.

The parameters most commonly used to assess the effectiveness of waste water treatment in removing organic contaminants are biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS).  In addition, for larger towns and cities (those with a population equivalent > 10,000), the UWWTD requires a more stringent level of effluent treatment with regards to excessive nutrient (phosphorous and nitrogen) concentrations being discharged directly into sensitive areas.  Compliance of all large (> 10,000 person equivalents and areas > 2,000 person equivalents discharging into freshwater bodies or estuaries) urban areas with BOD, COD and TSS standard rose from 42% in 2009 to 70% in 2015.  In parallel, the number of larger towns and cities complying with standards relating to phosphorous in the UWWTD has increased from 66% in 2009 to 84% in 2015, and nitrogen compliance increased from 35% in 2009 to 56% in 2015.  Overall, the proportion of larger towns and cities in compliance with both phosphorus and nitrogen standards has risen from 35% in 2009 to 79% in 2015.

Responsibility for effluent sampling, analyses and reporting the results to the EPA was transferred to Irish Water on 1st January 2014.  The EPA assesses the results reported on an annual basis against the quality standards and sampling frequencies specified in the Directive, and reports on the findings.

More information on wastewater treatment in Ireland can be found here:

Sensitive areas are listed in the Urban Waste Water Treatment (Amendment) Regulations 2010 S.I. No. 48 of 2010:


Level of compliance with the Urban Waste Water Treatment Directive

The Urban Waste Water Treatment Directive (UWWTD) aims to protect the environment from the adverse impacts of discharges of urban waste water from population centres.  This indicator tracks the level of compliance with the UWWTD in urban waste water collection systems and treatment plants.

Created: 2014-11-21 12:36:02 | Updated: 2019-05-17 12:54:21