CONTRIBUTION, CONVEYANCE AND ASSUMPTION AGREEMENT

Exhibit 10.10

CONTRIBUTION, CONVEYANCE AND
ASSUMPTION AGREEMENT

BY AND AMONG

ENTERPRISE PRODUCTS OPERATING L.P.

ENTERPRISE GC, L.P.,

ENTERPRISE HOLDING III, L.L.C.

ENTERPRISE GTM HOLDINGS L.P.,

ENTERPRISE GTMGP, LLC

ENTERPRISE PRODUCTS GTM, LLC

AND

SOUTH TEXAS NGL PIPELINES, LLC

TABLE OF CONTENTS

CONTRIBUTION, CONVEYANCE AND ASSUMPTION AGREEMENT

     THIS CONTRIBUTION, CONVEYANCE AND ASSUMPTION AGREEMENT, dated as of January 23, 2007 (this “ Agreement ”), is entered into by and among ENTERPRISE PRODUCTS OPERATING L.P., a Delaware limited partnership (“ EPOLP ”), ENTERPRISE GC, L.P., a Delaware limited partnership (“ Enterprise GC ”), ENTERPRISE HOLDING III, L.L.C., a Delaware limited liability company (“ Holding III ”), ENTERPRISE GTM HOLDINGS L.P., a Delaware limited partnership (“ GTM Holdings ”), ENTERPRISE GTMGP, LLC, a Delaware limited liability company (“ GTMGP ”), ENTERPRISE PRODUCTS GTM, LLC, a Delaware limited liability company (“ GTM ”) and SOUTH TEXAS NGL PIPELINES, LLC, a Delaware limited liability company (“ STX NGL ”). The foregoing shall be referred to individually as a “ Party ” and collectively as the “ Parties. ” Certain capitalized terms used are defined in Article I hereof.

RECITALS

     NOW, THEREFORE, in consideration of their mutual undertakings and agreements hereunder, the Parties undertake and agree as follows:

ARTICLE I
DEFINITIONS; RECORDATION

      1.1 Definitions. The following capitalized terms have the meanings given below.

     “ Agreement ” has the meaning assigned to such term in the first paragraph of this Agreement.

     “ Delaware LLC Act ” has the meaning assigned to such term in the first recital of this Agreement.

     “ Effective Date ” means January 1, 2007.

     “ Effective Time ” means the time when the transactions contemplated by Article II hereof have been consummated.

      “ Enterprise GC ” has the meaning assigned to such term in the first paragraph of this Agreement.

     “ EPOLP ” has the meaning assigned to such term in the first paragraph of this Agreement.

      “ Excluded Assets ” has the meaning assigned to such term in Section 2.2 .

      “ Excluded Liabilities ” has the meaning assigned to such term in Section 3.2 .

     “ GTM ” has the meaning assigned to such term in the first paragraph of this Agreement.

     “ GTMGP ” has the meaning assigned to such term in the first paragraph of this Agreement.

     “ GTM Holdings ” has the meaning assigned to such term in the first paragraph of this Agreement.

     “ Holding III ” has the meaning assigned to such term in the first paragraph of this Agreement.

     “ Laws ” means any and all laws, statutes, ordinances, rules or regulations promulgated by a governmental authority, orders of a governmental authority, judicial decisions, decisions of arbitrators or determinations of any governmental authority or court.

     “ Party and Parties ” have the meanings assigned to such terms in the first paragraph of this Agreement.

      “ Registration Statement ” means the registration statement on Form S-1 (File No. 333-138371) filed by Duncan Energy Partners L.P.

     “ Restriction ” has the meaning assigned to such term in Section 7.2 .

      “ Restriction Asset ” has the meaning assigned to such term in Section 7.2 .

      “ South Texas Assets ” has the meaning assigned to such term in Section 2.1 .

     “ South Texas Asset Liabilities ” shall mean all liabilities and obligations relating to the South Texas Assets. The South Texas Asset Liabilities shall not include the Excluded Liabilities.

     “ Specific Conveyances ” has the meaning assigned to such term in Section 2.3 .

     “ STX NGL ” has the meaning assigned to such term in the first paragraph of this Agreement.

      1.2 Schedules. The following schedules are attached hereto:

ARTICLE II
THE CONVEYANCE

      2.1 Contribution and Conveyance of the South Texas Assets by Enterprise GC to STX NGL. Enterprise GC hereby grants, contributes, transfers, assigns and conveys to STX NGL, its successor and assigns, for its and their own use forever, all of its right, title and interest in and to all of the assets described on Schedule 2.1 (the “ South Texas Assets ”), and STX NGL hereby accepts the South Texas Assets, as a contribution to the capital of STX NGL in exchange for membership interests in STX NGL, subject to all matters to be contained in the instruments of conveyance covering the South Texas Assets to evidence such contribution and conveyance, if any. The South Texas Assets shall not include the Excluded Assets.

     TO HAVE AND TO HOLD the South Texas Assets unto STX NGL, its successors and assigns, together with all and singular the rights and appurtenances thereto in anywise belonging, subject, however, to the terms and conditions stated in this Agreement, and in such instruments of conveyance, forever.

