Long-term debt as of the fiscal years ended March 31 consisted of the following:

(Amounts in thousands)	2021			2020
Term Loan Facility	$	441,250		$	648,250
Senior Notes		350,000			350,000
Revolving Credit Facility		—			100,000
Equipment financing		—			1,492
Total		791,250			1,099,742
Unamortized debt issuance costs		(2,030	)		(2,419	)
Current maturities		(7,000	)		(7,955	)
Long-term debt obligations	$	782,220		$	1,089,368

Bridge Credit Facility - On July 31, 2019, the Company entered into a credit agreement (the “Base Credit Agreement”) by and among the Company, as borrower, Barclays Bank PLC, as administrative agent, the several lenders from time to time party thereto.

The Base Credit Agreement provided for a term loan facility in an initial aggregate principal amount of up to $1.3 billion (the “Bridge Loan Facility”), a revolving credit facility in an initial aggregate principal amount of up to $350 million (the “Bridge Revolving Credit Facility”), a letter of credit sub-facility in the initial aggregate available amount of up to $50 million, as a sublimit of such Revolving Credit Facility (the “Bridge L/C Facility”) and a swing line sub-facility in the aggregate available amount of up to $50 million, as a sublimit of the Revolving Credit Facility (together with the Bridge Loan Facility, the Bridge Revolving Credit Facility and the Bridge L/C Facility, the “Bridge Credit Facility”).

On July 31, 2019, the Company borrowed approximately $1.3 billion under the Bridge Loan Facility and $145 million under the Bridge Revolving Credit Facility, which amounts were to (i) finance the consideration paid in connection with the closing of the Acquisition, (ii) repay the total outstanding amount as of the Closing Date under the Company’s then existing revolving credit facility with PNC, (iii) repay outstanding amounts of existing indebtedness incurred by Infiltrator under its outstanding credit facility in effect prior to the Acquisition, and (iv) pay certain transaction fees and expenses associated with the Acquisition and the Bridge Loan Facility. Approximately $300.0 million of outstanding borrowings under the Base Credit Agreement were repaid on September 10, 2019 with proceeds from the Company’s public offering of common stock as further described in “Note 19. Net Income Per Share and Stockholders’ Equity” and approximately $300.0 million of outstanding borrowings under the Bridge Loan Facility were repaid on September 23, 2019 with proceeds from the Company’s offering of $350.0 million Senior Notes, as defined and further described below.

As a result of this borrowing, on July 31, 2019, the Company initially capitalized approximately $46.9 million of deferred financing fees associated with the Bridge Credit Facility. This amount was later reduced by $14.9 million due to refunds received by ADS. The remaining deferred financing costs were written off due to loss on early extinguishment of debt resulting from the $300.0 million principal payment primarily from the Common Stock Offering, $300.0 million principal payment from the issuance of Senior Notes due 2027, and $700.0 million principal payment from the issuance of the Senior Secured Credit Facility on September 24, 2019. These financings resulted in the Company treating the Bridge Credit Facility as having been extinguished and replaced with the Common Stock Offering, Senior Notes due 2027 and the syndicated Senior Secured Credit Facility for accounting purposes under ASC 470-50 Modifications and Extinguishments. The loss on early extinguishment of debt, which is included in Interest expense in the Company's Consolidated Statements of Operations, primarily reflects the write-off of unamortized debt issuance costs and discounts.

Repayment of Prudential Senior Notes - On July 29, 2019, the Company repaid in full all of its and its subsidiaries’ indebtedness and other obligations totaling $104.4 million under that certain Second Amended and Restated Private Shelf Agreement, dated as of June 22, 2017 (as amended the “Shelf Note Agreement”) of the Company’s Senior Notes (“Prudential Senior Notes”), by and among the Company, as issuer, the guarantors from time to time a party thereto, PGIM, Inc., as a purchaser and the other purchasers from time to time a party thereto. The Company repaid the outstanding indebtedness under the Shelf Note Agreement using borrowings from the Company’s Second Amended and Restated Credit Agreement (the “PNC Credit Agreement”) as in effect as of July 29, 2019. Concurrently with the repayment, the Shelf Noteholders authorized and directed PNC Bank, National Association, in its capacity as Collateral Agent (as defined in the Shelf Note Agreement) to release the security interests and liens securing the Shelf Note Agreement and the Shelf Note Agreement was terminated.

As a result of the repayment described above, the Company expensed approximately $4.2 million primarily consisting of prepayment premium or penalty associated with the debt payoff activity and the write-off of unamortized deferred financing fees, as the payoff meets the criteria to be accounted for as a debt extinguishment.

Repayment of PNC Credit Agreement - On the Closing Date, using borrowings of the new Bridge Loan Facility the Company repaid in full all of its and its subsidiaries indebtedness and other obligations totaling $239.2 million under the PNC Credit Agreement. Concurrently with the repayment, all security interests and liens held by the Collateral Agent (as defined in the PNC Credit Agreement) securing the PNC Credit Agreement were terminated and released and the PNC Credit Agreement was terminated.

As a result of the repayment described above, the Company expensed approximately $2.0 million primarily consisting of the write-off of unamortized deferred financing fees associated with the debt payoff activity, as the payoff meets the criteria to be accounted for as a debt extinguishment.

