We evaluate, oversee and manage the financial performance of our Solid Waste business subsidiaries through our 17 Areas. The 17 Areas constitute our operating segments and we have evaluated the aggregation criteria and concluded that, based on the similarities between our Areas, including the fact that our Solid Waste business is homogenous across geographies with the same services offered across the Areas, aggregation of our Areas is appropriate for purposes of presenting our reportable segments. Accordingly, we have aggregated our 17 Areas into three tiers that we believe have similar economic characteristics and future prospects based in large part on a review of the Areas’ income from operations margins. The economic variations experienced by our Areas are attributable to a variety of factors, including regulatory environment of the Area; economic environment of the Area, including level of commercial and industrial activity; population density; service offering mix and disposal logistics, with no one factor being singularly determinative of an Area’s current or future economic performance.

Tier 1 is comprised of our operations across the Southern U.S., with the exception of Southern California and the Florida peninsula, and also includes the New England states, the tri-state area of Michigan, Indiana and Ohio, and Western Canada. Tier 2 includes Southern California, Eastern Canada, Wisconsin and Minnesota. Tier 3 encompasses all the remaining operations including the Pacific Northwest, Northern California, the Mid-Atlantic region of the U.S., the Florida peninsula, Illinois and Missouri.

The operating segments not evaluated and overseen through the 17 Areas are presented herein as “Other” as these operating segments do not meet the criteria to be aggregated with other operating segments and do not meet the quantitative criteria to be separately reported.

Summarized financial information concerning our reportable segments is shown in the following table (in millions):

(a)

“Other” includes (i) our Strategic Business Solutions (“WMSBS”) organization; (ii) those elements of our landfill gas-to-energy operations and third-party subcontract and administration revenues managed by our Energy and Environmental Services (“EES”) and WM Renewable Energy organizations that are not included in the operations of our reportable segments; (iii) our recycling brokerage services and (iv) certain other expanded service offerings and solutions. In addition, our “Other” segment reflects the results of non-operating entities that provide financial assurance and self-insurance support for our Solid Waste business, net of intercompany activity.

The mix of operating revenues from our major lines of business are as follows (in millions):


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2019		2018		2019		2018
Commercial	$	1,069	$	1,007	$	3,147	$	2,948
Residential		661		639		1,956		1,885
Industrial		766		723		2,190		2,068
Other		130		117		361		333
Total collection		2,626		2,486		7,654		7,234
Landfill		993		926		2,880		2,646
Transfer		471		445		1,357		1,257
Recycling		245		337		800		954
Other (a)		469		430		1,345		1,296
Intercompany (b)		(837)		(802)		(2,427)		(2,315)
Total	$	3,967	$	3,822	$	11,609	$	11,072

(a)

The “Other” line of business includes (i) our WMSBS organization; (ii) our landfill gas-to-energy operations; (iii) certain services within our EES organization, including our construction and remediation services and our services associated with the disposal of fly ash and (iv) certain other expanded service offerings and solutions. In addition, our “Other” line of business reflects the results of non-operating entities that provide financial assurance and self-insurance support for our Solid Waste business, net of intercompany activity.

(b)	Intercompany revenues between lines of business are eliminated in the Condensed Consolidated Financial Statements included within this report.

Fluctuations in our operating results may be caused by many factors, including period-to-period changes in the relative contribution of revenue by each line of business, changes in commodity prices and general economic conditions. In addition, our revenues and income from operations typically reflect seasonal patterns. Our operating revenues tend to be somewhat higher in summer months, primarily due to higher construction and demolition waste volumes. The volumes of industrial and residential waste in certain regions where we operate also tend to increase during the summer months. Our second and third quarter revenues and results of operations typically reflect these seasonal trends.

Service disruptions caused by severe storms, extended periods of inclement weather or climate extremes resulting from climate change can significantly affect the operating results of the Areas impacted. On the other hand, certain destructive weather and climate conditions, such as wildfires in the Western U.S. and hurricanes that most often impact our operations in the Southern and Eastern U.S. during the second half of the year, can increase our revenues in the Areas affected. While weather-related and other event driven special projects can boost revenues through additional work for a limited time, such revenue can generate earnings at comparatively lower margins as a result of significant start-up costs and other factors.