Waste Management is North America's largest environmental services company, collecting trash and recycling for tens of millions of homes and businesses. The moat is physical: a network of landfills that are nearly impossible to permit anew, transfer stations and collection routes whose density drives cost advantage. Pricing typically outruns inflation because disposal is non-discretionary. The company converts landfill gas into renewable energy and automates recycling plants. Steady volumes plus annual price increases produce famously durable cash flow.