Exhibit 4.2

WESTLAKE CHEMICAL CORPORATION AND THE SUBSIDIARY

GUARANTORS PARTY HERETO

3.50% Senior Notes due 2032

Tenth Supplemental Indenture

Dated as of November 29, 2017

THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.

Trustee

TABLE OF CONTENTS

-i-

TENTH SUPPLEMENTAL INDENTURE dated as of November 29, 2017 (this “ Supplemental Indenture ”), to the Indenture dated as of January 1, 2006 (as amended, modified or supplemented from time to time in accordance therewith, the “ Indenture ”), by and among WESTLAKE CHEMICAL CORPORATION, a Delaware corporation (the “ Company ”), each of the Subsidiary Guarantors (as defined herein) and THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. (as successor to JPMorgan Chase Bank, National Association), as trustee (the “ Trustee ”).

Each party agrees as follows for the benefit of the other parties and for the equal and ratable benefit of the Holders of the Notes (as defined herein):

WHEREAS, the Company and the Louisiana Local Government Environmental Facilities and Community Development Authority (the “ Authority ”) have entered into that certain Amended and Restated Loan Agreement dated as of November 1, 2017 (the “ Loan Agreement ”) in connection with the conversion and reoffering as of the date hereof of $250,000,000 aggregate principal amount of Louisiana Local Government Environmental Facilities and Community Development Authority Revenue Refunding Bonds (Westlake Chemical Corporation Projects), Series 2017 (GO Zone)(Non-AMT) (the “ GO Zone Bonds ”), under the Amended and Restated Indenture of Trust, dated as of November 1, 2017 (the “ GO Zone Indenture ”), between the Authority and The Bank of New York Mellon Trust Company, N.A., as trustee (the “ GO Zone Trustee ”);

WHEREAS, the Company and the Subsidiary Guarantors desire to issue the Notes to the trustee for the GO Zone Bonds to evidence the Company’s payment obligations under the Loan Agreement

WHEREAS, the Company, the Subsidiary Guarantors and the Trustee have duly authorized the execution and delivery of the Indenture to provide for the issuance from time to time of the Company’s debentures, notes, bonds or other evidences of indebtedness to be issued in one or more series as in the Indenture provided (as defined therein, “ Securities ”);

WHEREAS, the Company and the Subsidiary Guarantors desire and have requested the Trustee to join them in the execution and delivery of this Supplemental Indenture in order to establish and provide for the issuance by the Company of a series of Securities designated as its 3.50% Senior Notes due 2032, substantially in the form attached hereto as Exhibit  A (the “ Notes ”), guaranteed by the Subsidiary Guarantors, on the terms set forth herein;

WHEREAS, Section 2.01 of the Indenture provides that a supplemental indenture may be entered into by the Company, the Subsidiary Guarantors and the Trustee for such purpose provided certain conditions are met;

WHEREAS, the conditions set forth in the Indenture for the execution and delivery of this Supplemental Indenture have been complied with; and

WHEREAS, all things necessary to make this Supplemental Indenture a valid agreement of the Company, the Subsidiary Guarantors and the Trustee, in accordance with its terms, and a valid amendment of, and supplement to, the Indenture have been done;

NOW, THEREFORE:

In consideration of the premises and the purchase and acceptance of the Notes by the Holders thereof, the Company and the Subsidiary Guarantors mutually covenant and agree with the Trustee, for the equal and ratable benefit of the Holders, that the Indenture is supplemented and amended, to the extent expressed herein, as follows:

ARTICLE ONE

Scope of Supplemental Indenture; General

The changes, modifications and supplements to the Indenture effected by this Supplemental Indenture shall be applicable only with respect to, and govern the terms of, the Notes, which shall not be limited in aggregate principal amount, and shall not apply to any other Securities that may be issued under the Indenture unless a supplemental indenture with respect to such other Securities specifically incorporates such changes, modifications and supplements. Pursuant to this Supplemental Indenture, there is hereby created and designated a series of Securities under the Indenture entitled “3.50% Senior Notes due 2032.” The Notes shall be in the form of Exhibit  A hereto, which is hereby incorporated into this Supplemental Indenture by reference. The Notes shall be guaranteed by the Subsidiary Guarantors as provided in such form and the Indenture. If required, the Notes may bear an appropriate legend regarding original issue discount for federal income tax purposes.

The obligation of the Company to make any payment of principal or premium, if any, on the Note, whether at maturity or otherwise, shall be fully or partially, as the case may be, deemed to have been paid or otherwise satisfied and discharged to the extent that the Company has paid or caused to be paid to the GO Zone Trustee the Payments (as such term is defined in the Loan Agreement) in respect of the principal or premium, if any, then due and payable on the GO Zone Bonds. If the Trustee is not also the GO Zone Trustee, then the Trustee may conclusively presume that the obligation of the Company to pay the principal of, premium, if any, and interest on the Note pursuant to this Supplemental Indenture shall have been fully satisfied and discharged unless and until it shall have received a written notice from the GO Zone Trustee, signed by an authorized officer of the GO Zone Trustee and attested by the Secretary or an Assistant Secretary of the GO Zone Trustee, stating that the payment of principal of, premium, if any, or interest on this Note has not been fully paid when due and specifying the amount of funds required to make such payment.

-2-

ARTICLE TWO

Certain Definitions

The following terms have the meanings set forth below in this Supplemental Indenture. Capitalized terms used but not defined herein have the meanings ascribed to such terms in the Indenture. To the extent terms defined herein differ from the Indenture the terms defined herein will govern.

“ Attributable Debt ” means, as to any lease in respect of a Sale and Leaseback Transaction under which any Person is at the time liable, at any date as of which the amount thereof is to be determined, the total net amount of rent required to be paid by such Person under such lease during the remaining term thereof (or, if earlier, the first date upon which such lease may be terminated without penalty), discounted from the respective due dates thereof to such date at the weighted average rate per annum borne by the Notes, compounded annually. The net amount of rent required to be paid under any such lease for any such period shall be the aggregate amount of the rent payable by the lessee with respect to such period after excluding amounts required to be paid on account of maintenance and repairs, insurance, taxes, assessments, water rates and similar charges. Unless the Company elects to calculate the total amount of rent required to be paid through the first date upon which such lease may be terminated without penalty (if such a provision exists), in the case of any lease which is terminable by the lessee upon the payment of a penalty, such net amount shall also include the amount of such penalty, but no rent shall be considered as required to be paid under such lease subsequent to the first date upon which it may be so terminated.

“ Authority ” has the meaning provided in the Recitals.

“ Below Investment Grade Rating Event ” means the rating on the Notes is lowered and as a result the Notes cease to be rated Investment Grade by each of the Rating Agencies on any date during the period (the “ Trigger Period ”) commencing on the earlier of (a) the occurrence of a Change of Control and (b) the first public announcement by the Company of any Change of Control (or pending Change of Control) and ending 60 days following the consummation of such Change of Control (which Trigger Period will be extended if the rating of the Notes is under publicly announced consideration for possible downgrade by any Rating Agency on such 60th day, such extension to last with respect to each Rating Agency until the date on which such Rating Agency considering such possible downgrade either (x) rates the Notes below Investment Grade or (y) publicly announces that it is no longer considering the Notes for possible downgrade; provided, that no such extension will occur if on such 60th day the Notes are rated Investment Grade not subject to review for possible downgrade by any Rating Agency); provided, that a rating event will not be deemed to have occurred in respect of a particular Change of Control (and thus will not be deemed a Below Investment Grade Rating Event for purposes of the definition of Change of Control

-3-

Triggering Event contained in this Article Two) if each Rating Agency making the reduction in rating does not publicly announce or confirm or inform the Trustee in writing at the Company’s request that the reduction was the result, in whole or in part, of any event or circumstance comprised of or arising as a result of, or in respect of, the Change of Control (whether or not the applicable Change of Control has occurred at the time of the Below Investment Grade Rating Event). If any Rating Agency withdraws its rating on the Notes or otherwise ceases to provide a rating on the Notes on any day during the Trigger Period for any reason and the Company has not selected a replacement Rating Agency pursuant to the terms of this Supplemental Indenture, the rating of such Rating Agency shall be deemed to be rated below Investment Grade on such day.

“ Beneficial Owner ” has the meaning assigned to such term in Rule 13d-3 and Rule 13d-5 under the Exchange Act, except that in calculating the beneficial ownership of any particular “person” as such term is used in Section 13(d)(3) of the Exchange Act, such “person” will be deemed to have beneficial ownership of all securities that such “person” has the right to acquire by conversion or exercise of other securities, whether such right is currently exercisable or is exercisable only upon the occurrence of a subsequent condition.

“ Capital Stock ” means:

(1)    in the case of a corporation, capital stock;

(2)    in the case of an association or business entity, any and all shares, interests, participations, rights or other equivalents (however designated) of capital stock;

(3)    in the case of a partnership or limited liability company, partnership interests (whether general or limited) or membership interests, respectively; and

(4)    any other interest or participation that confers on a Person the right to receive a share of the profits and losses of, or distributions of assets of, the issuing Person, but excluding from all of the foregoing any debt securities convertible into Capital Stock, whether or not such debt securities include any right of participation with Capital Stock.

“ Change of Control ” means the occurrence of any of the following after the date of this Supplemental Indenture:

(1)    the direct or indirect sale, lease, transfer, conveyance or other disposition (other than by way of merger or consolidation), in one or a series of related transactions, of all or substantially all of the assets of the Company and the Subsidiaries taken as a whole to any “person” or “group” (as those terms are used in Section 13(d)(3) of the Exchange Act) other than to the Company or a Subsidiary;

-4-

(2)    the consummation of any transaction (including, without limitation, any merger or consolidation) the result of which is that any “person” or “group” (as those terms are used in Section 13(d)(3) of the Exchange Act, it being agreed that an employee of the Company or any Subsidiary for whom shares are held under an employee stock ownership, employee retirement, employee savings or similar plan and whose shares are voted in accordance with the instructions of such employee shall not be a member of a “group” (as that term is used in Section 13(d)(3) of the Exchange Act) solely because such employee’s shares are held by a trustee under said plan) becomes the ultimate Beneficial Owner, directly or indirectly, of Voting Stock of the Company representing more than 50% of the voting power of the outstanding Voting Stock of the Company;

(3)    the Company consolidates with, or merges with or into, any Person, or any Person consolidates with, or merges with or into, the Company, in any such event pursuant to a transaction in which any of the outstanding Voting Stock of the Company or Voting Stock of such other Person is converted into or exchanged for cash, securities or other property, other than any such transaction where the Voting Stock of the Company outstanding immediately prior to such transaction constitutes, or is converted into or exchanged for, Voting Stock representing more than 50% of the voting power of the Voting Stock of the surviving Person or its parent immediately after giving effect to such transaction;

(4)    during any period of 24 consecutive calendar months, the majority of the members of the Board of Directors of the Company shall no longer be composed of individuals (a) who were members of the Board of Directors of the Company on the first day of such period or (b) whose election or nomination to the Board of Directors of the Company was approved by individuals referred to in clause (a) above constituting, at the time of such election or nomination, at least a majority of the Board of Directors of the Company or, if directors are nominated by a committee of the Board of Directors of the Company, constituting at the time of such nomination, at least a majority of such committee; or

(5)    the adoption of a plan relating to the liquidation or dissolution of the Company.

Notwithstanding the foregoing, a transaction will not be deemed to involve a Change of Control if (i) the Company becomes a direct or indirect wholly-owned subsidiary of a holding company and (ii) the direct or indirect holders of the Voting Stock of such holding company immediately following that transaction are substantially the same as the holders of the Voting Stock in the Company immediately prior to that transaction.

“ Change of Control Offer ” means an offer made by the Borrower Designee (as defined in the GO Zone Indenture) upon a Change of Control Triggering Event to purchase all or any part (which shall be in an amount equal to an Authorized Denomination) of a Holder’s Notes for a payment in cash equal to 101% of the aggregate principal amount of Notes repurchased plus accrued and unpaid interest on the Notes repurchased. A payment under a

-5-

Change of Control Offer shall be deemed to have been made to the extent that the Borrower Designee has made a corresponding payment under a Change of Control Offer for the GO Zone Bonds.

“ Change of Control Triggering Event ” means the occurrence of both a Change of Control and a Below Investment Grade Rating Event. Notwithstanding the foregoing, no Change of Control Triggering Event will be deemed to have occurred in connection with any particular Change of Control unless and until such Change of Control has actually been consummated.

“ Company ” has the meaning provided in the Preamble.

“ Consolidated Net Tangible Assets ” means the aggregate amount of assets (less applicable reserves and other properly deductible items) after deducting therefrom (1) all current liabilities, except for (a) notes and loans payable, (b) current maturities of long-term debt and (c) current maturities of obligations under capital leases and (2) all goodwill, trade names, trademarks, patents, unamortized debt discount and expense and other like intangibles, all as set forth on the most recent balance sheet of the Company and its consolidated Subsidiaries and computed in accordance with GAAP. Deferred income taxes, deferred investment tax credit or other similar items, as calculated in accordance with GAAP, will not be considered as a liability or as a deduction from or adjustment to total assets.

“ Debt ” has the meaning provided in Section 4.08.

“ Domestic Subsidiary ” means any Subsidiary that was formed under the laws of the United States or any state of the United States or the District of Columbia.

“ Fair Market Value ” means the price that could be negotiated in an arm’s-length transaction between a willing buyer and a willing seller not involving distress or necessity of either party, determined in good faith by the Board of Directors of the Company.

“ Funded Debt ” means all indebtedness for money borrowed having a maturity of more than 12 months from the date of the most recent balance sheet of the Company and its consolidated Subsidiaries or having a maturity of less than 12 months but by its terms being renewable or extendible beyond 12 months from the date of such balance sheet at the option of the borrower of such indebtedness.

“ GO Zone Bonds ” has the meaning provided in the Recitals.

“ GO Zone Indenture ” has the meaning provided in the Recitals.

“ GO Zone Trustee ” has the meaning provided in the Recitals.

-6-

“ Holder ” means the Person in whose name a Note is registered in the books of the Registrar for the Notes.

“ Indenture ” has the meaning provided in the Preamble.

“ Investment Grade ” means a rating of Baa3 or better by Moody’s (or its equivalent under any successor rating category of Moody’s) and a rating of BBB- or better by S&P (or its equivalent under any successor rating category of S&P), and the equivalent investment grade credit rating from any replacement rating agency or rating agencies selected by the Company under the circumstances specified in this Supplemental Indenture permitting the Company to select a replacement rating agency and in the manner specified in this Supplemental Indenture for selecting a replacement rating agency, in each case as set forth in the definition of “Rating Agency.”

“ Moody’s ” means Moody’s Investors Service, Inc., a subsidiary of Moody’s Corporation, and its successors.

“ Mortgage ” and “ Mortgages ” have the meanings provided in Section 4.08.

“ Notes ” has the meaning provided in the Recitals.

“ Paying Agent ” means The Bank of New York Mellon Trust Company, N.A. or any successor paying agent.

“ Person ” means any individual, corporation, limited liability company, partnership, joint venture, incorporated or unincorporated association, joint stock company, trust, estate, unincorporated organization or government or any agency, instrumentality or political subdivision thereof or any other entity of any kind.

“ Principal Property ” means any single parcel of real estate, any single manufacturing plant or any single warehouse owned or leased in connection with a Sale and Leaseback Transaction by the Company or any Subsidiary which is located within the United States and the net book value of which on the date as of which the determination is being made exceeds 1% of Consolidated Net Tangible Assets, other than any such manufacturing plant or warehouse or portion thereof (1) which is a pollution control or other facility financed by obligations issued by a state or local government unit and described in Sections 141(a), 142(a)(5), 142(a)(6), 142(a)(10) or 144(a) of the Internal Revenue Code (or their successor provisions) or by any other obligations the interest of which is excluded under Section 103 of the Internal Revenue Code (or its successor provision), or (2) which, in the good-faith opinion of the Board of Directors of the Company, as evidenced by a Board Resolution, is not of material importance to the total business conducted by the Company and the Subsidiaries taken as a whole.

-7-

“ Rating Agency ” means each of Moody’s and S&P; provided, that if any of Moody’s or S&P ceases to provide rating services to issuers or investors, the Company may appoint another “nationally recognized statistical rating organization” (as defined under the Exchange Act) as a replacement for such Rating Agency; provided, that the Company shall give written notice of such appointment to the Trustee.

“ Registrar ” means The Bank of New York Mellon Trust Company, N.A., or any successor registrar of the Notes.

“ Restricted Subsidiary ” means a wholly-owned Subsidiary of the Company substantially all of the assets of which are located in the United States (excluding territories or possessions) and which owns a Principal Property; provided, however, that the term Restricted Subsidiary shall not include any Subsidiary that is principally engaged in (1) the business of financing; (2) the business of owning, buying, selling, leasing, dealing in or developing real property; or (3) the business of exporting goods or merchandise from or importing goods or merchandise into the United States.

“ S&P ” means S&P Global Ratings, a division of S&P Global, Inc., and its successors.

“ Sale and Leaseback Transaction ” has the meaning provided in Section 4.09.

“ Secured Debt ” has the meaning provided in Section 4.08.

“ Subsidiary ” means a Person more than 50% of the outstanding Voting Stock of which is owned, directly or indirectly, by the Company or by one or more other Subsidiaries, or by the Company and one or more other Subsidiaries.

“ Subsidiary Guarantors ” means:

(1)    each of the Subsidiaries of the Company listed on Schedule A to this Supplemental Indenture; and

(2)    any other Subsidiary that executes a Guarantee in accordance with the provisions of this Supplemental Indenture;

-8-

and their respective successors and assigns; provided that any Person constituting a Subsidiary Guarantor as described above shall cease to constitute a Subsidiary Guarantor when its respective Guarantee is released in accordance with the terms of this Supplemental Indenture.

“ Supplemental Indenture ” has the meaning provided in the Preamble.

“ Trustee ” has the meaning provided in the Preamble.

“ Voting Stock ” of any specified Person as of any date means the capital stock (or comparable equity interests) of such Person that is at the time entitled to vote generally in the election of the board of directors (or members of the governing body) of such Person.

ARTICLE THREE

Redemption

The following covenants are added to the Indenture for the benefit of Holders of the Notes:

Section 3.12. Redemption Based on Article III of the GO Zone Indenture .

Except as otherwise provided herein, the Notes shall not be redeemable at the option of the Company; provided, however, that in the event of a redemption of GO Zone Bonds under Article III of the GO Zone Indenture and as reflected in the GO Zone Bonds set forth in Exhibit A thereto, the Company shall redeem Notes equal in principal amount to the GO Zone Bonds to be redeemed at a Redemption Price equal to the redemption price of the GO Zone Bonds to be redeemed, plus accrued interest to the redemption date.

-9-

ARTICLE FOUR

Covenants

The following covenants are added to the Indenture for the benefit of Holders of the Notes:

Section 4.08. Restrictions on Secured Debt .

The Company shall not, and the Company shall not permit any Restricted Subsidiary to, incur, issue, assume or guarantee any notes, bonds, debentures or other similar evidences of indebtedness for money borrowed (“ Debt ”), secured by pledge of, or mortgage or lien on, any Principal Property, or any shares of Capital Stock of or Debt of any Restricted Subsidiary (such pledges, mortgages and liens being called “ Mortgage ” or “ Mortgages ” and such Debt secured by such Mortgages being called “ Secured Debt ”), without effectively providing that the Notes (together with, if the Company shall so determine, any other indebtedness of the Company or such Restricted Subsidiary then existing or thereafter created which is not subordinate to the Notes) shall be secured equally and ratably with (or prior to) such Secured Debt, so long as such Secured Debt shall be so secured, unless after giving effect thereto, the aggregate amount of all such Secured Debt plus all Attributable Debt of the Company and its Restricted Subsidiaries in respect of any Sale and Leaseback Transaction would not, at the time of such incurrence, issuance, assumption or guarantee, exceed 15% of Consolidated Net Tangible Assets; provided, however, that this restriction shall not apply to, and there shall be excluded from Secured Debt in any computation under such restriction, indebtedness secured by:

(a)    Mortgages on such property or shares of Capital Stock or Debt existing on the date of this Supplemental Indenture;

(b)    Mortgages on such property or shares of Capital Stock of or Debt of any Person, which Mortgages are existing at the time (i) such Person became a Restricted Subsidiary, (ii) such Person is merged into or consolidated with the Company or any Subsidiary or (iii) the Company or a Subsidiary merges into or consolidates with such Person (in a transaction in which such Person becomes a Restricted Subsidiary), which Mortgage was not incurred in anticipation of such transaction and was outstanding prior to such transaction;

(c)    Mortgages in favor of the Company or any Subsidiary Guarantor;

(d)    Mortgages in favor of a governmental entity or in favor of the holders of securities issued by any such entity, pursuant to any contract or statute (including Mortgages to secure debt of the pollution control or industrial revenue bond type) or to secure any indebtedness incurred for the purpose of financing all or any part of the purchase price or the cost of construction of the property subject to such Mortgages;

(e)    Mortgages in favor of any governmental entity to secure progress, advance or other payments pursuant to any contract or provision of any statute;

(f)    Mortgages on such property or shares of Capital Stock or Debt existing at the time of acquisition thereof (including acquisition through merger or consolidation);

(g)    Mortgages on such property or shares of Capital Stock or Debt to secure the payment of all or any part of the purchase price or construction cost thereof or

-10-

to secure any Debt incurred prior to, at the time of, or within 180 days after, the acquisition of such property or shares or Debt, the completion of any construction or the commencement of full operation, for the purpose of financing all or any part of the purchase price or construction cost thereof;

(h)    Mortgages incurred in connection with a Sale and Leaseback Transaction satisfying the provisions set forth in Section 4.09; and

(i)    any extension, renewal or replacement (or successive extensions, renewals or replacements), as a whole or in part, of any Mortgage referred to in the foregoing clauses; provided that such extension, renewal or replacement Mortgage shall be limited to all or a part of the same such property or shares of Capital Stock or Debt that secured the Mortgage extended, renewed or replaced (plus improvements on such property).

