The pig population here is projected to increase by one million within the next five years, but with soils increasingly overloaded with phosphorous - from slurry or fertiliser - the options for locating piggeries are shrinking fast. A development push seems to heading westwards, towards less intensively farmed land. It so happens that some of the most sensitive freshwater resources in Europe are there too.
So it is not surprising that plans by Mr Leo O'Reilly of Murneen, Claremorris, to build a 500-sow unit at Coolaght near Kiltimagh, Co Mayo, have met stern opposition from angling interests.
What is surprising is that planning permission for the development was refused twice, yet the Environmental Protection Agency, with a new role as arbiter on environmental aspects of planning, has proposed granting it an integrated pollution control (IPC) licence.
At the third attempt, Mr O'Reilly got planning permission in 1997 to build the piggery, subject to an IPC licence (under new legislation the council could not rule on environmental aspects of the application). However, his arrangements for disposal of slurry threaten two of Europe's most important fishery catchments, according to two fishery boards and the Central Fisheries Board - Lough Conn/River Moy catchment in north Mayo, and Loughs Carra and Mask to the south, which in turn feed into Lough Corrib.
It is rare that a development is claimed to have environmental implications for hundreds of square miles surrounding it. In this case, it is primarily because the areas proposed for slurry spreading are concentrated around Barnacarroll Hill, halfway between Claremorris and Knock.
Phosphate run-off from its northern side is likely to contaminate the Moy system, while to the south Lough Nanannagh, the river Robe and Lough Mask are put at immediate risk, the fishery boards claim.
There are compounding difficulties. Most group water supply schemes in the region are already contaminated by coliform bacteria (indicating faecal matter arising from farming or septic tanks). Excessive nutrients from farming are already straining the Robe - algal blooms frequently dot its surface.
Environmental issues aside, Mr Tony Waldron of the Connacht Angling Council believes the case has exposed a serious flaw in the planning process. The transfer to the EPA of responsibility for environmental planning for developments which generate pollutants introduced inherent unfairness into the system, he said.
"This changing of the goalposts is cutting out Bord Pleanala and not allowing local authorities to adjudicate on environmental aspects of pig or poultry developments. It is not in the public interest. It allows the licensing division of the EPA to be judge and jury. At the very least, we should be entitled to an oral hearing on this."
Ironically, County Council is among the most forthright objectors to the licence. The "disposal of slurry, whether treated or not, would undoubtedly lead to pollution of surface waters in the Moy and Robe catchments," it said.
The development was likely to conflict with its moves to curtail phosphate discharges from farms. The Arctic charr fish species had disappeared from Lough Conn due to pollution, and its population in Lough Mask was now threatened, it added.
Piggeries, it told the EPA, had created "environmental difficulties throughout the State, principally in areas of poor soil and high rainfall . . . The location of this type of activity in possibly the most sensitive lake catchments in Europe will make it impossible for the local authority to satisfy EU legislation on water quality and habitats."
With its objection, it included the views of an expert group, part of a technical committee involved in rehabilitating Loughs Conn and Mask. It was "unanimous in its concern that the proposed licence, if issued, would undermine the ef forts of the committee in effecting further improvements in surface water quality".
The EPA's regional inspectorate based in Castlebar is represented on the committee, and The Irish Times has confirmed that its representative was present at the meeting when this position was agreed.
The EPA declined to comment on any aspect of the proposed development, as the objection process was in train. A final determination on the licence is expected within a fortnight.
The EPA's licensing and control division, it is understood, regards the conditions spelt out in the proposed determination in July (i.e., signalling intention to grant a licence) as being so stringent that the development would not threaten what it accepts is a highly-sensitive location. The agency is believed to take the view that its demand that slurry be digested/thermally treated amounts, in effect, to a prohibition on slurry spreading.
This is unprecedented, as far as piggery operations are concerned. Thus dried material would be added to the land in much the same way that fertiliser is (with no controls) at present. This is contrary to the interpretation of the conditions by many of the objectors.
The Central Fisheries Board said the proposed determination was "significantly flawed". The EPA's intention to grant a licence subject to a proposal for treatment of slurry, such as digestion or thermal drying, "is completely unsatisfactory", it found.
"The precise treatment method should have been decided and stated in this proposed determination - not some months after a licence has been granted," CFB senior research officer Dr Trevor Champ said. He also disputed that the proposed applications of phosphorus were justified agronomically. They "clearly constitute dumping", he added.
North Western Regional Fisheries Board chief officer Mr Vincent Roche asked the agency to reassess the application in view of expert opinion that there was no possibility of safe disposal of such slurry volumes in that area.
It should then refuse the licence, he said.
Western Regional Fisheries Board manager Mr Michael Kennedy said major restoration of the Corrib was threatened.
Freshwaters were at risk despite being "amongst that small number of European lakes that are capable of producing self-sustaining and productive wild brown trout populations", he told the EPA.