Water Quality


Environmental Protection Agency (EPA)

Key information

River water quality; lake water quality; bathing water quality; groundwater quality; estuarine and coastal water quality; river risk assessment; lake risk assessment; transitional risk assessment; coastal risk assessment; groundwater risk assessment; river basin districts; Water Framework Directive (WFD); fish kills; pollution at sea incidents.


EPA and local authorities water quality monitoring, EPA water quality assessments and River Basin Districts' water risk assessments.


All types and areas of water, including River Basin Districts that are shared with Northern Ireland.



Reference period

Varying dependent on location and type of water

Start date

Varying dependent on location and type of water


Varying dependent on location and type of water


  • Lake water quality (trophic status)
    Oligotrophic; Mesotrophic; Moderately eutrophic; Strongly eutrophic; Highly eutrophic; Hypertrophic.
  • River Basin Districts (RBD)
    South western; Western; North western; Shannon; South eastern; Eastern; Neagh Bann.
  • Water WFD Risk Assessment Status
    Strongly expected to achieve good status; Expected to achieve good status; Possibly at risk of not achieving good status; At risk of not achieving good status.
  • River Water Quality (Q values)
    Q4-5, Q5 High status; Q4 Good status; Q3-4 Moderate status; Q2-3, Q3 Poor status; Q1, Q1-2, Q2 Bad status.
  • Estuarine and Coastal Water Quality
    Unpolluted; Intermediate; Potentially eutrophic; Eutrophic.
  • Bathing Water Quality
    Compliant with guide values; Compliant with mandatory values; Non-compliant with mandatory values.


Environment, Climate and Energy - Environment

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assessment bann basin bathing coastal district compliant environment environmental epa estuarine eutrophic groundwaters hypertrophic indicators kills lake lakes mesotrophic monitoring neagh non-compliant oligotrophic pollution quality rbd risk river rivers shannon status surface transitional trophic water wfd