Peak Energy Services Ltd. Announces Completion of Acquisition by Clean Harbors, Inc.

CALGARY, ALBERTA--(Marketwire - June 10, 2011) - Peak Energy Services Ltd. (TSX:PES) ("Peak") is pleased to announce the successful completion of the previously announced plan of arrangement (the "Arrangement") under the Business Corporations Act (Alberta) pursuant to which Clean Harbors, Inc. ("Clean Harbors") through its wholly-owned subsidiary Clean Harbors Industrial Services Canada, Inc. has acquired all of the issued and outstanding common shares of Peak ("Peak Shares") held by public shareholders for cash consideration of $0.95 per share. Holders of Peak Shares, or their intermediaries, that have submitted duly completed letter(s) of transmittal as outlined in the Information Circular dated April 26, 2011 should expect to receive their cash consideration in 3 to 5 business days, unless they have provided instructions to the contrary.

About Peak Energy Services Ltd.

Peak Energy Services Ltd. is a diversified energy services organization operating in western Canada and the United States of America. Through its various operating divisions, Peak provides drilling and production services to its customers both in the conventional and unconventional oil and natural gas industry as well as the oil sands regions of western Canada. Peak also provides water technology solutions to a variety of customers throughout North America.

About Clean Harbors, Inc.

Clean Harbors, Inc. is the leading provider of environmental, energy and industrial services throughout North America. Clean Harbors serves over 50,000 customers, including a majority of the Fortune 500 companies, thousands of smaller private entities and numerous federal, state, provincial and local governmental agencies. Headquartered in Norwell, Massachusetts, United States of America, Clean Harbors has more than 175 locations, including over 50 waste management facilities, throughout North America in 36 U.S. states, seven Canadian provinces, Mexico and Puerto Rico. Clean Harbors also operates international locations in Bulgaria, China, Singapore, Sweden, Thailand and the United Kingdom. For more information, visit www.cleanharbors.com.