REVENUES

Revenue Recognition

Revenues are recognized when control of the promised goods or services is transferred to the Company’s customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services.

Nature of Goods and Services

The Company generates services and product revenues through its Environmental Services and Safety-Kleen operating segments. The majority of the Company’s contracts are for services, which are recognized based on time and materials incurred at contractually agreed-upon rates. Product revenues are recognized when the products are delivered and control transfers to the customer. The Company’s payment terms vary by the type and location of its customers and the products or services offered. The term between invoicing and when payment is due is not significant. The Company excludes sales taxes that it collects from customers from its revenues.

Disaggregation of Revenue

The following table presents the Company’s revenues disaggregated by revenue source (in thousands):



	For the Three Months Ended June 30, 2018
	Environmental Services		Safety-Kleen		Corporate		Total
Primary Geographical Markets
United States	$	408,127	$	306,059	$	363	$	714,549
Canada	111,789		22,656		146		134,591
	519,916		328,715		509		849,140
Sources of Revenue (1)
Technical Services	257,006		—		—		$	257,006
Field and Emergency Response Services	76,092		—		—		76,092
Industrial Services	161,046		—		—		161,046
Oil, Gas and Lodging Services and Other	25,772		—		509		26,281
Safety-Kleen Environmental Services	—		200,034		—		200,034
Kleen Performance Products	—		128,681		—		128,681
Total third party revenues	$	519,916	$	328,715	$	509	$	849,140



	For the Three Months Ended June 30, 2017
	Environmental Services		Safety-Kleen		Corporate		Total
Primary Geographical Markets
United States	$	343,323	$	280,617	$	155	$	624,095
Canada	106,308		22,339		46		128,693
	449,631		302,956		201		752,788
Sources of Revenue (1)
Technical Services	254,487		—		—		254,487
Field and Emergency Response Services	70,707		—		—		70,707
Industrial Services	99,733		—		—		99,733
Oil, Gas and Lodging Services and Other	24,704		—		201		24,905
Safety-Kleen Environmental Services	—		192,817		—		192,817
Kleen Performance Products	—		110,139		—		110,139
Total third party revenues	$	449,631	$	302,956	$	201	$	752,788



	For the Six Months Ended June 30, 2018
	Environmental Services		Safety-Kleen		Corporate		Total
Primary Geographical Markets
United States	$	752,099	$	593,701	$	508	$	1,346,308
Canada	207,505		44,932		173		252,610
	959,604		638,633		681		1,598,918
Sources of Revenue (1)
Technical Services	493,312		—		—		493,312
Field and Emergency Response Services	146,027		—		—		146,027
Industrial Services	264,809		—		—		264,809
Oil, Gas and Lodging Services and Other	55,456		—		681		56,137
Safety-Kleen Environmental Services	—		394,195		—		394,195
Kleen Performance Products	—		244,438		—		244,438
Total third party revenues	$	959,604	$	638,633	$	681	$	1,598,918



	For the Six Months Ended June 30, 2017
	Environmental Services		Safety-Kleen		Corporate		Total
Primary Geographical Markets
United States	$	657,106	$	552,688	$	288	$	1,210,082
Canada	188,432		43,169		46		231,647
	845,538		595,857		334		1,441,729
Sources of Revenue (1)
Technical Services	484,705		—		—		484,705
Field and Emergency Response Services	131,726		—		—		131,726
Industrial Services	174,801		—		—		174,801
Oil, Gas and Lodging Services and Other	54,306		—		334		54,640
Safety-Kleen Environmental Services	—		384,544		—		384,544
Kleen Performance Products	—		211,313		—		211,313
Total third party revenues	$	845,538	$	595,857	$	334	$	1,441,729

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1.	All revenue except Kleen Performance Products and product sales within Safety-Kleen Environmental Services, including allied products and direct blended oil sales, are recognized over time. Kleen Performance Products and Safety-Kleen Environmental Services product revenues are recognized at a point in time.

