By SHERRIE MINNICK
State Department of Ecology

Federal and state agencies have teamed up to study the feasibility of building a confined disposal or treatment facility designed to handle contaminated sediment dredged from the Puget Sound region. The $3.5 million project, nicknamed “MUDS” (multiuser disposal site), would be the first of its kind in the United States and would result in a regional facility available to anyone in the state needing to manage contaminated sediment.

Current options for managing contaminated sediment include covering it with heavy layers of sand (capping), dredging it up and taking it to an existing solid waste landfill, or dredging it up and confining it elsewhere at or near each site.

It’s estimated that such a facility would cost millions to design, construct and operate over 20 years, and that building it could lead to a surge in sediment cleanups, environmental dredging and transport activities. Having a MUDS facility would not only lead to a cleaner environment but also demand for those working in architecture, engineering, construction and environmental fields.

Current options for managing contaminated sediment include covering it with heavy layers of sand (“capping”), dredging it up and taking it to an existing solid waste landfill, or dredging it up and confining it elsewhere at or near each site. There is also a large volume of contaminated sediment that is simply left in place because these remedies are not feasible or too expensive. On-site treatment has either not been shown to be effective or is too expensive for projects on a scale common for many sediment sites.

“Some sediment cleanups have been delayed because there are simply too few places to take the contaminated sediment, ” said Tom Gries, MUDS project manager for the state Department of Ecology. “We hope to have a disposal or treatment facility located near the majority of contaminated sediment sites that would be more environmentally sound, less expensive to use and more easily managed than long-haul transport and disposal at an existing landfill. If a MUDS facility is built, then companies responsible for cleaning up multiple contaminated sediment sites would be able to manage material from several sites at one central location.”

To date, more than 112 sediment cleanup sites have been identified by Ecology -- the majority being in Puget Sound. “Three to seven million cubic yards is our low estimate of how much sediment contamination there is to clean up,” said Gries, "and this estimate may increase substantially when the National Marine Fisheries Service proposes rules to protect salmon and other fish under the Endangered Species Act.”

In addition to managing contaminated sediment resulting from cleanup action, a MUDS facility would be used for managing some sediment dredged for navigation purposes.“There are 54 miles of federal navigation channels, more than 200 small boat harbors, and 34 public port districts throughout the Puget Sound. All need periodic dredging. Some of this material would not pass guidelines for disposal at open water sites,” noted Steve Babcock, project manager for the U.S. Army Corps of Engineers.

Waterfront development projects are another possible source of contaminated sediment that could be disposed at a MUDS facility.

What are the alternatives?

Aquatic: A pit dug in the bottom of Puget Sound filled with contaminated sediment and covered with one or more layers of clean sediment. Nearshore: A walled-in area near the shoreline filled with contaminated sediment and covered with clean sediment. Upland: A specifically designed landfill located within 30 miles of the shore. The fourth alternative would be a facility that would decontaminate the sediment and produce a product – such as construction fill for resale. The final alternative would be to design and build some combination of these.

The MUDS team, which also includes the Washington Department of Natural Resources, Puget Sound Water Quality Action Team, U.S. Environmental Protection Agency, Washington Public Ports Association and others, completed a programmatic environmental impact statement last year that proposed several alternative types of MUDS facilities. The first alternative “aquatic” would consist of a pit dug in the bottom of Puget Sound filled with contaminated sediment and covered with one or more layers of clean sediment. The second alternative “nearshore” would be a walled-in area near the shoreline filled with contaminated sediment and covered with clean sediment. The third alternative “upland” would be a specifically designed landfill located within 30 miles of the shore. The fourth alternative “treatment” would be a facility that would decontaminate the sediment by various means and produce a product – such as construction fill for resale. The final alternative would be to design and build some combination of these.

In August 2000, the MUDS agencies will jointly decide whether the MUDS facility should be publicly or privately owned. If they decide it would be in the public’s interest for a private firm to build, own, and operate the facility, then they will likely develop a Request for Proposal to choose a company to do the work. If the facility is publicly owned, a private management firm would probably operate it under contract to one or more public agencies.

In either case, a fee would be established for disposing of or treating each cubic yard or ton of contaminated sediment. This fee would be used to pay back the costs of building the facility and for managing and monitoring it. Trained staff would be required to operate the facility – which could be operational for 20 years or more. The facility would also need to be monitored for many years after it’s closed.

In addition to what kind of facility to build and whether it should be privately or publicly owned, the big decision will be exactly where to locate the facility. Agency representatives recently began searching for a location somewhere between the tip of Whidbey Island and the Tacoma Narrows. With public input, the project team hopes to have it narrowed down to two sites by February 2001.

In the next nine months, community meetings will be held and fact sheets will be available to keep the public apprised of the siting process. The public will have a substantial say in which two sites eventually are proposed for the MUDS facility and what type of facility will be built.

In all, the MUDS facility may be the solution needed to increase the region’s ability to clean up contaminated sediment, maintain harbors, restore vital marine habitat, and develop waterfront property. It will also be a means for industry and the environmental community to work together to achieve a common goal – a cleaner and safer environment.