A plan on how to deal with the biggest illegal dump in Northern Ireland is expected to be unveiled soon.
The cost of dealing with the massive landfill at Mobuoy near Londonderry could range from £20m to £250m depending on how it is handled.
It has been suggested that more than one million tonnes of waste was illegally dumped on the site.
It includes domestic rubbish as well as demolition and construction waste.
A number of men are before the courts on charges linked to the case.
More than £1m has been spent monitoring the site to prevent leachate [waste liquid that drains or leaches from a landfill] reaching the River Faughan.
It runs alongside and supplies Derry with drinking water.
There are also issues with landfill gas.
Plans range from digging all the waste out to leaving some in place with additional protection.
£270,000 has been spent funding five pilot projects to investigate innovative ways of treating the waste and reducing its environmental impact.
They include a Queen's University proposal for speeding up the rate of decay of the waste.
A plan by Northern Ireland's Agri-Food and Biosciences Institute for treating the leachate has also been funded.
There is also an idea by an English company to grow biomass crops on the land.
It is hoped that if the technologies work, they can be used at other waste sites.
A spokesman for the Northern Ireland Environment Agency (NIEA) said: "The NIEA is currently identifying and evaluating suitable remediation treatments for managing the waste and its environmental impacts at the Mobuoy Waste site and this is due to report shortly."