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Urban Waste Water Treatment Directive

Last updated: 14 August 2009

Sensitive Areas

The European Commission (EC) Urban Waste Water Treatment Directive is designed to reduce the pollution of freshwater, estuarine and coastal waters by domestic sewage and industrial waste water - collectively known as 'urban waste water'.

The directive sets minimum standards for the collection, treatment and discharge of urban waste water, and also sets timetables for the achievement of these standards.

The directive outlines the standards required before urban waste water can be discharged.

Where receiving waters are vulnerable to eutrophication (i.e. nutrient enrichment) the directive requires higher standards of treatment. This involves the removal of nutrients from waste water. The waters into which these waste waters are discharged must be identified as 'Sensitive Areas' (SA's) and must be subjected to regular review.

The directive was brought into force in Northern Ireland law by a set of regulations in 1995. At the same time, the Department of Environment formally identified the Lough Erne and Lough Neagh catchments as SA's. The identification of these two areas, which cover over 50 % of Northern Ireland's land area, was based on  'precautionary principle', in other words their waters were either eutrophic or were likely to become eutrophic if preventive action was not taken.

Appropriate treatment involving the removal of nutrients from sewage discharges has since been provided at all but two of the treatment works affecting these SA's.

Subsequently, we commissioned a number of studies of sea loughs and estuaries around the coast of Northern Ireland. Information from these studies suggested that inner Belfast Lough, tidal River Lagan and the Quoile Pondage were eutrophic and should be identified as SA's.

The directive requires action to remove nutrients from the treated sewage discharges to these SA's. In light of the three new identified sites the following actions have been taken:

  • Department of Regional Development (DRD) Water Service has already met a requirement by us to remove nutrients at the Belfast and Kinnegar Waste Water Treatment Works in 1999 and 2000 respectively.
  • The nitrogen loading in the discharge to inner Belfast Lough and the tidal River Lagan from a local industrial source is being steadily reduced
  • Action by DRD Water Service on its sewage treatment works at Downpatrick, upstream of the Quoile Pondage, is also planned. A more detailed assessment of the importance of nitrate from agricultural sources in this respect is planned.

The Minister has therefore concluded that the three new sensitive areas at the tidal River Lagan, inner Belfast Lough and the River Quoile Pondage should be formally identified under the terms of the directive, and suitable management actions put in place.

Further information

Regulation of Sewage Discharges

Department of Environment, Food and Rural Affairs (Defra): Water Quality - Sewage Treatment in the UK: Sensitive AreasOpens in New window