NuStar Logistics is party to a short-term line of credit agreement with an uncommitted borrowing capacity of up to $35.0 million, which allows us to better manage fluctuations in our daily cash requirements and minimize our excess cash balances. The interest rates and maturities vary and are determined at the time of borrowing. Obligations under this short-term line of credit agreement are guaranteed by NuStar Energy. As of December 31, 2019 and 2018, the weighted-average interest rates related to outstanding borrowings under our short-term line of credit were 3.6% and 4.4%, respectively.

Long-term debt consisted of the following:



				December 31,
	Maturity			2019			2018
				(Thousands of Dollars)
Revolving Credit Agreement		2021		$	475,000		$	745,000
4.80% senior notes		2020		450,000			450,000
6.75% senior notes		2021		300,000			300,000
4.75% senior notes		2022		250,000			250,000
6.00% senior notes		2026		500,000			—
5.625% senior notes		2027		550,000			550,000
Subordinated Notes		2043		402,500			402,500
GoZone Bonds	2038	thru	2041	365,440			365,440
Receivables Financing Agreement		2021		62,200			61,800
Net fair value adjustments, unamortized discounts and unamortized debt issuance costs		N/A		(23,301		)	(12,744		)
Total long-term debt (excluding finance leases)				3,331,839			3,111,996
Finance leases (refer to Note 17)				55,446			—
Less current portion				452,367			—
Long-term debt, less current portion				$	2,934,918		$	3,111,996

Interest payments totaled $183.8 million, $190.9 million and $163.6 million for the years ended December 31, 2019, 2018 and 2017, respectively, related to debt obligations. We amortized an aggregate of $6.5 million, $7.1 million and $5.0 million of debt issuance costs and debt discount combined for the years ended December 31, 2019, 2018 and 2017, respectively.

For the rolling period ending December 31, 2019, the maximum allowed consolidated debt coverage ratio (as defined in the Revolving Credit Agreement) may not exceed 5.00-to-1.00 and the minimum consolidated interest coverage ratio (as defined in the Revolving Credit Agreement), must not be less than 1.75-to-1.00. If we complete one or more acquisitions for aggregate net consideration of at least $50.0 million, our maximum consolidated debt coverage ratio will increase to 5.50-to-1.00 for two rolling periods. The maximum consolidated debt coverage ratio and minimum consolidated interest coverage ratio requirements may limit the amount we can borrow under the Revolving Credit Agreement to an amount less than the total amount available for borrowing. The Revolving Credit Agreement also contains customary restrictive covenants, such as limitations on indebtedness, liens, mergers, asset transfers and certain investing activities. As of December 31, 2019, we believe that we are in compliance with the covenants in the Revolving Credit Agreement.

As of December 31, 2019, we had $721.0 million available for borrowing. Obligations under the Revolving Credit Agreement are guaranteed by NuStar Energy and NuPOP. Letters of credit issued under the Revolving Credit Agreement totaled $4.0 million as of December 31, 2019. Letters of credit are limited to $400.0 million and also may restrict the amount we can borrow under the Revolving Credit Agreement.

The Revolving Credit Agreement bears interest, at our option, based on an alternative base rate, a LIBOR-based rate or a EURIBOR-based rate. The interest rate on the Revolving Credit Agreement is subject to adjustment if our debt rating is downgraded (or upgraded) by certain credit rating agencies. As of December 31, 2019, our weighted-average interest rate was 3.9%, and we had $475.0 million outstanding. During the year ended December 31, 2019, the weighted-average interest rate related to borrowings under the Revolving Credit Agreement was 4.4%.

NuStar Logistics Senior Notes. On May 22, 2019, NuStar Logistics issued $500.0 million of 6.0% senior notes due June 1, 2026. We received net proceeds of $491.6 million, which we used to repay outstanding borrowings under our Revolving Credit Agreement. The interest on the 6.0% senior notes is payable semi-annually in arrears on June 1 and December 1 of each year, beginning on December 1, 2019.

