You’re mixing dry material from the sides with the sludge in the base to make a semi-manageable mix you can remove the the backhoe front bucket?
Did that once with a football field sized detention basin 6m deep ... the mixed material had to be optimised for specified engineering compaction ... took me a couple of hours a day for two months keeping the contractor from taking regrettable shortcuts.
If the weather is with you you might be better off using the rear swing arm bucket to throw the sludge thinly on the banks behind to dry out to a manageable consistency?
