An unpublished Aer Rianta report from 1995, which outlines the levels of illegal dumping at Shannon Airport, shows that Aer Rianta knew it was polluting lands in an unlicensed dump at Dernish Island near the airport.
However, it continued to officially dump waste there for a further three years until an Environmental Protection Agency (EPA) report last year produced strong evidence that dumping was still going on at the site.
An Taisce called yesterday for an independent investigation into the dumping, some of it hazardous, over the past 30 years.
The report has only come to light through Aer Rianta lodging additional information to Clare County Council in order to secure planning permission for its €2.25 million sewage treatment plant for Shannon.
The Aer Rianta report, drawn up by TMS Consultancy, says that while there was no significant pollution of surface water on the sites at Dernish Island used for waste disposal, "results from monitoring soil samples, however, are not favourable".
It says results for "metals are varied, with aluminium, iron, zinc and arsenic unacceptably high", while it also describes hazardous waste, including fluorescent tubes, paint and primer cans being visible.
The disposal of waste at the unlicensed site began in 1972 and the 1995 report describes how Aer Rianta personnel would dump non-hazardous waste into a site and burn it. It says ash and unburned waste such as bottles, cans and metal were mixed with soil and pushed into a second site, which was piled six feet high with rubbish.
Aer Rianta indicated in court earlier this month that it is to plead guilty to polluting the Shannon estuary arising from the absence of sewage treatment facilities at the airport - an EPA report last year outlined that 100,000 cubic metres of raw sewage is pumped annually into the Shannon.
The TMS Consultancy report says: "This waste is usually disposed of by incineration but when the incinerator is overloaded or broken down it is disposed of on Dernish Island. During the survey, four loads of waste were disposed in this way."
The report also says this area was used for the disposal of biological waste from aircraft where "the waste is dumped in an open pit, diesel is poured in on top and the material is burned. When combustion is complete, the burned layer is covered with soil and the process continued".
In response to the report, An Taisce's Mr Ian Lumley yesterday called for an independent investigation into the waste disposal practices of Aer Rianta.
"It is obvious that Aer Rianta was operating a private unlicensed dump at Shannon Airport for years and had a fly-by-night attitude towards waste disposal.
"The semi-State saved a lot of money through not disposing of the waste at licensed landfills so now it must pay for a remedial programme for the lands at Dernish island."
