Our operations are managed in two reportable segments, Environmental Services and Field & Industrial Services, reflecting our internal reporting structure and nature of services offered. See Note 17 for additional information on our operating segments.

The following table presents our revenue disaggregated by our reportable segments and service lines:

(1)

We categorize our treatment and disposal revenue as either “Base Business” or “Event Business” based on the underlying nature of the revenue source. We define Event Business as non-recurring projects that are expected to equal or exceed 1,000 tons, with Base Business defined as all other business not meeting the definition of Event Business. For the three months ended June 30, 2020 and 2019, 27% and 23%, respectively, of our treatment and disposal revenue was derived from Event Business projects. Base Business revenue accounted for 73% and 77% of our treatment and disposal revenue for the three months ended June 30, 2020 and 2019, respectively. For the six months ended June 30, 2020 and 2019, 26% and 19%, respectively, of our treatment and disposal revenue was derived from Event Business projects. Base Business revenue accounted for 74% and 81% of our treatment and disposal revenue for the six months ended June 30, 2020 and 2019, respectively.

(2)	Includes collection and transportation of non-hazardous and hazardous waste.

(3)	Includes industrial cleaning and maintenance for refineries, chemical plants, steel and automotive plants, marine terminals and refinery services such as tank cleaning and temporary storage.

(4)	Includes retail services, laboratory packing, less-than-truck-load service and household hazardous waste collection. Contracts for Small Quantity Generation may extend beyond one year and a portion of the transaction price can be fixed.

(5)

Through our total waste management (“TWM”) program, customers outsource the management of their waste compliance program to us, allowing us to organize and coordinate their waste management disposal activities and environmental compliance. TWM contracts may extend beyond one year and a portion of the transaction price can be fixed.

(6)	Includes site assessment, onsite treatment, project management and remedial action planning and execution. Contracts for Remediation may extend beyond one year and a portion of the transaction price can be fixed.

(7)	Includes spill response, waste analysis and treatment and disposal planning.

(8)

We provide government-mandated, commercial standby oil spill compliance solutions to companies that store, transport, produce or handle petroleum and certain nonpetroleum oils on or near U.S. waters. Our standby services customers pay annual retainer fees under long-term or evergreen contracts for access to our regulatory certifications, specialized assets and highly trained personnel. When a customer with a retainer contract experiences a spill incident, we coordinate and manage the spill response, which results in incremental revenue for the services provided, in addition to the retainer fees.

(9)	Includes equipment rental and other miscellaneous services.

We provide services primarily in the United States, Canada and the Europe, Middle East, and Africa (“EMEA”) region. The following table presents our revenue disaggregated by our reportable segments and geographic location where the underlying services were performed:


	Three Months Ended June 30, 2020						Three Months Ended June 30, 2019
			Field &						Field &
	Environmental		Industrial				Environmental		Industrial
$s in thousands	Services		Services		Total		Services		Services		Total
United States	$	93,709	$	97,656	$	191,365	$	85,785	$	42,958	$	128,743
Canada		16,700		498		17,198		27,059		—		27,059
EMEA		—		3,915		3,915		—		—		—
Other (1)		—		1,440		1,440		—		—		—
Total revenue	$	110,409	$	103,509	$	213,918	$	112,844	$	42,958	$	155,802


	Six Months Ended June 30, 2020						Six Months Ended June 30, 2019
			Field &						Field &
	Environmental		Industrial				Environmental		Industrial
$s in thousands	Services		Services		Total		Services		Services		Total
United States	$	201,637	$	203,202	$	404,839	$	163,144	$	81,662	$	244,806
Canada		35,517		1,575		37,092		42,033		—		42,033
EMEA		—		9,154		9,154		—		—		—
Other (1)		—		3,553		3,553		—		—		—
Total revenue	$	237,154	$	217,484	$	454,638	$	205,177	$	81,662	$	286,839

(1)	Includes Mexico, Asia Pacific, and Latin America and Caribbean geographical regions.

Deferred Revenue

We record deferred revenue when cash payments are received, or advance billings are charged, prior to performance of services, such as waste that has been received but not yet treated or disposed. Revenue is recognized when these services are performed. During the three months ended June 30, 2020 and 2019, we recognized $4.5 million and $1.5 million of revenue that was included in the deferred revenue balance at the beginning of each year, respectively. During the six months ended June 30, 2020 and 2019, we recognized $12.9 million and $9.0 million of revenue that was included in the deferred revenue balance at the beginning of each year, respectively.

Receivables

Our receivables include invoiced and unbilled amounts where the Company has an unconditional right to payment.

Principal versus Agent Considerations

The Company commonly contracts with third-parties to perform certain waste-related services that we have promised in our customer contracts. We consider ourselves the principal in these arrangements as we direct the timing, nature and pricing of the services ultimately provided by the third-party to the customer.

Costs to obtain a contract

The Company pays sales commissions to employees, which qualify as costs to obtain a contract. Sales commissions are expensed as incurred as the commissions are earned by the employee and paid by the Company over time as the related revenue is recognized. Other commissions and incremental costs to obtain a contract are not material.

Practical Expedients and Optional Exemptions

Our payment terms may vary based on type of service or customer; however, we do not adjust the promised amount of consideration in our contracts for the time value of money as payment terms extended to our customers do not exceed one year and are not considered a significant financing component in our contracts.

We do not disclose the value of unsatisfied performance obligations as contracts with an original expected length of more than one year and contracts for which we do not recognize revenue at the amount to which we have the right to invoice for services performed is insignificant and the aggregate amount of fixed consideration allocated to unsatisfied performance obligations is not material.