Clean Harbors, Inc. (NASDAQ: CLHB)

One of North America's leading hazardous waste management companies, Clean Harbors does more than its name suggests. Clean Harbors' technical services, which account for most of the company's sales, encompass the collection, transportation, treatment, and disposal of hazardous waste, including chemical and laboratory waste but not nuclear waste. The company's site services include industrial maintenance, facility decontamination, environmental remediation, and spill cleanup. Among Clean Harbors' 45,000-plus customers are commercial and industrial companies, educational and research organizations, and health care providers. Alan McKim, the company's chairman, president, and CEO, controls 30% of Clean Harbors.