SERVICE AGREEMENT between TRANSCONTINENTAL GAS PIPE LINECORPORATION and WASHINGTON GAS LIGHT COMPANY DATED AUGUST 1, 1991

Exhibit 10.13

TRANSCONTINENTAL GAS PIPE LINE CORPORATION

SERVICE AGREEMENT

between

TRANSCONTINENTAL GAS PIPE LINE CORPORATION

and

WASHINGTON GAS LIGHT COMPANY

DATED

AUGUST 1, 1991

TRANSCONTINENTAL GAS PIPE LINE CORPORATION

SERVICE AGREEMENT

     THIS AGREEMENT entered into this 1st day of August, 1991, by and between TRANSCONTINENTAL GAS PIPE LINE CORPORATION, a Delaware corporation, hereinafter referred to as “Seller,” first party, and WASHINGTON GAS LIGHT COMPANY, hereinafter referred to as “Buyer,” second party,

W I T N E S S E T H

     WHEREAS, Seller has offered to interested parties pursuant to a letter dated December 11, 1987 certain firm transportation capacity under Seller’s Rate Schedule FT; and

     WHEREAS, Buyer has nominated for firm transportation service pursuant to the December 11, 1987 letter; and

     WHEREAS, Seller agrees to receive, transport and redeliver or cause the redelivery of such quantities of natural gas as requested under the terms and conditions hereinafter set forth;

     NOW, THEREFORE, Seller and Buyer agree as follows:

ARTICLE I

     1.     Subject to the terms and provisions of this agreement and of Seller’s Rate Schedule FT, Buyer agrees to deliver or cause to be delivered to Seller gas for transportation and Seller agrees to receive, transport and redeliver natural gas to Buyer or for the account of Buyer, on a firm basis, up to the dekatherm equivalent of a Transportation Contract Quantity (“TCQ”) of 1,750 Mcf per day.

     2.     Transportation service rendered hereunder shall not be subject to curtailment or interruption except as provided in Section 11 of the General Terms and Conditions of Seller’s FERC Gas Tariff.

ARTICLE II

     Buyer shall deliver or cause to be delivered gas at the point(s) of receipt hereunder at a pressure sufficient to allow the gas to enter Seller’s pipeline system at the varying pressures that may exist in such system from time to time; provided, however, that such pressure of the gas delivered or caused to be delivered by Buyer shall not exceed the maximum operating pressure(s) specified below. In the event the maximum operating pressure(s) of Seller’s pipeline system, at the point(s) of receipt hereunder, is from time to time increased or decreased, then the maximum allowable pressure(s) of the gas

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TRANSCONTINENTAL GAS PIPE LINE CORPORATION

SERVICE AGREEMENT

delivered or caused to be delivered by Buyer to Seller at the point(s) of receipt shall be correspondingly increased or decreased upon written notification of Seller to Buyer. The point(s) of receipt for natural gas received for transportation pursuant to this agreement shall be:

See EXHIBIT A for Points of Receipt

ARTICLE III

      Seller shall redeliver to Buyer or for the account of Buyer the gas transported hereunder at the following point(s) of delivery and at a pressure(s) of:

See EXHIBIT B for Points of Delivery

ARTICLE IV

      This agreement shall be effective as of August 1, 1991 and shall remain in force and effect until 8:00 a.m. Eastern Standard Time March 2, 1998 and thereafter until terminated by Seller or Buyer upon at least three (3) years written notice; provided, however, this agreement shall terminate immediately and, subject to the receipt of necessary authorizations, if any, Seller may discontinue service hereunder if (a) Buyer, in Seller’s reasonable judgment fails to demonstrate credit worthiness, and (b) Buyer fails to provide adequate security in accordance with Section 8.3 of Seller’s Rate Schedule FT. As set forth in Section 8 of Article II of Seller’s August 7, 1989 revised Stipulation and Agreement in Docket Nos. RP88-68 et. al., (a) pregranted abandonment under Section 284.221(d) of the Commission’s Regulations shall not apply to any long term conversions from firm sales service to transportation service under Seller’s Rate Schedule FT and (b) Seller shall not exercise its right to terminate this service agreement as it applies to transportation service resulting from conversions from firm sales service so long as Buyer is willing to pay rates no less favorable than Seller is otherwise able to collect from third parties for such service.

ARTICLE V

      1.     Buyer shall pay Seller for natural gas delivered to Buyer hereunder in accordance with Seller’s Rate Schedule FT and the applicable provisions of the General Terms and Conditions of Seller’s FERC Gas Tariff as filed with the Federal Energy Regulatory Commission, and as the same may be legally amended or superseded from

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TRANSCONTINENTAL GAS PIPE LINE CORPORATION

SERVICE AGREEMENT

time to time. Such Rate Schedule and General Terms and Conditions are by this reference made a part hereof.

      2.     Seller and Buyer agree that the quantity of gas that Buyer delivers or causes to be delivered to Seller shall include the quantity of gas retained by Seller for applicable compressor fuel, line loss make-up (and injection fuel under Seller’s Rate Schedule GSS, if applicable) in providing the transportation service hereunder, which quantity may be changed from time to time and which will be specified in the currently effective Sheet No. 44 of Volume No. 1 of this Tariff which relates to service under this agreement and which is incorporated herein.

      3.     In addition to the applicable charges for firm transportation service pursuant to Section 3 of Seller’s Rate Schedule FT, Buyer shall reimburse Seller for any and all filing fees incurred as a result of Buyer’s request for service under Seller’s Rate Schedule FT, to the extent such fees are imposed upon Seller by the Federal Energy Regulatory Commission or any successor governmental authority having jurisdiction.

ARTICLE VI

      1.     This Agreement supersedes and cancels as of the effective date hereof the following contract(s) between the parties hereto:

              Agreement between Buyer and Seller dated April 10, 1990.

      2.     No waiver by either party of any one or more defaults by the other in the performance of any provisions of this agreement shall operate or be construed as a waiver of any future default or defaults, whether of a like or different character.

      3.     The interpretation and performance of this agreement shall be in accordance with the laws of the State of Texas, without recourse to the law governing conflict of laws, and to all present and future valid laws with respect to the subject matter, including present and future orders, rules and regulations of duly constituted authorities.

      4.     This agreement shall be binding upon, and inure to the benefit of the parties hereto and their respective successors and assigns.

      5.     Notices to either party shall be in writing and shall be considered as duly delivered when mailed to the other party at the following address:

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