"has been dug" is correct and usable in written English.
You can use it when talking about something that has already been completed. For example: The hole for the new garden pond has been dug.
But the tree has been dug up.
A giant pit has been dug where 50,000 people once worked.
It sounds timeless – as if it has been dug up from the eighth century.
Dirt has been dug on anyone supposed to be the "enemy" of free speech.
A groundbreaking ceremony was held five years ago, but no foundation has been dug.
Coal has been dug out of the ground since pre-Roman times.
Camden High Street in London has been dug up 144 times in a year; Glasgow's Great Western Road, 223 times.
Nearly 60 tonnes of soil has been dug from the valley below and hauled up the 250m hill.
It will be months, maybe years, before the Evert family knows for sure what has been dug up.
Since then, a ditch has been dug around the city to prevent rebel pickup trucks from getting quickly in and out of town.
Excavation began late in the 19th century, and most of the accumulation has been dug away, down to the level at which Julius Caesar knew it.