Section 4.09. Limitations on Sale and Leaseback Transactions .

The Company shall not, and shall not permit any Restricted Subsidiary to, enter into any arrangement with any bank, insurance company or other lender or investor (not including the Company or any Restricted Subsidiary) or to which any such lender or investor is a party, providing for the leasing by the Company or a Restricted Subsidiary for a period, including renewals, in excess of three years of any Principal Property the ownership of which has been or is to be sold or transferred, more than 180 days after the completion of construction and commencement of full operation thereof, by the Company or such Restricted Subsidiary to such lender or investor or to any Person to whom funds have been or are to be advanced by such lender or investor on the security of such Principal Property (referred to as a “ Sale and Leaseback Transaction ”) unless:

(a)    such Sale and Leaseback Transaction is with a governmental entity that provides financial or tax benefits;

(b)    the Company or such Restricted Subsidiary could create Secured Debt pursuant to the provisions set forth in Section 4.08 on the Principal Property to be leased in an amount equal to the Attributable Debt with respect to such Sale and Leaseback Transaction without equally and ratably securing the Notes; or

(c)    the net proceeds of the sale or transfer of the Principal Property leased pursuant to such Sale and Leaseback Transaction is at least equal to the Fair Market Value of such Principal Property and within 180 days after such sale or transfer shall have been made by the Company or by a Restricted Subsidiary, the Company shall apply an amount not less than the greater of (i) the net proceeds of the sale of the Principal Property leased pursuant to such arrangement or (ii) the Fair Market Value of the Principal Property so leased at the time of entering into such arrangement (as evidenced

-11-

by an Officers’ Certificate delivered to the Trustee) to the retirement of Funded Debt of the Company; provided that the amount to be applied to the retirement of Funded Debt of the Company shall be reduced by (x) the principal amount of Notes delivered within 180 days after such sale to the Trustee for retirement and cancellation, and (y) the principal amount of Funded Debt other than Notes, voluntarily retired by the Company within 180 days after such sale. No retirement referred to in this clause (c) may be effected by payment at maturity or pursuant to any mandatory sinking fund payment or mandatory prepayment provision.

Section 4.10.      Change of Control . In the event of a Change of Control Triggering Event, the Company shall promptly provide written notice to the Trustee. Additionally, in respect of a Change of Control Triggering Event, the GO Zone Indenture shall provide as follows (capitalized terms used herein have the meanings set forth in the GO Zone Indenture):

“(a)    Upon the occurrence of a Change of Control Triggering Event, each Bondholder shall have the right to require the Borrower, who may designate a third party for this purpose (in either case, the “Borrower Designee” ), to repurchase all or any part (which will be in an amount equal to an Authorized Denomination) of that Bondholder’s Bonds pursuant to an offer (the “Change of Control Offer” ) on the terms set forth in this Section 3.7. In the Change of Control Offer, the Borrower Designee shall offer a payment in cash equal to 101% of the aggregate principal amount of Bonds repurchased, plus accrued and unpaid interest on the Bonds repurchased, if any, to the date of purchase, subject to the rights of Bondholders on the relevant record date to receive interest due on the relevant Interest Payment Date (such payment, a “Change of Control Payment” ). Within 30 days following any Change of Control Triggering Event, at the written direction of the Borrower Designee (which direction shall include a description of the transaction or transactions that constitute the Change of Control Triggering Event), the Trustee will mail a notice to each Bondholder describing the transaction or transactions that constitute the Change of Control Triggering Event and offering to repurchase Bonds on behalf of and at the direction of the Borrower on the date specified in the notice (such date, the “Change of Control Payment Date” ), which date will be no earlier than 30 days and no later than 60 days from the date such notice is mailed, pursuant to the procedures required by this Indenture and described in such notice.

(b)    On the Change of Control Payment Date, the Borrower Designee shall, to the extent lawful:

(i)    accept for payment all Bonds or portions of Bonds properly tendered pursuant to the Change of Control Offer;

-12-

(ii)    deposit with the Paying Agent an amount equal to the Change of Control Payment in respect of all Bonds or portions of Bonds properly tendered;

(iii)    deliver or cause to be delivered to the Trustee the Bonds properly accepted together with an officers’ certificate stating the aggregate principal amount of Bonds or portions of Bonds being purchased by the Borrower Designee; and

(iv)    deliver to the Trustee and Paying Agent a written direction or instruction to effect the Change of Control Payment in respect of the Bonds or portions of Bonds properly tendered (such direction or instruction may be contained within the Officer’s Certificate set forth in (iii) above).

(c)    The Paying Agent shall promptly pay to each Bondholder of Bonds properly tendered the Change of Control Payment for such Bonds, and the Trustee shall promptly authenticate and mail (or cause to be transferred by book entry) to each Bondholder a new Bond equal in principal amount to any unpurchased portion of the Bonds surrendered, if any; provided that each new Bond will be in a principal amount equal to an Authorized Denomination.

(d)    Sections 3.7(a) and 3.7(b) will be applicable whether or not any other provisions of this Indenture are applicable to the transaction.

(e)    The Borrower Designee shall not be required to make a Change of Control Offer upon a Change of Control if (1) a third party makes the Change of Control Offer in the manner, at the times and otherwise in compliance with the requirements set forth in this Indenture applicable to a Change of Control Offer made by the Borrower Designee and purchases all Bonds properly tendered and not withdrawn under the Change of Control Offer, or (2) notice of redemption has been given pursuant to this Indenture unless and until there is a default in payment of the applicable redemption price.”

Section 4.11. Additional Guarantees .

If, after the date of this Supplemental Indenture, any Domestic Subsidiary that is not already a Subsidiary Guarantor (including, without limitation, any Domestic Subsidiary acquired or created after the date of this Supplemental Indenture) guarantees any Debt in excess of $40 million of either the Company or a Subsidiary Guarantor, then in either case that Subsidiary shall become a Subsidiary Guarantor by executing a supplemental indenture and delivering it to the Trustee within 15 Business Days of the date on which it guaranteed such Debt.

-13-

ARTICLE FIVE

Guarantee

Section 5.01. Release of Subsidiary Guarantors from Guarantee .

Section 10.04 of the Indenture shall be amended by replacing that section of the Indenture with the following, but only with respect to the Notes:

(a)    Notwithstanding any other provisions of this Indenture, the Guarantee of any Subsidiary Guarantor may be released upon the terms and subject to the conditions set forth in this Section 10.04. Provided that no Event of Default shall have occurred and shall be continuing under this Indenture, any Guarantee incurred by a Subsidiary Guarantor pursuant to this Article X shall be unconditionally released and discharged automatically:

(i)    upon any sale or other disposition of all or substantially all of the assets of that Subsidiary Guarantor (including by way of merger or consolidation) to a Person that is not (either before or after giving effect to such transaction) the Company or a Subsidiary;

(ii)    upon any sale or other disposition of all of the Capital Stock of a Subsidiary Guarantor to a Person that is not (either before or after giving effect to such transaction) the Company or a Subsidiary;

(iii)    upon legal defeasance or satisfaction and discharge of the Notes as provided in Article VIII; or

(iv)    at such time as such Subsidiary Guarantor ceases to guarantee any Debt of the Company or a Subsidiary Guarantor in excess of $40 million other than Debt under one of more series of Securities issued pursuant to the Indenture; provided that, if such Guarantor solely guarantees Debt under one or more series of Securities issued pursuant to the Indenture, the guarantees of each such series of Securities may be released concurrently.

(b)    The Trustee shall deliver an appropriate instrument evidencing any release of a Subsidiary Guarantor from its Guarantee upon receipt of a written request of the Company accompanied by an Officers’ Certificate and an Opinion of Counsel to the effect that the Subsidiary Guarantor is entitled to such release in accordance with the provisions of this Indenture. If the Subsidiary Guarantor is not so released it shall remain liable for the full amount of principal of (and premium, if any, on) and interest on the Notes, subject to the limitations of Section 10.03.

-14-

ARTICLE SIX

Miscellaneous

Section 6.01. No Recourse Against Others .

Section 11.08 of the Indenture shall be amended by replacing that section of the Indenture with the following, but only with respect to the Notes:

A director, officer, member, manager, employee, stockholder, partner or other owner of the Company, any Subsidiary Guarantor or the Trustee, as such, shall not have any liability for any obligations of the Company under the Notes, for any obligations of any Subsidiary Guarantor under any Guarantee, or for any obligations of the Company, any Subsidiary Guarantor or the Trustee under this Indenture or for any claim based on, in respect of or by reason of such obligations or their creation. Each Holder by accepting a Note waives and releases all such liability. The waiver and release shall be part of the consideration for the issuance of Notes.

Section 6.02. Governing Law .

The laws of the State of New York shall govern this Supplemental Indenture, the Notes and the related Guarantees.

Section 6.03. No Adverse Interpretation of Other Agreements .

This Supplemental Indenture may not be used to interpret another indenture (other than the Indenture), loan or debt agreement of the Company, any Subsidiary Guarantor or a Subsidiary. Any such indenture, loan or debt agreement may not be used to interpret this Supplemental Indenture.

Section 6.04. Successors and Assigns .

All covenants and agreements of the Company and each of the Subsidiary Guarantors in this Supplemental Indenture and the Notes shall bind its successors and assigns. All agreements of the Trustee in this Supplemental Indenture shall bind its successors and assigns.

Section 6.05. Duplicate Originals .

The parties may sign any number of copies of this Supplemental Indenture. Each signed copy shall be an original, but all of them together represent the same agreement.

-15-

Section 6.06. Severability .

In case any provision in this Supplemental Indenture or in the Notes or in any Guarantee of a Subsidiary Guarantor shall be invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions shall, to the fullest extent permitted by applicable law, not in any way be affected or impaired thereby.

Section 6.07. Amendments Without Consent of Holders .

Section 9.01 of the Indenture is supplemented with the addition of the following with respect to the Notes:

(12)    to confirm as further assurance any mortgage or pledge of additional property, revenues, securities or funds;

(13)    to provide any other modifications which, in the sole judgment of the Trustee, are not prejudicial to the interests of the Holders of the Notes; or

(14)    to conform the covenants and provisions of the Company contained in the Indenture to any different financial statement presentation required by the Financial Accounting Standard Board which is different than the presentation required as of the date of issuance of the Notes, so long as the effect of such conformed covenants and provisions is substantially identical to the effect of the covenants and provisions as in effect on the date of issuance of the Notes.

Section 6.08. Rights of Trustee.

In no event shall the Trustee be responsible or liable for special, indirect, punitive or consequential loss or damage of any kind whatsoever (including, but not limited to, loss of profit) irrespective of whether the Trustee has been advised of the likelihood of such loss or damage and regardless of the form of action.

The Trustee may request that the Company or any Subsidiary Guarantor deliver an Officers’ Certificate setting forth the names of individuals and/or titles of officers (with specimen signatures) authorized at such times to take specific actions pursuant to this Supplemental Indenture, which Officers’ Certificate may be signed by any person specified as so authorized in any such certificate previously delivered and not superseded.

Section 6.09. Waiver of Jury Trial.

Each of the Company, the Subsidiary Guarantors and the Trustee hereby irrevocably waives, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to this Supplemental Indenture, the Indenture, the Notes or the transactions contemplated hereby.

Section 6.10. Force Majeure.

In no event shall the Trustee be responsible or liable for any failure or delay in the performance of its obligations under this Supplemental Indenture arising out of or caused by, directly or indirectly, forces beyond its reasonable control, including, without limitation, strikes, work stoppages, accidents, acts of war or terrorism, civil or military disturbances, nuclear or natural catastrophes or acts of God, and interruptions, loss or malfunctions of utilities, communications or computer (software or hardware) services.

-16-

Section 6.11. No Recitals, etc.

The Trustee shall not be responsible in any manner whatsoever for or in respect of the validity or sufficiency of this Supplemental Indenture or for or in respect of the recitals contained herein, all of which are made solely by the Company and the Subsidiary Guarantors.

Section 6.12. Notices.

The Trustee agrees to accept and act upon instructions or directions pursuant to this Indenture sent by unsecured e-mail, pdf, facsimile transmission or other similar unsecured electronic methods, provided, however, that the Trustee shall have received an incumbency certificate listing persons designated to give such instructions or directions and containing specimen signatures of such designated persons, which such incumbency certificate shall be amended and replaced as necessary prior to the giving of such instructions or directions. If the Company elects to give the Trustee e-mail or facsimile instructions (or instructions by a similar electronic method) and the Trustee in its discretion elects to act upon such instructions, the Trustee’s understanding of such instructions shall be deemed controlling. The Trustee shall not be liable for any losses, costs or expenses arising directly or indirectly from the Trustee’s reliance upon and compliance with such instructions notwithstanding such instructions conflict or are inconsistent with a subsequent written instruction. The Company agrees to assume all risks arising out of the use of such electronic methods to submit instructions and directions to the Trustee, including without limitation the risk of the Trustee acting on unauthorized instructions, and the risk or interception and misuse by third parties.

Section 6.13. Foreign Account Tax Compliance Act.

Each of the Company and the Trustee agrees to provide the other with such information in its possession (subject in all cases to applicable privacy laws) as reasonably requested by the other to enable the determination of whether any payment to a Holder pursuant to the Indenture is subject to withholding imposed pursuant to Sections 1471 through 1474 of the Internal Revenue Code, any regulations thereunder, intergovernmental agreements in respect thereof or official interpretations of any of the foregoing (“Applicable FATCA Law”). The Trustee shall be entitled to make any withholding or deduction from payments under the Notes or this Indenture to the extent necessary (in the Trustee’s reasonable judgment) to comply with Applicable FATCA Law, for which the Trustee shall not have any liability.

Section 6.14 Submission to Jurisdiction .

The Company and each Subsidiary Guarantor hereby irrevocably submits to the jurisdiction of any New York State court sitting in the Borough of Manhattan in the City of New York or any federal court sitting in the Southern District in the Borough of

-17-

Manhattan in the City of New York in respect of any suit, action or proceeding arising out of or relating to this Indenture, the Guarantees and the Notes, and irrevocably accepts for itself and in respect of its property, generally and unconditionally, jurisdiction of the aforesaid courts.

-18-

SIGNATURES

IN WITNESS WHEREOF, the parties have caused this Supplemental Indenture to be duly executed, all as of the date first above written.

SUBSIDIARY GUARANTORS :

WESTLAKE CHEMICAL CORPORATION, a corporation duly organized and existing under the laws of the State of Delaware (herein called the “ Company ,” which term includes any successor under the Indenture referred to below), for value received, hereby promises to pay to THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., a national banking organization, as Trustee under the GO Zone Indenture (as herein defined) or its registered assigns (the “GO Zone Trustee ”), the principal sum of TWO HUNDRED FIFTY MILLION DOLLARS, in whole or in installments on such date or dates (subject to the tenth paragraph hereof) and in such amounts, and to pay to the GO Zone Trustee premium, if any, in whole or in installments on such date or dates and in such amounts, as the Issuer (as defined herein) has any obligations under the Amended and Restated Indenture of Trust (as may be amended and supplemented from time to time, the “ GO Zone Indenture ”), dated as of November 1, 2017, between the Louisiana Local Government Environmental Facilities and Community Development Authority (the “ Issuer ”) and the GO Zone Trustee to repay any principal or to pay premium, if any, in respect of the Revenue Refunding Bonds (Westlake Chemical Corporation Projects), Series 2017 (GO Zone)(Non-AMT) issued under the GO Zone Indenture (hereinafter referred to as the “ GO Zone Bonds ”),

A-1

but not later than the Stated Maturity specified above. The obligation of the Company to make any payment of principal or premium, if any, on this Note, whether at maturity or otherwise, shall be fully or partially, as the case may be, deemed to have been paid or otherwise satisfied and discharged to the extent that the Company has paid or caused to be paid to the GO Zone Trustee the Payments (as defined below) in respect of the principal or premium, if any, then due and payable on the GO Zone Bonds.

Interest shall be payable on this Note on the same dates as interest is payable from time to time in respect of the GO Zone Bonds pursuant to the GO Zone Indenture (each such date herein called an “ Interest Payment Date ”), at such rate or rates per annum as shall cause the amount of interest payable on such Interest Payment Date on this Note to equal the amount of interest payable on such Interest Payment Date in respect of the GO Zone Bonds under the GO Zone Indenture. Such interest shall be payable until the maturity of this Note, or, if the Company shall default in the payment of the principal due on this Note, until the Company’s obligation with respect to the payment of such principal shall be discharged as provided in the Indenture (as defined below). The amount of interest payable from time to time in respect of the GO Zone Bonds under the GO Zone Indenture, the basis on which such interest is computed and the dates on which such interest is payable are set forth in the GO Zone Indenture. This Note shall bear interest from the Original Interest Accrual Date listed on the first page of this Note. The obligation of the Company to make any payment of interest on this Note shall be fully or partially, as the case may be, deemed to have been paid or otherwise satisfied and discharged to the extent that the Company has paid or caused to be paid to the GO Zone Trustee the Payments in respect of the interest then due and payable on the GO Zone Bonds.

This Note is issued to the GO Zone Trustee in order that the GO Zone Trustee shall have the benefit as a holder (the “ Holder ”) of this Note of the lien of the Indenture in the event of the non-payment by the Company of the Payments (the “ Payments ”), as defined in and pursuant to the Amended and Restated Loan Agreement (as may be amended and supplemented from time to time, the “ Loan Agreement ”), dated as of November 1, 2017, between the Issuer and the Company entered into with respect to the GO Zone Bonds. Any capitalized terms used herein and not defined herein shall have the meanings specified in the Indenture, unless otherwise noted.

THIS NOTE SHALL NOT BE TRANSFERABLE EXCEPT AS REQUIRED TO EFFECT AN ASSIGNMENT HEREOF TO A SUCCESSOR OR AN ASSIGN OF THE GO ZONE TRUSTEE UNDER THE GO ZONE INDENTURE.

The GO Zone Trustee shall surrender this Note to the Trustee (as defined below) in accordance with Section 4.6(d) of the Loan Agreement.

Payments of the principal of, premium, if any, and interest on this Note shall be made at the Corporate Trust Department of The Bank of New York Mellon Trust Company, N.A., as Trustee, located at 601 Travis Street, 16th Floor, Houston, Texas 77002, or at such other office or agency as may be designated for such purpose by the Company from time to time. Payment of the principal of, premium, if any, and interest on this Note, as aforesaid, shall be made in such coin or currency of the United States of America as at the time of payment shall be legal tender for the payment of public and private debts.

A-2

This Note is one of a duly authorized issue of securities of the Company (herein called the “ Securities ”), issued and issuable in one or more series under and equally secured by an Indenture, by and among the Company, the Potential Subsidiary Guarantors (as defined therein) and The Bank of New York Mellon Trust Company, N.A. (as successor to JPMorgan Chase Bank, National Association), as trustee, dated as of January 1, 2006, as supplemented by the Tenth Supplemental Indenture, by and among the Company, the Subsidiary Guarantors (as defined therein) and The Bank of New York Mellon Trust Company, N.A., as trustee (herein called the “ Trustee ,” which term includes any successor trustee under the Indenture), dated as of November 29, 2017 (the “ Indenture ”), to which Indenture reference is hereby made for a description of the nature and extent of the security and the respective rights, limitations of rights, duties and immunities of the Company, the Trustee and the Holders of the Securities thereunder and of the terms and conditions upon which the Securities are, and are to be, authenticated and delivered and secured. The acceptance of this Note shall be deemed to constitute the consent and agreement by the Holder hereof to all of the terms and provisions of the Indenture. This Note is one of the series designated above.

