A public inquiry is due to examine whether a company over-filled a Flintshire landfill site.
The inquiry at Ewloe will consider an appeal by Morgan plc against three enforcement notices served by Flintshire Council.
The notices concerned the alleged over-filling of the Sea View Farm site, near Hawarden, and a disputed access road.
A council spokesman said the inquiry would be conducted by a Welsh Assembly Government planning inspector.
The inquiry at Ewloe Social Club had been due to take place in July, but was re-arranged because insufficient time had been allocated.
The first stage of the inquiry, expected to last two days, will examine the legal validity of the council's enforcement notices.
If the planning inspector rules the notices were valid, there will be a second inquiry at a later date.
If the notices are deemed invalid, they will be dropped and no further inquiry will be needed.