

Current Obligations:	December 31, 2019			December 31, 2018
Senior secured Term Loan Agreement ("Term Loan Agreement")	$	7,535		$	7,535

Long-Term Obligations:
Senior secured Term Loan Agreement due June 30, 2024	$	727,162		$	734,697
Unsecured senior notes, at 4.875%, due July 15, 2027 ("2027 Notes")	545,000			—
Unsecured senior notes, at 5.125%, due July 15, 2029 ("2029 Notes")	300,000			—
Unsecured senior notes, at 5.125%, due June 1, 2021 ("2021 Notes")	—			845,000
Long-term obligations, at par	1,572,162			1,579,697
Unamortized debt issuance costs and premium, net	(18,046		)	(14,676		)
Long-term obligations, at carrying value	$	1,554,116		$	1,565,021

Unsecured Senior Notes. On July 2, 2019, the Company completed a private placement of $545.0 million aggregate principal amount of 2027 Notes and $300.0 million aggregate principal amount of 2029 Notes (collectively, the "New Notes"). The 2027 Notes will mature on July 15, 2027, and the 2029 Notes will mature on July 15, 2029. Interest payments on each series of the New Notes will be paid semiannually on January 15 and July 15, commencing on January 15, 2020.

The Company may redeem all or any portion of the 2027 Notes prior to July 15, 2022 or the 2029 Notes prior to July 15, 2024 at a redemption price equal to 100% of the principal amount redeemed plus a make whole premium as of the date of redemption including accrued and unpaid interest, if any, up to the date of redemption. Additionally, prior to July 15, 2022 for the 2027 Notes and July 15, 2024 for the 2029 Notes, the Company may use cash proceeds of one or more equity offerings to redeem up to 35% in aggregate principal of the 2027 Notes or the 2029 Notes at a redemption price equal to 104.875% or 105.125%, respectively, plus accrued and unpaid interest thereon, if any, up to the date of redemption.

After the dates in the preceding paragraph, the Company may redeem all or any portion of the New Notes which remain outstanding at any time upon proper notice at the following redemption prices if redeemed during the twelve-month period commencing on July 15 of the years set forth below plus accrued and unpaid interest, if any, up to the date of redemption:

Concurrently with the closing of the New Notes on July 2, 2019, the Company repurchased, using a portion of the net proceeds from the sale of the New Notes, an aggregate principal amount of $701.0 million of the 2021 Notes. The total amount paid in repurchasing the 2021 Notes was $706.2 million including $3.1 million of accrued interest. On July 17, 2019, the Company redeemed the remaining $144.0 million outstanding 2021 Notes, including $0.9 million of accrued interest, using the remaining net proceeds from the sale of the New Notes and available cash. In connection with this early repurchase and redemption of the 2021 Notes, the Company recorded a loss on early extinguishment of debt of $6.1 million during the year ended December 31, 2019. With the repurchase and redemption of the 2021 Notes, none of the Company’s outstanding debt is registered under the Securities Act of 1933, as amended.

The New Notes and the related indenture contain various customary non-financial covenants and are guaranteed by substantially all of the Company’s current and future domestic subsidiaries. The New Notes are effectively subordinated to the Company's Term Loan Agreement, revolving credit facility and finance lease obligations to the extent of the value of the assets securing such secured indebtedness. The New Notes are effectively subordinated to all indebtedness and other liabilities of the Company's subsidiaries that are not guarantors of the New Notes.

Senior Secured Term Loans. On April 17, 2018, the Company, and substantially all of the Company's domestic subsidiaries as guarantors, entered into the first amendment (the “First Amendment”) of the Term Loan Agreement. The First Amendment reduced the applicable interest rate margin for the Company’s term loans (the "Term Loans") outstanding under the Term Loan Agreement by 25 basis points for both Eurocurrency borrowings and base rate borrowings. After giving effect to the repricing, the applicable interest rate margins for the Term Loans are 1.75% for Eurocurrency borrowings and 0.75% for base rate borrowings.

On July 19, 2018, the Company, and substantially all of the Company’s domestic subsidiaries as guarantors, entered into an Incremental Facility Amendment (the “Incremental Facility Amendment”) to the Company’s Term Loan Agreement. The Incremental Facility Amendment increased the principal amount of the Term Loans outstanding under the Term Loan Agreement by $350.0 million. The Term Loans under the Term Loan Agreement will mature on June 30, 2024 and may be prepaid at any time without premium or penalty other than customary breakage costs with respect to Eurodollar based loans. The Company’s obligations under the Term Loan Agreement are guaranteed by all of the Company’s domestic restricted subsidiaries and secured by liens on substantially all of the assets of the Company and the guarantors. The effective annual interest rate of the Term Loans on December 31, 2019 was 3.55%.

was $330.9 million inclusive of $7.9 million of accrued interest and $1.0 million of debt redemption fees. On August 1, 2018, the Company redeemed the remaining $78.0 million of principal of the previously outstanding notes. In connection with this redemption, the Company recorded a loss on early extinguishment of debt of $2.5 million during the year ended December 31, 2018.