Except as otherwise provided in this Note and the Tenth Supplemental Indenture, the Notes of this series will not be entitled to the benefit of any sinking fund or voluntary redemption provisions.

If an Event of Default, as defined in the Indenture, shall occur and be continuing, the principal of this Note may be declared due and payable in the manner and with the effect provided in the Indenture.

Except as otherwise provided in this Note and the Tenth Supplemental Indenture, this Note shall not be redeemable at the option of the Company or otherwise pursuant to the requirements of the Indenture, provided however that in the event of a redemption of GO Zone Bonds under Article III of the GO Zone Indenture and as reflected in the GO Zone Bonds set forth in Exhibit A thereto, the Company will redeem Notes equal in principal amount to the GO Zone Bonds to be redeemed at a redemption price equal to the redemption price of the GO Zone Bonds to be redeemed, plus accrued interest to the date fixed for redemption.

The Indenture permits, with certain exceptions as therein provided, the Trustee to enter into one or more supplemental indentures for the purpose of adding any provisions to, or changing in any manner or eliminating any of the provisions of, the Indenture with the consent of the Holders of not less than a majority in aggregate principal amount of the Securities of all series then outstanding under the Indenture, considered as one class; PROVIDED, HOWEVER, that if there shall be Securities of more than one series outstanding under the Indenture and if a proposed supplemental indenture shall directly affect the rights of the Holders of Securities of one or more, but less than all, of such series, then the consent only of the Holders of a majority in aggregate principal amount of the outstanding Securities of all series so directly affected, considered as one class, shall be required; and PROVIDED, FURTHER, that if the Securities of any series shall have been issued in more than one tranche and if the proposed supplemental indenture shall directly affect the rights of the Holders of Securities of one or more, but less than all, of such tranches, then the consent only of the Holders of a majority in aggregate principal amount of the outstanding Securities of all tranches so directly affected, considered as one class, shall be required; and PROVIDED, FURTHER, that the Indenture permits the Trustee to enter into one or

A-3

more supplemental indentures for limited purposes without the consent of any Holders of Securities. The Indenture also contains provisions permitting the Holders of a majority in principal amount of the Securities then outstanding, on behalf of the Holders of all Securities, to waive compliance by the Company with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent or waiver by the Holder of this Note shall be conclusive and binding upon such Holder and upon all future Holders of this Note and of any Security issued upon the registration of transfer hereof or in exchange therefor or in lieu hereof, whether or not notation of such consent or waiver is made upon this Note.

As provided in the Indenture and subject to certain limitations therein and herein set forth, the transfer of this Note is registrable in the Security Register, upon surrender of this Note for registration of transfer at the Corporate Trust Office of The Bank of New York Mellon Trust Company, N.A., in Houston, Texas or such other office or agency as may be designated by the Company from time to time, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or his attorney duly authorized in writing, and thereupon one or more new Notes of this series of authorized denominations and of like tenor and aggregate principal amount, will be issued to the designated transferee or transferees.

The Company, the Trustee and any agent of the Company or the Trustee may deem and treat the person in whose name this Note shall be registered upon the Security Register for the Notes of this series as the absolute owner of such Note for the purpose of receiving payment of or on account of the principal of and interest on this Note and for all other purposes, whether or not this Note be overdue, and neither the Company nor the Trustee shall be affected by any notice to the contrary; and all such payments so made to such registered owner or upon his order shall be valid and effectual to satisfy and discharge the liability upon this Note to the extent of the sum or sums paid.

The Trustee may conclusively presume that the obligation of the Company to pay the principal of, premium, if any, and interest on this Note shall have been fully satisfied and discharged unless and until it shall have received a written notice from the GO Zone Trustee, signed by an authorized officer of the GO Zone Trustee and attested by the Secretary or an Assistant Secretary of the GO Zone Trustee, stating that the payment of principal of, premium, if any, or interest on this Note has not been fully paid when due and specifying the amount of funds required to make such payment.

The obligation of the Company to make any payment of the principal of, premium, if any, or interest on this Note, whether at maturity, upon redemption (including any redemption due to the occurrence of a Determination of Taxability as required by Section 3.6(d) of the Go Zone Indenture, as such term is defined in Section 1.1 of the GO Zone Indenture and reflected in the Form of the GO Zone Bonds set forth in Exhibit A thereof) or otherwise, shall be fully or partially, as the case may be, deemed to have been paid or otherwise satisfied and discharged to the extent that at the time any such payment shall be due, the then due principal, premium, if any, or interest on the GO Zone Bonds which corresponds to such amounts under this Note shall have been fully or partially paid, deemed to have been paid or otherwise satisfied and discharged. In addition, such obligation to make any payment of the principal of, premium, if any, or interest on this Note at any time shall be deemed to have been satisfied and discharged to the extent that the amount of the Company’s obligation to make any payment of the principal of, premium, if any, or interest on this Note exceeds the obligation of the Company at that time to make any Payment.

A-4

No recourse under or upon any obligation, covenant or agreement contained in the Indenture or in any indenture supplemental thereto, or in any Note or coupon thereby secured, or because of any indebtedness thereby secured, shall be had against any incorporator, member, manager, stockholder, officer, director or employee, as such, past, present or future, of the Company or any predecessor or successor corporation or company, either directly or through the Company or any predecessor or successor corporation or company, whether by virtue of any constitution, statute or rule of law, or by the enforcement of any assessment or penalty or otherwise; it being expressly agreed and understood that the Indenture, any indenture supplemental thereto and the obligations thereby secured, are solely corporate obligations of the Company, and that no personal liability whatsoever shall attach to, or be incurred by, such incorporators, members, managers, stockholders, officers, directors or employees, as such, of the Company or of any predecessor or successor corporation or company, or any of them, because of the creation of the indebtedness thereby authorized, or under or by reason of any of the obligations, covenants or agreements contained in the Indenture or in any indenture supplemental thereto or in any of the Notes or coupons thereby secured, or implied therefrom.

The Holder of this Note by acceptance of this Note agrees to restrictions on transfer and to waivers of certain rights of exchange as set forth herein. THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 AND MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED IN THE ABSENCE OF SUCH REGISTRATION OR AN APPLICABLE EXEMPTION THEREFROM. No service charge shall be made for the registration of transfer or exchange of this Note.

This Note shall be governed by and construed in accordance with the law of the State of New York except as provided in the Indenture.

Unless the certificate of authentication hereon has been executed by the Trustee or an Authenticating Agent by manual signature, this Note shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

[The remainder of this page is intentionally left blank.]

A-5

IN WITNESS WHEREOF, the Company has caused this instrument to be duly executed.

CERTIFICATE OF AUTHENTICATION

This is one of the Securities of the series designated therein referred to in the within-mentioned Indenture.

Date of Authentication:                     , 20    

THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. ,

Trustee

A-6

ASSIGNMENT FORM

If you the Holder want to assign this Security, fill in the form below:

I or we assign and transfer this Security to

(Insert assignee’s social security or tax ID number)

(Print or type assignee’s name, address, and zip code)

and irrevocably appoint

agent to transfer this Security on the books of the Company. The agent may substitute another to act for him.

A-7

[FORM OF NOTATION ON SECURITY RELATING TO GUARANTEE]

NOTATION OF GUARANTEE

The undersigned (the “ Subsidiary Guarantors ”) have unconditionally guaranteed, jointly and severally (such guarantee by each Subsidiary Guarantor being referred to herein as the “ Guarantee ”), (i) the due and punctual payment of the principal of, and premium, if any, and interest on the Notes, whether at maturity, by acceleration or otherwise, the due and punctual payment of interest on the overdue principal and interest, if any, on the Notes, to the extent lawful, and the due and punctual performance of all other obligations of the Company to the Holders or the Trustee all in accordance with, and subject to the limitations of, the terms set forth in Article X of the Indenture and (ii) in case of any extension of time of payment or renewal of any Notes or any of such other obligations, that the same will be promptly paid in full when due or performed in accordance with the terms of the extension or renewal, whether at stated maturity, by acceleration or otherwise.

The obligation of the Subsidiary Guarantors to make any payment under this Guarantee shall be fully or partially, as the case may be, deemed to have been paid or otherwise satisfied and discharged to the extent that at the time any such payment shall be due, the then due principal, premium, if any, or interest on the GO Zone Bonds which corresponds to such amounts under this Guarantee shall have been fully or partially paid, deemed to have been paid or otherwise satisfied and discharged. In addition, such obligation to make any payment on this Guarantee at any time shall be deemed to have been satisfied and discharged to the extent that the amount of the Company’s obligation to make any payment of the principal of, premium, if any, or interest on the Note exceeds the obligation of the Company at that time to make any Payment.

No past, present or future stockholder, officer, director, member, manager, partner, employee or incorporator, as such, of any of the Subsidiary Guarantors shall have any liability under the Guarantee by reason of such person’s status as stockholder, officer, director, member, manager, partner, employee or incorporator. Each Holder of a Note by accepting a Note waives and releases all such liability. This waiver and release are part of the consideration for the issuance of the Guarantees.

Each Holder of a Note by accepting a Note agrees that any Subsidiary Guarantor named below shall have no further liability with respect to its Guarantee if such Subsidiary Guarantor otherwise ceases to be liable in respect of its Guarantee in accordance with the terms of the Indenture.

A-8

The Guarantee shall not be valid or obligatory for any purpose until the certificate of authentication on the Notes upon which the Guarantee is noted shall have been executed by the Trustee under the Indenture by the manual signature of one of its authorized officers.

A-9

A-10

Exhibit 4.3

WESTLAKE CHEMICAL CORPORATION AND THE SUBSIDIARY

GUARANTORS PARTY HERETO

4.375% Senior Notes due 2047

Eleventh Supplemental Indenture

Dated as of November 28, 2017

THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.

Trustee

TABLE OF CONTENTS

-i-

ELEVENTH SUPPLEMENTAL INDENTURE dated as of November 28, 2017 (this “ Supplemental Indenture ”), to the Indenture dated as of January 1, 2006 (the “ Indenture ”), by and among WESTLAKE CHEMICAL CORPORATION, a Delaware corporation (the “ Company ”), each of the Subsidiary Guarantors (as defined herein) and THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. (as successor to JPMorgan Chase Bank, National Association), as trustee (the “ Trustee ”).

Each party agrees as follows for the benefit of the other parties and for the equal and ratable benefit of the Holders (as defined herein):

WHEREAS, the Company, the Subsidiary Guarantors and the Trustee have duly authorized the execution and delivery of the Indenture to provide for the issuance from time to time of the Company’s debentures, notes, bonds or other evidences of indebtedness to be issued in one or more series as in the Indenture provided (as defined therein, “ Securities ”);

WHEREAS, the Company and the Subsidiary Guarantors desire and have requested the Trustee to join them in the execution and delivery of this Supplemental Indenture in order to establish and provide for the issuance by the Company of a series of Securities designated as its 4.375% Senior Notes due 2047, substantially in the form attached hereto as Exhibit  A (the “ Notes ”), guaranteed by the Subsidiary Guarantors, on the terms set forth herein;

WHEREAS, Section 2.01 of the Indenture provides that a supplemental indenture may be entered into by the Company, the Subsidiary Guarantors and the Trustee for such purpose provided certain conditions are met;

WHEREAS, the conditions set forth in the Indenture for the execution and delivery of this Supplemental Indenture have been complied with; and

WHEREAS, all things necessary to make this Supplemental Indenture a valid agreement of the Company, the Subsidiary Guarantors and the Trustee, in accordance with its terms, and a valid amendment of, and supplement to, the Indenture have been done;

NOW, THEREFORE:

In consideration of the premises and the purchase and acceptance of the Notes by the Holders thereof, the Company and the Subsidiary Guarantors mutually covenant and agree with the Trustee, for the equal and ratable benefit of the Holders, that the Indenture is supplemented and amended, to the extent expressed herein, as follows:

ARTICLE ONE

Scope of Supplemental Indenture; General

The changes, modifications and supplements to the Indenture effected by this Supplemental Indenture shall be applicable only with respect to, and govern the terms of, the Notes, which shall not be limited in aggregate principal amount, and shall not apply to any other Securities that may be issued under the Indenture unless a supplemental indenture with respect to such other Securities specifically incorporates such changes, modifications and supplements. Pursuant to this Supplemental Indenture, there is hereby created and designated a series of Securities under the Indenture entitled “4.375% Senior Notes due 2047.” The Notes shall be in the form of Exhibit  A hereto, which is hereby incorporated into this Supplemental Indenture by reference. The Notes shall be guaranteed by the Subsidiary Guarantors as provided in such form and the Indenture.

ARTICLE TWO

Certain Definitions

The following terms have the meanings set forth below in this Supplemental Indenture. Capitalized terms used but not defined herein have the meanings ascribed to such terms in the Indenture. To the extent terms defined herein differ from the Indenture the terms defined herein will govern.

“ Attributable Debt ” means, as to any lease in respect of a Sale and Leaseback Transaction under which any Person is at the time liable, at any date as of which the amount thereof is to be determined, the total net amount of rent required to be paid by such Person under such lease during the remaining term thereof (or, if earlier, the first date upon which such lease may be terminated without penalty), discounted from the respective due dates thereof to such date at the weighted average rate per annum borne by the Notes, compounded annually. The net amount of rent required to be paid under any such lease for any such period shall be the aggregate amount of the rent payable by the lessee with respect to such period after excluding amounts required to be paid on account of maintenance and repairs, insurance, taxes, assessments, water rates and similar charges. Unless the Company elects to calculate the total amount of rent required to be paid through the first date upon which such lease may be terminated without penalty (if such a provision exists), in the case of any lease which is terminable by the lessee upon the payment of a penalty, such net amount shall also include the amount of such penalty, but no rent shall be considered as required to be paid under such lease subsequent to the first date upon which it may be so terminated.

-2-

“ Below Investment Grade Rating Event ” means the rating on the Notes is lowered and as a result the Notes cease to be rated Investment Grade by each of the Rating Agencies on any date during the period (the “ Trigger Period ”) commencing on the earlier of (a) the occurrence of a Change of Control and (b) the first public announcement by the Company of any Change of Control (or pending Change of Control) and ending 60 days following the consummation of such Change of Control (which Trigger Period will be extended if the rating of the Notes is under publicly announced consideration for possible downgrade by any Rating Agency on such 60th day, such extension to last with respect to each Rating Agency until the date on which such Rating Agency considering such possible downgrade either (x) rates the Notes below Investment Grade or (y) publicly announces that it is no longer considering the Notes for possible downgrade; provided, that no such extension will occur if on such 60th day the Notes are rated Investment Grade not subject to review for possible downgrade by any Rating Agency); provided, that a rating event will not be deemed to have occurred in respect of a particular Change of Control (and thus will not be deemed a Below Investment Grade Rating Event for purposes of the definition of Change of Control Triggering Event contained in this Article Two) if each Rating Agency making the reduction in rating does not publicly announce or confirm or inform the Trustee in writing at the Company’s request that the reduction was the result, in whole or in part, of any event or circumstance comprised of or arising as a result of, or in respect of, the Change of Control (whether or not the applicable Change of Control has occurred at the time of the Below Investment Grade Rating Event). If any Rating Agency withdraws its rating on the Notes or otherwise ceases to provide a rating on the Notes on any day during the Trigger Period for any reason and the Company has not selected a replacement Rating Agency pursuant to the terms of this Supplemental Indenture, the rating of such Rating Agency shall be deemed to be rated below Investment Grade on such day.

“ Beneficial Owner ” has the meaning assigned to such term in Rule 13d-3 and Rule 13d-5 under the Exchange Act, except that in calculating the beneficial ownership of any particular “person” as such term is used in Section 13(d)(3) of the Exchange Act, such “person” will be deemed to have beneficial ownership of all securities that such “person” has the right to acquire by conversion or exercise of other securities, whether such right is currently exercisable or is exercisable only upon the occurrence of a subsequent condition.

“ Capital Stock ” means:

(1)    in the case of a corporation, capital stock;

(2)    in the case of an association or business entity, any and all shares, interests, participations, rights or other equivalents (however designated) of capital stock;

(3)    in the case of a partnership or limited liability company, partnership interests (whether general or limited) or membership interests, respectively; and

-3-

(4)    any other interest or participation that confers on a Person the right to receive a share of the profits and losses of, or distributions of assets of, the issuing Person, but excluding from all of the foregoing any debt securities convertible into Capital Stock, whether or not such debt securities include any right of participation with Capital Stock.

“ Change of Control ” means the occurrence of any of the following after the date of this Supplemental Indenture:

(1)    the direct or indirect sale, lease, transfer, conveyance or other disposition (other than by way of merger or consolidation), in one or a series of related transactions, of all or substantially all of the assets of the Company and the Subsidiaries taken as a whole to any “person” or “group” (as those terms are used in Section 13(d)(3) of the Exchange Act) other than to the Company or a Subsidiary;

(2)    the consummation of any transaction (including, without limitation, any merger or consolidation) the result of which is that any “person” or “group” (as those terms are used in Section 13(d)(3) of the Exchange Act, it being agreed that an employee of the Company or any Subsidiary for whom shares are held under an employee stock ownership, employee retirement, employee savings or similar plan and whose shares are voted in accordance with the instructions of such employee shall not be a member of a “group” (as that term is used in Section 13(d)(3) of the Exchange Act) solely because such employee’s shares are held by a trustee under said plan) becomes the ultimate Beneficial Owner, directly or indirectly, of Voting Stock of the Company representing more than 50% of the voting power of the outstanding Voting Stock of the Company;

(3)    the Company consolidates with, or merges with or into, any Person, or any Person consolidates with, or merges with or into, the Company, in any such event pursuant to a transaction in which any of the outstanding Voting Stock of the Company or Voting Stock of such other Person is converted into or exchanged for cash, securities or other property, other than any such transaction where the Voting Stock of the Company outstanding immediately prior to such transaction constitutes, or is converted into or exchanged for, Voting Stock representing more than 50% of the voting power of the Voting Stock of the surviving Person or its parent immediately after giving effect to such transaction;

(4)    during any period of 24 consecutive calendar months, the majority of the members of the Board of Directors of the Company shall no longer be composed of individuals (a) who were members of the Board of Directors of the Company on the first day of such period or (b) whose election or nomination to the Board of Directors of the Company was approved by individuals referred to in clause (a) above constituting, at the time of such election or nomination, at least a majority of the Board of Directors of the Company or, if directors are nominated by a committee of the Board of Directors of the Company, constituting at the time of such nomination, at least a majority of such committee; or

-4-

(5)    the adoption of a plan relating to the liquidation or dissolution of the Company.

Notwithstanding the foregoing, a transaction will not be deemed to involve a Change of Control if (i) the Company becomes a direct or indirect wholly-owned subsidiary of a holding company and (ii) the direct or indirect holders of the Voting Stock of such holding company immediately following that transaction are substantially the same as the holders of the Voting Stock in the Company immediately prior to that transaction.

“ Change of Control Offer ” has the meaning provided in Section 4.10(a).

“ Change of Control Payment ” has the meaning provided in Section 4.10(a).

“ Change of Control Payment Date ” has the meaning provided in Section 4.10(b).

“ Change of Control Triggering Event ” means the occurrence of both a Change of Control and a Below Investment Grade Rating Event. Notwithstanding the foregoing, no Change of Control Triggering Event will be deemed to have occurred in connection with any particular Change of Control unless and until such Change of Control has actually been consummated.

“ Company ” has the meaning provided in the Indenture.

“ Comparable Treasury Issue ” means the U.S. Treasury security selected by an Independent Investment Banker as having a maturity comparable to the remaining term of the Notes to be redeemed (assuming for this purpose, that the Notes matured on May 15, 2047) that would be used, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of the Notes to be redeemed.

“ Comparable Treasury Price ” means, with respect to any Redemption Date, as determined by the Independent Investment Banker, (a) the average of the Reference Treasury Dealer Quotations for the Redemption Date, after excluding the highest and lowest of such Reference Treasury Dealer Quotations, or (b) if the Independent Investment Banker obtains fewer than four such Reference Treasury Dealer Quotations, the average of all quotations obtained.

“ Consolidated Net Tangible Assets ” means the aggregate amount of assets (less applicable reserves and other properly deductible items) after deducting therefrom (1) all current liabilities, except for (a) notes and loans payable, (b) current maturities of long-term debt and (c) current maturities of obligations under capital leases and (2) all goodwill, trade names, trademarks, patents, unamortized debt discount and expense and other like intangibles,

-5-

all as set forth on the most recent balance sheet of the Company and its consolidated Subsidiaries and computed in accordance with GAAP. Deferred income taxes, deferred investment tax credit or other similar items, as calculated in accordance with GAAP, will not be considered as a liability or as a deduction from or adjustment to total assets.

“ Debt ” has the meaning provided in Section 4.08.

“ Domestic Subsidiary ” means any Subsidiary that was formed under the laws of the United States or any state of the United States or the District of Columbia.

