Farmers have been identified as the principal culprits for Ireland's "most serious environmental pollution problem" - the eutrophication (over- enrichment) of rivers and lakes.
Agriculture is responsible for an estimated 73 per cent of all phosphorous inputs to water and 82 per cent of nitrate inputs, according to the Government's national sustainable development review.
It describes eutrophication of waters as "a classic example of the impact of economic development on the environment", with nearly all sectors - domestic, public, industrial and agricultural - making their contribution.
Besides the main sources, such as discharges of sewage and industrial wastes and losses from agricultural activities, eutrophication may be caused by fish farming, forestry development, road building and other types of land disturbance.
However, the review identifies agriculture as "the single biggest contributor" to what it describes as "Ireland's most serious environmental problem", even though negative water quality trends "are beginning to be reversed".
It says the EU Water Framework Directive "will be the pre-eminent context for water quality" over the next decade. It requires a co-ordinated approach, based on river basins, with a view to achieving "good status" for all waters by 2015.
In dealing with eutrophication, the report published yesterday says such a catchment-based strategy will be applied to all waters in the State (rivers, lakes, coastal, estuarine and ground-waters) and "will be pursued vigorously".
Greater efforts will be applied to the agriculture sector to give further effect to the EU Nitrates Directive and to meet the 10-year water quality targets set by the 1998 Phosphorous Regulations.
On air quality, the review says Ireland must meet "ambitious targets" to reduce sulphur dioxide, nitrous oxides, volatile organic compounds and benzene under the EU National Emissions Ceilings Directive and the Gothenburg Protocol.
"New and more stringent EU air quality standards for local pollutants to be achieved by 2010 will be challenging to meet in Ireland, particularly if road transport emissions continue to grow at the rate seen in recent years", the review concedes.
It says the main challenge to air quality in urban areas now stems from rising vehicle emissions, given the unprecedented growth in the number of vehicles - in the case of private cars, up from 796,000 in 1990 to 1.3 million in 2000.
The review identifies a number of key issues in transport, including managing increasing volumes of road traffic and resulting congestion, reducing harmful emissions, more sustainable land use and arresting the growth in energy consumption.
It refers to the Dublin Transportation Office's Platform for Change, under which the capital would acquire a metro as well as enhanced bus, Luas and suburban rail networks, better pedestrian and cycling facilities and traffic management measures.
It also mentions the Greater Dublin Area Strategic Planning Guidelines, which aim to reduce transport demand by consolidating future population growth in a limited number of locations and making public transport more attractive to car users.
The National Spatial Strategy, due to be published in September, would seek to strike a balance between "the need to maintain the continuing vitality of rural areas and the need to develop stronger and better urban structures required to support investment".
It would set out at a national level how Ireland can be spatially developed, with the emphasis on "gateways" and "development hubs", while conserving the environment.