Issuance of Senior Notes due 2027 - On September 23, 2019, the Company issued $350.0 million aggregate principal amount of 5.0% senior notes due 2027 (the “Senior Notes”) pursuant to an Indenture, dated September 23, 2019 (the “Indenture”), among the Company, the guarantors party thereto (the “Guarantors”) and U.S. Bank National Association, as Trustee (the “Trustee”). The Senior Notes are guaranteed by each of the Company’s present and future direct and indirect wholly owned domestic subsidiaries that is a guarantor under the Company's Senior Secured Credit Facility. The Senior Notes were offered and sold either to persons reasonably believed to be “qualified institutional buyers” pursuant to Rule 144A under the Securities Act of 1933 (the “Securities Act”) or to persons outside the United States under Regulation S of the Securities Act.

Interest on the Senior Notes will be payable semi-annually in cash in arrears on March 31 and September 30 of each year, commencing on March 31, 2020, at a rate of 5.0% per annum. The Senior Notes will mature on September 30, 2027. The Company used the majority of the net proceeds from the offering of the Senior Notes for the repayment of $300.0 million of its outstanding borrowings under the Company’s Bridge Loan Facility. The deferred financing costs associated with the Senior Notes totaled $2.1 million and are recorded as a direct reduction from the carrying amount of the related debt.

The Company may redeem the Senior Notes, in whole or in part, at any time on or after September 30, 2022 at established redemption prices. At any time prior to September 30, 2022, the Company may also redeem up to 40% of the Senior Notes with net cash proceeds of certain equity offerings at a redemption price equal to 105.0% of the principal amount of the Senior Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. In addition, at any time prior to September 30, 2022, the Company may redeem the Senior Notes, in whole or in part, at a redemption price equal to 100% of the principal amount of the Senior Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date plus an applicable “make-whole” premium.

The Indenture contains customary events of default, including, among other things, payment default, failure to comply with covenants or agreements contained in the Indenture or the Senior Notes and certain provisions related to bankruptcy events. The Indenture also contains customary negative covenants.

New Senior Secured Credit Facility - On September 24, 2019, the Company successfully completed a $700 million syndication of the remaining balance of the Bridge Credit Facility subsequent to the aforementioned Common Stock Offering and Senior Notes due 2027 and in connection with the syndication, the Company amended the Base Credit Agreement (the “Senior Secured Credit Facility”). The Senior Secured Credit Facility reduced the applicable margin utilized in the determination of the interest rate, as well as other provisions.

The Senior Secured Credit Facility provides for a term loan facility in an initial aggregate principal amount of $700 million (the “Term Loan Facility”), a revolving credit facility in an initial aggregate principal amount of up to $350 million (the “Revolving Credit Facility”), a letter of credit sub-facility in the initial aggregate available amount of up to $50 million, as a sublimit of such Revolving Credit Facility (the “L/C Facility”) and a swing line sub-facility in the aggregate available amount of up to $50 million, as a sublimit of the Revolving Credit Facility (together with the Term Loan Facility, the Revolving Credit Facility and the L/C Facility, the “Senior Secured Credit Facility”). During fiscal 2020, the Company paid $51.8 million of the Term Loan Facility. During fiscal 2021, the Company paid $207.0 million of the Term Loan Facility and $100.0 million of the Revolving Credit Facility. Letters of credit outstanding at March 31, 2021 amount to $11.0 million and reduced the availability of the Revolving Credit Facility.

In connection with entering into the Senior Secured Credit Facility, the Company capitalized approximately $0.4 million in deferred financing fees. To the extent not previously paid, all then-outstanding amounts under the Term Loan Facility are due and payable on the maturity date of the Term Loan Facility, which is seven years from the Closing Date. Borrowings under the Revolving Credit Facility are available beginning on September 24, 2019 and, to the extent not previously paid, all then-outstanding amounts under the Revolving Credit Facility are due and payable on the maturity date of the Revolving Credit Facility, which is five years from the Closing Date.

At the option of the Company, borrowings under the Term Loan Facility and under the Revolving Credit Facility (subject to certain limitations) bear interest at either a base rate (as determined pursuant to the Senior Secured Credit Facility) or at a Eurocurrency Rate, based on LIBOR (as defined in the Senior Secured Credit Facility), plus the applicable margin as set forth therein from time to time. In the case of the Revolving Credit Facility, the applicable margin is based on the Company’s consolidated senior secured net leverage ratio (as defined in the Senior Secured Credit Facility). All borrowings under the Term Loan Facility used to finance the Merger Consideration as described above initially bear interest at a Eurocurrency Rate applicable to Eurocurrency Loans (as defined in the Senior Secured Credit Facility) denominated in U.S. Dollars.

The Company is also required to pay a commitment fee that is based upon the undrawn amounts of the Revolving Credit Facility at a rate per annum based upon a calculated ratio as prescribed within the Senior Secured Credit Facility. As of March 31, 2021, the rate the Company was committed to paying on the undrawn portion was equal to 0.2%.

The Company’s obligations under the Senior Secured Credit Facility have been secured by granting a first priority lien on substantially all of the Company’s assets (subject to certain exceptions and limitations), and each of StormTech, LLC, Advanced Drainage of Ohio, Inc. and Infiltrator Water Technologies, LLC (collectively the “Guarantors”) has agreed to guarantee the obligations of the Company under the Senior Secured Credit Facility and to secure the obligations thereunder by granting a first priority lien in substantially all of such Guarantor’s assets (subject to certain exceptions and limitations).

Principal Maturities - Maturities of long-term debt (excluding interest and deferred financing costs) as of March 31, 2021 are summarized below:

	Fiscal Years Ending March 31,
(Amounts in thousands)	2022		2023		2024		2025		2026		Thereafter		Total
Principal maturities	$	7,000	$	7,000	$	7,000	$	7,000	$	7,000	$	756,250	$	791,250