Introduction

Ireland has an abundant supply of water that is used for drinking water, provides an important habitat for plants and animals, and is an amenity for recreational activities.  Although freshwater is abundant, it is not limitless in quantity, is not evenly distributed across the country, nor everywhere of good quality status.  Nutrient enrichment causing eutrophication is the main threat to Ireland’s aquatic systems.

State and Impacts

Groundwater

Elevated nitrate concentration in groundwater is an issue, particularly in the southeast and south of the country. It may contribute to eutrophication of surface waters and affect drinking waters. Diffuse agricultural pollution is considered the most significant source.

Rivers

Forty-nine percent of river water bodies are classified as having good or better ecological status, i.e. satisfactory, based on the WFD Interim Biological Classification for river water quality in 2008.  28 per cent of river water bodies are classified as having moderate, 21 per cent poor and 2 per cent bad ecological status.

In the case of nitrate pollution the majority of sites with elevated nitrate concentrations occur in the southeast.  The contrast between the western and eastern rivers is not as immediately apparent for phosphate as nitrate pollution, however half of the surveillance monitoring sites in the South-Eastern River Basin District (SERBD) would not achieve Good Status in 2008 based on phosphate levels.

High Ecological Quality River Sites

High ecological quality at river sites is an indicator of largely undisturbed conditions and reflects the natural background status or only minor distortion by anthropogenic influences. Such sites are used as reference sites from which deviation in quality is measured. These sites play an important part in conserving individual species and overall catchment biodiversity and must be protected under the WFD.   

The percentage number of high quality sites has almost halved in the last 21 years from almost 30 per cent of the total sampled in the 1987-1990 period to less than 17 per cent in 2006-2008. The seven-fold decrease in sites attaining Reference Condition (Q5) is particularly striking.  These sites now comprise less than two per cent of the total surveyed.

Lakes

Of the 271 lakes assessed for WFD Interim Biological Status in 2008, over 55 per cent had at least good status.

Only very modest nitrogen loading was recorded in 2008 for the 75 lakes on the surveillance monitoring programme, and 81 per cent of surveillance lakes sampled in 2008 were of good or better status for phosphorus concentrations.

Drivers & Pressures

The two main sources of pressure on water quality are from agricultural activities and municipal wastewaters.  These activities can contribute to nutrient enrichment, organic pollution and siltation of water bodies.

Agricultural activities associated with pollution include land spreading of artificial fertilisers and animal manures in unsuitable climatic and ground conditions, silage effluent discharges, farmyard runoff, and watering animals. 

Municipal pollution sources include sewage, waterworks effluent, on-site wastewater treatment systems and diffuse urban inputs. Sewage discharges comprise the main municipal pollution source. Pollution from municipal wastewater treatment plants arises where there is inadequate treatment, combined storm overflows and direct untreated discharges.  In most rural areas the majority of the population uses individual septic tanks that, if poorly sited and/or not properly maintained, can pollute groundwater, surface water and drinking water supplies.

Other activities which may impact on water bodies include forestry, industrial activities, quarrying, dredging, fish farming, bog development, civil works and housing development.

Outlook

Many water bodies will require remedial measures to meet the objectives of the Water Framework Directive (WFD). Protection and restoration of high quality waters will also be a significant challenge.  Eight water management issues have been identified as being of national importance:

1. Wastewater and industrial discharges
2. Landfills, quarries, mines and contaminated lands
3. Agriculture
4. Waste from unsewered properties
5. Forestry
6. Usage and discharge of dangerous substances
7. Physical modifications to surface waters
8. Abstractions

Programmes of measures under River Basin Management Plans aim to address these issues as they arise within individual river basin districts. 

The priorities for Government water services investment over the coming years include measures: to improve drinking water conservation (e.g., leakage control); to meet drinking water and wastewater treatment standards and ensure compliance with the WFD; and to meet forecasted increases in demand.

More generally water resources are likely to be impacted by the projected changes in climate over the coming decades. These impacts are expected to include summer water shortages in the east, the need for crop irrigation, potential deterioration in water quality, and an increased likelihood of flooding and coastal erosion.

Responses

Significant investment has gone into improving the water services infrastructure (for drinking water and urban wastewater), with over €4.6 billion invested over the last decade.

This has resulted in a dramatic improvement in the level of treatment of urban wastewater.  92 per cent of urban wastewaters now receive at least secondary treatment compared to 25 per cent at the start of 2000. In addition, a system for EPA licensing or certification of wastewater discharges from areas served by local authority sewer networks was brought into effect in September 2007.  This aims to reduce the input of nutrients and other dangerous substances to receiving waters. 

This investment has also resulted in increased treatment capacity for drinking water by a level equivalent to the needs of a population of 855,000 and storage capacity has increased by a level equivalent to the needs of a population of 1,510,000.

In 2009 the EPA revised its code of practice establishing a framework of best practice in relation to the development of wastewater treatment and disposal systems in unsewered rural areas.

The implementation and enforcement of the Nitrates Action Plan under the EU Nitrates Directive is the most important measure to address diffuse agricultural pollution of freshwaters.

In line with elsewhere in Europe a series of river basin management plans has been developed under the Water Framework Directive. The challenge for water resources management in Ireland will be the successful development and rollout of effective programmes of measures.