“ Fair Market Value ” means the price that could be negotiated in an arm’s-length transaction between a willing buyer and a willing seller not involving distress or necessity of either party, determined in good faith by the Board of Directors of the Company.

“ Funded Debt ” means all indebtedness for money borrowed having a maturity of more than 12 months from the date of the most recent balance sheet of the Company and its consolidated Subsidiaries or having a maturity of less than 12 months but by its terms being renewable or extendible beyond 12 months from the date of such balance sheet at the option of the borrower of such indebtedness.

“ Holder ” means the Person in whose name a Note is registered in the books of the Registrar for the Notes.

“ Indenture ” has the meaning provided in the Preamble.

“ Independent Investment Banker ” means one of the Reference Treasury Dealers appointed by the Company.

“ Investment Grade ” means a rating of Baa3 or better by Moody’s (or its equivalent under any successor rating category of Moody’s) and a rating of BBB- or better by S&P (or its equivalent under any successor rating category of S&P), and the equivalent investment grade credit rating from any replacement rating agency or rating agencies selected by the Company under the circumstances specified in this Supplemental Indenture permitting the Company to select a replacement rating agency and in the manner specified in this Supplemental Indenture for selecting a replacement rating agency, in each case as set forth in the definition of “Rating Agency.”

“ Moody’s ” means Moody’s Investors Service, Inc., a subsidiary of Moody’s Corporation, and its successors.

“ Mortgage ” and “ Mortgages ” have the meanings provided in Section 4.08.

“ Notes ” has the meaning provided in the Recitals.

-6-

“ Paying Agent ” means The Bank of New York Mellon Trust Company, N.A. or any successor paying agent.

“ Person ” means any individual, corporation, limited liability company, partnership, joint venture, incorporated or unincorporated association, joint stock company, trust, estate, unincorporated organization or government or any agency, instrumentality or political subdivision thereof or any other entity of any kind.

“ Principal Property ” means any single parcel of real estate, any single manufacturing plant or any single warehouse owned or leased in connection with a Sale and Leaseback Transaction by the Company or any Subsidiary which is located within the United States and the net book value of which on the date as of which the determination is being made exceeds 1% of Consolidated Net Tangible Assets, other than any such manufacturing plant or warehouse or portion thereof (1) which is a pollution control or other facility financed by obligations issued by a state or local government unit and described in Sections 141(a), 142(a)(5), 142(a)(6), 142(a)(10) or 144(a) of the Internal Revenue Code (or their successor provisions) or by any other obligations the interest of which is excluded under Section 103 of the Internal Revenue Code (or its successor provision), or (2) which, in the good-faith opinion of the Board of Directors of the Company, as evidenced by a Board Resolution, is not of material importance to the total business conducted by the Company and the Subsidiaries taken as a whole.

“ Rating Agency ” means each of Moody’s and S&P; provided, that if any of Moody’s or S&P ceases to provide rating services to issuers or investors, the Company may appoint another “nationally recognized statistical rating organization” (as defined under the Exchange Act) as a replacement for such Rating Agency; provided, that the Company shall give written notice of such appointment to the Trustee.

“ Reference Treasury Dealer ” means each of Merrill Lynch, Pierce, Fenner & Smith Incorporated, Deutsche Bank Securities Inc., Goldman, Sachs & Co. LLC and Wells Fargo Securities, LLC, and their respective successors, and one other nationally recognized investment banking firm that is a primary U.S. government securities dealer specified from time to time by the Company. If, however, any of them shall cease to be a primary U.S. government securities dealer, the Company will substitute another nationally recognized investment banking firm that is such a dealer.

“ Reference Treasury Dealer Quotations ” means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Independent Investment Banker, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Independent Investment Banker by such Reference Treasury Dealer as of 5:00 p.m., New York time, on the third Business Day preceding the Redemption Date.

-7-

“ Registrar ” means The Bank of New York Mellon Trust Company, N.A., or any successor registrar of the Notes.

“ Remaining Scheduled Payments ” means the remaining scheduled payments of the principal of and interest on each Note to be redeemed that would be due after the related Redemption Date but for such redemption.

“ Restricted Subsidiary ” means a wholly-owned Subsidiary of the Company substantially all of the assets of which are located in the United States (excluding territories or possessions) and which owns a Principal Property; provided, however, that the term Restricted Subsidiary shall not include any Subsidiary that is principally engaged in (1) the business of financing; (2) the business of owning, buying, selling, leasing, dealing in or developing real property; or (3) the business of exporting goods or merchandise from or importing goods or merchandise into the United States.

“ S&P ” means Standard & Poor’s Ratings Services LLC, a division of S&P Global, Inc., and its successors.

“ Sale and Leaseback Transaction ” has the meaning provided in Section 4.09.

“ Secured Debt ” has the meaning provided in Section 4.08.

“ Subsidiary ” means a Person more than 50% of the outstanding Voting Stock of which is owned, directly or indirectly, by the Company or by one or more other Subsidiaries, or by the Company and one or more other Subsidiaries.

“ Subsidiary Guarantors ” means:

(1)    each of the Subsidiaries of the Company listed on Schedule A to this Supplemental Indenture; and

(2)    any other Subsidiary that executes a Guarantee in accordance with the provisions of this Supplemental Indenture;

and their respective successors and assigns; provided that any Person constituting a Subsidiary Guarantor as described above shall cease to constitute a Subsidiary Guarantor when its respective Guarantee is released in accordance with the terms of this Supplemental Indenture.

“ Supplemental Indenture ” has the meaning provided in the Preamble.

“ Treasury Rate ” means, for any Redemption Date, the rate per annum equal to the semi-annual equivalent yield to maturity, computed as of the second Business Day immediately preceding that Redemption Date, of the Comparable Treasury Issue, assuming a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for that Redemption Date.

-8-

“ Trustee ” has the meaning provided in the Preamble.

“ Voting Stock ” of any specified Person as of any date means the capital stock (or comparable equity interests) of such Person that is at the time entitled to vote generally in the election of the board of directors (or members of the governing body) of such Person.

ARTICLE THREE

Redemption

Section 3.01. Selection of Securities To Be Redeemed .

Section 3.03 of the Indenture shall be amended by replacing that section of the Indenture with the following, but only with respect to the Notes:

If less than all of the Notes are to be redeemed, the particular Notes to be redeemed shall be selected not more than 60 days prior to the Redemption Date by the Trustee from the outstanding Notes not previously called for redemption, either pro rata or by lot; provided that, if at the time of redemption such Notes are registered as a Global Security, the Depositary shall determine, in accordance with its procedures, the principal amount of such Notes held by each beneficial owner of Notes to be redeemed.

The Trustee shall promptly notify the Company and the Registrar in writing of the Notes selected for redemption and, in the case of any Notes selected for partial redemption, the principal amount thereof to be redeemed. For purposes of this Indenture, unless the context otherwise requires, all provisions relating to redemption of Notes shall relate, in the case of any of the Notes redeemed or to be redeemed only in part, to the portion of the principal amount thereof which has been or is to be redeemed.

Section 3.02. Notice of Redemption

Section 3.04 of the Indenture shall be amended by replacing that section of the Indenture with the following, but only with respect to the Notes:

Notice of redemption shall be sent not less than 10 days nor more than 60 days prior to the Redemption Date, to each Holder of Securities to be redeemed, at the address of such Holder appearing in the register of Securities maintained by the Registrar.

-9-

All notices of redemption shall identify the Securities to be redeemed and shall state:

(1) the Redemption Date;

(2) the Redemption Price (or the method of calculating or determining the Redemption Price);

(3) that, unless the Company and the Subsidiary Guarantors default in making the redemption payment, interest on Securities called for redemption ceases to accrue on and after the Redemption Date, and the only remaining right of the Holders of such Securities is to receive payment of the Redemption Price upon surrender to the Paying Agent of the Securities redeemed;

(4) if any Security is to be redeemed in part, the portion of the principal amount thereof to be redeemed and that on and after the Redemption Date, upon surrender for cancellation of such Security to the Paying Agent, a new Security or Securities in the aggregate principal amount equal to the unredeemed portion thereof will be issued without charge to the Holder;

(5) that Securities called for redemption must be surrendered to the Paying Agent to collect the Redemption Price and the name and address of the Paying Agent;

(6) that the redemption is for a sinking or analogous fund, if such is the case;

(7) if such Securities are convertible into or exchangeable for capital stock, other debt securities (including Securities), warrants, other equity securities or any other securities or property of the Company, any Subsidiary Guarantor or any other Person, the name and address of the conversion or exchange agent, the date on which the right to convert or exchange is terminated and the conversion or exchange rate; and

(8) the CUSIP number, if any, relating to such Securities.

Notice of redemption of Securities to be redeemed at the election of the Company shall be given by the Company or, at the Company’s written request, given to the Trustee at least 5 days before the notice of redemption is delivered to the Holders (unless the Trustee agrees to a shorter period), by the Trustee in the name and at the expense of the Company.

-10-

Section 3.03. Effect of Notice of Redemption

Section 3.05 of the Indenture shall be amended by replacing that section of the Indenture with the following, but only with respect to the Notes:

Once notice of redemption is sent, Securities called for redemption become due and payable on the Redemption Date and at the Redemption Price. Upon surrender to the Paying Agent, such Securities called for redemption shall be paid at the Redemption Price, but interest installments whose maturity is on or prior to such Redemption Date will be payable on the relevant Interest Payment Dates to the Holders of record at the close of business on the relevant record dates specified pursuant to Section 2.01.

Section 3.04. Redemption at the Option of the Company .

The following Section 3.12 shall be added to Article III of the Indenture, but only with respect to the Notes:

Section 3.12.     Redemption at the Option of the Company .

(a)    The Company may redeem the Notes, at its option, in whole or in part, at any time and from time to time prior to May 15, 2047, in principal amounts of $1,000 and integral multiples of $1,000 in excess thereof, provided that the unredeemed portion of a Note must be in a minimum principal amount of $2,000, for a Redemption Price equal to the greater of:

(i)    100% of the principal amount of the Notes to be redeemed; and

(ii)    the sum, as determined by an Independent Investment Banker, of the present values of the Remaining Scheduled Payments on the Notes being redeemed that would be due if the notes matured on May 15, 2047 (excluding accrued and unpaid interest to the Redemption Date), discounted to the Redemption Date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate plus 25 basis points,

plus, accrued and unpaid interest on the Notes being redeemed to the Redemption Date.

(b)    The Company may redeem the Notes, at its option, in whole or in part, at any time and from time to time on or after May 15, 2047, in principal amounts of $1,000 and integral multiples of $1,000 in excess thereof, provided that the unredeemed portion of a Note must be in a minimum principal amount of $2,000, at a Redemption Price equal to 100% of the principal amount of the Notes being redeemed plus accrued and unpaid interest on the Notes being redeemed to the Redemption Date.

(c)    The Company may at any time, and from time to time, purchase the Notes at any price or prices in the open market, through negotiated transactions, by tender offer or otherwise.

-11-

(d)    The Company shall have no obligation to make mandatory redemption of the Notes or to redeem, purchase or repay Notes pursuant to any sinking fund or analogous provision or, except as provided in Section 4.10, at the option of a Holder thereof.

(e)    With respect to any redemption occurring prior to November 15, 2047, the Company shall deliver notice to the Trustee of the related Redemption Price promptly after the calculation thereof and the Trustee shall not have any responsibility for such calculation.

ARTICLE FOUR

Covenants

The following covenants are added to Article IV of the Indenture for the benefit of Holders, but only with respect to the Notes:

Section 4.08. Restrictions on Secured Debt .

The Company shall not, and the Company shall not permit any Restricted Subsidiary to, incur, issue, assume or guarantee any notes, bonds, debentures or other similar evidences of indebtedness for money borrowed (“ Debt ”), secured by pledge of, or mortgage or lien on, any Principal Property, or any shares of Capital Stock of or Debt of any Restricted Subsidiary (such pledges, mortgages and liens being called “ Mortgage ” or “ Mortgages ” and such Debt secured by such Mortgages being called “ Secured Debt ”), without effectively providing that the Notes (together with, if the Company shall so determine, any other indebtedness of the Company or such Restricted Subsidiary then existing or thereafter created which is not subordinate to the Notes) shall be secured equally and ratably with (or prior to) such Secured Debt, so long as such Secured Debt shall be so secured, unless after giving effect thereto, the aggregate amount of all such Secured Debt plus all Attributable Debt of the Company and its Restricted Subsidiaries in respect of any Sale and Leaseback Transaction would not, at the time of such incurrence, issuance, assumption or guarantee, exceed 15% of Consolidated Net Tangible Assets; provided, however, that this restriction shall not apply to, and there shall be excluded from Secured Debt in any computation under such restriction, indebtedness secured by:

(a)    Mortgages on such property or shares of Capital Stock or Debt existing on the date of this Supplemental Indenture;

(b)    Mortgages on such property or shares of Capital Stock of or Debt of any Person, which Mortgages are existing at the time (i) such Person became a Restricted Subsidiary, (ii) such Person is merged into or consolidated with the Company

-12-

or any Subsidiary or (iii) the Company or a Subsidiary merges into or consolidates with such Person (in a transaction in which such Person becomes a Restricted Subsidiary), which Mortgage was not incurred in anticipation of such transaction and was outstanding prior to such transaction;

(c)    Mortgages in favor of the Company or any Subsidiary Guarantor;

(d)    Mortgages in favor of a governmental entity or in favor of the holders of securities issued by any such entity, pursuant to any contract or statute (including Mortgages to secure debt of the pollution control or industrial revenue bond type) or to secure any indebtedness incurred for the purpose of financing all or any part of the purchase price or the cost of construction of the property subject to such Mortgages;

(e)    Mortgages in favor of any governmental entity to secure progress, advance or other payments pursuant to any contract or provision of any statute;

(f)    Mortgages on such property or shares of Capital Stock or Debt existing at the time of acquisition thereof (including acquisition through merger or consolidation);

(g)    Mortgages on such property or shares of Capital Stock or Debt to secure the payment of all or any part of the purchase price or construction cost thereof or to secure any Debt incurred prior to, at the time of, or within 180 days after, the acquisition of such property or shares or Debt, the completion of any construction or the commencement of full operation, for the purpose of financing all or any part of the purchase price or construction cost thereof;

(h)    Mortgages incurred in connection with a Sale and Leaseback Transaction satisfying the provisions set forth in Section 4.09; and

(i)    any extension, renewal or replacement (or successive extensions, renewals or replacements), as a whole or in part, of any Mortgage referred to in the foregoing clauses; provided that such extension, renewal or replacement Mortgage shall be limited to all or a part of the same such property or shares of Capital Stock or Debt that secured the Mortgage extended, renewed or replaced (plus improvements on such property).

Section 4.09. Limitations on Sale and Leaseback Transactions .

The Company shall not, and shall not permit any Restricted Subsidiary to, enter into any arrangement with any bank, insurance company or other lender or investor (not including the Company or any Restricted Subsidiary) or to which any such lender or investor is a party, providing for the leasing by the Company or a Restricted Subsidiary for a period,

-13-

including renewals, in excess of three years of any Principal Property the ownership of which has been or is to be sold or transferred, more than 180 days after the completion of construction and commencement of full operation thereof, by the Company or such Restricted Subsidiary to such lender or investor or to any Person to whom funds have been or are to be advanced by such lender or investor on the security of such Principal Property (referred to as a “ Sale and Leaseback Transaction ”) unless:

(a)    such Sale and Leaseback Transaction is with a governmental entity that provides financial or tax benefits;

(b)    the Company or such Restricted Subsidiary could create Secured Debt pursuant to the provisions set forth in Section 4.08 on the Principal Property to be leased in an amount equal to the Attributable Debt with respect to such Sale and Leaseback Transaction without equally and ratably securing the Notes; or

(c)    the net proceeds of the sale or transfer of the Principal Property leased pursuant to such Sale and Leaseback Transaction is at least equal to the Fair Market Value of such Principal Property and within 180 days after such sale or transfer shall have been made by the Company or by a Restricted Subsidiary, the Company shall apply an amount not less than the greater of (i) the net proceeds of the sale of the Principal Property leased pursuant to such arrangement or (ii) the Fair Market Value of the Principal Property so leased at the time of entering into such arrangement (as evidenced by an Officers’ Certificate delivered to the Trustee) to the retirement of Funded Debt of the Company; provided that the amount to be applied to the retirement of Funded Debt of the Company shall be reduced by (x) the principal amount of Notes delivered within 180 days after such sale to the Trustee for retirement and cancellation, and (y) the principal amount of Funded Debt other than Notes, voluntarily retired by the Company within 180 days after such sale. No retirement referred to in this clause (c) may be effected by payment at maturity or pursuant to any mandatory sinking fund payment or mandatory prepayment provision.

Section 4.10. Change of Control Triggering Event .

(a)    Upon the occurrence of a Change of Control Triggering Event, unless the Company, subject to Section 4.10(d), has exercised its right to redeem the Notes in accordance with Section 3.12, each Holder will have the right to require the Company to purchase all or a portion ($1,000 or an integral multiple of $1,000 in excess thereof) of such Holder’s Notes pursuant to the offer described below (the “ Change of Control Offer ”), at a purchase price equal to 101% of the principal amount thereof plus accrued and unpaid interest, if any, to the date of purchase (the “ Change of Control Payment ”), subject to the rights of Holders on the relevant record date to receive interest due on the relevant Interest Payment Date; provided that the principal amount of a Note remaining outstanding after a repurchase in part shall be $2,000 or an integral multiple of $1,000 in excess thereof.

-14-

(b)    Within 30 days following the date upon which the Change of Control Triggering Event occurred, or at the Company’s option, prior to any Change of Control but after the public announcement of the pending Change of Control, the Company shall deliver a notice to each Holder of Notes that were not redeemed, with a copy to the Trustee, which notice shall govern the terms of the Change of Control Offer. Such notice will, among other things, state the purchase date, which must be no earlier than 30 days nor later than 60 days from the date such notice is sent, other than as may be required by applicable law (the “ Change of Control Payment Date ”), describe the transaction or transactions constituting the Change of Control Triggering Event and offer to repurchase the Notes. The notice, if sent prior to the date of consummation of the Change of Control, shall state that the Change of Control Offer is conditioned on the Change of Control being consummated on or prior to the Change of Control Payment Date.

(c)    On the Change of Control Payment Date, the Company shall, to the extent lawful:

(i)    accept or cause a third party to accept for payment all Notes or portions of Notes properly tendered pursuant to the Change of Control Offer;

(ii)    deposit or cause a third party to deposit with the Paying Agent an amount equal to the Change of Control Payment in respect of all Notes or portions of Notes properly tendered; and

(iii)    deliver or cause to be delivered to the Trustee the Notes to be redeemed properly accepted together with an Officers’ Certificate stating the aggregate principal amount of Notes or portions of Notes being repurchased and that all conditions precedent to the Change of Control Offer and to the repurchase by the Company of Notes pursuant to the Change of Control Offer have been complied with.

(d)    The Company will not be required to make a Change of Control Offer with respect to the Notes if (i) a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for such an offer otherwise required to be made by the Company and such third party purchases all such Notes properly tendered and not withdrawn under its offer or (ii) a notice of redemption has been given to the Holders of all of the Notes in accordance with the terms of the Indenture, unless and until there is a default in payment of the Redemption Price.

(e)    A Change of Control Offer may be made in advance of a Change of Control, conditional upon such Change of Control, if a definitive agreement is in place with respect to the Change of Control at the time of making of the Change of Control Offer.

(f)    The Company will comply in all material respects with the requirements of Rule 14e-1 under the Exchange Act, and any other securities laws and regulations

-15-

thereunder to the extent those laws and regulations are applicable in connection with the repurchase of the Notes as a result of a Change of Control Triggering Event. To the extent that the provisions of any such securities laws or regulations conflict with this Section 4.10, the Company will comply with those securities laws and regulations and will not be deemed to have breached its obligations under this Section 4.10 by virtue of any such conflict.

Section 4.11. Additional Guarantees .

If, after the date of this Supplemental Indenture, any Domestic Subsidiary that is not already a Subsidiary Guarantor (including, without limitation, any Domestic Subsidiary acquired or created after the date of this Supplemental Indenture) guarantees any Debt in excess of $40 million of either the Company or a Subsidiary Guarantor, then in either case that Subsidiary shall become a Subsidiary Guarantor by executing a supplemental indenture and delivering it to the Trustee within 15 Business Days of the date on which it guaranteed such Debt.

ARTICLE FIVE

Guarantee

Section 5.01. Release of Subsidiary Guarantors from Guarantee .

