Document:

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            ASSIGNMENT No. 15 OF RECEIVABLES IN ADDITIONAL ACCOUNTS, dated as of
August 1, 2000, by and between CHASE MANHATTAN BANK USA, NATIONAL ASSOCIATION, a
national banking corporation organized and existing under the laws of the United
States of America ("Chase USA"), and THE BANK OF NEW YORK, a banking corporation
organized and existing under the laws of the State of New York (the "Trustee")
pursuant to the Pooling and Servicing Agreement referred to below.

                              W I T N E S S E T H:

            WHEREAS, Chase USA, as Transferor on and after June 1, 1996, The
Chase Manhattan Bank, as Transferor prior to June 1, 1996 and as Servicer, and
the Trustee are parties to the Third Amended and Restated Pooling and Servicing
Agreement, dated as of November 15, 1999 (hereinafter as such agreement may have
been, or may from time to time be, amended, supplemented or otherwise modified,
the "Pooling and Servicing Agreement");

            WHEREAS, pursuant to the Pooling and Servicing Agreement, Chase USA
wishes to designate Additional Accounts of Chase USA to be included as Accounts
and to convey the Receivables of such Additional Accounts, whether now existing
or hereafter created, to the Trust as part of the corpus of the Trust (as each
such term is defined in the Pooling and Servicing Agreement); and

            WHEREAS, the Trustee is willing to accept such designation and
conveyance subject to the terms and conditions hereof;

            NOW, THEREFORE, Chase USA and the Trustee hereby agree as follows:

                  1. Defined Terms. All terms defined in the Pooling and
      Servicing Agreement and used herein shall have such defined meanings when
      used herein, unless otherwise defined herein.

                  "Addition Date" shall mean, with respect to the Additional
      Accounts designated hereby, August 1, 2000.

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                  "Notice Date" shall mean, with respect to the Additional
      Accounts designated hereby, July 12, 2000.

                  2. Designation of Additional Accounts. Chase USA shall deliver
      to the Trustee not later than five Business Days after the Addition Date,
      a computer file or microfiche list containing a true and complete list of
      each MasterCard and VISA account which as of the Addition Date shall be
      deemed to be an Additional Account, such accounts being identified by
      account number and by the amount of Receivables in such accounts as of the
      close of business on the Addition Date. Such list shall be delivered five
      Business Days after the date of this Agreement and shall be marked as
      Schedule 1 to this Assignment and, as of the Addition Date, shall be
      incorporated into and made a part of this Assignment.

                  3. Conveyance of Receivables.

                  A. Chase USA does hereby transfer, assign, set-over and
      otherwise convey to the Trust for the benefit of the Certificateholders,
      without recourse on and after the Addition Date, all right, title and
      interest of Chase USA in and to the Receivables now existing and hereafter
      created in the Additional Accounts designated hereby, all monies due or to
      become due with respect thereto (including all Finance Charge Receivables)
      and all proceeds of such Receivables, Recoveries, Interchange, Insurance
      Proceeds relating to such Receivables and the proceeds of any of the
      foregoing.

                  B. In connection with such transfer, Chase USA agrees to
      record and file, at its own expense, a financing statement with respect to
      the Receivables now existing and hereafter created in the Additional
      Accounts designated hereby (which may be a single financing statement with
      respect to all such Receivables) for the transfer of accounts as defined
      in Section 9-106 of the UCC as in effect in the State of New York meeting
      the requirements of applicable state law in such manner and such
      jurisdictions as are necessary to perfect the assignment of such
      Receivables to the Trust, and to deliver a file-stamped copy of such
      financing statement or other evidence of such filing (which may, for
      purposes of this Section 3, consist of telephone confirmation of such
      filing) to the Trustee on or prior to the date of this Agreement.

                  C. In connection with such transfer, Chase USA further agrees,
      at its own expense, on or prior to the date of this Assignment to
      indi-

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      cate in its computer files that Receivables created in connection with the
      Additional Accounts designated hereby have been transferred to the Trust
      pursuant to this Assignment for the benefit of the Certificateholders.

                  D. Chase USA hereby grants to the Trustee a security interest
      in all of Chase USA's right, title and interest in, to and under the
      Receivables now existing and hereafter created in the Additional Accounts
      designated hereby, all monies due or to become due with respect to such
      Receivables, Insurance Proceeds relating to such Receivables, Recoveries,
      Interchange and the proceeds to any of the foregoing to secure a loan in
      an amount equal to the unpaid principal amount of the Investor
      Certificates issued or to be issued pursuant to the Pooling and Servicing
      Agreement and the interests accrued at the related Certificate Rates, and
      this Agreement shall constitute a security agreement under applicable law.

