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Public Notice: EPA proposes cleanup alternatives for the Terminal 25 South site in Seattle

EPA proposes cleanup alternatives for the Terminal 25 South site in Seattle
How to Comment
Comments Due
March 12, 2026

Comment period extended to March 12 by request.

You can provide comments on the T-25S site EE/CA by email to region10@epa.gov.

Or by mail:
Attn: T-25S Site EE/CA
c/o Laura Knudsen
U.S. EPA Region 10
1200 Sixth Avenue, Suite 155
Superfund Records Center, MS 17-C04-1
Seattle, WA 98101

Questions? Contact EPA Community Involvement Coordinator Laura Knudsen (knudsen.laura@epa.gov), 206-553-1838.

Publish Date
January 26, 2026

Summary

This public notice is also available in other languages:

  • ភាសាខ្មែរ (Khmer)(pdf)
  • Español (Spanish)(pdf)
  • Tiếng Việt (Vietnamese)(pdf)

EPA is requesting public comments on cleanup alternatives for the Terminal 25 South (also called T-25 South or T-25S) site area. The site is located along the southeast portion of the East Waterway Operable Unit of the Harbor Island Superfund site in Seattle.

The goal of the T-25S site Engineering Evaluation/Cost Analysis is to promptly reduce exposure risks to human health and the environment. The EE/CA proposes three cleanup alternatives to address contaminated sediments and soils within the in-water and upland portions. Each cleanup alternative includes varying amounts of removal, backfill, and capping any remaining contamination.

Following the removal action, the Port of Seattle will construct a habitat project at the T-25S site that will restore habitat by creating an off‐channel marsh and restored shoreline for fish and wildlife habitat.

A copy of the Engineering Evaluation/Cost Analysis document is available for review below.

EPA will accept public comments on the EE/CA for 45 days, from January 26 through March 12, 2026 (extended from February 25 by request).

For more information about the cleanup, visit Harbor Island Superfund site.

Documents

  • T-25 South Site Engineering Evaluation/Cost Analysis (pdf)(226 pp, 35MB)
  • Fact Sheet: T-25 South Early Action Cleanup Alternatives (pdf)(4 pp, 600K)

For additional site documents, visit EPA's Terminal 25 EE/CA Administrative Record.

For alternative formats or languages

If you need materials in an alternative format or language translation, please contact EPA Community Involvement Coordinator Laura Knudsen (knudsen.laura@epa.gov), 206-643-4299.

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Last updated on January 27, 2026
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