Section 10.04 of the Indenture shall be amended by replacing that section of the Indenture with the following, but only with respect to the Notes:

(a)    Notwithstanding any other provisions of this Indenture, the Guarantee of any Subsidiary Guarantor may be released upon the terms and subject to the conditions set forth in this Section 10.04. Provided that no Event of Default shall have occurred and shall be continuing under this Indenture, any Guarantee incurred by a Subsidiary Guarantor pursuant to this Article X shall be unconditionally released and discharged automatically:

(i)    upon any sale or other disposition of all or substantially all of the assets of that Subsidiary Guarantor (including by way of merger or consolidation) to a Person that is not (either before or after giving effect to such transaction) the Company or a Subsidiary;

(ii)    upon any sale or other disposition of all of the Capital Stock of a Subsidiary Guarantor to a Person that is not (either before or after giving effect to such transaction) the Company or a Subsidiary;

-16-

(iii)    upon legal defeasance or satisfaction and discharge of the Notes as provided in Article VIII; or

(iv)    at such time as such Subsidiary Guarantor ceases to guarantee any Debt of the Company or a Subsidiary Guarantor in excess of $40 million other than Debt under one of more series of Securities issued pursuant to the Indenture; provided that, if such Guarantor solely guarantees Debt under one or more series of Securities issued pursuant to the Indenture, the guarantees of each such series of Securities may be released concurrently.

(b)    The Trustee shall deliver an appropriate instrument evidencing any release of a Subsidiary Guarantor from its Guarantee upon receipt of a written request of the Company accompanied by an Officers’ Certificate and an Opinion of Counsel to the effect that the Subsidiary Guarantor is entitled to such release in accordance with the provisions of this Indenture. If the Subsidiary Guarantor is not so released it shall remain liable for the full amount of principal of (and premium, if any, on) and interest on the Notes, subject to the limitations of Section 10.03.

ARTICLE SIX

Miscellaneous

Section 6.01. No Recourse Against Others .

Section 11.08 of the Indenture shall be amended by replacing that section of the Indenture with the following, but only with respect to the Notes:

A director, officer, member, manager, employee, stockholder, partner or other owner of the Company, any Subsidiary Guarantor or the Trustee, as such, shall not have any liability for any obligations of the Company under the Notes, for any obligations of any Subsidiary Guarantor under any Guarantee, or for any obligations of the Company, any Subsidiary Guarantor or the Trustee under this Indenture or for any claim based on, in respect of or by reason of such obligations or their creation. Each Holder by accepting a Note waives and releases all such liability. The waiver and release shall be part of the consideration for the issuance of Notes.

Section 6.02. Governing Law .

The laws of the State of New York shall govern this Supplemental Indenture, the Notes and the related Guarantees.

-17-

Section 6.03. No Adverse Interpretation of Other Agreements .

This Supplemental Indenture may not be used to interpret another indenture (other than the Indenture), loan or debt agreement of the Company, any Subsidiary Guarantor or a Subsidiary. Any such indenture, loan or debt agreement may not be used to interpret this Supplemental Indenture.

Section 6.04. Successors and Assigns .

All covenants and agreements of the Company and each of the Subsidiary Guarantors in this Supplemental Indenture and the Notes shall bind its successors and assigns. All agreements of the Trustee in this Supplemental Indenture shall bind its successors and assigns.

Section 6.05. Duplicate Originals .

The parties may sign any number of copies of this Supplemental Indenture. Each signed copy shall be an original, but all of them together represent the same agreement.

Section 6.06. Severability .

In case any provision in this Supplemental Indenture or in the Notes or in any Guarantee of a Subsidiary Guarantor shall be invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions shall, to the fullest extent permitted by applicable law, not in any way be affected or impaired thereby.

Section 6.07. Amendments Without Consent of Holders .

Section 9.01 of the Indenture is supplemented with the addition of the following with respect to the Notes:

(12)    to provide any other modifications which do not adversely affect the interests of the Holders in any material respect.

Section 6.08. Rights of Trustee.

In no event shall the Trustee be responsible or liable for special, indirect, punitive or consequential loss or damage of any kind whatsoever (including, but not limited to, loss of profit) irrespective of whether the Trustee has been advised of the likelihood of such loss or damage and regardless of the form of action.

The Trustee may request that the Company or any Subsidiary Guarantor deliver an Officers’ Certificate setting forth the names of individuals and/or titles of officers (with specimen signatures) authorized at such times to take specific actions pursuant to this Supplemental Indenture, which Officers’ Certificate may be signed by any person specified as so authorized in any such certificate previously delivered and not superseded.

-18-

Section 6.09. Waiver of Jury Trial.

Each of the Company, the Subsidiary Guarantors and the Trustee hereby irrevocably waives, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to this Supplemental Indenture, the Indenture, the Notes or the transactions contemplated hereby.

Section 6.10. Force Majeure.

In no event shall the Trustee be responsible or liable for any failure or delay in the performance of its obligations under this Supplemental Indenture arising out of or caused by, directly or indirectly, forces beyond its reasonable control, including, without limitation, strikes, work stoppages, accidents, acts of war or terrorism, civil or military disturbances, nuclear or natural catastrophes or acts of God, and interruptions, loss or malfunctions of utilities, communications or computer (software or hardware) services.

Section 6.11. No Recitals, etc.

The Trustee shall not be responsible in any manner whatsoever for or in respect of the validity or sufficiency of this Supplemental Indenture or for or in respect of the recitals contained herein, all of which are made solely by the Company and the Subsidiary Guarantors.

Section 6.12. Notices.

The Trustee agrees to accept and act upon instructions or directions pursuant to this Indenture sent by unsecured e-mail, pdf, facsimile transmission or other similar unsecured electronic methods, provided, however, that the Trustee shall have received an incumbency certificate listing persons designated to give such instructions or directions and containing specimen signatures of such designated persons, which such incumbency certificate shall be amended and replaced as necessary prior to the giving of such instructions or directions. If the Company elects to give the Trustee e-mail or facsimile instructions (or instructions by a similar electronic method) and the Trustee in its discretion elects to act upon such instructions, the Trustee’s understanding of such instructions shall be deemed controlling. The Trustee shall not be liable for any losses, costs or expenses arising directly or indirectly from the Trustee’s reliance upon and compliance with such instructions notwithstanding such instructions conflict or are inconsistent with a subsequent written instruction. The Company agrees to assume all risks arising out of the use of such electronic methods to submit instructions and directions to the Trustee, including without limitation the risk of the Trustee acting on unauthorized instructions, and the risk or interception and misuse by third parties.

-19-

Section 6.13. Foreign Account Tax Compliance Act.

Each of the Company and the Trustee agrees to provide the other with such information in its possession (subject in all cases to applicable privacy laws) as reasonably requested by the other to enable the determination of whether any payment to a Holder pursuant to the Indenture is subject to withholding imposed pursuant to Sections 1471 through 1474 of the Internal Revenue Code, any regulations thereunder, intergovernmental agreements in respect thereof or official interpretations of any of the foregoing (“Applicable FATCA Law”). The Trustee shall be entitled to make any withholding or deduction from payments under the Notes or this Indenture to the extent necessary (in the Trustee’s reasonable judgment) to comply with Applicable FATCA Law, for which the Trustee shall not have any liability.

Section 6.14 Submission to Jurisdiction .

The Company and each Subsidiary Guarantor hereby irrevocably submits to the jurisdiction of any New York State court sitting in the Borough of Manhattan in the City of New York or any federal court sitting in the Southern District in the Borough of Manhattan in the City of New York in respect of any suit, action or proceeding arising out of or relating to this Indenture, the Guarantees and the Notes, and irrevocably accepts for itself and in respect of its property, generally and unconditionally, jurisdiction of the aforesaid courts.

-20-

SIGNATURES

IN WITNESS WHEREOF, the parties have caused this Supplemental Indenture to be duly executed, all as of the date first above written.

[Signature Page to Eleventh Supplemental Indenture]

[Signature Page to Eleventh Supplemental Indenture]

[Signature Page to Eleventh Supplemental Indenture]

The Bank of New York Mellon Trust Company, N.A. ,

    as Trustee

[Signature Page to Eleventh Supplemental Indenture]

Schedule A

Subsidiary Guarantors

AXIALL CORPORATION

AXIALL HOLDCO, INC.

AXIALL NOTECO, INC.

AXIALL, LLC

EAGLE NATRIUM LLC

EAGLE SPINCO INC.

EAGLE US 2 LLC

GVGP, INC.

LAGOON LLC

NORTH AMERICAN SPECIALTY PRODUCTS LLC

PLASTIC TRENDS, INC.

ROME DELAWARE CORPORATION

ROYAL BUILDING PRODUCTS (USA) INC.

WESTECH BUILDING PRODUCTS (EVANSVILLE) LLC

WESTLAKE CHEMICAL INVESTMENTS, INC.

WESTLAKE CHEMICAL ENERGY LLC

WESTLAKE CHEMICAL VINYLS LLC

WESTLAKE LONGVIEW CORPORATION

WESTLAKE MANAGEMENT SERVICES, INC.

WESTLAKE NG I CORPORATION

WESTLAKE OLEFINS CORPORATION

WESTLAKE PETROCHEMICALS LLC

WESTLAKE POLYMERS LLC

WESTLAKE STYRENE LLC

WESTLAKE VINYL CORPORATION

WESTLAKE VINYLS COMPANY LP

WESTLAKE VINYLS, INC.

WPT LLC

EXHIBIT A

FORM

OF

4.375% SENIOR NOTE DUE 2047

A-1

[FORM OF FACE OF NOTE]

Global Notes Legend

[THIS NOTE IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF THE DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) OR OTHER DULY APPOINTED DEPOSITORY (THE “DEPOSITARY”) OR THEIR RESPECTIVE NOMINEES. UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR NOTES IN CERTIFICATED FORM, THIS NOTE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITORY TRUST COMPANY OR OTHER DULY APPOINTED DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH SUCCESSOR DEPOSITARY.

Unless this certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation, to the issuer hereof or its agent for registration of transfer, exchange, or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name as is requested by an authorized representative of The Depository Trust Company (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of The Depository Trust Company), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein.]

Exhibit 4.6

AMENDED AND RESTATED LOAN AGREEMENT

By and Between

LOUISIANA LOCAL GOVERNMENT ENVIRONMENTAL

FACILITIES AND COMMUNITY DEVELOPMENT AUTHORITY

and

WESTLAKE CHEMICAL CORPORATION

Relating to

CONVERSION AND REMARKETING OF:

$250,000,000

LOUISIANA LOCAL GOVERNMENT ENVIRONMENTAL

FACILITIES AND COMMUNITY DEVELOPMENT AUTHORITY

REVENUE REFUNDING BONDS

(WESTLAKE CHEMICAL CORPORATION PROJECTS)

SERIES 2017 (GO ZONE) (NON-AMT)

TABLE OF CONTENTS

i

Annex A –Form of Continuing Disclosure Agreement

ii

AMENDED AND RESTATED LOAN AGREEMENT

This AMENDED AND RESTATED LOAN AGREEMENT dated as of November 1, 2017 (together with any amendments and supplements hereto as permitted hereunder, this “ Agreement ”), is made by and between the Louisiana Local Government Environmental Facilities and Community Development Authority (the “ Authority ”), a political subdivision of the State of Louisiana created pursuant to the authority of Chapter 10-D of Title 33 of the Louisiana Revised Statutes of 1950, as amended (La. R.S. 33:4548.1 through 4548.16), (and all future acts supplemental thereto and amendatory thereof, the “ Act ”), and Westlake Chemical Corporation, a Delaware corporation (the “Borrower” ) for the purpose of amending and restating the Loan Agreement dated as of November 1, 2017 (the “Original Loan Agreement” ).

W I T N E S S E T H:

WHEREAS, on December 13, 2007, in accordance with the provisions of the Gulf Opportunity Zone Act of 2005 (Public Law 109-135) and any rules and regulations promulgated thereunder (the “GO Zone Act” ), the Authority issued its $250,000,000 Revenue Bonds (Westlake Chemical Corporation Projects), Series 2007 (the “Series 2007 Bonds” ), and loaned the funds derived from the sale thereof to the Borrower for the purpose of providing funds to allow the Borrower to finance (1) the costs of designing, constructing and equipping a new expansion to the Borrower’s manufacturing facilities in the Parish of Ascension, State of Louisiana (the “Geismar Facilities”), including all equipment, furnishings, fixtures and facilities incidental or necessary in connection therewith that are allowed to be financed under the GO Zone Act, and/or (b) the costs of expanding, renovating, equipping and improving the Geismar Facilities, including all equipment, furnishings, fixtures and facilities incidental or necessary in connection therewith that are allowed to be financed under the GO Zone Act (collectively, the “Ascension Projects”); (2) the costs of expanding, equipping and improving the Borrower’s manufacturing facilities located in the Parish of Calcasieu, State of Louisiana, including all equipment, furnishings, fixtures and facilities incidental or necessary in connection therewith that are allowed to be financed under the GO Zone Act (the “Calcasieu Projects” and, together with the Ascension Projects, the “Projects”); and (3) the costs of issuance of the Series 2007 Bonds; and

WHEREAS, under the provisions of Chapter 14-A of Title 39 of the Louisiana Revised Statutes of 1950, as amended (the “Refunding Act” ), the Authority has the express authority to issue revenue refunding bonds for the purpose of refunding all or a part of the Series 2007 Bonds; and

WHEREAS, on November 1, 2017, the Authority issued its $250,000,000 Revenue Refunding Bonds (Westlake Chemical Corporation Projects), Series 2017 (the “Series 2017 Bonds” ), pursuant to the Indenture of Trust dated as of November 1, 2017 (the “Original Indenture” ), by and between the Authority and the Trustee, and loaned the funds derived from the sale thereof to the Borrower pursuant to the Original Loan Agreement, for the purpose of refunding the outstanding principal amount of the Series 2007 Bonds; and

1

WHEREAS, the Series 2017 Bonds were initially issued bearing interest at a Weekly Rate; and

WHEREAS, pursuant to Section 2.4 of the Original Indenture, the Borrower has elected to convert all of the Series 2017 Bonds from a Weekly Rate Period to a Term Rate Period; and

WHEREAS, in connection with such conversion of the Series 2017 Bonds from a Weekly Rate Period to a Term Rate Period, and in accordance with Section 9.1 of the Original Agreement, the Authority and the Borrower desire to amend and restate the Original Loan Agreement; and

WHEREAS, in connection with such conversion, the Authority and the Trustee have executed and delivered an Amended and Restated Indenture of Trust dated as of November 1, 2017 (the “Indenture” ); and

WHEREAS, the Trustee has provided its written consent to the amendment and restatement of the Original Loan Agreement; and

WHEREAS, the Borrower and the Authority are empowered to consummate the transactions contemplated hereunder and to do all acts and exercise all powers and assume all obligations necessary, or incident thereto; and

WHEREAS, in consideration of the issuance of the Bonds by the Authority, the Borrower will agree to make payments pursuant to this Agreement in an amount sufficient to pay the principal of, premium, if any, and interest on the Bonds and to pay such other amounts as are required by this Agreement; and

WHEREAS, the Executive Committee of the Authority has adopted resolutions authorizing (i) the sale and the issuance of the Bonds, and (ii) the conversion and remarketing of the Bonds from a Weekly Rate Period to a Term Rate Period, and the execution and delivery of instruments related thereto, including but not limited to the Agreement and the Indenture; and

WHEREAS, all acts, conditions and things required by the laws of the State to happen, exist and be performed precedent to and in the execution and delivery of this Agreement have happened, exist and have been performed as so required in order to make this Agreement a valid and binding agreement in accordance with its terms; and

WHEREAS, each of the parties hereto represents that it is fully authorized to enter into and perform and fulfill the obligations imposed upon it under this Agreement and the parties are now prepared to execute and deliver this Agreement; and

WHEREAS, in consideration of the respective representations and agreements contained herein, the parties hereto, recognizing that under the Act and the Refunding Act this Agreement shall not in any way obligate the State or any political subdivision thereof, including, without limitation, the Authority, to raise any money by taxation or use other public moneys for any purpose in relation to the Bonds and that neither the State nor the Authority, shall pay or promise to pay any debt or meet any financial obligation to any person at any time in relation to

2

the Bonds except from moneys received or to be received under the provisions of this Agreement and the Indenture or derived from the exercise of the rights of the Authority thereunder, agree as follows:

NOW, THEREFORE, THIS AGREEMENT WITNESSETH (provided that any obligation of the Authority created by or arising out of this Agreement will not constitute a debt or a general obligation or a pledge of the faith and credit of the Authority, the State or any political subdivision thereof, and the Bondholders (as hereinafter defined) will have no right to compel the exercise of the taxing powers of the State or any political subdivision thereof for the payment of principal of or any interest on the Bonds):

3

ARTICLE I

DEFINITIONS AND RULES OF CONSTRUCTION

SECTION 1.1 Definitions.

All capitalized terms not otherwise defined herein shall have the meanings assigned thereto in the Indenture. In addition to words and terms elsewhere defined in this Agreement, the following words and terms as used in this Agreement shall have the following meanings, unless some other meaning is plainly intended:

“Act” has the meaning set forth in the Preamble hereto.

“Administrative Expenses” means the necessary, reasonable and direct out-of-pocket expenses incurred by the Authority or the Trustee pursuant to this Agreement and the Indenture, the compensation of the Trustee under the Indenture (including, but not limited to an annual administrative fee charged by the Trustee), and the necessary, reasonable and direct out-of-pocket expenses of the Trustee incurred by the Trustee in the performance of its duties under the Indenture.

“Agreement” has the meaning set forth in the Preamble hereto.

“Ascension Projects” has the meaning set forth in the Recitals hereto.

“Authority” has the meaning set forth in the Preamble hereto.

“Authority Indemnitees” has the meaning set forth in Section 6.3(a) hereof.

“Authorized Borrower Representative” means either (i) the President and Chief Executive Officer of the Borrower, (ii) the Executive Vice President and Chief Financial Officer of the Borrower, (iii) the Vice President and Treasurer of the Borrower, or (iv) any person subsequently designated to act under this Agreement and the Indenture on behalf of the Borrower by a written certificate furnished to the Trustee containing the specimen signature of such person(s) and signed on behalf of the Borrower by either (i) the President and Chief Executive Officer of the Borrower, (ii) the Executive Vice President and Chief Financial Officer of the Borrower, or (iii) the Vice President and Treasurer of the Borrower.

“Bond Counsel” means Breazeale, Sachse & Wilson, L.L.P. and its successors, or such other nationally recognized bond counsel as may be selected by the Authority and acceptable to the Borrower.

“Bondholder” or “owner” , when used with reference to a Bond or Bonds, means the registered owner of any Outstanding Bond or Bonds.

“Bond” or “Bonds” means the Louisiana Local Government Environmental Facilities and Community Development Authority Revenue Refunding Bonds (Westlake Chemical Corporation Projects), Series 2017 (GO Zone) (Non-AMT), in the aggregate principal amount of $250,000,000, including such Bonds issued in exchange for other such Bonds pursuant to the Indenture, or in replacement for mutilated, destroyed, lost or stolen Bonds pursuant to the Indenture.

4

“Borrower” has the meaning set forth in the Preamble hereto.

“Business Day” means any day other than (i) a Saturday, (ii) a Sunday, (iii) any other day on which banking institutions in New York, New York or Baton Rouge, Louisiana are authorized or required not to be open for the transaction of regular banking business, and (iv) any other day on which the New York Stock Exchange is closed.

“Calcasieu Project” has the meaning set forth in the Recitals hereto.

“Change of Control Payment” has the meaning set forth in Section 4.2(b).

“Closing Date” means the date on which the Bonds are delivered and payment therefor is received by the Authority.

“Code” means the Internal Revenue Code of 1986, as amended, together with any regulations and rulings promulgated thereunder or applicable thereto, and shall include the applicable provisions of the GO Zone Act.

“Continuing Disclosure Agreement” means the agreement substantially in the form of Annex A attached hereto.

“Defeasance Obligations” means investments described in paragraphs (1) and (2) of the definition of Permitted Investments in the Indenture.

“Environmental Regulation” means any federal, state or local law, statute, code, ordinance, regulation, requirement or rule relating to dangerous, toxic or hazardous pollutants, contaminants, chemical waste, materials or substances.

“Event of Default” and “Default” have the meanings set forth in Article IX hereof.

“Exchange Act” means the Securities Exchange Act of 1934, as amended.

“Facilities” has the meaning set forth in the Recitals hereto.

“Geismar Facilities” has the meaning set forth in the Recitals hereto.

“GO Zone Act” has the meaning set forth in the Recitals hereto.

“Hazardous Substance” means dangerous, toxic or hazardous pollutants, contaminants, chemicals, waste, materials or substances as defined in Environmental Regulations, and also any urea formaldehyde, polychlorinated biphenyls, asbestos, asbestos-containing materials, nuclear fuel or waste, radioactive materials, explosives, carcinogens and petroleum products, or any other waste, material, substance, pollutant or contaminant which would subject the owner or mortgagee or any holder to any damages, penalties or liabilities under any applicable Environmental Regulation.

