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Seattle City Light DEBRA SMITH, General Manager and CEO
Denny Substation Project
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Environmental Review

The project has undergone a SEPA environmental review as well as a site clean-up in preparation for site construction.

Environmental Review

Seattle City Light completed the Final Environmental Impact Statement (EIS) in January 2015. Review and download the Draft EIS and Final EIS.

The Final EIS expands on the Draft EIS. Together, these documents compose the "Denny Substation Project EIS" and should be read in tandem for a full understanding of the project's likely environmental impacts and proposed mitigation.

The Final EIS volume includes:
  • additional analysis on several topics (noise and land use, for example),
  • a summary of probable adverse impacts for all project components,
  • responses to public and agency comments on the Draft EIS, and
  • a list of commitments and actions that City Light now proposes to avoid, minimize, or otherwise mitigate environmental impacts where possible.
While three transmission line route alternatives were studied in the EIS, a preferred alternative was not identified. Please see the Program Site Map to view the transmission routes.

Site Clean-up

The completion of the environmental clean-up at the Denny Substation site in early 2014 marked an important milestone for the project. The soil and groundwater at the former Greyhound Bus Maintenance Facility were contaminated with gasoline, diesel and waste oil, and needed to be cleaned up prior to development of the property. The site clean-up efforts involved demolishing the maintenance facility, removing underground storage tanks, removing contaminated soils, installing a stormwater detention system and backfilling the site with clean dirt.
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    P.O. Box 34023
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