Labourer David Willis, aged 29, failed to return home to St Marks Road, Tipton, after work on September 15, 2018.
His employers, Timmins Waste, of Mander Street, Wolverhampton, denied the corporate manslaughter of Mr Willis.
Company manager Brian Timmins, of Fair Lawn, Albrighton, denied offences of manslaughter, gross negligence and perverting the course of justice.
The allegations heard at Wolverhampton Crown Court on Tuesday were brought under the Health and Safety at Work Act.
A trial has been set for next year. Timmins was granted bail until then.
After Mr Willis vanished police launched a two-month search of the Poplars landfill tip in Cannock but found nothing.
Paying tribute following his disappearance Mr Willis's family said: “David’s a dear, loving son and brother to Emily and Sean and a devoted and loving uncle to his nephew, Lewis, who he worshipped.
“David was a fun-loving person who would get on with all people he would also go out his way to help people if he could. David had many friends and family members who will sadly miss his fun charming personality.”