Swift Creek project

Excavator-run pile driver in gravel and sand with two workers.

Read "Construction underway at Swift Creek" (2022 blog)

A large landslide on Sumas mountain deposits naturally-occurring asbestos and metals in sediment of Swift Creek. Ecology and Whatcom County Public Works Department are collaborating on a flood control and sediment management project east of Everson near Sumas Mountain.

We finalized the Swift Creek Action plan at the end of 2019. Construction began in 2021. See the construction section below for an estimated timeline and description of the project. 

warning

In dry weather, sediments containing asbestos pose a hazard. AVOID walking, driving, cycling, riding horses, or distrubing the riverbed or dredge piles along Swift Creek and Sumas River, or where flooding may have left deposits.

The Swift Creek project

The flood control and sediment management project follows the Swift Creek Action Plan. Construction is phased over several years and depends on funding from the state legislature.

  • Ongoing: Continue project implementation and remaining design based on 2023–2025 state budget.

  • Early 2025: Seek additional funding from the Legislature to continue construction in the 2025–2027 biennium.

Construction progress and estimated schedule

This map shows the different parts of the project and the order of construction. 

Download a PDF or a text explanation of the construction diagram.

Work by biennium

Within each biennium, specific engineered controls are listed generally from uphill to downhill, which is right to left on the construction map.


About the Swift Creek Action Plan

Click image to enlarge or download a text explanation.

The Swift Creek Action Plan calls for a flood control and sediment management system designed to reduce risk from naturally-occurring asbestos and metals in Swift Creek sediment that harm, or could potentially harm, humans and the environment.

The map at right, from 2019, gives an overview of the different techniques and methods that will be used to help capture, contain, and manage sediment. These methods are called engineered controls.

Components of the plan


Creating the action plan

Whatcom County and Ecology collaborated on the Swift Creek Action Plan. We held a public comment period in 2019 to get input. 

Based on the comments submitted, we made no changes to the documents. You can read our response to Comments Summary as well as the final documents:

  • Swift Creek Action Plan: describes flood control and sediment management actions to take place in the Swift Creek watershed.

  • Consent Decree and exhibits: a legal agreement between the state of Washington, Ecology, Whatcom County, and other parties that requires Whatcom County to:

    • Develop detailed design documents.
    • Construct and operate the project. 
    • Manage deposited sediment.
    • Perform regular maintenance and monitoring.
    • Control future use and access.
    • Purchase additional property or easements, as may be required.​
  • Public Participation Plan: explains how people can become involved in the project.

Health information

Asbestos and metals in Swift Creek and Sumas River sediments can pose a hazard in dry weather and during flooding. We send out a postcard every year to let people know know about the asbestos risk.

In dry weather

Avoid walking, driving, cycling, riding horses, or distrubing the riverbed or dredge piles along Swift Creek and Sumas River, or where flooding may have left deposits.

When Swift Creek or Sumas River flood

  • Assume that floodwater, dirt, mud, and soil from Swift Creek and Sumas River contain asbestos. Asbestos fibers are too small to see.
  • Take steps to limit your exposure to asbestos fibers in the air or floodwater. Use respiratory protection when you are in flooded areas or cleaning up after a flood.

For more detail, read Swift Creek and Sumas River Flooding & Asbestos.

Keeping an eye out for longer-term risks

The Washington State Department of Health checks periodically for asbestos-related health issues in people living around Swift Creek and Sumas Mountain. Their October 2021 report found no evidence of increased risk of lung and bronchial cancer, mesothelioma, or asbestosis hospitalizations. These findings are consistent with previous studies of this area.

Questions?

For health-related Swift Creek questions, please contact the Whatcom County Environmental Health Department, 360-778-6000.

Background

Swift Creek is in the northeastern lowlands of Whatcom County. The South Fork of Swift Creek originates from the bottom of an ongoing, slowly moving landslide on Sumas Mountain. Swift Creek flows generally westward before joining the Sumas River near the city of Nooksack.

Swift Creek watershed map (Click image above to enlarge or download a text explanation.)

Sumas Mountain landslide facing north, not to scale (click image above to enlarge or download text explanation.)

Landslide, flooding, and sediment

The 225-acre landslide on Sumas Mountain has resulted in a large amount of sediment containing naturally-occurring asbestos (NOA) and metals continuously filling up the creek bed. For several decades Swift Creek has been dredged to manage sediment and limit downstream flooding. When the deposited sediment material dries, NOA in the sediment can become airborne and present a risk to human health and the environment. The main concern with the metals in the sediment is the impact to plants on land and aquatic life. 

Sumas Mountain landslide facing east
Landslide material in Swift Creek containing naturally-occurring asbestos and metals.
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