On April 25, 2012, Tacoma Public Utilities' Board of Directors approved Tacoma Power's current version of the Open Access Transmission Tariff (OATT) under resolution U-10537. The Tacoma City Council approved the current OATT Transmission and Ancillary Service Rates under rates ordinance #28071 on May 15, 2012. The current version of Tacoma Power's OATT was made effective June 1, 2012.

Requests or inquiries about transmission service can be sent to TransmissionService@cityoftacoma.org or can be obtained by calling Marc Donaldson at (253) 502-8352.

Tacoma Power's Open Access Same-Time Information System (OASIS) contains additional transmission and regulatory-related information. 

Attachment K transmission planning process
Tacoma Power supports a coordinated, open and transparent transmission planning process that is outlined in Attachment K of the OATT.

Local and sub-regional transmission planning
Tacoma Power is a member of the ColumbiaGrid and has executed ColumbiaGrid's Planning and Expansion Functional Agreement (PEFA). The PEFA provides a foundation and process to coordinate planning activities on a sub-regional basis through a single-system approach for public utility and non-public utility transmission providers. Tacoma Power conducts transmission planning for service under its OATT through the ColumbiaGrid planning process as outlined in Part III of Attachment K.

Regional transmission planning
Tacoma Power participates in coordinated planning throughout the Western Interconnection through its membership in the Western Electricity Coordinating Council (WECC) and also in the WECC Transmission Expansion Planning Policy Committee (TEPPC). WECC's regional planning process is described more fully in Part IV of Attachment K.

Contact Marc Donaldson at (253) 502-8352 or mdonaldson@cityoftacoma.org with any questions or comments.