2005/10/05 Council Agenda Packet

5 lines with ASCR 795 conductors on wood poles connect the switchyard to the PUD substations at Lake Chaplain and Sultan. See Figure 1 (one line diagram of Jackson Project powerhouse and switchyard). As a result of improvements to the transmission system in the area,the South Line is now an element of two single-circuit 115 kV transmission lines that,among other things,move power from or around the Jackson Project in a manner known as the"Jackson Loop." See Figure 2 (115 kV Jackson Loop • detail). The Jackson Loop can be isolated from Jackson Project powerhouse generation by oil circuit breakers 1776, 1777, and 1778. See Figure 1. The North Line(which is not covered under the current Jackson Project license) comprises the"top"circuit of the Jackson Loop and extends16.89 miles between the Jackson powerhouse switchyard and the Bonneville Power Administration("BPA") Snohomish Substation. Traveling in a westerly direction, it connects the Jackson Project to the PUD's Lake Chaplain and Three Lakes distribution substations and then extends on to the BPA substation at Snohomish. The South Line of the Jackson Loop connects the Jackson Project powerhouse to several PUD distribution substations(Sultan,Woods Creek,West Monroe, and Goldbar) before connecting to the BPA Snohomish substation. The total length of this line is 26.83 miles. The Goldbar substation connects to Puget Sound Energy's electrical distribution system. This interconnection with Puget Sound Energy at Goldbar allows emergency transmission of power between the PUD's system and Puget Sound Energy's system to address outages in either utility's system if the need arises. Variations in time-of-day and season-of-year loading affect the powerflow on both lines of the Jackson Loop between the Jackson Project powerhouse and the BPA 3 15