A Supreme Court appeal by local residents against An Bord Pleanala's decision to grant planning permission to Apple to build a data centre in Athenry, Co Galway has been rejected.

However, the decision will have no immediate impact on the €850 million project, as Apple has already shelved plans for the facility.

Nevertheless, the judgment is being seen as important determination of issues around Environmental Impact Assessments (EIA) that could impact future infrastructure projects.

Appellants Sinead Fitzpatrick, who lives close to the location where the centre was to be developed at Derrydonnell Woods , and Allan Daly of Athenry took the legal action after Apple got planning permission from the board in 2016.

Their appeal centred on the extent to which An Bord Pleanala was obliged to assess the environmental impact of the entire Apple plan for eight data halls rather than just the first phase which received the permission.

Even though Apple withdrew from the project in May of last year following years of delays, the Supreme Court agreed to hear the appeal because the issues could affect future planning of other data centre developments.

Today the five judge Supreme Court unanimously ruled An Bord Pleanala was not obliged to carry out a full EIA on the entire masterplan.

The court also said the it did not consider it necessary to refer the issues for ruling by the European Court of Justice.

Each side is to pay their own costs, the court decided.

Apple first announced plans to construct the data centre on the greenfield site in February 2015.

Construction of the first phase of eight promised to generate 300 temporary jobs, with up to 150 permanent staff required to run it.

The following September, Galway County Council gave permission for it to proceed subject to conditions, but that decision was subsequently appealed to An Bord Pleanála.

Following an oral hearing the planning authority confirmed the permission in August of 2016.

However, a review of that decision was sought by three objectors, locals Mr Daly and Ms Fitzpatrick, and businessman Brian McDonagh in the High Court.

In October 2017, the High Court cleared the way for the project to proceed and the following month, the court refused to give the objectors permission to appeal its decision to the Court of Appeal.

But the following December, Mr Daly and Ms Fitzpatrick then asked the Supreme Court to hear an appeal of the High Court decision and in May the court granted their request.

The body responsible for attracting foreign investment to Ireland has welcome the decision of the Supreme Court.

However, speaking on RTÉ's News at One, IDA Chief Executive Martin Shanahan said the company has made it clear they do not plan to proceed with the Athenry project.

He said Apple first announced the investment in 2015 and it has taken until April 2019 to get to the end of the planning process.

Mr Shanahan said this points to the need for more certainty around the planning process, particularly when it comes to the timeline.

"We have a lot of large infrastructure projects that have proceeded without any impediment. They go through the planning process and I think we and our clients respect the planning process, we respect the fact that there are checks and balances in place.

"It is certainty around the process and timing rather than certainty around outcome that people are looking for."

He added that Ireland competes for foreign direct investment with other countries who are capable of completing the planning process "at speed".