      2.2 Excluded Assets . Notwithstanding anything contained in Section 2.1 to the contrary, Enterprise GC shall not grant, contribute, transfer, assign or convey to STX NGL (or cause to be granted, contributed, transferred, assigned or conveyed), and STX NGL shall neither assume, purchase nor acquire from Enterprise GC any of the assets described on Schedule 2.2 (collectively, the “ Excluded Assets ”).

      2.3 Specific Conveyances . To further evidence the contributions of the South Texas Assets reflected in this Agreement, Enterprise GC may have executed and delivered to STX NGL certain conveyance, assignment and bill of sale instruments (the “ Specific Conveyances ”). The Specific Conveyances shall evidence and perfect such contribution and conveyance made by this Agreement and shall not constitute a second conveyance of any assets or interests therein and shall be subject to the terms of this Agreement.

      2.4 Distribution of STX NGL Interest . Enterprise GC hereby distributes, transfers and assigns all of its right, title and interest in and to its membership interest in STX NGL to Holding III and GTM Holdings, 1% and 99%, respectively. Holding III in turn distributes such 1% membership interest to GTM Holdings. GTM Holdings accepts such membership interest distributed by Enterprise GC.

     GTM Holdings hereby distributes, transfers and assigns all of its right, title and interest in and to its membership interest in STX NGL to GTMGP and EPOLP, 1% and 99%, respectively. GTMGP in turn distributes such 1% membership interest to GTM and GTM in turn distributes such membership interests to EPOLP. EPOLP accepts such membership interests in STX NGL distributed by GTM Holdings and GTM.

     TO HAVE TO AND TO HOLD, said membership interest in STX NGL unto EPOLP, its successors and assigns, together with all and singular the rights and appurtenances thereto in anywise belonging, subject, however, to the terms and conditions stated in this Agreement.

ARTICLE III
ASSUMPTION OF CERTAIN LIABILITIES

      3.1 Assumption of South Texas Asset Liabilities by STX NGL . In connection with the contribution by Enterprise GC of the South Texas Assets to STX NGL, as set forth in Section 2.1 above, STX NGL hereby assumes and agrees to duly and timely pay, perform and discharge all of the South Texas Asset Liabilities, to the full extent that Enterprise GC has been heretofore or would have been in the future obligated to pay, perform and discharge the South Texas Asset Liabilities were it not for such contribution and the execution and delivery of this Agreement; provided, however, that said assumption and agreement to duly and timely pay, perform and discharge the South Texas Asset Liabilities shall not (a) increase the obligation of STX NGL with respect to the South Texas Asset Liabilities beyond that of Enterprise GC, (b) waive any valid defense that was available to Enterprise GC with respect to the South Texas Asset Liabilities or (c) enlarge any rights or remedies of any third party under any of the South Texas Asset Liabilities. In addition, STX NGL and each of the other parties hereto hereby agree to execute an amendment to the limited liability company agreement of STX NGL or such other agreements as necessary to evidence the issuance of the STX NGL membership interest to Enterprise GC as consideration for the contributions made pursuant to Section 2.1 and the distributions of such membership interests pursuant to Section 2.2 . Each of the parties hereto agree that after giving effect to and as a result of such transactions, EPOLP will remain the sole member of STX NGL.

      3.2 General Provisions Relating to Assumption of Liabilities

          (a) Notwithstanding any other provisions of this Agreement to the contrary, Enterprise GC and STX NGL agree that STX NGL shall not be obligated to, and shall not, assume any liabilities or obligations related to the Excluded Assets (collectively, the “ Excluded Liabilities ”).

          (b) Notwithstanding anything to the contrary contained in this Agreement including, without limitation, the terms and provisions of this Article III , STX NGL shall not be deemed to have assumed, and the South Texas Assets have not been or are not being contributed subject to, any liens or security interests securing consensual indebtedness covering any of the South Texas Assets, and all such liens and security interests shall be deemed to be excluded from the assumptions of liabilities made under this Article III .

ARTICLE IV
TITLE MATTERS

      4.1 Encumbrances .

          (a) Except to the extent provided in Section 3.2 or any other document executed in connection with this Agreement, the contribution and conveyance (by operation of Law or otherwise) of the South Texas Assets as reflected in this Agreement are made expressly subject to all recorded encumbrances, agreements, defects, restrictions, and adverse claims covering the South Texas Assets and all Laws, rules, regulations, ordinances, judgments and orders of governmental authorities or tribunals having or asserting jurisdiction over the South Texas Assets and operations conducted thereon or therewith, in each case to the extent the same are valid and enforceable and affect the South Texas Assets, including, without limitation, (i) all matters that a current on the ground survey, title insurance commitment or policy, or visual inspection of the South Texas Assets would reflect, (ii) the applicable liabilities assumed in Article III , and (iii) all matters contained in the Specific Conveyances.

          (b) To the extent that certain jurisdictions in which the South Texas Assets are located may require that documents be recorded in order to evidence the transfers of title reflected in this Agreement, then the provisions set forth in Section 4.1(a) immediately above shall also be applicable to the conveyances under such documents.

      4.2 Disclaimer of Warranties; Subrogation; Waiver .

          (a) EXCEPT TO THE EXTENT PROVIDED IN ANY OTHER DOCUMENT EXECUTE