In a statement, the department said it had acted on best expert advice when deciding how to deal with the waste at the site.
The department said it had hired Hammond Lane Metal Company Ltd to carry out a “surface clearance” of the site and its waste tip.
The waste and debris on the surface had been caused by the demolition and decontamination of the Irish Steel buildings.
Inert waste beneath the surface — such as in the lagoons — was to remain untouched. It is understood expert advice suggested this inert waste would prove an immediate threat only if disturbed.
The surface clearance was the “final step” in getting the site to a position where a risk analysis, could be carried out and decisions taken on its future remediation.
However, the site surface clearance was not undertaken by Hammond Lane, but by subcontractors Louis J O’Regan Ltd.
The department made clear it had never entered a contract with the latter.
“Louis J O’Regan Ltd is a sub-contractor of a sub-contractor of Hammond Lane Metal Company Ltd,” said the department.
Louis J O’Regan Ltd uncovered a “sub-surface sludge pit” of hazardous waste and began “a series of unauthorised works”, the department said — in other words, removing some of the waste from the lagoon.
The department, with the Environmental Protection Agency and Cork County Council, wanted the lagoon capped with inert slag material — to ensure the waste did not pose a threat.
“Despite repeated instructions to stop these unauthorised works, including by letter from the Chief State Solicitor’s Office on May 23, 2008, the sub-contractor continued to excavate significant volumes of buried hazardous material,” said the statement.
“Following legal advices, the contract with Hammond Lane was terminated with immediate effect on May 30, 2008, with instructions to vacate the site by 17.00 Tuesday, June 3, 2008.
“The sub-contractors refused and continued to operate without authorisation and in a piecemeal fashion, causing a threat to the environment by its actions. They finally left the site following discussions with Hammond Lane Metal Company Ltd,” the department added.
With the EPA and the council, the department said it organised “an immediate assessment” of the situation by environment consultants.
“All such necessary works will be undertaken to secure the site and ensure that no danger is presented to the local environment or residents arising from unauthorised actions by Louis J O’Regan Ltd and pending the Government’s decision on the future use of the site.”