The company has expanded through organic growth and acquisitions to approximately 400 service locations in North America including over 50 hazardous waste management facilities in 38 U.S. states, seven Canadian provinces, Mexico, and Puerto Rico.

[4] Clean Harbors, Inc. was founded in 1980 in Brockton, Massachusetts,[5][6] a Boston suburb, by Alan S. McKim, who continues as the company's CEO and chairman.

Clean Harbors, still solely an environmental services company, purchased Occupational Safety and Health Administration (OSHA) Resource Conservation and Recovery Act (RCRA) certified hazardous waste incinerators in Arkansas, Nebraska, Ontario, Quebec, Texas and Utah, which it continues to own and operate to this day.

Its first project came in 1984 when it removed 130,000 gallons of fuel oil from the tanker Eldia, which became the largest ship to have been beached off Cape Cod.

Significant acquisitions include:[8] On May 20, 2003, Clean Harbors revised previously announced treatment of the non-cash cumulative effect of adopting SFAS No.

Clean Harbors, Inc. announced to restate financial statements for the years 2003 and 2002, and financial information for the years 2001, 2000, and 1999, to correct errors relating to the methodology it had established for estimating self-insured workers' compensation and motor vehicle liability claims.