5

“Indemnified Party” has the meaning set forth in Section 10.3 hereof.

“Indenture” means the Amended and Restated Indenture of Trust, dated as of November 1, 2017, between the Authority and the Trustee providing for the issuance of the Bonds, as it may be amended or supplemented from time to time by supplemental indentures in accordance with the provisions thereof, which Indenture amends and restates the Indenture of Trust dated as of November 1, 2017, by and between the Authority and the Trustee.

“Interest Payment Date” or “interest payment date” , when used with respect to the Bonds bearing interest during the Term Rate Period, means each May 1 and November 1, commencing May 1, 2018. Provided, however, during a Commercial Paper, Daily or Weekly Rate Period, “Interest Payment Date” means (i) when used with respect to any particular Bond accruing interest at a Commercial Paper Rate, the day after the last day of each Commercial Paper Rate Period applicable thereto; (ii) when used with respect to Bonds accruing interest at Daily or Weekly Rates, the first Business Day of each calendar month following a month in which interest at such rate has accrued; and (iii) the Maturity Date.

“Interest Payments” has the meaning set forth in Section 4.2(a) hereof.

“Investment Grade” means a rating of (i) Baa3 or better by Moody’s or BBB- or better by S&P (or, if either such entity ceases to rate the unsecured senior debt securities of the Borrower for reasons outside of the control of the Borrower, the equivalent investment grade credit rating from any other “nationally recognized statistical rating organization” within the meaning of Rule 15c3-1(c)(2)(vi)(F) under the Exchange Act selected by the Borrower as a replacement agency) and (ii) the equivalent investment grade credit rating from another “nationally recognized statistical rating organization” within the meaning of Rule 15c3-1(c)(2)(vi)(F) under the Exchange Act (including, for the avoidance of doubt, S&P if the agency referred to in clause (i) is Moody’s, or vice versa).

“Lake Charles Facilities” has the meaning set forth in the Recitals hereto.

“Loan” means the aggregate amount of the moneys loaned to the Borrower pursuant to this Agreement.

“Losses” has the meaning set forth in Section 6.3(b) hereof.

“Maturity Date” means the stated maturity or such earlier date as the Bonds shall be redeemed.

“ Moody’s ” means Moody’s Investor Service, Inc.

“Net Proceeds” means amounts received upon the issuance and sale of the Bonds, together with any investment earnings thereon, prior to the expenditure thereof pursuant to Article III of this Agreement.

6

“Notes” has the meaning set forth in Section 4.6(a) hereof.

“Notes Trustee” has the meaning set forth in Section 4.6(a) hereof.

“Original Loan Agreement” has the meaning set forth in the Recitals hereto.

“Outstanding” or “Outstanding Bonds” , when used with reference to Bonds, means all Bonds which have been authenticated and issued under the Indenture by the Trustee, except:

(a) Bonds canceled by the Trustee pursuant to the Indenture;

(b) Bonds for the payment of which moneys or Defeasance Obligations shall be held in trust for their payment by the Trustee as provided in the defeasance provisions of the Indenture;

(c) Bonds which have been duly called for redemption and for which the redemption price thereof is held in trust by the Trustee as provided in the Indenture;

(d) Bonds in exchange for which other Bonds shall have been authenticated and delivered by the Trustee as provided in the Indenture;

(e) for all purposes regarding consents and approvals or directions of Bondholders under this Agreement or the Indenture, Bonds held by or for the Authority, the Borrower or any person controlling, controlled by or under common control with either of them; provided, however, that only Bonds that a Trust Officer of the Trustee knows are so owned shall be disregarded; and

(f) Bonds in lieu of which other Bonds have been authenticated under Sections 3.6, 3.9, 4.1 and 4.2 of the Indenture.

“Payments” means the amounts to be paid by the Borrower as provided in Article IV of this Agreement for the purpose of repaying the loan made by the Authority under this Agreement from the proceeds of the Bonds.

“Person” , “person” or words importing persons mean and include firms, associations, partnerships (including without limitation, general and limited partnerships), joint ventures, estates, trusts, corporations, limited liability companies, public or governmental bodies or other legal entities and natural persons.

“Principal Payment” has the meaning set forth in Section 4.2(a) hereof.

“Projects” has the meaning set forth in the Recitals hereto.

“S&P” means S&P Global Rating, a division of S&P Global, Inc.

7

“Senior Notes Indenture” means that certain Indenture among the Borrower, the Potential Subsidiary Guarantors (as defined therein) and The Bank of New York Mellon Trust Company, N.A. (as successor to JPMorgan Chase Bank, National Association), as trustee, dated as of January 1, 2006, as supplemented by the Tenth Supplemental Indenture, by and among the Borrower, the Subsidiary Guarantors (as defined therein) and The Bank of New York Mellon Trust Company, N.A., as trustee, dated as of November 29, 2017.

“Series 2007 Bonds” has the meaning set forth in the Recitals hereto.

“State” has the meaning set forth in the Recitals hereto.

“Tax Regulatory Agreement” means, collectively, the Tax Regulatory Agreement of the Borrower dated the Issue Date, as amended by the Supplemental Tax Regulatory Agreement dated November 29, 2017, by and among the Authority, the Borrower and the Trustee.

“Trustee” means the state banking corporation or national banking association with corporate trust powers qualified to act as Trustee under the Indenture which may be designated (originally or as a successor) as Trustee for the owners of the Bonds issued and secured under the terms of the Indenture, initially The Bank of New York Mellon Trust Company, N.A. “Corporate Trust Office” of the Trustee means its designated corporate trust office, initially 301 Main St., Suite 1510, Baton Rouge, Louisiana 70801 and thereafter the office designated as such in writing to the Bondholders, the Borrower, the Remarketing Agent and the Credit Facility Provider.

“Trustee Indemnitees” has the meaning set forth in Section 6.3(b) hereof.

SECTION 1.2 Rules of Construction.

(a) Words of the masculine gender shall be deemed and construed to include correlative words of the feminine and neuter genders.

(b) The terms defined herein have the meanings assigned to them and include the plural as well as the singular.

(c) Provisions calling for the redemption of Bonds or the calling of Bonds for redemption do not mean or include the payment of Bonds at their stated maturity or maturities.

(d) All references in this Agreement to designated “Articles”, “Sections” and other subdivisions are to the designated Articles, Sections and other subdivisions of this Agreement. The words “herein”, “hereof, “hereunder” and other words of similar import refer to this Agreement as a whole and not to any particular Article, Section or other subdivision.

(e) References to agreements and other instruments include subsequent amendments thereto and restatements thereof.

(f) “Including” means “including without limitation.”

8

ARTICLE II

REPRESENTATIONS

SECTION 2.1 Representations of the Authority.

The Authority represents and warrants as follows:

(a) The Authority is a political subdivision of the State existing under the Constitution and laws of the State;

(b) The Authority has complied and continues to comply and will comply in all respects with all applicable provisions of the laws of the State relating to its organization and existence;

(c) The Authority has duly accomplished all conditions and has taken all steps necessary to be accomplished or taken by it prior to issuance and delivery of the Bonds and the execution and delivery of this Agreement and the Indenture;

(d) The Authority is not in violation of or conflict with any provisions of the laws of the State which would impair its ability to undertake the transactions contemplated by this Agreement and the Indenture or carry out its obligations under this Agreement and the Indenture;

(e) The Authority is empowered to enter into the transactions contemplated by this Agreement and the Indenture, and the execution and performance of this Agreement by the Authority will not violate or conflict with any document or instrument by which the Authority or its properties are bound;

(f) The Authority has duly authorized the execution, delivery and performance of this Agreement and the Indenture and such authorization has not been repealed or modified; and

(g) The Authority will do all things in its power in order to maintain its existence or assure the assumption of its obligations under this Agreement and the Indenture by any successor public body.

SECTION 2.2 Representations of the Borrower.

The Borrower makes the following representations and warranties:

(a) The Borrower is a corporation duly organized and validly existing under the laws of the State of Delaware;

(b) The Borrower has full power and authority to execute and deliver this Agreement and to enter into and carry out the transactions contemplated on its part herein and therein. Such execution, delivery and performance are not in contravention of applicable local, state or federal law or the Borrower’s certificate of incorporation, or any

9

indenture, agreement or undertaking which is material to the Borrower, to which the Borrower is a party or by which it is bound (provided that the foregoing does not apply to any action required under state securities or Blue Sky laws in connection with the original sale by the Authority and purchase and distribution of the Bonds). This Agreement has, by proper action, been duly authorized, executed and delivered by the Borrower and all steps necessary have been taken by the Borrower to constitute this Agreement valid and binding obligations of the Borrower, except as enforceability may be limited by applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting the rights of creditors generally and by general principles of equity (regardless of whether enforcement thereof is sought in a proceeding at law or in equity);

(c) Each component of the Projects constituted “nonresidential real property” within the meaning of the GO Zone Act, including fixed improvements associated with such property, and are located within the geographical limits of the State of Louisiana and within the area comprising the “Gulf Opportunity Zone” pursuant to the GO Zone Act;

(d) The Projects constitute an “Authorized Project” under La. R.S. 33:4548.3.B, and the Borrower presently intends to operate the Projects as an “Authorized Project” under La. R.S. 33:4548.3.B for so long as the Bonds remain Outstanding;

(e) The Borrower presently does not intend to sell or dispose of the Projects or any portion thereof;

(f) No Costs of the Projects were paid or incurred by or on behalf of the Borrower were paid or incurred prior to August 30, 2005;

(g) The Projects are substantially the same in all material respects to that described in the notice of public hearing published on September 24, 2010;

(h) The Projects were acquired, constructed and installed and are operated by the Borrower in such manner as to conform with all applicable zoning, planning, building, environmental and other regulations of the governmental authorities having jurisdiction over the Projects;

(i) The Borrower caused all of the proceeds of the Series 2007 Bonds to be applied solely to the payment of (x) costs of the Projects, and (y) the costs of issuance of the Series 2007 Bonds;

(j) The Borrower has taken no action, and has not omitted to take any action, which action or omission to take action would in any way affect or impair the excludability of interest on the Bonds from gross income of the Bondholders thereof for Federal income tax purposes;

(k) All of the representations and warranties of the Borrower contained in the Tax Regulatory Agreement are hereby reaffirmed and incorporated herein by reference;

10

ARTICLE III

TERM, NATURE AND BENEFITS OF AGREEMENT;

PERFORMANCE OF THE PROJECTS

SECTION 3.1 Term.

The term of this Agreement shall commence on the Closing Date for the Bonds, and shall terminate (unless discharged upon prepayment of all sums due hereunder by the Borrower prior thereto as hereinafter provided) on the date on which the Bonds and all other sums due hereunder shall have been paid or provision for their payment shall have been made in accordance herewith. Notwithstanding the foregoing, the indemnification provisions of this Agreement shall survive the termination thereof and the defeasance of the Bonds under the Indenture.

SECTION 3.2 Use of Proceeds of the Bonds.

The Borrower covenants and agrees that it will use all of the proceeds of the Bonds to redeem the outstanding principal amount of the Series 2007 Bonds on November 1, 2017.

SECTION 3.3 Nature and Benefits.

This Agreement has been executed and delivered in part to induce concurrently herewith the purchase by others of the Bonds, and, accordingly, all covenants and agreements on the part of the Borrower and the Authority, as set forth therein and herein, are hereby declared to be for the benefit of the Trustee for the owners from time to time of the Bonds. The Borrower consents and agrees to the assignment by the Authority to the Trustee under the Indenture of all of the Authority’s right, title and interest (except for certain rights relating to receipt of notices, exculpation, indemnification and payment of expenses) in, to and under this Agreement and agrees that the provisions hereof may be enforced by the Trustee under the provisions of the Indenture. The Borrower agrees to do all things within its power in order to comply with, and to enable the Authority to comply with, all requirements and to fulfill, and to enable the Authority to fulfill, all covenants of the Indenture and the Bonds.

This Agreement is a debt obligation of the Borrower not subject to cancellation due to inability to appropriate funds to make Payments and shall remain in full force and effect until the Bonds and the interest thereon and all amounts due and owing hereunder and under the Indenture have been fully paid or otherwise provided for or discharged.

ARTICLE IV

AGREEMENT TO ISSUE BONDS; DISBURSEMENT OF BOND PROCEEDS;

PAYMENTS; CREDITS; OBLIGATIONS UNCONDITIONAL;

PREPAYMENT; REDEMPTION; CORRESPONDING NOTES

SECTION 4.1 Agreement to Issue Bonds.

(a) To provide funds for the refunding of the Series 2007 Bonds on November 1, 2017, the Authority agrees that it will sell, issue and deliver the Bonds in the

11

aggregate principal amount of $250,000,000 and make the proceeds of sale of the Bonds available to the Borrower pursuant to this Agreement in order to refund the Series 2007 Bonds on November 1, 2017. The aggregate principal amount of the Bonds issued under the Indenture shall not exceed $250,000,000.

(b) The Authority agrees, upon the terms and conditions contained in this Agreement and the Indenture, to lend to the Borrower the proceeds derived by the Authority from the sale of the Bonds. The loan shall be made by depositing the proceeds from the sale of the Bonds in accordance with Section 2.1 of the Original Indenture.

SECTION 4.2 Amounts Payable.

Upon the terms and conditions of this Agreement, the Authority shall loan to the Borrower the proceeds of the sale of the Bonds. The proceeds of the Loan shall be deposited with the Trustee and applied in accordance with the Indenture.

The Borrower, for and in consideration of the issuance of the Bonds under the Indenture by the Authority and the application of the proceeds thereof by the Authority as provided in the Indenture for the benefit of the Borrower, hereby promises to repay the Loan in accordance with the terms hereof, by making the following payments (collectively, the “Payments” ) to or for the account of the Authority:

(a) Regular Payments :

(i) “Interest Payments” being an amount sufficient for the payment in full of the total interest due and payable to the date of payment thereof on the Bonds from time to time issued under the Indenture and then Outstanding. The Interest Payments with respect to the Bonds shall be payable directly to the Trustee for the account of the Authority on the Interest Payment Dates.

(ii) “Principal Payment” being an amount sufficient for the payment in full of all Bonds from time to time issued under the Indenture and then Outstanding. The Principal Payment with respect to the Bonds shall be payable directly to the Trustee for the account of the Authority on the Maturity Date.

(iii) Each installment of the Payments and premium, if any, payable by the Borrower hereunder shall be in an amount which, without regard to the payments required under Article IV of the Indenture, shall be designed to provide for the timely payment in full of the principal of, premium, if any, and interest on the Bonds.

(iv) Notwithstanding anything to the contrary contained herein, the Borrower promises that it will pay the Payments in accordance with the terms hereof at such times and in such amounts so as to assure that no default in the payment of the principal of, premium, if any, or interest on the Bonds shall at any time occur. The Borrower does hereby obligate itself and its successors to budget and appropriate annually a sum of money sufficient to make the Payments required by this Agreement, including any principal and/or interest on the Bonds theretofore matured and unpaid and to collect revenues sufficient to make such Payments.

12

(v) Whenever the Borrower shall fail to pay the full amount of any installment of Payments payable under Section 4.2(a) by the date on which such installment is due, the Trustee shall give immediate telephonic notice thereof, promptly confirmed in writing, to an Authorized Borrower Representative.

(b) Special Payments :

(i) “Change of Control Payment” being an amount sufficient for the payment in full in satisfaction of a Change of Control Offer (as defined in the Indenture). The Change of Control Payment with respect to the Bonds shall be payable directly to the Trustee for the account of the Borrower Designee (as defined in the Indenture) on the Change of Control Payment Date (as defined in the Indenture).

(c) Default or Delay Payments consisting of the amounts, fees and expenses which the Authority may incur or be or become legally obligated to pay under the terms of the Bonds or the Indenture by reason of any default hereunder or thereunder or any default or delay in Payment of the sums due hereunder or thereunder, provided that such default or delay shall have resulted in the Borrower’s default or breach of covenant under this Agreement; the amount expended by the Authority or the Trustee or indebtedness incurred by the Authority or the Trustee for the purpose of curing the Borrower’s defaults hereunder or in connection with any defaults under the Bonds or the Indenture (provided that such default shall have resulted in the Borrower’s default or breach of covenant under this Agreement) and all costs, expenses and charges, including reasonable attorneys’ fees, incurred by the Authority or the Trustee in collecting the Payments or in enforcing any covenant or agreement of the Borrower contained in this Agreement or incurred in pursuing any remedy hereunder or under the Indenture.

(d) Costs of Issuance and Trustee Expense Payments consisting of costs of issuance of the Bonds and the Administrative Expenses, including the Authority’s fees, the Trustee’s initial acceptance fee, and the fees and expenses of counsel to the Trustee in connection with the issuance of the Bonds, to be paid directly to the Authority, the Trustee or counsel to the Trustee upon demand, and, commencing on the Closing Date and continuing until the principal of and interest on all Outstanding Bonds shall have been fully paid, all expenses owed under the Indenture or this Agreement, including (i) the annual fee, if any, of the Trustee for the reasonable ordinary services of the Trustee rendered and ordinary expenses incurred under the Indenture during the twelve month period preceding that date, (ii) the reasonable fees, charges and expenses of the Authority or the Trustee, and all costs relating to the exchanging of Bonds as provided in the Indenture, as and when the same become due, and (iii) the reasonable fees, charges and expenses of the Authority or the Trustee for necessary extraordinary services rendered by it and extraordinary expenses incurred by it under the Indenture, including reasonable attorneys’ fees, as and when the same become due, provided that the Borrower may, without creating a default hereunder, contest in good faith the necessity for any such

13

extraordinary services and extraordinary expenses and the reasonableness of any such fees, charges or expenses, and in the event of such contest may only withhold payment of the contested fees, charges or expenses.

(e) The Borrower agrees to pay to the Trustee amounts sufficient and at such times as to enable the Trustee to pay the purchase price of any Bonds to be purchased pursuant to Section 4.1 or Section 4.2 of the Indenture on each purchase date of such Bonds as set forth in said Section 4.1 or Section 4.2, as the case may be. All such payments shall be made to the Trustee in lawful money of the United States of America in federal or other immediately available funds at the Corporate Trust Office of the Trustee with instructions from the Borrower to the Trustee to deposit such payments into the Bond Purchase Fund in accordance with the provisions of Section 5.1(c) of the Indenture. Each payment pursuant to this Section 4.2(e) shall at all times be sufficient to pay the purchase price of any Bonds to be purchased on such date pursuant to Section 4.1 or Section 4.2 of the Indenture; provided that any amount held by the Trustee in the Bond Purchase Fund on any such date and available to pay any such purchase price pursuant to Section 5.2(b)(i) of the Indenture shall be credited against the amount due on such date pursuant to this Section 4.2(e) to the extent available to pay the purchase price of such Bonds on such date.

The obligation of the Borrower to make these payments shall be fully or partially, as the case may be, satisfied and discharged to the extent that, at the time any such payments shall be due or owing, payment of the purchase price of the Bonds which would have been paid with such payments shall be paid (or provision for such payment shall be made as set forth in the Indenture) with amounts received by the Trustee from (i) proceeds of remarketing of the Bonds or (ii) any other source under the Indenture so long as the amounts are available for such purpose.

SECTION 4.3 Credits Against Payments.

A credit against and reduction of the Payments shall be derived only from the following sources:

(a) Any capitalization of interest from the proceeds of the Bonds;

(b) Surplus moneys (including investment earnings) contained in the funds and accounts held by the Trustee under the Indenture;

(c) Advance payments or prepayments of Payments; and

(d) Reductions in principal and interest requirements of Bonds due to the purchase or redemption of Bonds as provided in the Indenture.

SECTION 4.4 Obligation to Make Payments.

As authorized by the Act and the Refunding Act, the obligation of the Borrower to repay the Loan by making the Payments in accordance with the terms hereof, shall be absolute and unconditional and shall not be subject to, nor shall the Borrower be entitled to assert, any rights

14

of non-appropriation, abatement, deduction, reduction, deferment, recoupment, setoff, offset or counterclaim by the Borrower or any other person, nor shall the same be abated, abrogated, waived, diminished, postponed, delayed or otherwise modified under or by reason of any circumstance or occurrence that may arise or take place, irrespective of what statutory rights the Borrower may have to the contrary, including but without limiting the generality of the foregoing:

(a) Any damage to or destruction of part or all of the Projects;

(b) The taking or damaging of part or all of the Projects or any temporary or partial use thereof by any public authority or agency in the exercise of the power of eminent domain, sequestration or otherwise;

(c) Any assignment, novation, merger, consolidation, transfer of assets, leasing or other similar transaction of, by or affecting the Borrower, except as otherwise provided in this Agreement;

(d) Any change in the tax or other laws of the United States, the State or any governmental authority;

(e) Any failure of title or any lawful or unlawful prohibition of the Borrower’s use of the Projects or any portion thereof or the interference with such use by any Person or any commercial frustration of purpose or loss or revocation of any permits, licenses or other authorizations required for the operation of the Projects; and

(f) Any failure of the Authority or the Trustee to perform and observe any agreement or covenant, express or implied, or any duty, liability or obligation arising out of or in connection with this Agreement, the invalidity, enforceability or disaffirmance of any of this Agreement, the Indenture or the Bonds or for any other cause similar or dissimilar to the foregoing.

