State bodies, local industries, farmers and householders are responsible for increasing amounts of organic pollutants and nutrient discharges finding their way into the Liffey, Boyne and Suir rivers, according to two major reports on their water quality.
Unrelenting decline in the quality of the rivers, which has occurred "in spite of major public investment in waste-water treatment" can be halted and reversed, but only if every sector within their catchments takes full responsibility for pollution.
The reports are published by the Three Rivers Project, a Government initiative aimed at developing "catchment-based" water-quality monitoring and management systems with a view to conserving the rivers.
A comprehensive education campaign is essential "if the public living in the vicinity of the river catchments is to have a full understanding of their role in pollution prevention", a preliminary report finds. The Minister for the Environment, Mr Dempsey, marked its publication with a baseline study yesterday.
The catchments account for 10.5 per cent of land mass in the Republic, support about 15 per cent of its population and, perhaps most significantly, supply 206 million cubic metres of drinking water a year.
Population growth, the study notes, will make further demands on the Liffey and Boyne. In addition, more extensive monitoring of water flow is needed on the Liffey to determine the environmental impact of extraction for electricity generation and flood control the ESB currently manages this river system.
While most municipal effluent discharged into the rivers receives some treatment, there are "few treatment plants in the catchments that achieve a high level of phosphorus removal", though some £223 million is being spent in upgrading plants feeding into the rivers.
Limiting wastes and pollutants that may contain phosphorus is critical to the well-being of freshwater and preventing eutrophication (enriching of the waters).
In the light of continuing phosphate contamination, the preliminary report finds urban wastewater treatment regulations do not provide adequate protection against eutrophication.
Some 56 per cent of municipal waste water generated in the Suir catchment and 50 per cent in the Boyne catchment is discharged untreated. All effluent in the Liffey catchment receives some treatment before discharge.
The project team recommends more sophisticated monitoring to include water going into and leaving treatment plants. This should be carried out by local authorities as frequently as once a week and reported regularly, it recommends.
The three-year project, sponsored by the Department of the Environment and local authorities in the catchments, is being conducted by consultants led by M.C. O'Sullivan, specialists in environmental management.
The main industrial threat comes from food-processing, catering establishments or detergent companies, although agriculture generates the greatest amount of sludge/slurry.
The project has set up a series of pilot studies to evaluate how best to secure cross-sector and cross-community co-operation where all parties take responsibility for the pollution they generate and work together towards reversing deteriorating water quality.
In these areas, monitoring is at a much higher level to demonstrate whether the approach is effective or not. Two agricultural areas in the Suir catchment and one in the Boyne, and a forestry and urban area in the Liffey catchment, are the subject of these studies.
A forestry monitoring programme focusing on the King's River (a Liffey tributary) is examining the impact of tree felling, clearing and replanting with a view to providing catchment managers with an indication of potential nutrient loads from this activity.
The Camac river, a Liffey tributary which flows through west Co Dublin, is being studied to determine the influence of urban drainage on water quality and singling out drainage outfalls and evaluated potential pollution sources from paved areas, such as those in industrial complexes.
An awareness campaign is already in place in the pilot areas, where the public is advised against using detergents containing phosphates, excessive use of water and poor septic tank management. A "happy fish campaign" is also aimed at primary schoolchildren.
