
1.	Basis of Presentation

The financial statements presented in this report represent the consolidation of Waste Management, Inc., a Delaware corporation; Waste Management’s wholly-owned and majority-owned subsidiaries; and certain variable interest entities for which Waste Management or its subsidiaries are the primary beneficiary. Waste Management is a holding company and all operations are conducted by its subsidiaries. When the terms “the Company,” “we,” “us” or “our” are used in this document, those terms refer to Waste Management, Inc., its consolidated subsidiaries and consolidated variable interest entities. When we use the term “WM,” we are referring only to Waste Management, Inc., the parent holding company.

We manage and evaluate our principal operations through five Groups. Our four geographic operating Groups, which are comprised of our Eastern, Midwest, Southern and Western Groups, provide collection, transfer, disposal (in both solid waste and hazardous waste landfills) and recycling services. Our fifth Group is the Wheelabrator Group, which provides waste-to-energy services and manages waste-to-energy facilities and independent power production plants. We also provide additional services that are not managed through our five Groups, including the operations of Oakleaf Global Holdings (“Oakleaf”) acquired on July 28, 2011, which are presented in this report as “Other.” Additional information related to our segments and to our acquisition of Oakleaf can be found in Note 9 and in Note 10, respectively.

The Condensed Consolidated Financial Statements as of and for the three and nine months ended September 30, 2011 and 2010 are unaudited. In the opinion of management, these financial statements include all adjustments, which, unless otherwise disclosed, are of a normal recurring nature, necessary for a fair presentation of the financial position, results of operations, and cash flows for the periods presented. The results for interim periods are not necessarily indicative of results for the entire year. The financial statements presented herein should be read in connection with the financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2010.

In preparing our financial statements, we make numerous estimates and assumptions that affect the accounting for and recognition and disclosure of assets, liabilities, equity, revenues and expenses. We must make these estimates and assumptions because certain information that we use is dependent on future events, cannot be calculated with a high degree of precision from data available or simply cannot be readily calculated based on generally accepted methods. In some cases, these estimates are particularly difficult to determine and we must exercise significant judgment. In preparing our financial statements, the most difficult, subjective and complex estimates and the assumptions that present the greatest amount of uncertainty relate to our accounting for landfills, environmental remediation liabilities, asset impairments, deferred income taxes and reserves associated with our insured and self-insured claims. Actual results could differ materially from the estimates and assumptions that we use in the preparation of our financial statements.

Adoption of New Accounting Pronouncements

Multiple-Deliverable Revenue Arrangements — In October 2009, the Financial Accounting Standards Board (“FASB”) amended authoritative guidance associated with multiple-deliverable revenue arrangements. This amended guidance addresses the determination of when individual deliverables within an arrangement are required to be treated as separate units of accounting and modifies the manner in which consideration is allocated across the separately identifiable deliverables. The amendments to authoritative guidance associated with multiple-deliverable revenue arrangements became effective for the Company on January 1, 2011. The new accounting standard has been applied prospectively to arrangements entered into or materially modified after the date of adoption. The adoption of this guidance has not had a material impact on our consolidated financial statements. However, our adoption of this guidance may significantly impact our accounting and reporting for future revenue arrangements to the extent they are material.