Furthermore, the Borrower covenants and agrees that it will remain obligated under this Agreement in accordance with its terms, and that it will not take or participate or acquiesce in any action to terminate, rescind or avoid this Agreement.

SECTION 4.5 Prepayment and Redemption.

The Borrower shall have the option to prepay its obligations hereunder at the times and in the amounts as necessary to exercise its option to cause the Bonds to be redeemed as set forth in the Indenture and in the Bonds. The Borrower hereby agrees that it shall prepay its obligations hereunder at the times and in the amounts as necessary to accomplish the extraordinary mandatory redemption of the Bonds as set forth in the Indenture and in the Bonds. The Authority, at the request of the Borrower, shall forthwith take all steps (other than the payment of the money required for such redemption) necessary under the applicable redemption provisions of the Indenture to effect redemption of all or part of the Outstanding Bonds, as may be specified by the Borrower, on the date established for such redemption.

15

Payments owed hereunder due to the early redemption of the Bonds shall be paid to the Trustee on or prior to the date set for redemption thereof.

SECTION 4.6 Issuance, Delivery and Surrender of the Notes.

(a) In order to secure, on behalf of the Authority, the obligation of the Borrower to make the Payments, concurrently with the issuance and delivery by the Authority of the Bonds, the Borrower shall issue and deliver to the Trustee a note (the “Notes” ) under the Senior Notes Indenture (i) maturing on the same date and in the same principal amount as the Bonds, (ii) bearing interest at an interest rate at all times equal to the interest rate borne by the Bonds, payable on the dates on which interest is payable on the Bonds, (iii) containing correlative redemption provisions (a) to the provisions of Section 3.4 of the Indenture and reflected in the Form of Bond set forth in Exhibit A thereto and (b) providing that upon receipt by the trustee under the Senior Notes Indenture (the “Notes Trustee” ) of a written demand from the Trustee stating that the principal amount of all Bonds then Outstanding under the Indenture has been declared immediately due and payable, the Borrower, subject to the terms and provisions of the Notes, will redeem the Notes not more than 180 days after receipt by the Notes Trustee of such written demand, and (iv) subject to the provisions of subsection (b) of this Section 4.6, requiring payments of the principal thereof and the premium, if any, and interest thereon to be made to the Trustee.

(b) The obligation of the Borrower to make any payment of the principal of, premium, if any, or interest on the Notes, whether at maturity, upon redemption (including any redemption due to the occurrence of a Determination of Taxability, as such term is defined in the Indenture) or otherwise, shall be fully or partially, as the case may be, deemed to have been paid or otherwise satisfied and discharged to the extent that at the time any such payment shall be due, the then due principal or purchase price of, premium, if any, or interest on the Bonds which corresponds to such amounts under the Notes shall have been fully or partially paid, deemed to have been paid or otherwise satisfied and discharged. In addition, such obligation to make any payment of the principal of, premium, if any, or interest on the Notes at any time shall be deemed to have been satisfied and discharged to the extent that the amount of the Borrower’s obligation to make any payment of the principal of, premium, if any, or interest on the Notes exceeds the obligation of the Borrower at that time to make any Payment.

(c) The Authority shall not attempt to sell, assign or transfer the Notes, except to the extent of the assignment and pledge thereof to the Trustee under the Indenture. In view of such pledge and assignment, (i) the Notes shall be issued and delivered to, registered in the name of and held by the Trustee for the benefit of the Bondholders and in no respect shall the Notes be deemed to be owned or held by or for the account, benefit or interest of the Borrower; (ii) the Senior Notes Indenture shall provide that the Trustee shall not sell, assign or transfer the Notes except to a successor trustee under the Indenture, and shall surrender the Notes to the Notes Trustee in accordance with the provisions of subsection (d) of this Section 4.6; and (iii) the Borrower may take such actions as it shall deem to be desirable to effect compliance with such restrictions on transfer, including the placing of an appropriate legend on the Notes and the issuance of stop-transfer instructions to the Notes Trustee or any other transfer agent under the Senior Notes Indenture.

16

(d) At the time any Bonds cease to be Outstanding (other than by reason of the payment or redemption of the Notes), the Authority shall cause the Trustee to surrender to the Notes Trustee for cancellation a corresponding principal amount of the Notes, bearing interest at a rate equal to the interest rate borne by such Bonds, and maturing on the same date as such Bonds.

(e) The Trustee, as holder of the Notes, shall have and exercise the remedies provided under the Senior Notes Indenture for holders of notes issued thereunder. To the extent that moneys recovered under the Senior Notes Indenture are insufficient to pay in full the Payments, the Borrower shall remain liable for any such deficiency under the terms of Section 4.4 hereof.

ARTICLE V

NON-ARBITRAGE

SECTION 5.1 Covenants as to Arbitrage.

The Borrower hereby agrees to prepare or to have prepared and provided, instructions to the Trustee as to the investment and reinvestment of moneys held as part of any fund or account relating to the Bonds. Any such moneys so held as part of any fund or account shall be invested or reinvested by the Trustee in Permitted Investments as specified in Section 5.8 of the Indenture. The Borrower hereby covenants that it will comply with the terms of the Tax Regulatory Agreement and that it will make such use of the proceeds of the Bonds and all other funds held by the Trustee under the Indenture, regulate the investment of such proceeds and other funds and take such other and further action as may be required so that the Bonds will not constitute arbitrage bonds under Section 148 of the Code and the regulations promulgated thereunder. The Borrower agrees that it will comply with the terms of any letter of instructions provided to it by nationally recognized bond counsel relating to compliance with the provisions of Section 148 of the Code.

If the Borrower determines that it is necessary to restrict or limit the yield on the investment of any money paid to or held by the Trustee hereunder or under the Indenture in order to avoid classification of the Bonds as arbitrage bonds within the meaning of the Code, the Borrower may issue to the Trustee an instrument to such effect (along with appropriate written instructions) instructing the Trustee which investments to invest in so as to restrict or limit the yield of such moneys.

17

ARTICLE VI

CERTAIN COVENANTS

SECTION 6.1 Covenants Regarding the Projects.

(a) The Borrower expressly covenants and agrees:

(i) That the Authority and its duly authorized agents shall have the right at any reasonable time upon not less than three day’s prior written notice to inspect the Projects in a manner which will not interfere unreasonably with the Borrower’s use thereof;

(ii) That it shall maintain or cause to be maintained the Projects in good operating order and condition, reasonable and ordinary wear and tear alone excepted, and make all necessary repairs thereto, interior and exterior, structural and non-structural, ordinary and extraordinary, foreseen and unforeseen, and otherwise to make all replacements, alterations, improvements and modifications to the Projects necessary to ensure that the same at all times shall be suitable for the efficient operation thereof for the purpose intended;

(iii) That it shall have full and sole responsibility for the condition, repair, replacement, maintenance and management of the Projects; provided, however, no such condition, repair, replacement, maintenance or management shall be made to any inadequate, obsolete, worn-out, unsuitable, undesirable or unnecessary portions of the Projects; and

(iv) That, subject to its obligations and rights to maintain, repair or remove portions of the Projects as provided by this Section 6.1, it will use commercially reasonable efforts to continue operation of the Projects so long as and to the extent that operation thereof is, in the judgment of the Borrower, in the Borrower’s best interest.

(b) The Authority and Borrower expressly covenant and agree that the Borrower shall have the right from time to time to substitute personal property or fixtures for any portions of the Projects. Any such substituted property or fixtures shall, when so substituted, become a part of the Projects. The Borrower shall also have the right to remove any portions of the Projects, without substitution therefor.

(c) If, during the term of this Agreement, the Projects or any substantial portion thereof is destroyed or damaged in whole or in part by fire or other casualty, or title to, or the temporary use of, the Projects or any portion thereof shall have been taken by the exercise of the power of eminent domain, the Borrower shall (unless it shall have exercised its option to prepay the Bonds pursuant to the Indenture) promptly repair, rebuild or restore the portion of the Projects so damaged, destroyed or taken with such changes, alterations and modifications (including the substitution and addition of other property) as may be necessary or desirable for the administration and operation of the Projects and as shall not impair the character or significance of the Projects as furthering the purposes of the Act.

Nothing in this Section 6.1 shall prevent or restrict the Borrower, in its sole discretion, at any time, from discontinuing or suspending either permanently or temporarily its use of any facility of the Borrower served by the Projects and in the event such discontinuance or suspension shall render unnecessary the continued operation of the Projects, the Authority and the Borrower agree that the Borrower shall have the right to discontinue the operation of the Projects during the period of any such discontinuance or suspension.

18

SECTION 6.2 Environmental Covenants.

(a) The Borrower shall not engage in any activities relating to the Projects that will result in the material violation of any current or future Environmental Regulations. The Borrower shall obtain from time to time all permits required under any current or future environmental laws so that its operation of the Projects will be in accordance with such laws, except where the failure to so obtain would not result in a material adverse effect on the Projects or the Borrower’s ability to meet its obligations hereunder.

(b) The Borrower shall indemnify the Trustee and the Authority and shall hold the Trustee and the Authority harmless from, and shall reimburse the Trustee and the Authority for, any and all claims, demands, judgments, penalties, liabilities, costs or damages imposed upon and out-of-pocket expenses incurred, including court costs and reasonable attorneys’ fees directly or indirectly incurred by the Trustee or the Authority (prior to trial, at trial and on appeal) in any action against or involving the Trustee or the Authority, resulting from any breach of Section 6.2(a), or from the discovery of any Hazardous Substance, in, upon, under or over, or emanating from, the Projects, whether or not the Borrower is responsible therefor, it being the intent of the Borrower that the Trustee and the Authority shall have no liability or responsibility for damage or injury to human health, the environment or natural resources caused by, for abatement and/or clean-up of, or with respect to, Hazardous Substances by virtue of their interests, if any, in the Projects created by the Indenture and this Agreement, or hereafter created, or as the result of the Trustee or the Authority exercising any instrument, including but not limited to becoming the owner thereof. The foregoing covenants shall be deemed continuing covenants for the benefit of the Trustee and the Authority and any successors and assigns thereof, including but not limited to any transferee of the title of the Trustee and any subsequent owner of the Projects, and shall survive the satisfaction and release of the Indenture and this Agreement, or under any other instrument.

(c) In case any action or proceeding is brought against the Authority or the Trustee in respect of which indemnity may be sought under this Section 6.2, the party seeking indemnity promptly shall give notice of that action or proceeding to the Borrower, and the Borrower, upon receipt of such notice, shall have the obligation and the right to assume the defense of the action or proceeding; provided, that failure of a party to give such notice shall not relieve the Borrower from any of its obligations under this Section 6.2 unless such failure prejudices the defense of the action or proceeding by the Borrower. The Borrower agrees that in the case of any action or proceeding involving the Authority or the Trustee, any counsel employed by the Borrower shall be reasonably acceptable to the Authority and Trustee. At its own expense, an indemnified party may employ separate counsel and participate in the defense; provided, however, where it is ethically inappropriate for one firm to represent the interests of the Authority, the Trustee, and/or any other indemnified party or parties, the Borrower shall pay such indemnified party’s reasonable legal expenses in connection with its retention of separate counsel. The Borrower shall not be liable for any settlement made without its written consent.

19

SECTION 6.3 Indemnification.

The Borrower further expressly covenants and agrees:

(a) That it shall indemnify and hold harmless the Authority and its directors, officers, agents and employees (collectively, the “Authority Indemnitees” ) from and against any and all liabilities, claims, costs and reasonable out-of-pocket expenses imposed upon or asserted against the Authority Indemnitees on account of (i) any loss or damage to property or injury to or death of or loss by any Person that may be occasioned by any cause whatsoever pertaining to the maintenance, operation and use of the Projects; (ii) any breach or default on the part of the Borrower in the performance of any covenant or agreement of the Borrower under this Agreement or any related document, or arising from any act or failure to act by the Borrower, or any of its agents, contractors, servants, employees or licensees; (iii) the authorization, issuance and sale of the Bonds, and the provision of any information furnished in connection therewith concerning the Projects or the Borrower (including, without limitation, any information furnished by the Borrower for inclusion in any certifications made by the Authority or for inclusion in, or as a basis for preparation of, the information statements filed by the Authority pursuant to the Code or otherwise included in the Preliminary Official Statement or the Official Statement relating to the Bonds (except for information regarding the Authority)); and (iv) any claim or action or proceeding with respect to the matters set forth in clauses (i), (ii) and (iii) above brought thereon. The Borrower shall not be liable for any of the foregoing arising from the Authority Indemnitee’s gross negligence or bad faith;

(b) That it shall indemnify and hold harmless the Trustee and its directors, officers, agents and employees (collectively, the “Trustee Indemnitees” ) from and against any and all claims, liabilities, losses, damages, fines, penalties, and expenses (including out-of-pocket and incidental expenses and reasonable fees and expenses of in-house or outside counsel) ( “Losses” ) that may be imposed on, incurred by, or asserted against, the Trustee Indemnitees or any of them for following any instruction or other direction upon which the Trustee is authorized to rely pursuant to the terms of this Agreement and the Indenture. In addition to and not in limitation of the immediately preceding sentence, the Borrower also covenants and agrees to indemnify and hold the Trustee Indemnitees and each of them harmless from and against any and all Losses that may be imposed on, incurred by, or asserted against the Trustee Indemnitees or any of them in connection with or arising out of the Trustee’s performance and/or exercise of its rights under this Agreement and the Indenture provided the Trustee has not acted with negligence or engaged in willful misconduct. The provisions of this Section 6.3(b) shall survive the termination of this Agreement and the Indenture, the final payment for defeasance of the Bonds and the resignation or removal of the Trustee for any reason; and

(c) In case any action or proceeding brought against the Authority and the Trustee in respect of which indemnity may be sought under this Section 6.3, the party seeking indemnity promptly shall give notice of that action or proceeding to the

20

Borrower, and the Borrower, upon receipt of such notice, shall have the obligation and the right to assume the defense of the action or proceeding; provided, that failure of a party to give such notice shall not relieve the Borrower from any of its obligations under this Section 6.3 unless such failure prejudices the defense of the action or proceeding by the Borrower. The Borrower agrees that in the case of any action or proceeding involving the Authority or the Trustee, any counsel employed by the Borrower shall be reasonably acceptable to the Authority and Trustee. At its own expense, an indemnified party may employ separate counsel and participate in the defense; provided, however, where it is ethically inappropriate for one firm to represent the interests of the Authority and any other indemnified party or parties, the Borrower shall pay such indemnified party’s reasonable legal expenses in connection with the its retention of separate counsel. The Borrower shall not be liable for any settlement made without its written consent.

SECTION 6.4 Compliance with Continuing Disclosure.

The Borrower has executed the Continuing Disclosure Agreement and has agreed to comply timely with the requirements set forth therein. The Borrower shall cause copies of any filings and/or disclosures that are required to be made pursuant to the terms of the Continuing Disclosure Agreement to be delivered to the Authority within five days of any such filing or disclosure.

SECTION 6.5 Covenants, Representations and Warranties Relating to Federal Income Taxation.

The Borrower covenants that it shall make such use of the proceeds of the Bonds, regulate investment of proceeds thereof and take such other and further actions as may be required by the Code and applicable temporary, proposed and final Regulations and procedures, necessary to assure that interest on the Bonds is excludable from gross income for Federal income tax purposes. Without limiting the generality of the foregoing covenant, the Borrower hereby covenants, represents and warrants, as follows:

(a) The Borrower will not take, fail to take or permit the commission of any action within its control necessary to be taken in order that interest on the Bonds will continue to be excludable from gross income for Federal income tax purposes; provided, however, that the Borrower, which is a “substantial user” of the Projects refinanced by the Bonds within the meaning of Section 147(a) of the Code, will purchase the Bonds on November 1, 2017, and the parties hereto acknowledge and understand that the interest received by the Borrower during the period of time in which the Borrower owns the Bonds, will not be excludable from gross income of the Borrower for Federal income tax purposes;

(b) The Borrower will timely file a statement with the United States Internal Revenue Service setting forth the information required pursuant to Section 149(e) of the Code;

21

(c) The average term of the Bonds, calculated in proportion to the “issue price” (as defined in Section 1273 of the Code) of the Bonds of each stated maturity of such Bonds is not later than the average term of the Series 2007 Bonds, calculated in proportion to the “issue price” (as defined in Section 1273 of the Code) of the Series 2007 Bonds of each stated maturity of such Series 2007 Bonds;

(d) The Borrower will not cause the Bonds to be treated as “federally guaranteed” obligations within the meaning of Section 149(b) of the Code (as may be modified in any applicable rules, rulings, policies, procedures, regulations or other official statements promulgated or proposed by the Department of the Treasury or the Internal Revenue Service with respect to “federally guaranteed” obligations described in Section 149(b) of the Code);

(e) Based upon all facts and estimates now known or reasonably expected to be in existence on the date the Bonds are delivered, the Borrower reasonably expects that the proceeds of the Bonds will not be used in a manner that would cause the Bonds or any portion thereof to be an “arbitrage bond” within the meaning of Section 148 of the Code;

(f) The Borrower will monitor or cause to have monitored the yield on the investment of the proceeds of the Bonds and moneys pledged to the repayment of the Bonds, other than amounts not subject to yield restriction and will restrict the yield on such investments to the extent required by the Code or the Regulations;

(g) The Borrower agrees to comply with all its covenants and agreements set forth in the Tax Regulatory Agreement executed in connection with the issuance and sale, and the remarketing, of the Bonds, and to perform the covenants and duties imposed on it contained therein; and

(h) All of the representations of the Borrower contained in Section 6.5(h), (i), (j), and (k) of the Loan Agreement dated as of November 1, 2007, by and between the Authority and the Trustee, executed and delivered in connection with the Series 2007 Bonds, are hereby reaffirmed and incorporated herein by reference.

All officers, employees and agents of the Borrower are authorized and directed to provide certifications of facts and estimates that are material to the reasonable expectations of the Borrower as of the date the Bonds are delivered. In complying with the foregoing covenants, the Borrower may rely from time to time upon a written opinion issued by Bond Counsel to the effect that any action by the Borrower or reliance upon any interpretation of the Code or Regulations contained in such opinion will not cause interest on the Bonds to be includable in gross income for Federal income tax purposes under existing law.

SECTION 6.6 Reliance.

The Authority may rely conclusively on the truth and accuracy of any document furnished to it by the Trustee, the Borrower or any Bondholder as to a matter required to be noticed by the Authority hereunder. The Authority shall not be under any obligation to perform any recordkeeping or to provide any legal service, it being understood that such services shall be performed or caused to be performed by the Trustee or the Borrower.

22

SECTION 6.7 No Violations of Law.

In no event shall this Agreement be construed as depriving the Authority of any right or privilege or requiring the Authority or any agent, employee, representative or advisor of the Authority to take or omit to take, or to permit or suffer the taking of, any action by itself or by anyone else, which deprivation or requirement would violate or result in the Authority’s being in violation of the Act or any other applicable state or federal law. At no time and in no event will the Borrower permit, suffer or allow any of the proceeds of this Agreement or the Bonds to be transferred to any Person in violation of, or to be used in any manner that is prohibited by, the Act, the Refunding Act, the GO Zone Act or any other state or federal law.

SECTION 6.8 Immunity of Officers, Employees and Members of the Authority.

No recourse shall be had for the payment of the principal of, premium, if any, or interest on any of the Bonds or for any claim based thereon or upon any obligation, covenant or agreement contained in this Agreement against any past, present or future officer, director, member, employee or agent of the Authority, or of any successor public corporation, under any rule of law or equity, statute or constitution, or by the enforcement of any assessment or penalty or otherwise, and all such liability of any such officers, directors, members, employees or agents as such is hereby expressly waived and released as a condition of and consideration for the execution of this Agreement and the issuance of such Bonds.

SECTION 6.9 Borrower Option to Elect Interest Rate.

The Borrower shall have, and is hereby granted, the option to elect to convert the interest rate borne by the Bonds to any Interest Rate pursuant to the provisions of Section 3.2 of the Indenture, subject to the terms and conditions set forth therein.

SECTION 6.10 Credit Facility.

(a) On and after the date the interest rate borne by all or a portion of the Bonds is converted to a new Interest Rate as set forth in Section 6.9 hereof, or if the holder of any of the Bonds is not the Borrower, the Borrower may be required to obtain and deliver to the Trustee a Credit Facility for such Bonds. The terms of such Credit Facility, if any, shall be as set forth in subsection (b) below or as may be set forth in an amendment to this Agreement.

