"The Puget Sound Confined Disposal Site Study"

Frequently Asked Questions

What is "The Puget Sound Confined Disposal Study"?

It’s an effort to find safe and cost effective ways to manage contaminated sediment by "confining" and isolating it from the rest of the environment. One possible way is to build specially designed Multi-User Disposal Sites or "MUDS" facilities. A MUDS facility could operate like a landfill where people and cities pay to dispose of wastes. In this case, though, proponents of many different private and public dredging projects would pay to dispose of contaminated sediment.

What is "contaminated" sediment and how bad is it?

Sediment is the often-mucky material found at the bottom of water bodies. It’s where many natural and man-made chemicals tend to build up.

If exposure to sediment chemicals causes no or only minor problems, it is considered safe to dispose of it at open water disposal sites already established in Puget Sound.

If chemicals reach high enough levels, the sediment can cause harm to aquatic plants and animals and is considered "contaminated".

Exposure to contaminated sediment can cause severe harm. Studies conducted during the 1970s and 1980s found an unusual number of bottom fish like English sole with major tissue lesions, organ damage and tumors. Fish and shellfish have also been found to accumulate and concentrate certain sediment chemicals in their tissues. If eaten regularly, these fish and shellfish may pose an unacceptable risk to public health.

When sediment causes serious harm to aquatic life and/or too high a risk to human health, then it needs to be properly managed. This can mean confining and isolating it from the rest of the environment.

Isn’t contaminated sediment just another type of toxic waste?

Contaminated sediment is not the same as toxic waste. However, in rare cases, it must be taken to a specially designed landfill located outside the state.

Who dredges up contaminated sediment?

Port authorities, marinas and private industries that are located on or near the water, as well as governments (federal, State and local), are the ones that need to dredge bottom sediments.

Why dredge up contaminated sediment, why not just leave where it is?

There are several good reasons why contaminated sediment sometimes needs to be dredged. One is that urban navigation channels, shipping berths and marinas have to be maintained and sometimes deepened to ensure vessel passage. Another is that we need to "clean up" areas of contaminated sediment that we know or suspect harm bottom-dwelling organisms and are the source of chemicals transferred up the food chain to people. Cleaning up contaminated sediment helps to restore healthy aquatic habitat, prevent the decline in populations of fish and other species, and reduce health risks. Finally, safe dredging and disposal of contaminated sediment aids in appropriately developing waterfront property for business and commercial purposes.

What’s happening now?

Right now, contaminated sediment can be covered over or permanently "capped" with a thick layer of clean sediment (if water depth allows), taken to an existing landfill (where it can use up space intended for other wastes), or taken to a landfill designed for toxic waste. However, in many cases, contaminated sediment often remains undredged because these options are not appropriate or are too expensive.

Why a "multi-user" disposal site?

Large ports or industries can often afford to build disposal facilities for the contaminated sediment they dredge. But these "single-user" facilities do not accept contaminated sediment from other dredgers. And it is too costly and inefficient for everyone with a relatively small dredging project to build their own disposal facility. So it only makes sense to look at the feasibility of building disposal facilities that can accept contaminated sediment from a variety of dredgers and projects.

Does this region really need one?

Officials from the U.S. Army Corps of Engineers, Washington State Departments of Ecology and Natural Resources, Puget Sound Water Quality Action Team, U.S. Environmental Protection Agency and Washington Public Ports Association estimate that Puget Sound has as much as 10,000,000 cubic yards of contaminated sediment that needs to be dredged during the next 20 years. Each year that’s about 250 barge loads of 2000 cubic yards or 50,000 dump truck loads of 10 cubic yards.

And it is clear that lack of environmentally safe and cost effective options for disposal of contaminated sediment can delay or prevent many important dredging activities. A more timely, appropriate and economical solution is needed.

Having one or more MUDS facilities located in or near Puget Sound might greatly increase the region’s ability to maintain harbors, clean up contaminated sediments, restore vital marine habitat and develop waterfront property. The MUDS project hopes to provide that solution.

