2003/03/26 Council Agenda Packet

Exhibit A Scope 2.1 - Standby Power Needs Assessment(AWWD and City) This subtask will address the following issues: • Identify the elements that impact the reliability of the power supply grid and substations serving the EWPS and the two AWWD Pump Stations. Using existing data available from the Snohomish PUD and/or other sources, provide an opinion of the percentage of risk, both now and in the future, of line power loss at the EWPS and AWWD Pump Stations for durations of four hours, twelve hours and 24 hours. • Coordinate with Snohomish PUD to identify existing and proposed future substation trip sequence priorities in the event of power loss or rolling blackouts. • Coordinate with Snohomish PUD, AWWD and the City on the feasibility of automating the breakers at the on-site substation for automatic/ commanded transfer of primary feeds. (Two independent power feeds presently feed the pump stations. If power is lost in one of the feeds, maintenance crews must manually switch from one feed to the other. Automating this activity would improve overall system reliability.) • Determine backup power supply required to serve EWPS and AWWD Pump Stations as separate and as combined loads. Based on above issues, develop three alternatives for backup power supply. Alternatives will include: • Shared backup power supply between AWWD and the City, • Separate backup power for AWWD and the City, and • No backup power for the City—backup power for AWWD only. Develop capital and life cycle 0 &M costs for each of the three alternatives identified above. Compare the capital and operations cost tradeoffs of diesel versus natural gas engines, as well as the potential impacts of these two alternatives on air quality and related permits. This task will be coordinated with the results of Task 2.6,below. 2.2—EWPS Capacity Evaluation (City) • Verify/update demand forecast from 2000 Water System Plan based on recent water use and forecast trends. • Recommend timing and size of capacity upgrades. • Determine future flow and head requirements for EWPS. • Develop hydraulic profiles from Reservoir 3, through the EWPS to Reservoir 6 for existing and future peak flow conditions. • Identify hydraulic issues and benefits associated with use of the existing intertie between the AWWD Pump Stations and the City distribution system. 2 � 5 Phase I Scope(2/28/03)