(b) The Borrower may at any time cause a Credit Facility or an Alternate Credit Facility with respect to all or a portion of the Bonds to be delivered to the Trustee. The Borrower shall give the Trustee prior written notice of the delivery of any Credit Facility or Alternate Credit Facility. Each Credit Facility or Alternate Credit Facility shall be in an amount (A) as to principal equal to (i) the then-Outstanding aggregate principal amount of the Bonds to be secured by such Credit Facility less (ii) the principal amount of such Bonds covered by any other outstanding Credit Facility, if any, and (B) as to interest, equal to or greater than such interest coverage amount as may be required by any Rating Agency then providing a rating on such Bonds. The Credit Facility or Alternate Credit Facility shall have a term ending on or subsequent to the Stated Expiration Date of the Credit Facility to be replaced, if a Credit Facility is then in effect; provided, however, in no event shall the term of the Credit Facility or Alternate Credit Facility be less than one (1) year. Concurrently with the delivery of the Credit Facility or

23

Alternate Credit Facility, the Borrower shall deliver to the Trustee (i) an opinion of Bond Counsel that such Credit Facility or Alternate Credit Facility is authorized under this Agreement and the Indenture and complies with the terms hereof and that the provision thereof will not have an adverse effect on the exclusion of the interest on the Bonds from the gross income of the owners thereof for federal income tax purposes, (ii) an opinion of Counsel to the Credit Facility Provider issuing the Credit Facility or Alternate Credit Facility stating that such Credit Facility or Alternate Credit Facility is a legal, valid, binding and enforceable obligation of such Credit Facility Provider (subject to certain customary exceptions with respect to creditors’ rights and equitable considerations), and (iii) an opinion of counsel to the Credit Facility Provider issuing the Credit Facility or Alternate Credit Facility stating that such Credit Facility or Alternate Credit Facility is not required to be registered under the Securities Act of 1933, as amended (which opinion, in the case of a Credit Facility or an Alternate Credit Facility issued by a domestic branch or agency of a foreign bank, may be a reasoned opinion taking into account, among other things, positions and pronouncements of the Securities and Exchange Commission). The Trustee shall then accept such Credit Facility or Alternate Credit Facility and surrender any previously held Credit Facility to the Credit Facility Provider thereof for cancellation promptly upon such Alternate Credit Facility becoming effective; provided that the previous Credit Facility Provider has honored all demands for payment on any Credit Facility being replaced.

(c) The Trustee shall not sell, assign or otherwise transfer the Credit Facility, except to a successor Trustee under the Indenture and in accordance with the terms of the Credit Facility and the Indenture.

(d) Nothing in this Agreement or in the Indenture shall require the Borrower to cause a Credit Facility to be in place for the benefit of Bondholders during any Interest Rate Period.

ARTICLE VII

ASSIGNMENT

SECTION 7.1 Assignment of this Agreement.

The Borrower may, without the consent of the Authority or the Trustee, transfer or assign this Agreement or transfer or assign all or a portion of the Projects and any or all of its rights and delegate any or all of its duties hereunder, but no such transfer, assignment or delegation shall relieve the Borrower from its obligations hereunder.

Each transferee of the Borrower’s interest in this Agreement shall assume the obligations of the Borrower hereunder to the extent of the interest transferred or assigned, and the Borrower shall, on or prior to the effective date of any such transfer or assignment, furnish or cause to be furnished to the Authority and the Trustee a true and complete copy of each such transfer or assignment.

SECTION 7.2 Restrictions on Transfer of Authority’s Rights.

The Authority agrees that, except for the assignment of certain of its rights, title and interest under this Agreement (including its rights to receive payments to be made hereunder) to the Trustee pursuant to the Indenture, it will not during the term of this Agreement sell, assign, transfer or convey its interests in this Agreement except pursuant to the Indenture and as hereinafter in Section 7.3 provided.

24

SECTION 7.3 Assignment by the Authority.

It is understood, agreed and acknowledged that the Authority will assign to the Trustee pursuant to the Indenture certain of its rights, title and interests in and to this Agreement (reserving its rights, however, pursuant to sections of this Agreement providing that notices, reports and other statements be given to the Authority and also reserving its rights to reimbursement and payment of costs and expenses under Section 4.3 hereof and its individual and corporate rights to exemption from liability under Sections 6.2, 6.3, 6.8 and 10.13 hereof, and the Borrower hereby assents to such assignment and pledge.

ARTICLE VIII

SUPPLEMENTS AND AMENDMENTS

SECTION 8.1 Amendment Without Consent.

The Authority and the Borrower, with the consent of the Trustee with respect to Sections 8.1(e) and 8.1(f) hereof, but without the consent of the owners of any of the Outstanding Bonds, may enter into supplements or amendments to this Agreement for any of the purposes heretofore specifically authorized in this Agreement or the Indenture, and in addition thereto for the following purposes:

(a) to cure any ambiguity or formal defect, inconsistency or provide omitted language in this Agreement or to clarify matters or questions arising hereunder;

(b) to add covenants and agreements for the purpose of further securing the obligations of the Borrower hereunder;

(c) to confirm as further assurance any mortgage or pledge of additional property, revenues, securities or funds;

(d) to secure or maintain ratings on the Bonds from Moody’s and/or S&P;

(e) to conform the provisions of this Agreement in connection with the provisions of any supplements or amendments to the Indenture entered into pursuant to the provisions of Section 10.1 thereof;

(f) to provide any other modifications which are not prejudicial to the interests of the Bondholders; or

(g) to conform the covenants and provisions of the Borrower contained herein to any different financial statement presentation required by the Financial Accounting Standard Board which is different than the presentation required as of the date of issuance of the Bonds, so long as the effect of such conformed covenants and provisions is substantially identical to the effect of the covenants and provisions as in effect on the date of issuance of the Bonds;

25

provided, that with respect to any such supplement or amendment the Borrower provides (i) the Trustee with an opinion of Bond Counsel as set forth in Section 8.4 as well as an opinion of Bond Counsel to the effect that any such amendment, change or modification to this Agreement will not materially adversely affect the Bondholders, and (ii) the execution of the supplement or amendment is authorized or permitted by this Agreement and that all conditions precedent have been complied with.

SECTION 8.2 Amendment Upon Approval of a Majority of Bondholders.

The provisions of this Agreement may be amended in any particular manner with the written consent of the owners of not less than a majority in aggregate principal amount of the then Outstanding Bonds; provided, however, that no such amendment may be adopted which decreases the percentage of owners of Bonds required to approve any amendment, or which permits a change in the date of payment of the principal of or interest on any Bonds or of any redemption price thereof or the rate of interest thereon.

If at any time the Authority and the Borrower shall request the Trustee to consent to a proposed amendment for any of the purposes of this Section 8.2, the Trustee shall, upon being satisfactorily indemnified with respect to expenses, cause notice of the proposed execution of such proposed amendment to be given in the manner required by the Indenture to redeem Bonds. Such notice shall briefly set forth the nature of the proposed amendment and shall state that copies thereof are on file at the principal Corporate Trust Office of the Trustee for inspection by all Bondholders. If, within 90 days or such longer period as shall be prescribed by the Authority following such notice, the owners of not less than a majority in aggregate principal amount of the Outstanding Bonds at the time of the execution of any such proposed amendment shall have consented to and approved the proposed amendment as herein provided, no owner of any Bond shall have any right to object to any of the terms and provisions contained therein, or the operation thereof, or in any manner to question the propriety of the execution thereof, or to enjoin or restrain the Trustee, the Borrower or the Authority from executing or approving the same or from taking any action pursuant to the provisions thereof. Upon the execution of any such proposed amendment as in this Section permitted and provided, this Agreement shall be and be deemed to be modified and amended in accordance therewith.

SECTION 8.3 Filing.

Copies of any such supplement or amendment shall be filed with the Trustee and delivered to the Authority and the Borrower before such supplement or amendment may become effective.

SECTION 8.4 Reliance on Counsel.

The Authority and the Trustee shall be entitled to receive, and shall be fully protected in relying upon the opinion of counsel satisfactory to the Trustee, who may be counsel for the Authority, as conclusive evidence that any such proposed supplement or amendment complies with the provisions of this Agreement and the Indenture and that it is proper for the Authority and the Trustee under the provisions of this Article to execute or approve such supplement or amendment.

26

In connection with any amendment of this Agreement, there shall also be delivered to the Authority and the Trustee a written opinion of Bond Counsel (which counsel and opinion, including without limitation, the scope, form, substance and other aspects thereof, are acceptable to the Trustee) to the effect that under existing laws the proposed supplement or amendment would not adversely affect the validity of the Bonds or the exclusion otherwise available from gross income of interest on the Bonds for federal or state income tax purposes.

ARTICLE IX

EVENTS OF DEFAULT; REMEDIES

SECTION 9.1 Events of Default Defined.

The terms “Event of Default” and “Default” shall mean any one or more of the following events:

(a) An Event of Default shall exist under the Indenture, the Notes or the Senior Notes Indenture;

(b) The Borrower shall default in the timely payment of any Payment pursuant to Article IV of this Agreement; provided that such default with respect to an Interest Payment shall be deemed to occur upon the continuance of any such failure of payment for a period of 30 days after the applicable Interest Payment Date;

(c) The Borrower shall fail duly to perform, observe or comply with any other covenant, condition or agreement on its part under this Agreement (other than a failure to make any Payment required under this Agreement), and such failure continues for a period of 30 days after the date on which written notice of such failure, requiring the same to be remedied, shall have been given to the Borrower by the Trustee; provided, however, that if such performance, observation or compliance requires work to be done, action to be taken, or conditions to be remedied, which by their nature cannot reasonably be done, taken or remedied, as the case may be, within such 30 day period, no Event of Default shall be deemed to have occurred or to exist if, and so long as the Borrower shall commence such performance, observation or compliance within such period and shall diligently and continuously prosecute the same to completion;

(d) The entry of a decree or order by a court having jurisdiction in the premises adjudging the Borrower a bankrupt or insolvent, or approving as properly filed a petition seeking reorganization, arrangement, adjustment or composition of or in respect of the Borrower under the United States Bankruptcy Code or any other applicable federal or state law, or appointing a receiver, liquidator, custodian, assignee, or sequestrator (or other similar official) of the Borrower or of any substantial part of its property, or ordering the winding up or liquidation of its affairs, and the continuance of any such decree or order unstayed and in effect for it period of 90 consecutive days; and

27

(e) The institution by the Borrower of proceedings to be adjudicated a bankrupt or insolvent, or the consent by it to the institution of bankruptcy or insolvency against it, or the filing by it of a petition or answer or consent seeking reorganization or relief under the United States Bankruptcy Code or any other similar applicable federal or state law, or the consent by it to the filing of any such petition or to the appointment of a receiver, liquidator, custodian, assignee, trustee or sequestrator (or other similar official) of the Borrower or of any substantial part of its property, or the making by it of all assignment for the benefit of creditors, or the admission by it in writing of its inability to pay its debts generally as they become due.

SECTION 9.2 Remedies.

Whenever any Event of Default under Section 9.1 hereof shall have happened and be continuing, any one or more of the following remedial steps may be taken:

(a) The Authority or the Trustee may declare all Payments under Section 4.2 hereof to be immediately due and payable, whereupon the same shall become immediately due and payable;

(b) The Authority or the Trustee may take whatever action at law or in equity may appear necessary or desirable to collect the Payments then due and thereafter to become due, or to enforce performance and observance of any obligation, agreement or covenant of the Borrower under this Agreement;

(c) The Authority or the Trustee may have access to and inspect, examine and make copies of any and all books, accounts and records of the Borrower; and

(d) The Authority or the Trustee (or the owners of the Bonds in the circumstances permitted by the Indenture), and the Credit Facility Provider, so long as a Credit Facility is in place, may exercise any option and pursue any remedy provided by the Indenture.

Payments under subsections (a) and (b) of this Section 9.2 shall be deemed to have been made to the extent of any corresponding payments by the Borrower upon an Event of Default (as defined in the Senior Notes Indenture) under the Notes.

SECTION 9.3 No Remedy Exclusive; Selective Enforcement.

No remedy conferred upon or reserved to the Authority or the Trustee by this Agreement is intended to be exclusive of any other available remedy or remedies, but each and every such remedy shall be cumulative and shall be in addition to every other remedy given under this Agreement and as now or hereafter existing at law or in equity. No delay or omission to exercise any right or power accruing upon any event of nonperformance shall impair any such right or power or shall be construed to be a waiver thereof, but any such right and power may be exercised from time to time and as often as may be deemed expedient.

28

SECTION 9.4 Indenture Overriding.

All of the provisions of this Article are subject to and subordinate to the rights and remedies of the Bondholders and the Trustee pursuant to the Indenture. The Authority shall have no power to waive any event of default hereunder, except with respect to indemnification and its administrative payments, without the consent of the Trustee to such waiver.

SECTION 9.5 Agreement to Pay Attorneys’ Fees and Expenses.

In any Event of Default, if the Authority or the Trustee employs attorneys or incurs other expenses to collect any amounts payable hereunder or to enforce the performance or observance of any covenants or agreements in the event of a breach of this Agreement by the Borrower, the Borrower agrees that it will on demand therefor pay to the Authority or the Trustee the reasonable fees of such attorneys and such other reasonable expenses so incurred by the Authority or the Trustee.

SECTION 9.6 Authority and Borrower to Give Notice of Default.

The Authority and the Borrower covenant that they will, at the expense of the Borrower, promptly give to the Trustee written notice of any Event of Default under this Agreement of which they shall have actual knowledge or written notice, but the Authority shall not be liable (except as otherwise expressly provided herein) for failing to give such notice.

SECTION 9.7 Correlative Waivers.

If an Event of Default under Section 8.2 of the Indenture shall be cured or waived and any remedial action by the Trustee rescinded, any correlative Default under this Agreement shall be deemed to have been cured or waived.

ARTICLE X

MISCELLANEOUS

SECTION 10.1 References to the Bonds Ineffective After Bonds Paid.

Upon payment of the Bonds by the Authority in accordance with the Indenture, all references in this Agreement to the Bondholders shall be ineffective and the Authority and any Bondholder shall not thereafter have any rights hereunder, excepting those that shall have theretofore vested.

SECTION 10.2 Amounts Remaining in Funds.

It is agreed by the parties hereto that after payment in full of (i) the principal of, premium, if any, and interest on the Bonds (or provision for the payment thereof having been made in accordance with the provisions of the Indenture), (ii) the purchase price of all Bonds (other than Borrower Bonds) tendered or deemed to be tendered to the Trustee pursuant to Sections 4.1 and 4.2 of the Indenture (or the cancellation of all Bonds pursuant to Section 2.14 of the Indenture), (iii) the fees, charges and expenses of the Authority, the Trustee and the

29

Remarketing Agent in accordance with this Agreement and the Indenture and (iv) all other amounts required to be paid under this Agreement and the Indenture, any amounts remaining in any fund or accounts maintained under this Agreement or the Indenture and not applied to the payments of the above in accordance with the provisions of this Agreement and the Indenture shall belong to and be paid by the Trustee to the Credit Facility Provider so long as a Credit Facility is then in effect, but only to the extent of any obligations owed by the Borrower to the Credit Facility Provider thereunder, and otherwise to the Borrower as an overpayment of repayment installments.

Notice hereunder shall be deemed effective on the date of its receipt by the addressee. The Borrower, the Authority and the Trustee may, by notice given hereunder, designate any further or different addresses, counsel or counsel addresses to which subsequent notices, certificates, requests or other communications shall be sent.

SECTION 10.4 Binding Effect.

This Agreement shall inure to the benefit of and shall be binding upon the Authority, the Borrower and their respective successors and assigns, subject to the limitation that any obligation of the Authority created by or arising out of this Agreement shall not be a general debt of the Authority, but shall be payable solely out of the proceeds derived from this Agreement and the sale of the Bonds under the Indenture.

30

SECTION 10.5 Performance on Legal Holidays.

In any case where the date of maturity of interest on or principal of the Bonds or the date fixed for redemption or purchase of any Bonds or the date fixed for the giving of notice or the taking of any action under the Indenture shall not be a Business Day, then payment of such interest, principal, purchase price and redemption premium, if any, the giving of such notice or the taking of such action need not be made on such date but may be made on the next succeeding Business Day with the same force and effect as if made on the date of maturity or the date fixed for redemption or purchase, and no interest on such payment shall accrue for the period after such date.

SECTION 10.6 Execution In Counterparts.

This Agreement may be executed in several counterparts, each of which shall be regarded as an original and all of which shall constitute but one and the same instrument.

SECTION 10.7 Governing Law.

This Agreement shall be deemed to be a contract made under the laws of the State of Louisiana and for all purposes shall be governed exclusively by and construed in accordance with the laws of the State of Louisiana.

SECTION 10.8 Severability.

If any clause, provision, section or article of this Agreement be held illegal or invalid by any court, the invalidity of such clause, provision, section or article shall not affect any of the remaining clauses, provisions, sections or articles hereof and this Agreement shall be construed and enforced as if such illegal or invalid clause, provision, section or article had not been contained herein. In case any agreement or obligation contained in this Agreement be held to be in violation of law, then such agreement or obligation shall be deemed to be the agreement or obligation of the Authority or the Borrower, as the case may be, only to the extent permitted by law.

SECTION 10.9 Captions.

The table of contents, captions or headings of the several articles and sections of this Agreement are for convenience only and shall not control, affect the meaning of or be taken as an interpretation of any provisions of this Agreement.

SECTION 10.10 Consents and Approvals.

Whenever the consent or approval of the Authority, the Borrower or the Trustee shall be required under the provisions of this Agreement, such consent or approval shall not be unreasonably withheld or delayed.

31

SECTION 10.11 Obligations.

The obligations of the Borrower under this Agreement constitute unsecured, general obligations of the Borrower.

SECTION 10.12 Third Party Beneficiaries.

It is specifically agreed between the parties executing this Agreement that it is not intended by any of the provisions of any part of this Agreement to make any Person not a party to this Agreement, except as expressly provided herein or as contemplated in the Indenture, a third party beneficiary hereunder, or to authorize anyone not a party to this Agreement to maintain a suit for personal injuries or property damage pursuant to the terms or provisions of this Agreement. The duties, obligations and responsibilities, if any, of the parties to this Agreement with respect to third parties shall remain as imposed by law.

SECTION 10.13 Exculpatory Provision.

In the exercise of the powers of the Authority, the Trustee and their respective trustees, directors, officers, employees and agents (each, an “Indemnified Party” ) under this Agreement, each Indemnified Party shall not be accountable or liable to the Borrower for any actions taken or omitted by such Indemnified Party in good faith and believed by it or them to be authorized or within their discretion or rights or powers conferred upon them (other than the negligence or willful misconduct of such Indemnified Party), all such liability, if any, being expressly waived by the Borrower by the execution of this Agreement. The Borrower shall indemnify and hold harmless each Indemnified Party against any claim or liability based on the foregoing asserted by any other Person.

In case any action shall be brought against an Indemnified Party in respect of which indemnity may be sought against the Borrower, such Indemnified Party shall promptly notify the Borrower in writing and the Borrower shall assume the defense thereof, including the employment of counsel of the Borrower’s choice and the payment of all expenses. Such Indemnified Party shall have the right to employ separate counsel in any such action and participate in the defense thereof, but the fees and expenses of such counsel shall be paid by such Indemnified Party unless the employment of such counsel has been authorized by the Borrower. The Borrower shall not be liable for any settlement of any such action without its consent but if any such action is settled with the consent of the Borrower or if there be final judgment for the plaintiff of any such action, the Borrower agrees to indemnify and hold harmless such Indemnified Party from and against any loss or liability by reason of such settlement or judgment.

SECTION 10.14 Accounts and Audits.

The Authority shall cause the Trustee to keep proper books of records and accounts (separate from all other records and accounts) in which complete and correct entries shall be made of its transactions relating to the Bonds.

32

SECTION 10.15 Date of Loan Agreement.

The dating of this Agreement as of November 1, 2017 is intended as and for the convenient identification of this Agreement and is not intended to indicate that this Agreement was executed and delivered on said date, this Agreement being executed on the date of issuance of the Bonds.

SECTION 10.16 References to Credit Facility Provider.

If the Credit Facility is not in effect at any time, all references to the Credit Facility Provider shall be deemed ineffective. The provisions of this Agreement requiring the consent of the Credit Facility Provider or requiring action to be taken at the direction of the Credit Facility Provider shall be deemed ineffective if the Credit Facility Provider is at any such time in default in its obligations under the Credit Facility.

33

IN WITNESS WHEREOF, the Authority has caused this Agreement to be executed by its Chairman and has caused the seal of the Authority to be affixed hereto and attested by its Executive Director, and the Borrower has caused this Agreement to be executed by a duly authorized officer, as of the date first above written.

[Signature Page to Agreement]