**Exhibit 10.40**DEBT ASSUMPTION NOTE   $5,000,000 Hopewell, Virginia  July 26, 2007FOR VALUE RECEIVED, the undersigned, **Regional Enterprises, Inc.**, a Virginia corporation(“Borrower”), hereby unconditionally promises to pay to the order of **Rio Vista Energy PartnersL.P**., a Delaware limited partnership (the “Lender”), at c/o RZB Finance LLC, 1133 Avenue of theAmericas, New York, NY 10036, or at such other place as Lender may direct in writing, the principalamount of ***Five Million United States Dollars (US$5,000,000)***payable on (i) **DEMAND**(the “MaturityDate”), as such date may be extended by the Lender, or (ii) the date of any payment made under theNote, as hereinafter defined.This Debt Assumption Note is issued pursuant to a Debt Assumption Agreement dated as of evendate herewith between the Lender and Borrower. Until the termination of the Debt AssumptionAgreement, all payments due to the Lender under this Debt Assumption Note shall be paid to RZBFinance LLC.This Debt Assumption Note, together with interest hereon and other charges due, shall be dueand payable on the same dates and in the same amounts as payments (including mandatory prepayments)are due under, and shall bear interest at the same rate or rates as set forth in, that certain Noteof even date herewith in the original principal amount of $5,000,000 made by the Lender and payableto the order of RZB Finance LLC (as the same may be modified, extended or renewed, the “Note”),issued by the Lender pursuant to the terms of a Loan Agreement of even date herewith between theLender and RZB Finance LLC (as the same may be modified, extended or renewed, the “LoanAgreement”). Reference is hereby made to the Loan Agreement for provisions relating to interestrates, prepayment, default, default interest and acceleration of the Note. In the event of anymodification or amendment to the Note (which shall include any note given in substitution,extension, renewal or refinancing of the Note), Borrower agrees to execute and deliver to theLender a conforming amendment or modification to this Debt Assumption Note, or a conforming newnote in substitution, extension, renewal or refinancing of this Debt Assumption Note.The final payment on the Maturity Date shall equal the entire principal balance outstandinghereunder on such date, and Borrower agrees to pay interest on the unpaid principal amount hereoffor the period commencing on the date hereof until payment in full at the rates per annum and onthe dates set forth in the Note.Interest on this Debt Assumption Note shall be computed on the daily principal balance on thebasis of a 360 day year for the actual number of days elapsed in the period during which itaccrues.Borrower may, at any time upon not less than three (3) Business Days’ prior notice to Lenderprepay this Debt Assumption Note in whole or in part. Each prepayment shall be permanent andirrevocable and shall be accompanied by a payment of all interest accrued through and includingsuch date.
 
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All prepayments provided for in this Debt Assumption Note shall be without premium or penalty.All voluntary prepayments shall be in integral multiples of $50,000 or the outstanding principalbalance of this Debt Assumption Note. Once prepaid, whether in whole or in part, the prepaidamount of this Note may not be reborrowed. All prepayments of this Debt Assumption Note or anyportion thereof shall be made together with payment of all interest accrued on the amount repaidthrough the date of such prepayment. Prepayments of a LIBOR Loan (as defined in the LoanAgreement) may be made only on the last day of the Interest Period (as defined in the LoanAgreement) applicable to such Loan, unless Lender otherwise agrees.Payments of both principal and interest on this Debt Assumption Note are to be made in UnitedStates Dollars and in immediately available funds. Whenever any payment to be made hereunder shallbe stated to be due on a day that is not a Business Day, the payment may be made on the nextsucceeding Business Day, and such extension of time shall be included in the computation of theamount of interest or fees due hereunder.This Debt Assumption Note may not be modified, amended, waived, extended, changed, dischargedor terminated orally or by any act or failure to act on the part of Borrower or the Lender, butonly by an agreement in writing signed by the party against whom enforcement of any modification,amendment, waiver, extension, change, discharge or termination is sought.Borrower shall pay all costs and expenses of collection, including, without limitation,reasonable attorneys’ fees and disbursements, incurred by the Lender in connection with collectionor enforcement of this Debt Assumption Note.**BORROWER HEREBY WAIVES, TO THE FULLEST EXTENT PERMITTED BY LAW, THE RIGHT TO TRIAL BYJURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM, WHETHER IN CONTRACT, TORT OR OTHERWISE, RELATINGDIRECTLY OR INDIRECTLY TO THE LOAN EVIDENCED HEREBY, THIS            DEBT ASSUMPTION            NOTE, OR THEOTHER LOAN DOCUMENTS OR ANY ACTS OR OMISSIONS OF LENDER, ITS OFFICERS, EMPLOYEES, DIRECTORS ORAGENTS IN CONNECTION THEREWITH.**Except to the extent such waiver is prohibited by law, Borrower waives presentment,demand and protest and notice of presentment, demand, protest and non-payment and any other noticeof any kind in connection with this Debt Assumption Note.*[Signature page follows]*
 
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THIS DEBT ASSUMPTION NOTE SHALL BE GOVERNED BY, AND CONSTRUED AND ENFORCED IN ACCORDANCE WITH,THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO ITS RULES PERTAINING TO CONFLICTS OF LAWS.      **Regional Enterprises, Inc.**