1.0 Literature Review

1.1 River Water Quality in Ireland.

Rivers and lakes are attractive features on the landscape that contribute to tourism and the recreational value of an area, as well as providing a source of drinking water and supplying water for domestic, agricultural and industrial purposes. Despite the relatively good quality of most Irish surface waters, there has been a continuous decline in river water quality, mainly due to eutrophication or the over-enrichment of water by nutrients (Crawley 2001).

The most recent report on the water quality in Ireland covers the period 1995-1997. This shows a continuation of the trend of increasing slight and moderate pollution of the river system, which has been recorded since the 1970’s (Toner et al.,2000).

The results of the 13,084 kilometres of channel surveyed (biological survey) in the period 1995-1997 indicate that the bulk (67%) of surveyed channel length is in a satisfactory quality condition but a considerable length is affected by slight or moderate pollution. Approximately 18 per cent is classed as slightly polluted/eutrophic, a further 14 per cent is moderately polluted and 1 per cent is currently subject to a serious degree of pollution (Lucey et al.,1999).

Figure 1.1 outlines the recent trends in the 13,200 km base line (12,700 in 1987-1990). The % of channel length is divided into four Biological Quality classes. Class A: unpolluted.

Class B: Slightly polluted

Class C: Moderately polluted

Class D: Seriously polluted.

Figure 1.1: Recent trends in the levels of pollution of Irish rivers (Lucey et al.,1999).

It is clear that there is a continuous decline in river water quality.

1.2 Sources of pollution

In the surveying period 1995-1997, most recorded instances of serious pollution were apparently due to sewage discharges. In relation to slight to moderate pollution, most instances were attributed to agriculture and the bulk of the remainder to sewage (Toner et al, 2000).

Figure 1.2 overleaf outlines the suspected causes of pollution in our rivers during 1995-1997.

Figure 1.2: Suspected causes of pollution 1995-1997 (Lucey et al., 1999)

1.3 Legislation for the Quality of Irish waters

The principal legal framework for the prevention and control of water pollution is contained in the Local Government (Water Pollution) Act, 1977 (No. 1 of 1977) and the Local Government (Water Pollution) (Amendment) Act, 1990, (No. 21 of 1990). These acts include a general prohibition on causing water pollution, provisions concerning licensing of discharges to waters and to sewers, water quality standards, water quality management plans, nutrient management plans.

Other major Acts in relation to Water pollution include the Environmental protection Agency Act, 1992 and the Fisheries (Consolidation) Act, 1959.