1. Tree-trimming Standards and Practices City Council Work Session November 19, 2007

2. Introduction Two General Categories - Transmission - Distribution Work Performed by Outside Contractor - ANSI A300 (Tree Care Operations – Tree, Shrub, and other Woody Plant Maintenance – Standard Practices) - Interpretation and Implementation of A300 - Line clearances to GP&L standards Line Clearances - Transmission Standard (GP&L OH-907) - Distribution Standard (GP&L OH-908)

3. Transmission Standards Overview Subject to NERC Standard FAC-003-1 Lists ANSI A300 as industry “best practice” for vegetation management Transmission Vegetation Management Program (TVMP) per FAC-003-1 Passed ERCOT/NERC audit this year Liable for ALL vegetation related outages Increased penalties under nodal market

4. GP&L Standard OH-907

5. Typical Transmission Standard Zones defined by the TVMP - Border zone requires documented plan - Wire zone requires immediate resolution

6. New Transmission Design New transmission design increases clearances

7. Transmission Standards Outlook Development along transmission corridors - Increase compliance effort - Increase in vegetation encroachments - Increase interaction with property owners Reduce this impact by providing information to property owners along transmission corridors. Improve corridor access to insure timely identification of potential encroachments.

8. Distribution Standards Overview Majority of annual trimming operations Not currently subject to regulatory audits Line clearances per GP&L OH-908 Contractor adheres to ANSI A300 for vegetation management Trimming format (V-out, side, notch, etc.) chosen to provide desired clearances without killing tree. Trunk location typically dictates trim format

9. GP&L Standard OH-908

10. Distribution Standards V-Out Format

11. Distribution Standards Side Format

12. Distribution Standards Notch Format

13. Distribution Standards Outlook NERC regulatory voltage will continue to be lowered – distribution may be subject to standards in the near future? Increased trimming in past 3-5 years – greatly reduced storm related outages System reliability directly affected by magnitude of trimming operation Enhance customer notification process Provide information on clearance requirements to property owners

14. QUESTIONS ? Balancing aesthetics & reliability!