Gas Works Park Remedial Investigation/Feasibility Study and Remediation

City of Seattle

Seattle, Washington

Gasworks Park

Hart Crowser provided environmental technical and engineering support for investigation and cleanup of former manufactured gas plant site. From the early 1900s until 1956, a manufactured gas plant and tar refinery occupied the site on the shore of Lake Union. The City of Seattle redeveloped the site into a park. Site investigation and cleanup activities have been ongoing for several decades.

Highlights of our work include:

  • Conducting a terrestrial ecological evaluation and developing a comprehensive Remedial Investigation (RI) report for the upland portion of the site. We evaluated and summarized over 30 years of environmental investigations and cleanup actions; developed a conceptual site model that evaluated the connection between the uplands, shoreline, and Lake Union aquatic environment; evaluated terrestrial ecological and human health risks associated with residual contamination; and identified potential data gaps.
  • Designing and constructing an engineered cap to minimize surface water runoff impacts to the Lake Union aquatic habitat.
  • Assisting Ecology with reviewing a comprehensive upland and sediment RI/FS developed by the potentially liable parties and addressing potential concerns from the public and EPA.