You would expect the largest waste companies to embrace sustainability. And they do. It’s a way to shine up a reputation and attract and keep customers.

But you might not expect the same effort from medium-sized and smaller waste companies that must focus constantly on controlling rising costs and battling tough competitors.

In fact, medium-sized and smaller waste companies are indeed implementing comprehensive green operations.

“We’re not just picking up trash anymore,” says Ben Harvey, executive vice president of Westborough, Mass.-based E. L. Harvey & Sons Inc. “Our customers want to know what can we do to help them divert materials from landfills so they will look good to their customers.”

As customers demand more recycling, composting and other green services, the waste industry is becoming less and less a straightforward trash-collecting industry and more and more a service industry that helps people make their homes and businesses sustainable. Waste companies that want that kind of business are going to have to show their own sustainable....