Disaggregation of Revenue

In general, the Company’s business segmentation is aligned according to the nature and economic characteristics of our services and provides meaningful disaggregation of each business segment’s results of operations. The nature of the Company’s performance obligations within our Treatment and Services Segments result in the recognition of our revenue primarily over time. The following tables present further disaggregation of our revenues by different categories for our Services and Treatment Segments:

Contract Balances

The timing of revenue recognition, billings, and cash collections results in accounts receivable and unbilled receivables (contract assets). The Company’s contract liabilities consist of deferred revenues which represents advance payment from customers in advance of the completion of our performance obligation.

The following table represents changes in our contract assets and contract liabilities balances:

During the three and six months ended June 30, 2019, the Company recognized revenue of $2,866,000 and $7,446,000, respectively, which was included in the deferred revenue balance at the beginning of the year. During the three and six months ended June 30, 2018, the Company recognized revenue of $1,629,000 and $5,440,000, respectively, which was included in the deferred revenue balance at the beginning of the year. All revenue recognized in each period related to performance obligations satisfied within the respective period.

Remaining Performance Obligations

The Company applies the practical expedient in paragraph 606-10-50-14 and does not disclose information about remaining performance obligations that have original expected durations of one year or less.