The Environmental Protection Agency yesterday refused an application for construction of a major landfill facility on a site where 250,000 tonnes of illegally dumped rubbish were discovered five years ago.
The site is at Whitestown, near Baltinglass, Co Wicklow.
The applicant, Brownfield Restoration Ireland Ltd, was however granted a restricted waste licence to "remediate" the illegal dump.
In its decision, the EPA said it may appoint an independent technical expert to oversee the remediation programme and report to the agency on a regular basis.
The EPA said it had taken regard of the need for a high standard of environmental protection and the need for precaution in relation to the potentially harmful effects of emissions from the waste.
Minister for the Environment Dick Roche welcomed the decision, adding that he was "particularly happy" to note that the owners are required to carry out a full remediation of the site.
Wicklow County Council, which has spent hundreds of thousands of euro investigating the site since large-scale dumping was discovered in 2001, also welcomed the EPA decision.
Council cathaoirleach Cllr Andrew Doyle and county manager Eddie Sheehy called on the waste companies responsible for the illegal dumping and the landowners to immediately begin cleaning up the site.
Under Section 55, the council has already served notice on the landowners, the former landowner, the waste companies responsible for the illegal dumping and named directors of these companies. High Court proceedings to ensure compliance with these notices have been initiated by the council.