As of December 31, 2019 and December 31, 2018, the estimated fair value of the Company’s outstanding long-term obligations, including the current portion, was $1.6 billion. The Company’s estimates of the fair value of its long-term obligations, including the current portion, are based on quoted market prices or other available market data which are considered Level 2 measures according to the fair value hierarchy. Level 2 utilizes quoted market prices in markets that are not active, broker or dealer quotation, or alternative pricing sources with reasonable levels of price transparency for similar assets and liabilities.

Revolving Credit Facility. On November 1, 2016, the Company and one of the Company's subsidiaries (the "Canadian Borrower") entered into an amended and restated credit agreement for the Company's revolving credit facility with Bank of America, N.A. (“BofA”), as agent for the lenders under the facility (the "Agent"). Under the amended and restated facility, the Company has the right to obtain revolving loans and letters of credit for a combined maximum of up to $300.0 million (with a sub-limit of $250.0 million for letters of credit) and the Canadian Borrower has the right to obtain revolving loans and letters of credit for a combined maximum of up to $100.0 million (with a $75.0 million sub-limit for letters of credit). Availability under the U.S. line is subject to a borrowing base basically comprised of 85% of the eligible accounts receivable of the Company and its U.S. subsidiaries plus 100% of cash deposited in a controlled account with the Agent, and availability under the Canadian line is subject to a borrowing base basically comprised of 85% of the eligible accounts receivable of the Company’s Canadian subsidiaries plus 100% of cash deposited in a controlled account with the Agent’s Canadian affiliate. Subject to certain conditions, the facility will expire on November 1, 2021.

Borrowings under the revolving credit facility bear interest at a rate of, at the Company’s option, either (i) LIBOR plus an applicable margin ranging from 1.25% to 1.50% per annum based primarily on the level of the Company’s average liquidity for the most recent 30 day period or (ii) BofA’s base rate plus an applicable margin ranging from 0.25% to 0.50% per annum based primarily on such average liquidity. There is also an unused line fee, calculated on the then unused portion of the lenders’ $400.0 million maximum commitments, ranging from 0.25% to 0.30% per annum of the unused commitment. For outstanding letters of credit, the Company will pay to the lenders a fee equal to the then applicable LIBOR margin described above, and to the issuing banks a standard fronting fee and customary fees and charges in connection with all amendments, extensions, draws and other actions with respect to letters of credit.

The Company’s obligations under the revolving credit facility (including revolving loans and reimbursement obligations for outstanding letters of credit) are guaranteed by substantially all of the Company’s U.S. subsidiaries and secured by a first lien on the Company’s and its U.S. subsidiaries’ accounts receivable. The Canadian Borrower’s obligations under the facility are guaranteed by substantially all of the Company’s Canadian subsidiaries and secured by a first lien on the accounts receivable of the Canadian subsidiaries.

The Company utilizes letters of credit primarily as security for financial assurance which it has been required to provide to regulatory bodies for its hazardous waste facilities and which would be called only in the event that the Company fails to satisfy closure, post-closure and other obligations under the permits issued by those regulatory bodies for such licensed facilities. On August 1, 2018, the Company borrowed $50.0 million under the revolving credit facility in connection with the redemption of $78.0 million of previously outstanding unsecured senior notes. The Company repaid the $50.0 million borrowing during the fourth quarter of 2018. At December 31, 2019 and 2018, the revolving credit facility had no outstanding loan balances, availability of $229.2 million and $235.4 million, respectively, and outstanding letters of credit of $146.9 million and $130.1 million, respectively.

Although the interest rate on the Term Loans is variable, the Company has effectively fixed the interest rate on $350.0 million principal outstanding by entering into interest rate swap agreements in 2018 with a notional amount of $350.0 million. Under the terms of the interest rate swap agreements, the Company receives interest based on the 1-month LIBOR index and pays interest at a weighted average rate of approximately 2.92%, resulting in an effective annual interest rate of approximately 4.67%.

The Company recognizes derivative instruments as either assets or liabilities on the consolidated balance sheet at fair value. No ineffectiveness has been identified on these swaps and, therefore, the change in fair value is recorded in stockholders’ equity as a component of accumulated other comprehensive loss. Amounts are reclassified from accumulated other comprehensive loss into interest expense on the consolidated statement of operations in the same period or periods during which the hedged transaction affects earnings.

The fair value of the interest rate swaps is calculated using discounted cash flow valuation methodologies based upon the one-month LIBOR yield curves that are observable at commonly quoted intervals for the full term of the interest rate swaps and as such is considered a Level 2 measure according to the fair value hierarchy.