On April 28, 2017, NuStar Logistics issued $550.0 million of 5.625% senior notes due April 28, 2027. We used the net proceeds of $543.3 million from the offering to fund a portion of the purchase price for the Navigator Acquisition and to pay related fees and expenses. The interest on the 5.625% senior notes is payable semi-annually in arrears on April 28 and October 28 of each year, beginning on October 28, 2017.

Interest is payable semi-annually in arrears for the $450.0 million of 4.80% senior notes, $300.0 million of 6.75% senior notes, $250.0 million of 4.75% senior notes, $500.0 million of 6.0% senior notes and $550.0 million of 5.625% senior notes (collectively, the NuStar Logistics Senior Notes). We repaid the $350.0 million of 7.65% senior notes on April 15, 2018 with borrowings under our Revolving Credit Agreement.

The NuStar Logistics Senior Notes do not have sinking fund requirements. These notes rank equally with existing senior unsecured indebtedness and senior to existing subordinated indebtedness of NuStar Logistics and contain restrictions on NuStar Logistics’ ability to incur additional secured indebtedness unless the same security is also provided for the benefit of holders of the NuStar Logistics Senior Notes. In addition, the NuStar Logistics Senior Notes limit NuStar Logistics’ ability to incur indebtedness secured by certain liens and to engage in certain sale-leaseback transactions and engage in certain consolidations, mergers or asset sales. At the option of NuStar Logistics, the NuStar Logistics Senior Notes may be redeemed in whole or in part at any time at a redemption price, plus accrued and unpaid interest to the redemption date. If we undergo a change of control, as defined in the supplemental indentures for the 6.75% senior notes, the 6.0% senior notes or the 5.625% senior notes, each holder of the 6.75% senior notes, the 6.0% senior notes or the 5.625% senior notes may require us to repurchase all or a portion of its notes at a price equal to 101% of the principal amount of the notes repurchased, plus any accrued and unpaid interest to the date of repurchase. The NuStar Logistics Senior Notes are fully and unconditionally guaranteed by NuStar Energy and NuPOP.

NuStar Logistics Subordinated Notes. NuStar Logistics’ $402.5 million of fixed-to-floating rate subordinated notes are due January 15, 2043 (the Subordinated Notes). The Subordinated Notes are fully and unconditionally guaranteed on an unsecured and subordinated basis by NuStar Energy and NuPOP. Effective January 15, 2018, the interest rate on the Subordinated Notes switched from a fixed annual rate of 7.625%, payable quarterly in arrears, to an annual rate equal to the sum of the three-month LIBOR for the related quarterly interest period, plus 6.734% payable quarterly, commencing April 15, 2018, unless payment is deferred in accordance with the terms of the notes. NuStar Logistics may elect to defer interest payments on the Subordinated Notes on one or more occasions for up to five consecutive years. Deferred interest will accumulate additional interest at a rate equal to the interest rate then applicable to the Subordinated Notes until paid. If NuStar Logistics elects to defer interest payments, NuStar Energy cannot declare or make cash distributions to its unitholders during the period that interest payments are deferred. As of December 31, 2019, the interest rate was 8.7%.

The Subordinated Notes do not have sinking fund requirements and are subordinated to existing senior unsecured indebtedness of NuStar Logistics and NuPOP. The Subordinated Notes do not contain restrictions on NuStar Logistics’ ability to incur additional indebtedness, including debt that ranks senior in priority of payment to the notes. In addition, the Subordinated Notes do not limit NuStar Logistics’ ability to incur indebtedness secured by liens or to engage in certain sale-leaseback transactions. Effective January 15, 2018, we may redeem the Subordinated Notes in whole or in part at a redemption price equal to 100% of the principal amount plus accrued and unpaid interest to the redemption date.

In 2008, 2010 and 2011, the Parish of St. James, Louisiana issued Revenue Bonds Series 2008, Series 2010, Series 2010A, Series 2010B and Series 2011 associated with our St. James terminal expansions pursuant to the Gulf Opportunity Zone Act of 2005 for an aggregate $365.4 million (collectively, the GoZone Bonds). The interest rates on these bonds are based on a weekly tax-exempt bond market interest rate, and interest is paid monthly. Following the issuances, the proceeds were deposited with a trustee and were disbursed to us upon our request for reimbursement of expenditures related to our St. James terminal expansions. We include the amount remaining in the trust in “Other long-term assets, net,” and we include the amount of bonds issued in “Long-term debt” in our consolidated balance sheets. We did not receive any proceeds from the trustee for the years ended December 31, 2019 and 2018.

