============= Page 1 of 10 ============= Northern Natural Gas & Transwestern Bill Cordes President E0004391610 XH005-00910 ============= Page 2 of 10 ============= Northern Natural Gas Company Storage Monetization Unlocking the Value of Base Gas in Storage • Sold 12.2 Bcf @ $4.20: Book Value $0.74 • $51.2 MM Revenue - $34.7 Million Net Profit • This arrangement monetizes 100% of Cunningham Storage Field Base Gas • Purchase of a 3 year Gas Balancing Arrangement provides Service to Replace Base Gas Functionality E0004391611 1#19 XH005-00911 ============= Page 3 of 10 ============= 0 Existing Proposed Under Construction 3 s `t t E0004391612 sy 0 XH005-00912 Northern Natural Gas Company Market Area Power Plants ============= Page 4 of 10 ============= Transwestern Pipeline Company Average Throughput to California 1000 800 0 600 0 m 400 200 0 co I*- r r r Year cc C) 0 r r S 0 0 0 N y0 204391613 Q XH005-00913 ============= Page 5 of 10 ============= Transwestern Pipeline Company • Gallup Expansion - 140,0010 MMBtu/d to California -In service - May 1, 2000 • New Interconnects --Power plant markets East of California (In-service by 2nd Quarter 2001) -*, Calpine 500 MW Griffith Energy 050 MW + Southwest Gas interconnect 100,000 MMBtu/day In-service by November 1, 2000 ECO64391614 KHO05-00914 ============= Page 6 of 10 ============= California Natural Gas Capacity & Demand Dth/day 10,000,000 9,000,000 8,000,000 7,000,000 6,000,000 5,000,000 4,000,000 3,000,000 2,000,000 ~j 3y f` 1995 1000 02005 Year Capacity Demand E0004391615 XH005-00915 ============= Page 7 of 10 ============= Transwestern Pipeline Company Proposed Power Plant Projects Key: 0 Planned • Under Development Under Construction m Transwestern Pipeline 12,635 MW t ~ L proposed = 2.5 Bcf/d E0004391616 EXH005-00916 ============= Page 8 of 10 ============= Transwestern Pipeline Company ._ Mainline West Subscription MMBTU/D 1,200,000 1,000,000 800,000 600,000 400,000 200,000 0 E0004391617 kJ a ~ ' rf = t Expiring - Unsubscribed 1Subscribed 0 XH005-00917 o o O 0 O 0 0 Q V- Q V- Q LL Q ============= Page 9 of 10 ============= Transwestern Pipeline Company Navajo Right-of-Way • ROW expires year-end 2003. • Close to deal that finalizes ROW extension through 2009 for approximately $29.1 million. -_ Southern Utes - November 2000 - September 2005 M Laguna - December 2002 3 Navajo - December 2003 • Remaining issues are terms and conditions primarily Navajo sovereignty. E0004391618 y~ 0 XH005-00918 ============= Page 10 of 10 ============= GPG ECOMMERCE - In July of this year, GPG was the first pipeline to offer Capacity Bidding using EnronOnline Future offerings being considered include: -- Capacity Options Trading - Storage Capacity Auctions - Fuel Auctions - Capacity Release Program - Imbalance Trading ECOQ43g1r19 EXH005-00919