The Sustainable Water Network (SWAN), which represents 25 environmental groups in Ireland, has welcomed the European Commission's decision to reduce the limits on organic nitrates use on certain farms in Ireland.
The move by the commission affects over 3,000 Irish dairy and beef farmers from 1 January.
Many farmers may have to reduce stocking rates as a result.
"Approximately half of our rivers and lakes are now polluted, and two-thirds of our estuaries," says Sinéad O'Brien, SWAN Coordinator.
"It's clear from the science that agriculture is by far the biggest pressure on our waters and the EPA - not known for dramatic language - is referring to 'alarming declines' in water quality in our estuaries.
"The commission was clear 18 months ago that a reduction in the permitted level of nitrate that could be spread on derogation farms would be required in areas where there was 'worsening trends or a situation of pollution or risk of pollution as regards nitrate concentrations'."
Ms O'Brien also warned against the continual lack of Government leadership in planning for such changes, and failure to prepare and support farmers in delivering them.
"The science, the law and the requirements from the European Commission were all very clear and have been for a long time. Yet the response from the Government to date in tackling the issues has been an abject failure," she says.
"The fact that this seems to be coming as news to many farmers, shows an abysmal lack of leadership on the part of the Government and farming organisations, when the writing has been on the wall increasingly over the past decade regarding the need to address the link between dairy intensification and escalating water pollution.
"Supports for farmers should have been made long ago to transition away from derogation, but instead it was encouraged, and now some are facing real difficulties in order to meet these changes."
Among the 25 participant groups in SWAN, the Sustainable Water Network are An Taisce, Birdwatch Ireland, The Irish Wildlife Trust and Friends of the Irish Environment.
Meanwhile, Tánaiste Micheál Martin and Minister for Agriculture Charlie McConalogue had a "constructive" meeting with IFA leaders at the Fianna Fáil party think-in in Co Tipperary.
The meeting was arranged after protesters from the farming organisation refused to talk with Mr McConalogue over nitrates reductions and late farm payments.