                  4. Acceptance by Trustee. The Trustee hereby acknowledges its
      acceptance on behalf of the Trust for the benefit of the
      Certificateholders of all right, title and interest previously held by
      Chase USA in and to the Receivables now existing and hereafter created,
      and declares that it shall maintain such right, title and interest, upon
      the Trust herein set forth, for the benefit of all Certificateholders.

                  5. Representations and Warranties of Chase USA. Chase USA
      hereby represents and warrants to the Trust as of the Addition Date:

                  A. Legal, Valid and Binding Obligation. This Assignment
            constitutes a legal, valid and binding obligation of Chase USA
            enforceable against Chase USA in accordance with its terms, except
            as such enforceability may be limited by applicable bankruptcy,
            insolvency, reorganization, moratorium or other similar laws now or
            hereafter in effect affecting the enforcement of creditors' rights
            in general and the rights of creditors of banking associations and
            except as such enforceability may be limited by general principles
            of equity (whether considered in a suit at law or in equity).

                  B. Eligibility of Accounts and Receivables. Each Additional
            Account designated hereby is an Eligible Account and each Receivable
            in such Additional Account is an Eligible Receivable.

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                  C. Selection Procedures. No selection procedures believed by
            Chase USA to be materially adverse to the interests of the Investor
            Certificateholders were utilized in selecting the Additional
            Accounts designated hereby from the available Eligible Accounts in
            the Bank Portfolio.

                  D. Insolvency. Chase USA is not insolvent and, after giving
            effect to the conveyance set forth in Section 3 of this Assignment,
            will not be insolvent.

                  E. Security Interest. This Assignment constitutes either: (i)
            a valid transfer and assignment to the Trust of all right, title and
            interest of Chase USA in and to Receivables now existing and
            hereafter created in the Additional Accounts designated hereby, and
            all proceeds (as defined in the UCC) of such Receivables and
            Insurance Proceeds relating thereto, and such Receivables and any
            proceeds thereof and Insurance Proceeds relating thereto will be
            held by the Trust free and clear of any Lien of any Person claiming
            through or under Chase USA or any of its Affiliates except for (x)
            Liens permitted under subsection 2.5(b) of the Pooling and Servicing
            Agreement, (y) the interest of the holder of the Transferor
            Certificate and (z) Chase USA's right to receive interest accruing
            on, and investment earnings in respect of, the Finance Charge
            Account and the Principal Account as provided in the Pooling and
            Servicing Agreement; or (ii) a grant of a security interest (as
            defined in the UCC) in such property to the Trust, which is
            enforceable with respect to existing Receivables of the Additional
            Accounts, the proceeds (as defined in the UCC) thereof and Insurance
            Proceeds relating thereto, upon the conveyance of such Receivables
            to the Trust, and which will be enforceable with respect to the
            Receivables thereafter created in respect of Additional Accounts
            designated hereby, the proceeds (as defined in the UCC) thereof and
            Insurance Proceeds relating thereto, upon such creation; and (iii)
            if this Assignment constitutes the grant of a security interest to
            the Trust in such property, upon the filing of a financing statement
            described in Section 3 of this Assignment with respect to the
            Additional Accounts designated hereby and in the case of the
            Receivables of such Additional Accounts thereafter created and the
            proceeds (as defined in the UCC) thereof, and Insurance Proceeds
            relating to such Receivables, upon such creation, the Trust shall
            have a first priority perfected security

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            interest in such property (subject to Section 9-306 of the UCC as in
            effect in the State of Delaware), except for Liens permitted under
            subsection 2.5(b) of the Pooling and Servicing Agreement.

                  F. Breach of Representations and Warranties. The provision set
            forth in Section 2.4(d) of the Pooling and Servicing Agreement shall
            be applicable to any breach of the representations and warranties of
            this Section 5 with respect to any Receivable.

                  6. Conditions Precedent. The acceptance by the Trustee set
      forth in Section 4 and the amendment of the Pooling and Servicing
      Agreement set forth in Section 7 are subject to the satisfaction, on or
      prior to the Addition Date, of the following conditions precedent:

                        A. Officer's Certificate. Chase USA shall have delivered
            to the Trustee a certificate of a Vice President or more senior
            officer substantially in the form of Schedule 2 hereto, certifying
            that (i) all requirements set forth in Section 2.6 of the Pooling
            and Servicing Agreement for designating Additional Accounts and
            conveying the Principal Receivables of such Account, whether now
            existing or hereafter created, have been satisfied and (ii) each of
            the representations and warranties made by Chase USA in Section 5 is
            true and correct as of the Addition Date. The Trustee may
            conclusively rely on such Officer's Certificate, shall have no duty
            to make inquiries with regard to the matters set forth therein, and
            shall incur no liability in so relying.

