CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash Flows from Operating Activities:
Net income	$ 28,189	$ 22,587
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	67,281	58,144
Operating lease right-of-use assets expense	6,636	7,272
Interest accretion on landfill and environmental remediation liabilities	5,324	5,310
Amortization of debt issuance costs	1,597	1,724
Stock-based compensation	5,345	5,218
Loss (gain) on sale of property and equipment	254	(806)
Southbridge Landfill non-cash closure charge	2,077	58
Non-cash expense from acquisition activities	549	71
Withdrawal costs - multiemployer pension plan	0	3,591
Deferred income taxes	1,514	(1,267)
Changes in assets and liabilities, net of effects of acquisitions and divestitures:
Accounts receivable	6,400	(15,141)
Landfill operating lease contract expenditures	(3,386)	(3,197)
Accounts payable	(8,585)	1,634
Prepaid expenses, inventories and other assets	(2,908)	(1,297)
Accrued expenses, contract liabilities and other liabilities	(4,083)	(17,986)
Net cash provided by operating activities	111,915	71,495
Cash Flows from Investing Activities:
Acquisitions, net of cash acquired	(25,379)	(73,496)
Additions to property, plant and equipment	(77,271)	(75,998)
Proceeds from sale of property and equipment	430	542
Proceeds from property insurance settlement	0	332
Net cash used in investing activities	(102,220)	(148,620)
Cash Flows from Financing Activities:
Proceeds from debt borrowings	154,400	121,500
Principal payments on debt	(145,008)	(149,774)
Payments of debt issuance costs	(1,531)	0
Proceeds from the exercise of share based awards	100	3,355
Proceeds from the public issuance of Class A Common Stock	0	100,446
Proceeds from the unregistered sale of Class A Common Stock	0	2,619
Net cash provided by financing activities	7,961	78,146
Net increase in cash and cash equivalents	17,656	1,021
Cash and cash equivalents, beginning of period	3,471	4,007
Cash and cash equivalents, end of period	21,127	5,028
Cash paid during the period for:
Interest	15,239	17,200
Income tax (refunds) payments	(1,650)	84
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Non-current assets obtained through long-term obligations	16,937	9,797
Landfill
Adjustments to reconcile net income to net cash provided by operating activities:
Operating lease right-of-use assets expense	$ 5,711	$ 5,580