SIGNIFICANT ACCOUNTING POLICIES (Policies)

6 Months Ended

Jun. 30, 2011

SIGNIFICANT ACCOUNTING POLICIES

Property, Plant and Equipment (excluding landfill assets)

Property, plant and equipment are stated at cost and include amounts capitalized under capital lease obligations. Expenditures for major renewals and improvements which extend the life of the asset are capitalized. Items of an ordinary repair or maintenance nature are charged directly to operating expense as incurred. During the construction and development period of an asset, the costs incurred, including applicable interest costs, are classified as construction-in-progress. Interest in the amount of $0.4 million and $0.2 million was capitalized to fixed assets during the six months ended June 30, 2011, and 2010, respectively. Depreciation and amortization expense was $42.0 million and $35.9 million for the six months ended June 30, 2011, and 2010, respectively.

The Company depreciates and amortizes the cost of these assets, using the straight-line method as follows:

Asset Classification	Estimated Useful Life
Buildings and building improvements
Buildings	30—40 years
Land, leasehold and building improvements	5—40 years
Camp equipment	12—15 years
Vehicles	3—12 years
Equipment
Capitalized software and computer equipment	3 years
Solar equipment	20 years
Containers and railcars	15—20 years
All other equipment	3—10 years
Furniture and fixtures	5—8 years

Land, leasehold and building improvements have a weighted average life of 9.3 years.

Camp equipment consists of industrial lodging facilities that are utilized in the Company’s Industrial Services segment to provide lodging services to companies in the refinery and petrochemical industries.

Solar equipment consists of a solar array that is used to provide electric power for a continuously operating groundwater decontamination pump and treatment system at a closed and capped landfill located in New Jersey. The solar array was installed and became operable during the second quarter of 2011.

The Company recognizes an impairment in the carrying value of long-lived assets when the expected future undiscounted cash flows derived from the assets are less than their carrying value. For the three and six months ended June 30, 2011, and 2010, the Company has not recorded impairment charges related to long-lived assets.