                        B. Opinion of Counsel. Chase USA shall have delivered to
            the Trustee an Opinion of Counsel with respect to the Additional
            Accounts designated hereby substantially in the form of Exhibit E to
            the Pooling and Servicing Agreement.

                        C. Additional Information. Chase USA shall have
            delivered to the Trustee such information as was reasonably
            requested by the Trustee to satisfy itself as to the accuracy of the
            representation and warranty set forth in subsection 5(d) to this
            Agreement.

                  7. Amendment of the Pooling and Servicing Agreement. The
      Pooling and Servicing Agreement is hereby amended to provide that all

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      references therein to the "Pooling and Servicing Agreement," to "this
      Agreement" and "herein" shall be deemed from and after the Addition Date
      to be a dual reference to the Pooling and Servicing Agreement as
      supplemented by this Assignment and by Assignment No. 1 of Receivables in
      Additional Accounts, dated as of July 1, 1996, Assignment No. 2 of
      Receivables in Additional Accounts, dated as of September 1, 1996,
      Assignment No. 3 of Receivables in Additional Accounts, dated as of
      December 1, 1997, Assignment No. 4 of Receivables in Additional Accounts,
      dated as of February 1, 1998, Assignment No. 5 of Receivables in
      Additional Accounts, dated as of April 1, 1998, Assignment No. 6 of
      Receivables in Additional Accounts, dated as of August 1, 1998, Assignment
      No. 7 of Receivables in Additional Accounts, dated as of November 1, 1998,
      Assignment No. 8 of Receivables in Additional Accounts, dated as of
      February 1, 1999, Assignment No. 9 of Receivables in Additional Accounts,
      dated as of April 1, 1999, Assignment No. 10 of Receivables in Additional
      Accounts, dated as of July 1, 1999, Assignment No. 11 of Receivables in
      Additional Accounts, dated as of October 1, 1999, Assignment No. 12 of
      Receivables in Additional Accounts, dated as of February 1, 2000,
      Assignment No. 13 of Receivables in Additional Accounts, dated as of April
      1, 2000, Assignment No. 14 of Receivables in Additional Accounts, dated as
      of May 1, 2000, Reassignment No. 1 of Receivables in Removed Accounts,
      dated as of September 30, 1997 and Reassignment No. 2 of Receivables in
      Removed Accounts, dated as of December 1, 1997. Except as expressly
      amended hereby, all of the representations, warranties, terms, covenants
      and conditions to the Pooling and Servicing Agreement shall remain
      unamended and shall continue to be, and shall remain, in full force and
      effect in accordance with its terms and except as expressly provided
      herein shall not constitute or be deemed to constitute a waiver of
      compliance with or a consent to noncompliance with any term or provisions
      of the Pooling and Servicing Agreement.

                  8. Counterparts. This Assignment may be executed in two or
      more counterparts (and by different parties on separate counterparts),
      each of which shall be an original, but all of which together shall
      constitute one and the same instrument.

                  9. GOVERNING LAW. THIS AGREEMENT SHALL BE CONSTRUED IN
      ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK WITHOUT REFERENCE TO ITS
      CONFLICT OF LAW PROVISIONS, AND THE OBLIGATIONS,

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      RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL BE DETERMINED IN
      ACCORDANCE WITH SUCH LAWS.

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            IN WITNESS WHEREOF, the undersigned have caused this Assignment of
Receivables in Additional Accounts to be duly executed and delivered by their
respective duly authorized officers on the day and year first above written.

                                    CHASE MANHATTAN BANK USA,
                                    NATIONAL ASSOCIATION

                                    By:
                                       --------------------------------
                                       Name:
                                       Title:

                                    THE BANK OF NEW YORK,
                                      as Trustee

                                    By:
                                       --------------------------------
                                       Name:
                                       Title:

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                                                          Schedule 1
                                                       to Assignment of
                                                        Receivables in
                                                     Additional Accounts
                                                     -------------------

                               ADDITIONAL ACCOUNTS
                               -------------------<PAGE>

                                 EXHIBIT 10.15

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                                 LOAN AGREEMENT

      LOAN AGREEMENT, dated August 16, 2000 between Tengasco Pipeline
Corporation, a Tennessee corporation, ("Borrower"), and Morita Properties, Inc.
("Lender").

                                  WITNESSETH:

      WHEREAS, the Borrower has requested that the Lender make the loan (as
hereinafter defined) and the Lender has agreed to make the Loan on and subject
to the terms and conditions hereof;

      NOW, THEREFORE, each of the parties hereto, for good and valuable
consideration, the receipt and sufficiency of which is hereby acknowledged,
hereby agree as follows:

                                   AGREEMENT:

1.    Subject to the terms and conditions hereof, the Lender hereby agrees to
      make a loan (the "Loan") to the Borrower in the amount of $500,000 to be
      made available as follows: $250,000 on August 16, 2000 and the remainder
      to be made available as follows: $250,000 on August 31, 2000.

