Exhibit 10yy ATLANTA GAS LIGHT CO. August 10, 1995 Page 2 Contract Number: 3923 Amendment number: 1 Amendment effective date: July 1, 1995 ACCEPTED AND AGREED TO This 7 Day of Nov, 1995 TENNESSEE GAS PIPELINE COMPANY By: /s/ Lawrence G. Williams Title: Agent and Attorney-in-Fact ACCEPTED AND AGREED TO This 4th Day of Oct, 1995 ATLANTA GAS LIGHT CO. By: /s/ Stephen J. Gunther Title: Agent and Attorney-in-Fact GAS STORAGE SERVICE AGREEMENT EXHIBIT "A" AMENDMENT #1 TO GAS STORAGE SERVICE AGREEMENT DATED November 1, 1993 BETWEEN TENNESSEE GAS PIPELINE COMPANY AND ATLANTA GAS LIGHT CO ATLANTA GAS LIGHT CO EFFECTIVE DATE OF AMENDMENT: July 1, 1995 RATE SCHEDULE: FS SERVICE PACKAGE: 3923 SERVICE PACKAGE MSQ: 1,174,258 WITHDRAWAL QUANTITY: 8,699 INJECTION QUANTITY: 7,829 SERVICE POINT: PORTLAND METER METER NAME COUNTY ST ZONE I/W LEG TOTAL- BILLABLE- TQ TQ 060020 TGP-PORTLAND SUMNER TN 01 I 100 7,829 7,829 STORAGE INJECTION Total Injection TQ: 7,829 7,829 070020 TGP-PORTLAND SUMNER TN 01 W 100 8,699 8,699 STORAGE WITHDRAWAL Total Withdrawal TQ: 8,699 8,699 NUMBER OF INJECTION POINTS: 1 NUMBER OF WITHDRAWAL POINTS: 1 Note: Exhibit "A" is a reflection of the contract and all amendments as of the amendment effective date. GAS STORAGE SERVICE AGREEMENT EXHIBIT "A-1" SHOWING REQUESTED CHANGES AMENDMENT #1 TO GAS STORAGE SERVICE AGREEMENT DATED November 1, 1993 BETWEEN TENNESSEE GAS PIPELINE COMPANY AND ATLANTA GAS LIGHT CO ATLANTA GAS LIGHT CO EFFECTIVE DATE OF AMENDMENT: July 1, 1995 RATE SCHEDULE: FS SERVICE PACKAGE: 3923 SERVICE PACKAGE MSQ: 0 WITHDRAWAL QUANTITY: 166 INJECTION QUANTITY: 0 SERVICE POINT: PORTLAND METER METER NAME COUNTY ST ZONE I/W LEG TOTAL- BILLABLE- TQ TQ Total Injection TQ: 0 0 070020 TGP-PORTLAND SUMNER TN 01 W 100 166 166 STORAGE WITHDRAWAL Total Withdrawal TQ: 166 166 NUMBER OF INJECTION POINTS AFFECTED: 0 NUMBER OF WITHDRAWAL POINTS AFFECTED: 1