1. 1 NSTAR TRANSMISSION RELIABILITY PROJECT ENVIRONMENTAL BUSINESS COUNCIL UPDATE APRIL 21, 2005

2. 2 PROJECT NEED DRIVEN BY INCREASING GROWTH WITH DECLINING GENERATION Load Growth over Past 6 Years Exceeded Historic Average In Greater Boston Area & Communities Area Older & Some Newer Generation Stations Have Retired or Announced Plans to Retire By June 2006, System Overloads Are Experienced throughout the System without Relief Overloads Get Worse with Time, Lead to Outages

3. 3 GOAL WAS TO FIND MOST COST-EFFECTIVE ALTERNATIVE TO MINIMIZE IMPACT ON NATURAL & HUMAN ENVIRONMENT Type of Transmission Line—Underground Cable Technology—Pipe-Type Cable, Over 200 miles in Greater Boston Area Route Selected to be Most Direct with Least Impact to People & Environment Construction Impact – Tried to Minimize Interferences

4. 4 FINAL DESIGN Three 345 kV Underground Transmission Lines Located in One Trench Up to Route Split Pipe-type Cable, Proven Reliable Technology at 345 kV New Switchyard at Origin-Stoughton Expand Two Termination Substations-Hyde Park & K Street Heat Exchangers at Baker Street & Hyde Park Substations (Reverse Power Flow to W. Roxbury to Reinforce Area)

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6. 6 SUMMARY OF BENEFITS Increases Import Capability into Greater Boston & Surrounding Communities by 1200-1800MW Mitigates All Known Reliability Issues for More than 10 Years Reduces Dependence on Older Local Generation Stations that Plan to Retire Opens Corridor for Economic Generating Sources from SEMA/RI into Greater Boston Area

7. 7 PROJECT SCHEDULE OVERVIEW Planning & Design Permitting & Engineering Station Construction Street Construction Install & Splice Cable Mar 2004 Apr 2005 Jun 2006 Feb 2006 Install & Splice Cable Dec 2007 In-Service Phase 1 Phase 2 June 2006 In-Service

8. 8 PROJECT STATUS Major Permits Secured-MEPA, Siting Board, Con Coms Most Follow-on Permits Completed, Some Still in Process –Chapter 91 License for K Street Station-DEP –Stoughton Conservation Commission Appeal to DEP MOUs with Boston, Towns, & DCR bound Mitigation Risk, Define Extended Works Hours ISO-NE System Technical Issues Resolved (System Switching) Major Equipment, Property, and Easements Acquisition Complete

9. 9 PROJECT STATUS Major Equipment Purchases Complete; ISO Administered RFPs for high dollar items including Pipe-type cable and GIS Equipment NSTAR/ISO issued Construction Contract RFP in Nov 2004 Bid as Single GC for Entire Project or Separately for Lines & Stations Transmission Line Contract Awarded; Station Contract in Final Negotiation

10. 10 PERMITING PROCESS WAS INTENSE EENF Filed 12/15/03; EFSB Petition Filed 1/16/04 MEPA Public Meetings Feb 04; EFSB Public Meetings Mar 04 NSTAR met with Boston & Supplemented EFSB Petition with Additional Route Alternatives Mar 04 Additional EFSB Public Meeting on New Alternatives April 04 2 EFSB Interveners Filed—ISO-NE & City of Boston Siting Board Discovery followed by Intervener Discovery May 04 Submitted Single EIR to MEPA May 04 Unrest in Stoughton Led to Selectmen’s Meeting May 04 Stoughton Filed as Late EFSB Intervener June 04; Hired Counsel EFSB Accepted Stoughton as Intervener; Stoughton Discovery Jul 04 Received MEPA Certificate July 16, 2004 EFSB Hearings began late July 04

11. 11 PERMITING CONTINUED ON EFSB Hearings Covered Each Section of Petition in Order Initial Cross-Examination by Boston & Stoughton Tapered Off as Hearings Progressed NSTAR worked with Stoughton Counsel to Negotiate Agreement Town Selectmen Rejected Proposed Agreement NSTAR Testimony Concluded in Late Aug 04 Stoughton Presented Direct Case with Witnesses-Technical & Environmental Second Proposed Agreement with Town Approved; Stoughton withdrew from Proceedings Hearings Concluded Sept 04 Con Com Petitions filed Oct 04 Con Com Orders Received Dec 04 except Stoughton Jan 05 EFSB Tentative Decision Dec 04; Final Jan 14, 2005

12. 12 NEXT STEPS Final Permits/Licenses needed to Complete – DEP is lengthy; resource limited Construction Contract in Place; Shovels in the Ground Community Relations Plan Developed, Ready for Implementation Environmental Plan Ready for Implementation Target Completion June 2006