2.    The Borrower hereby unconditionally promises to pay to the Lender the full
      outstanding principal amount of the Loan, together with all unpaid
      interest thereon and all other outstanding unpaid amounts owing to the
      Lender under or in connection with the Loan Documents, on or before August
      16, 2005. The Borrower hereby agrees to pay interest on the unpaid
      principal amount of the Loan at the rate of 10.75% payable monthly with
      the first payment due on March 16, 2001. The Loan shall be evidenced by a
      Note in the form attached hereto.

3.    As part consideration for making the Loan, Borrower will pay Lender a
      throughput fee in accordance with the form of Throughput Agreement
      attached hereto, while the Loan is outstanding.

4.    The principal of the Note may be prepaid, in whole or in part, at any
      time.

5.    If all or a portion of any interest payment shall not be paid when due,
      such overdue amount shall, to the fullest extent permitted by law, bear
      interest at a rate of 10.75% per annum.

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6.    All payments to be made by the Borrower to the Lender at the following
      address:

                         35 Park Avenue, #8F
                         New York, NY 10016

       or such other address as the Lender may from time to time designate.

7.    The Loan is secured by a first lien upon all the pipeline properties,
      rights of way, and facilities owned by Borrower and to be constructed with
      the proceeds of the Loan.

8.    In the event the Borrower fails to pay any principal of or interest on the
      Loan when due and payment, or application is made by the Borrower for the
      appointment of a receiver, trustee or custodian for any of the Borrower's
      assets; or a petition under any section or chapter of the federal
      Bankruptcy Code or any similar law shall be filed by the Borrower; or the
      Borrower makes an assignment for the benefit of its creditors or any case
      or proceeding is filed by the Borrower for its dissolution, liquidation or
      termination and the Borrower shall fail to sure such default within ten
      (10) days of the receipt of written notice from the Lender, the balance
      due under the Note may, at the option of the Lender be declared, and
      immediately shall become, due and payable.

9.    The Borrower agrees unconditionally upon demand to pay or reimburse the
      Lender for all reasonable out-of-pocket costs, expenses and disbursements,
      including but not limited to fees and expenses of counsel, incurred by
      Lender in connection with the enforcement of this Agreement.

10.   No course of dealing and no delay or failure of the Lender in exercising
      any right, power, remedy or privilege under this Agreement shall affect
      any other or future exercise thereof or operate as a waiver thereof.

11.   This Agreement and the other Loan Documents shall be binding upon and
      inure to the benefit of the successors and assigns of the Borrower and the
      Lender.

12.   Except as otherwise expressly provided for in this Agreement, the Borrower
      waives presentment, demand and protest and notice of presentment, protest,
      default, nonpayment, maturity, release, compromise, settlement, extension
      or renewal of any and all commercial paper, accounts, contract rights,
      documents, instruments, chattel paper and guarantees at any time held by
      the Lender on which the Borrower may in any way be liable and hereby
      ratifies and confirms whatever the Lender may do in this regard; and (ii)
      the benefit of all valuation, appraisement and exemption laws.

13.   Except as otherwise provided herein, any notice or other written
      communication required hereunder shall be in writing, and shall be deemed
      to have been validly served, given or delivered (i) upon deposit in the
      United States mail, with proper

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       postage prepaid, (ii) by hand delivery, (iii) by overnight express mail
       courier, or (iv) by telecopier, and addressed to the party to be notified
       at the address set forth below or to such other address as each party may
       designate for itself in writing by like notice.

             To the Lender:

                    35 Park Avenue, #8F
                    New York, NY 10016

             To the Borrower:

                    Tengasco Pipeline Corporation
                    603 Main Avenue, Suite 500
                    Knoxville, TN 37902
                    Facsimile: (865) 523-9894

14.   This Agreement represents the entire agreement between the parties and may
      not be amended, modified or changed, except by a writing executed by both
      parties.

15.   This Agreement may be executed in counterparts.

      IN WITNESS WHEREOF, and intending to be legally bound hereby, this
Agreement has been duly signed, sealed and delivered by the undersigned as of
the day and year specified at the beginning hereof.

 ATTEST:                              BORROWER
                                      TENGASCO PIPELINE CORPORATION
  /s/ Elizabeth A. Wendelken          By: /s/ Robert M. Carter
-----------------------------------      ------------------------------------
 Elizabeth A. Wendelken, Secretary           Robert M. Carter, President

                                      LENDER MORITA PROPERTIES, INC.

                                      By: /s/ Shigemi Morita
                                         ------------------------------------
                                            Shigemi Morita, President

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