CLHB Clean Harbors (MM)

Clean Harbors, Inc. (NASDAQ: CLHB), the leading provider of environmental and hazardous waste management services throughout North America, today announced that the Company has been added to the Russell 2000(R) and Russell 3000(R) indexes. The newly reconstituted Russell indexes will become effective at the close of the U.S. markets on June 24, 2005. "Clean Harbors has developed and executed a plan to extend its leadership in the environmental and hazardous waste management services industry throughout North America," said Alan S. McKim, chairman and chief executive officer. "Our inclusion in the Russell indexes reflects our ongoing success in achieving this objective and building shareholder value. Clean Harbors' addition to these indexes will increase our visibility and afford us an opportunity to further expand our shareholder base." Membership in Russell's indexes is determined primarily by market capitalization rankings. Russell indexes are widely used by managers for index funds and as benchmarks for both passive and active investment strategies. More than $360 billion is invested in index funds based on Russell's indexes and an additional $850 billion is benchmarked to them. Investment managers who oversee these funds purchase shares of member stocks according to that company's weighting in the particular index. Russell Investment Group, a global leader in multi-manager investment services, provides investment products and services in more than 35 countries. Russell manages more than $131 billion in assets and advises clients worldwide representing more than $2.3 trillion. Founded in 1936, Russell is a subsidiary of Northwestern Mutual and is headquartered in Tacoma, Wash., with additional offices in New York, Toronto, London, Paris, Singapore, Sydney, Auckland and Tokyo. For more information, go to www.russell.com. About Clean Harbors, Inc. Clean Harbors, Inc. is North America's leading provider of environmental and hazardous waste management services. With an unmatched infrastructure of 48 waste management facilities, including nine landfills, five incineration locations and seven wastewater treatment centers, the Company provides essential services to over 45,000 customers, including more than 175 Fortune 500 companies, thousands of smaller private entities and numerous federal, state and local governmental agencies. Headquartered in Braintree, Massachusetts, Clean Harbors has more than 100 locations strategically positioned throughout North America in 36 U.S. states, six Canadian provinces, Mexico and Puerto Rico. For more information, visit www.cleanharbors.com.