Technical Services. Technical Services revenues are generated from fees charged for waste material management and disposal services including onsite environmental management services, collection and transportation, packaging, recycling, treatment and disposal of waste. Revenue is primarily generated by short-term projects, most of which are governed by master service agreements that are long-term in nature. These master service agreements are typically entered into with the Company's larger customers and outline the pricing and legal frameworks for such arrangements. Services are provided based on purchase orders or agreements with the customer and include prices based upon units of volume of waste, and transportation and other fees. Collection and transportation revenues are recognized over time, as the customer receives and consumes the benefits of the service as they are being performed and the Company has a right to payment for performance completed to date. The Company uses the input method to recognize revenue over time, based on time and materials incurred. Revenues for treatment and disposal of waste are recognized upon completion of treatment, final disposition in a landfill or incineration, or when the waste is shipped to a third party for processing and disposal. The Company periodically enters into bundled arrangements for the collection and transportation and disposal of waste. For such arrangements, transportation and disposal are considered distinct performance obligations and the Company allocates revenue to each based on their relative standalone selling price (i.e. the estimated price that a customer would pay for the services on a standalone basis). Revenues from waste that is not yet completely processed and disposed and the related costs are deferred. The revenue is recognized and the deferred costs are expensed when the related services are completed. The period between collection and transportation and the final processing and disposal ranges depending on location of the customer, but generally is measured in days.

Field and Emergency Response Services. Field Services revenues are generated from cleanup services at customer sites, including municipalities and utilities, or other locations on a scheduled or emergency response basis. Services include confined space entry for tank cleaning, site decontamination, large remediation projects, demolition, spill cleanup on land and water, railcar cleaning, product recovery and transfer and vacuum services. Additional services include filtration and water treatment services. Response services for environmental emergencies include any scale from man-made disasters such as oil spills, to natural disasters such as hurricanes. These services are provided based on purchase orders or agreements with customers and include prices generally based upon daily, hourly or job rates for equipment, materials and personnel. The Company recognizes revenue for these services over time, as the customer receives and consumes the benefits of the service as they are being performed and the Company has a right to payment for performance completed to date. The Company uses the input method to recognize revenue over time, based on time and materials incurred. The duration of such services can be over a number of hours, several days or even months for larger scale projects.

Industrial Services. Industrial Services revenues are generated from industrial and specialty services provided to refineries, mines, upgraders, chemical plants, pulp and paper mills, manufacturing facilities, power generation facilities and other industrial customers throughout North America. Services include in-plant cleaning and maintenance services, plant outage and turnaround services, decoking and pigging, chemical cleaning, high and ultra-high pressure water cleaning, pipeline inspection and coating services, large tank and surface impoundment cleaning, oilfield transport, daylighting, production services and directional boring services (previously included in Oil, Gas and Lodging service offerings) supporting drilling, completions and production programs. These services are provided based on purchase orders or agreements with the customer and include prices based upon daily, hourly or job rates for equipment, materials and personnel. The Company recognizes revenue for these services over time, as the customer receives and consumes the benefits of the service as they are being performed and the Company has a right to payment for performance completed to date. The Company uses the input method to recognize revenue over time, based on time and materials incurred.

Safety-Kleen Environmental Services. Safety-Kleen Environmental Services revenues are generated from providing parts washer services, containerized waste handling and disposal services, oil collection services, direct sales of blended oil products, and other complementary services and product sales. Containerized waste services consist of profiling, collecting, transporting and recycling or disposing of a wide variety of waste. Other complementary products and services include vacuum services, sale of allied supply products and other environmental services. Revenues from parts washer services include fees charged to customers for their use of parts washer equipment, to clean and maintain parts washer equipment and to remove and replace used cleaning fluids. Parts washer services are considered a single performance obligation due to the highly integrated and interdependent nature of the arrangement. Revenue from parts washer services is recognized over the service interval as the customer receives the benefit of the service. Collection and transportation revenues are recognized over time, as the customer receives and consumes the benefits of the service as they are being performed and the Company has a right to payment for performance completed to date. The Company uses the input method to recognize revenue over time, based on time and materials incurred. Product revenue is recognized upon the transfer of control. Control transfers when the products are delivered to the customer.

