Fears that dumped cement kiln dust would be a risk to health cannot be proved experts say. Castle Cement wants to tip dust waste from its new UK£56m kiln on farmland at the firm’s Padeswood factory near Buckley.
It will save the company hauling up to 10,000t of dust to special dumps outside North Wales.
But Flintshire councillors threw out the firm’s tip application, against officers’ advice, saying it posed a risk to health and water courses.
The company appealed to the Assembly, with an inquiry scheduled for August 30.
Now the authority’s consultants, brought in because councillors voted against officer advice, say it is not possible for them to defend the council’s case at the hearing.
Instead, Flintshire planners will argue the tip is premature because the North Wales Regional Waste Plan is still awaited and the tip will be an eyesore.