1 EXHIBIT 10.21 SERVICE AGREEMENT NO. 40251 CONTROL NO. 1993-10-14 - 0050 SIT SERVICE AGREEMENT THIS AGREEMENT, made and entered into this 13th day of December, 1993, by and between: COLUMBIA GAS TRANSMISSION CORPORATION ("SELLER") AND MOUNTAINEER GAS CO ("BUYER") WITNESSETH: That in consideration of the mutual covenants herein contained, the parties hereto agree as follows: Section 1. Service to be Rendered. Seller shall perform and Buyer shall receive the service in accordance with the provisions of the effective SIT Rate Schedule and applicable General Terms and Conditions of Seller's FERC Gas Tariff, Second Revised Volume No. I (Tariff), on file with the Federal Energy Regulatory Commission (Commission), as the same may be amended or superseded in accordance with the rules and regulations of the Commission. Seller shall store quantities of gas for Buyer up to but not exceeding Buyer's Maximum Balance Quantity as specified in Appendix A, as the same may be amended from time to time by agreement between Buyer and Seller, or in accordance with the rules and regulations of the Commission. Service hereunder shall be provided subject to the provisions of Part 284.223 of Subpart G of the Commission's regulations. Buyer warrants that service hereunder is being provided on behalf of BUYER. Section 2. Term. Service under this Agreement shall commence as of December 14, 1993, and shall continue in full force and effect from month-to-month thereafter unless terminated by either party upon thirty (30) days written notice to the other prior to the end of the initial term granted or any anniversary date thereafter. Pre-granted abandonment shall apply upon termination of this Service Agreement subject to any right of first refusal Buyer may have under the Commission's regulations and Seller's Tariff. Section 3. Rates. Buyer shall pay the charges and furnish the Retainage percentage set forth in the above-referenced Rate Schedule and specified in Seller's currently effective Tariff, unless otherwise agreed to by the parties in writing and specified as an amendment to this Service Agreement Section 4. Notices. Notices to Seller under this Agreement shall be addressed to it at Post Office Box 1273, Charleston, West Virginia 25325-1273, Attention: Director, Transportation and Exchange and notices to Buyer shall be addressed to it at: MOUNTAINEER GAS CO 414 SUMMERS ST. CHARLESTON, WV 25301 ATTN: PAM RUCKMAN; until changed by either party by written notice. 2 SERVICE AGREEMENT NO. 40251 CONTROL NO. 1993-10-14 - 0050 SIT SERVICE AGREEMENT Section 5. Superseded Agreements. This Service Agreement supersedes and cancels, as of the effective date hereof, the following Service Agreements: N/A. MOUNTAINEER GAS CO By: /s/ Michael S. Fletcher ---------------------------------- Title: Senior Vice President-CFO ------------------------------- COLUMBIA GAS TRANSMISSION CORPORATION By: /s/ Robert D. Stuart ---------------------------------- Title: Manager- T&E Implementation ------------------------------- -2- 3 Revision No. Control No. 1993-10-14 - 0050 Appendix A to Service Agreement No. 40251 Under Rate Schedule SIT Between (Seller) COLUMBIA GAS TRANSMISSION CORPORATION and (Buyer) MOUNTAINEER GAS CO Maximum Balance Quantity 125,000 Dth CANCELLATION OF PREVIOUS APPENDIX A Service changes pursuant to this Appendix A shall become effective as of NOVEMBER 0 1 , 1993. This Appendix A shall cancel and supersede the previous Appendix A effective N/A to the Service Agreement referenced above. With the exception of this Appendix A, all other terms and conditions of said Service Agreement shall remain in full force and effect. MOUNTAINEER GAS CO By /s/ Michael S. Fletcher ------------------------------------ Its Senior Vice President-CFO ----------------------------------- Date December 9, 1993 ---------------------------------- COLUMBIA GAS TRANSMISSION CORPORATION By /s/ Robert D. Stuart ------------------------------------ Robert D. Stuart Its Manager - T&E Implementation ----------------------------------- Date December 13, 1993 ---------------------------------- COLUMBIA GAS TRANSMISSION CORPORATION MOUNTAINEER GAS CO -3- 4 Control No. 1993-10-14 - 0050 Service Agreements Subject to SIT Balancing: Rate Schedule Agreement No. Shipper FTS 38113 MGC FTS 38137 MGC ITS 37507 MGC -4-