Kleen Performance Products. Kleen Performance Products revenues are generated from sales of high quality base and blended lubricating oils to third-party distributors, government agencies, fleets, railroads and industrial customers. The business also sells recycled fuel oil to asphalt plants, industrial plants, blenders, pulp and paper companies, vacuum gas oil producers and marine diesel oil producers. Revenue for oil products is recognized at a point in time, upon the transfer of control. Control transfers when the products are delivered to the customer.

Oil, Gas and Lodging Services and Other. Oil, Gas and Lodging Services and Other is primarily comprised of revenues generated from providing Oil and Gas Field Services that support upstream activities such as exploration and drilling for oil and gas companies and Lodging Services to customers in Western Canada. The Company recognizes Oil and Gas Field Services revenue over time, as the customer receives and consumes the benefits of the service as they are being performed and the Company has a right to payment for performance completed to date. The Company uses the input method to recognize revenue over time, based on time and materials incurred. Revenue for lodging accommodation services is recognized over time based on passage of time. Revenue for manufacturing services is recognized over time using a cost-to-cost measure of progress or completed units to depict the transfer of assets to the customer.

Contract Balances



	June 30, 2018		December 31, 2017		June 30, 2017		December 31, 2016
Receivables	$	590,580	$	528,924	$	512,375	$	496,226
Contract Assets (Unbilled Receivables)	62,762		35,922		46,576		36,190
Contract Liabilities (Deferred Revenue)	68,705		67,822		72,089		64,397

The timing of revenue recognition, billings and cash collections results in billed accounts receivable, unbilled receivables (contract assets), and customer advances and deposits or deferred revenue (contract liabilities) on the Consolidated Balance Sheet. Generally, billing occurs subsequent to revenue recognition, as a right to payment is not just subject to passage of time, resulting in contract assets. Contract assets are generally classified as current. The Company sometimes receives advances or deposits from its customers before revenue is recognized, resulting in contract liabilities. These assets and liabilities are reported on the Consolidated Balance Sheet on a contract-by-contract basis at the end of each reporting period. As part of the acquisition of the Veolia Business on February 23, 2018, the Company acquired receivables and contract assets of $20.5 million and $17.6 million, respectively. Changes in the contract asset and liability balances during the six-month period ended June 30, 2018 and June 30, 2017 were not materially impacted by any other factors. The contract liability balances at the beginning of each period presented were fully recognized in the subsequent three-month period.

Remaining Performance Obligations

Remaining performance obligations represent the transaction price of orders for which work has not been performed. As of June 30, 2018, all remaining performance obligations were for contracts with an original expected length of one year or less.

Variable Consideration

The nature of the Company's contracts gives rise to certain types of variable consideration, including in limited cases volume and payment discounts. The Company estimates the amount of variable consideration to include in the estimated transaction price based on historical experience, anticipated performance and its best judgment at the time and to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. Variable consideration was not material in any of the periods presented.

Contract Costs

Contract costs include direct and incremental costs to obtain or fulfill a contract. The Company’s contract costs that are subject to capitalization are comprised of costs associated with parts washer services and costs associated with the treatment and disposal of waste. Parts washer costs include costs of solvent, commissions paid relating to revenue generated from parts washer services, and transportation costs associated with transferring the product picked up from the services as it is returned to the Company’s facilities or a third party site. Costs related to the treatment of waste include costs for waste receiving, drum movement and storage, waste consolidation and transportation between facilities. Deferred costs associated with parts washer services are amortized ratably over the average service interval, which ranges between seven and 14 weeks. Deferred costs related to treatment and disposal of waste are recognized when the corresponding waste is disposed of and are included in Deferred Costs within total current assets in the Company’s consolidated balance sheets. The deferred contract cost balances at the beginning of each period presented were fully recognized in cost of revenue in the subsequent three-month period.