Check their cleanliness
See if the rubbish removal trucks are rusted and filthy. See if they clean the workplace when the junk has gone from the particular site. This is a good practice....
Workers Compensation Insurance
Hire a company that has liability insurance and is up to date with its WCB premiums.
See how they recycle your household junk
See what recycling practices the company follows. There are some companies that coordinate with recycling facilities, donation centers along with scrappers allowing salvageable items to be saved from going to the landfill. For example, TrashKing recycles up to 80% of the materials that it collects.
See their past jobs