Farmers in the Aghancon Valley, Co Offaly, have been advised by the Office of Environmental Enforcement not to dredge a local river because of fears of contamination from potentially lethal wood preservatives from an adjoining sawmills.
A number of landowners had sought permission to dredge the river to assist land drainage.
However, the office has said dredging should not be carried out "until further notice" as its parent body, the Environmental Protection Agency, is "seeking information concerning the removal of contaminated sediments".
In one letter seen by The Irish Times the office told the landowners that the decision to prohibit dredging was based on "the presence of heavy metals in the sediments of the Fuarawn River".
In a letter to another landowner, it said: "Dredging should not be carried out based on information contained in the report received from T&J Standish entitled 'Qualified risk assessment of the Fuarawn River with particular emphasis on the potential impact of chromium'."
Chromium is a potentially lethal poison found in wood preservative.
The Environmental Protection Agency has in the past prosecuted T&J Standish Sawmills for pollution of the Fuarawn with chromium.
The company's environmental consultants have been advising the EPA on the extent of pollution and possible remedial measures.
A new prosecution for breaches of the company's pollution control licence is being taken, the agency confirmed yesterday.
Standish Sawmills, one of the Republic's largest suppliers of pencil stakes and fencing products, was refused retention planning permission for its factory by Bord Pleanála in July 2003.
The company has remained on site and lodged a new planning application, which is due to be decided by Bord Pleanála next July.
Aghancon Concerned Residents' Association has appealed Offaly County Council's decision to twice grant retention permission.
The Office of Environmental Enforcement said it was proceeding "with a view to resolving the issue prior to the end of August".
Tom Standish told The Irish Times yesterday the company was "doing everything right".
Pressed on the company's environmental record which brought it into conflict with the EPA, Mr Standish said it had a licence from the agency "which they have to follow up".
He declined to comment further.
