An Taisce is preparing a legal complaint to the European Commission over alleged breaches of EU directives in relation to the Corrib gas project.
The environmental organisation maintains that Ireland could face "massive" fines if it permits the gas project's terminal to be built in a major drinking water catchment. Ireland is already in breach of the EU drinking water directive, and runs the risk of becoming a "serial offender", according to An Taisce spokesman Frank Corcoran.
The Environmental Protection Agency (EPA) is currently considering Shell E&P Ireland's application for an integrated pollution prevention and control (IPPC) licence for the terminal project, following a lengthy oral hearing.
Speaking after he had addressed a public meeting in Glenamoy, north Mayo, at the weekend, Mr Corcoran told The Irish Times the EPA would have to take the terminal's location into account.
"The location is on three catchments - the Carrowmore lake drinking water catchment, river and coastal water catchments. It would be very serious if the EPA ignored the relevant EU directives in relation to this," Mr Corcoran said.
"An Taisce is not part of Shell to Sea," Mr Corcoran emphasised. "An Taisce is not directing where the onshore pipeline linking the gas field to the onshore terminal should go.
"However, when Shell E&P Ireland makes an application for a new pipeline route under the Strategic Infrastructure Act, the organisation will respond as a statutory consultee."
Mr Corcoran is a lecturer in environmental law at the Dublin Institute of Technology and a former chairman of An Taisce.
Among those present were former Mayo TD Dr Jerry Cowley, parish priest Fr Michael Nallen and members of the Rossport Five and families, along with residents of the Kilcommon parish.
Mr Corcoran said he had asked the local community to provide information in relation to a legal claim, and would be holding another meeting in north Mayo shortly.
Mr Corcoran's brother, Leo, a former senior pipeline engineer with Bord Gáis, outlined concerns relating to the code of consent for the project and the terminal's proximity to Carrowmore lake.
Shell E&P Ireland has said that it has full planning permission for the terminal at Bellanaboy.
