An appeal is being sought against a judgment permitting tech giant Apple to develop the first phase of a planned €850m data centre in Co Galway, the High Court has been told.

The permission to appeal application – which only the High Court can grant – will be heard on October 25 but may not conclude then and may have to resume later.

Mr Justice Paul McDermott, in separate judgments last week, rejected two judicial review challenges to An Bord Pleanála’s August 2016 permission for a data hall at Derrydonnell, Athenry, the first of eight such halls Apple may build over a 15-year period.

The first challenge was by local residents Sinead Fitzpatrick and Allan Daly, of Lisheenkyle, Athenry, whose concerns included about the potential environmental impact of the entire development, particularly about greenhouse gas emissions.

The judge found the board and its inspector considered and assessed the potential environmental impact of the overall Apple “masterplan” and disagreed the board was required to carry out an environmental impact assessment of the entire proposed project.

Their counsel, Oisin Collins BL, said yesterday his clients did intend to seek a certificate for leave to appeal. When the judge said he was ready to hear arguments concerning the application, counsel said he wanted time to consider the matter.

Nuala Butler SC, for the board, said Mr Collins should outline within a week the point of law he intends to raise after which her side would provide written submissions.

The judge said he would hear the matter on October 25 and if it did not conclude by 10.45am that day, he would hear the remaining arguments on a later date.

In his judgment on the second case, by Brian McDonagh, of Ballymount Cross Business Park, Dublin, he found Mr McDonagh lacked the necessary legal standing to challenge the permission as he does not live close to the site and had not participated in the planning process. He should have disclosed at an early stage he was a director and shareholder of Ecologic Data Centre Ltd which had secured permission for a data centre on a Co Wicklow site considered as an alternative location for the Apple development, the judge added.

Mr McDonagh has not decided whether to seek leave to appeal. The judge said he would list his case for October 25.