The most expensive clean-up is taking place at the ex-Irish Steel/Irish Ispat plant at Haulbowline Island in Cork Harbour.
Last year alone, €52.3m was spent making the site safe.
This included soil investigation surveys, disposing of waste material and foreshore ecological surveys.
Last year, Agriculture Minister Simon Coveney decided that he would personally oversee the clean-up of the site. Work is continuing there to put a retaining wall around it and cap it with concrete.
An application for a waste licence permit to facilitate a further clean-up of part of the site will be submitted later this year, but as yet there is no estimate for what this will cost, although it is expected to be substantial.
Currently, there are 31 sites identified where it is necessary to remove or nullify the contaminants from soil or ground water.
The Comptroller and Auditor General’s report also highlighted that additional clean-up work at licensed landfills cost a significant amount of money last year.
Nearly €9m was spent on remediation works at a landfill at Silliot Hill, Kildare; a further €7m at a site at Kilbarry, Waterford; and nearly €6m at Bakerstown, Co Meath.
Meanwhile, it is expected that €3m will be spent next year on a clean-up at the Avoca mine in Co Wicklow.
In 2008 it was estimated that the cost of a clean-up programme there would be in the region of €58m.
However, in July 2010, the Government decided to proceed with a more limited programme to address prioritised hazards.
This work is expected to commence next year.
Over a number of years, €11.6m of work has also been carried out at Silvermines, Co Tipperary.
But with the current economic situation funding has been reduced significantly for this clean-up project.
Plans approved by Bord Pleanála for a €6m Mine Waste Management Facility on part of the Silvermines site have been put on hold until the Government has the necessary funding.