Skegness Household Waste Recycling Centre has been temporarily closed after an ammunition shell was discovered.
A Lincolnshire County Council statement said Lincolnshire Police are at the scene and investigating following the finding of the 13mm shell.
People are advised to avoid the site and more information to follow.
A Lincolnshire Police spokesman said there had been no evacuation, however, staff had been moved to a safe distance as a precaution and a small cordon had been set up.
The Explosive Ordinance Disposal team have been dispatched from RAF Cranwell and will arrive on site in about an hour-and-a-half.