Request of Dominion Transmission, Inc. under CP10-448.

Dominion Transmission, Inc. 701 East Cary Street, Richmond, VA 23219 January 11, 2012 Kimberly D. Bose, Secretary Federal Energy Regulatory Commission 888 First Street, N.E. Washington, D.C. 20426 Re: Dominion Transmission, Inc. Appalachian Gateway Project Docket No. CP10-448-000 Variance Request Dear Secretary Bose: By Order dated June 16, 2011, the Federal Energy Regulatory Commission (FERC) authorized Dominion Transmission, Inc. (Dominion) to construct and operate facilities which comprise the Appalachian Gateway Project. 135 FERC 61,239 (the Order) Dominion is hereby submitting a update to Variance Request TL-591-025 for the FERCs approval for those activities outlined in the enclosed document. If you have any questions, please contact me at 804-771-4456. Respectfully submitted, Scott B. Francis Scott B. Francis Regulatory and Certificates Analyst II cc: Janine Cefalu, FERC Interstate I-70 Horizontal Direction Drill Crossing Noise Impact Analysis Dominion Transmission, Inc. Appalachian Gateway Project TL-591 Pipeline Washington County, Pennsylvania GAI Project C080946.09 December, 2011 Revised, January 2012 Submitted By: Dominion Transmission, Inc. 445 West Main Street Clarksburg, West Virginia 26301 Prepared By: GAI Consultants, Inc. Pittsburgh Office 385 East Waterfront Drive Homestead, Pennsylvania 15120-5005 Interstate I-70 Horizontal Direction Drill Crossing, Noise Impact Analysis, Dominion Transmission, Inc., Appalachian Gateway Project, TL-591, Washington County, Pennsylvania TABLE OF CONTENTS Page LIST OF TABLES ........................................................................................................ ii LIST OF FIGURES ...................................................................................................... iii LIST OF APPENDICES............................................................................................... iv 1.0 INTRODUCTION ............................................................................................. 1 2.0 AMBIENT NOISE STANDARDS AND GUIDELINES ...................................... 2 3.0 EXISTING AMBIENT NOISE MONITORING................................................... 3 4.0 NOISE IMPACT ANALYSIS ............................................................................ 4 5.0 OPERATIONAL NOISE IMPACT ANALYSIS RESULTS ................................ 5 6.0 NOISE IMPACT MITIGATION ......................................................................... 6 7.0 NOISE MEASUREMENT EQUIPMENT .......................................................... 7 8.0 LIMITATIONS .................................................................................................. 8 TABLES FIGURES APPENDIX i Interstate I-70 Horizontal Direction Drill Crossing, Noise Impact Analysis, Dominion Transmission, Inc., Appalachian Gateway Project, TL-591, Washington County, Pennsylvania 2.0 AMBIENT NOISE STANDARDS AND GUIDELINES The Federal Energy Regulatory Commission (FERC) considers the