NuStar Logistics is solely obligated to service the principal and interest payments associated with the GoZone Bonds. Letters of credit were issued by various individual banks on our behalf to guarantee the payment of interest and principal on the bonds. All letters of credit rank equally with existing senior unsecured indebtedness of NuStar Logistics and generally contain the same restrictive covenants, maximum consolidated debt coverage ratio and minimum consolidated interest coverage ratio requirements as the Revolving Credit Agreement. Obligations under the letters of credit issued are guaranteed by NuStar Energy and NuPOP. The letters of credit issued by individual banks do not restrict the amount we can borrow under the Revolving Credit Agreement. At the option of NuStar Logistics, during any period when the bonds bear interest at a daily or weekly rate, the GoZone Bonds may be redeemed in whole or in part on any interest payment date for 100% of the outstanding principal amount plus accrued interest to the redemption date. On January 27, 2020, NuStar Logistics provided the trustee with notice to call the $43.3 million principal amount of the GoZone Bonds remaining in trust for redemption on March 4, 2020.

The following table summarizes the GoZone Bonds outstanding as of December 31, 2019:



Date Issued	Maturity Date	Amount Outstanding		Amount of Letter of Credit		Amount Received from Trustee		Amount Remaining in Trust (a)		Interest Rate (b)
		(Thousands of Dollars)
June 26, 2008	June 1, 2038	$	55,440	$	56,169	$	55,440	$	—	1.6	%
July 15, 2010	July 1, 2040	100,000		101,315		100,000		—		1.5	%
October 7, 2010	October 1, 2040	50,000		50,658		43,741		6,652		1.5	%
December 29, 2010	December 1, 2040	85,000		86,118		49,782		36,580		1.5	%
August 9, 2011	August 1, 2041	75,000		75,986		75,000		—		1.6	%
	Total	$	365,440	$	370,246	$	323,963	$	43,232

NuStar Energy and NuStar Finance LLC (NuStar Finance), a special purpose entity and wholly owned subsidiary of NuStar Energy, are parties to a $125.0 million receivables financing agreement with third-party lenders (the Receivables Financing Agreement) and agreements with certain of NuStar Energy’s wholly owned subsidiaries (together with the Receivables Financing Agreement, the Securitization Program). Under the Securitization Program, certain of NuStar Energy’s wholly owned subsidiaries (collectively, the Originators), sell their accounts receivable to NuStar Finance on an ongoing basis, and NuStar Finance provides the newly acquired accounts receivable as collateral for its revolving borrowings under the Receivables Financing Agreement. NuStar Energy provides a performance guarantee in connection with the Securitization Program. The amount available for borrowing is limited to $125.0 million and is based on the availability of eligible receivables and other customary factors and conditions. The Securitization Program contains various customary affirmative and negative covenants and default, indemnification and termination provisions, and the Receivables Financing Agreement provides for acceleration of amounts owed upon the occurrence of certain specified events. NuStar Finance’s sole activity consists of purchasing such receivables and providing them as collateral under the Securitization Program. NuStar Finance is a separate legal entity and the assets of NuStar Finance, including these accounts receivable, are not available to satisfy the claims of creditors of NuStar Energy, the Originators or their affiliates.

On April 29, 2019, we amended the Receivables Financing Agreement to extend the scheduled termination date from September 20, 2020 to September 20, 2021, with the option to renew for additional 364-day periods thereafter, and to amend certain provisions with respect to receivables related to certain customers. Borrowings by NuStar Finance under the Receivables Financing Agreement bear interest at the applicable bank rate, as defined under the Receivables Financing Agreement. As of December 31, 2019 and 2018, accounts receivable totaling $112.8 million and $95.5 million, respectively, were included in the Securitization Program. The weighted average interest rate related to outstanding borrowings under the Securitization Program during the year ended December 31, 2019 was 3.2%.