Dorchester's recycling centre has been closed after suspected unexploded ordnance was found at a scrapyard next door.
Wessex Water treatment works in St George's Road was also evacuated following the discovery at 12:00 BST on Thursday.
Dorset Council said the object was thought to be a World War Two-era tank round, although it had not been confirmed.
The authority said it expected the tip to reopen at 09:00 on Friday but would issue an update if that was not the case.
The council said its Louds Mill household recycling centre and and Wessex Water's Louds Mill were evacuated "as a safety precaution while the police investigate".
Dorset Police said it had been notified that "suspected ordnance had been found in the area of St George's Road in Dorchester".
It said the Explosive Ordnance Disposal team had been "made aware and a team will attend to assess the item".