Cleaning Up Nature: The Swift Creek Conundrum

Posted on February 28, 2020 by Andy Fitz

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Dredged spoils along the Swift Creek channel; landslide visible at upper right (author photo).

Swift Creek. The name evokes a clear, fast-moving mountain stream. 

The Swift Creek at issue, however, is hardly clear or swift for most of its length.  A massive, mile-long landslide hangs at the head of its southern fork, in the foothills of Washington’s North Cascades. The landslide has exposed a weak bed of serpentine rock, which weathers quickly into clay and delivers a heavy load of sediment to the creek—some 30,000 to 150,000 cubic yards annually. When the creek reaches the Nooksack Valley below, much of this material settles, clogging the channel, turning the creek sluggish, and creating a constant risk of flooding each winter.

In an effort to protect farms and rural homes, the affected local government, Whatcom County, began periodically dredging Swift Creek in the late 1950s, piling the dredged spoils along the channel. In 1971, the U.S. Army Corps of Engineers undertook its own large-scale dredging of the channel and further shaped the dredged spoils into levees.

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Swift Creek in May 2016 (author photo).

In 2006, however, this work largely came to a halt. In its place, a regulatory conundrum emerged.

Since at least the late 1970s, Swift Creek’s sediment has been known to contain a naturally occurring chrysotile form of asbestos derived from the serpentine bedrock. In 2006, the U.S. Environmental Protection Agency (EPA) sampled the dredged spoils and completed an activity-based risk assessment. That assessment, and a subsequent assessment in 2011, concluded that asbestos levels in dust generated from the sediment pose a human health threat, with the lifetime excess cancer risk approaching 8 in 1,000 under the most intensive exposure scenario. Making matters worse, naturally elevated levels of metals in the sediment retard plant growth, making the dredged spoils an attractive target for local four-wheelers and dirt-bike riders.

Left wholly to nature, there is no environmental liability associated with Swift Creek’s sediment: the “potentially responsible” entity is Mother Earth. And there is no clear environmental authority under which to address threats associated with the sediment. Under Section 104(a)(3)(A) of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), EPA cannot respond to a “naturally occurring substance . . . from a location where it is naturally found.” Likewise, under Washington’s Model Toxics Control Act (MTCA), there must be intentional or unintentional “entry” of a hazardous substance “into” the environment in order to have an actionable release. RCW 70.105D.020(32).

Once humans move and reconfigure the sediment, however, potential liability
may arise from those activities. See, e.g., United States v. W.R. Grace & Co.—Conn., 280 F.  Supp. 2d 1149, 1155, 1175 (D. Mont. 2003). Therein lies the conundrum: absent human intervention, there can be unabated exposure to naturally occurring asbestos from the creek channel and flood deposits, but no authority to address the situation under cleanup laws. But any human intervention to abate that exposure is discouraged by the specter of liability under those very same cleanup laws.

For more than ten years, this conundrum stymied efforts to address Swift Creek sediment, despite continued discussion among EPA, the Washington Department of Ecology, and Whatcom County. Neither EPA nor Ecology had the authority, mandate, or resources to address what at its heart is a civil engineering effort. And the entity with the clearest public works mandate—the County—did not want to assume full ownership of a situation it did not have the resources to address by itself, with potentially open-ended liability. This concern was heightened by EPA threats of cost recovery and enforcement under CERCLA.

In 2013, Whatcom County did complete an alternatives assessment and Environmental Impact Statement (EIS) for addressing Swift Creek sediment. The preferred alternative was a series of actions to capture and manage sediment in the upper reaches of Swift Creek, before it reaches the valley floor, including sediment traps, sedimentation basins, periodic dredging of those features, and disposal of the sediment in a constructed repository. The historic dredged spoils lining Swift Creek would also be armored and covered with clean soil.

Two key developments broke the Swift Creek stalemate. First, the Department of Ecology and the Washington State Attorney General’s Office reached agreement with the County on the terms of a proposed consent decree to be lodged under MTCA. With no traditional “site” to clean up, the basis for the decree is creative. It is premised on MTCA’s authority to prevent “threatened releases”—here, releases that would inevitably arise as local government and residents are forced to deal with flood-distributed sediment, but for preventive actions. The covenant not to sue is thus prospective, providing liability protection for the County within the specific areas where sediment will be managed under the decree, for activities to be undertaken by the County under a “Swift Creek Action Plan” that largely incorporates the preferred alternative from the 2013 EIS. The County is responsible for the operations and maintenance costs associated with this sediment management, up to an annual cap.

Second, bolstered by this provisional agreement, Washington’s Legislature appropriated the first installment of capital funding for the project, totaling $6.4 million. With initial construction funds in place, the parties moved to enter the decree, which became effective on December 6, 2019. Based on the plan and decree, EPA has indicated it does not intend to exercise CERCLA authority at the “site,” such as it is.

There are challenges ahead. Full construction of the engineering controls is still dependent on further state capital appropriations, with an estimated remaining cost of $11 million. And it remains to be seen whether the engineering controls are a long-term solution or only a temporary stopgap. Based on a creative application of cleanup law, however, the Swift Creek conundrum appears to have been broken.

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Conceptual layout of engineering controls to be constructed under the consent decree (sediment repository not shown). Source: Swift Creek Action Plan, Washington State Department of Ecology (December 2019).