Is this something new?

No. The need for a MUDS has been recognized for some time.

Remember reading in this fact sheet about the unusual number of bottom fish in Puget Sound having major tissue lesions, organ damage and tumors (see the response to the second question)? We’ve known for many years that contaminated sediments can cause ecological harm.

Because of the apparent need to confine and isolate contaminated sediments, the Puget Sound Management Plan identified the importance of having a MUDS ten years ago (Puget Sound Water Quality Authority, 1987).

Later, Ecology published a summary report on the need for a MUDS (1990) and the Corps of Engineers completed a MUDS "Reconnaissance Study" (Corps, 1996).

The Puget Sound Confined Disposal Study or MUDS project, which asks the question "Is a MUDS feasible?", is an outgrowth of all those efforts and findings. The start of the project was announced in July 1997, but received little public attention.

What would a MUDS disposal site look like?

There are several alternatives for a MUDS facility. It could be a pit that is dug beneath the surface of Puget Sound, filled with contaminated sediment and covered with one or more layers of clean sediment ("Aquatic"). It could be a "walled-in" area near the shore filled with contaminated sediment and covered with clean sediment ("Nearshore"). It could be a specially designed landfill located within 30 miles of the shore ("Upland").

Or, it could be some combination of all these. It is important to realize that there are already single-user examples of all three types of facilities right here in Puget Sound.

How much would a MUDS facility cost?

Estimates vary widely, depending mainly on the type of MUDS facility and its location. One could cost as little as $10,000,000 or as much as $75,000,000 to build. Many people think that’s small price to pay to help keep Puget Sound waters clean and navigable.

Who will pay for it?

Money to build a MUDS facility would have to come from a combination of sources. It’s not clear yet exactly how a MUDS would be financed. However, it’s likely that most construction, operations, closure and monitoring costs would be recovered through collection of disposal fees.

Would it be safe?

Yes. Many safe facilities for disposal of contaminated sediment have already been built.

The engineering design for a Puget Sound area MUDS facility would take advantage of knowledge gained from other successes and include an appropriate margin of safety.

A MUDS facility would be operated using strict procedures developed to protect people and the environment. Operators would also have in place detailed plans for dealing with even the most unlikely problems.

For these reasons, a MUDS facility is likely to have only minimal, short-duration environmental impacts. And even these impacts would be carefully monitored to ensure that no long-term harm occurs.

Who would be liable for cleanup if a MUDS leaked or failed?

There would have to be agreements developed that clearly assign responsibility to those who participate in and benefit from a MUDS. Advance agreements on the responsibilities of the landowner, and MUDS facility owner, operator, user, etc., would ensure careful facility design and operation, and increase accountability. The agreements would also ensure fast response to emergencies by reducing the likelihood of disputes over liability.

Has a specific disposal site been chosen?

Not yet. If, based on further analysis and public comment, the final PEIS concludes that building one or more MUDS facilities as the preferred alternative for the region, then the next step would be to compile a list of potential sites and select one or more for further consideration. This would not happen before mid-1999.

Why should people care?

Everyone stands to benefit from construction of one or more MUDS facilities if that helps to confine and isolate contaminated sediments from the environment. The benefits include the improved environmental quality of Puget Sound, the health of its marine habitats and the organisms that depend on them, as well as the level of contamination found in the fish and shellfish that we eat. And, as taxpayers that would benefit from a MUDS, we may be asked to pay for some portion of the project.

What’s next - how can I get involved now?

A draft Programmatic Environmental Impact Statement (PEIS) will be released in February 1999. Watch for announcements of several public meetings and hearings to be held during March. Written comments are strongly encouraged and welcome. The comment period will close in mid-April 1999. If you want to receive future newsletters, meeting and hearing announcements, other possible mailings, or general information about the project and comment deadlines, please contact Steve Martin (206/764-3631, stephen.g.martin@usace.army.mil) or Tom Gries (360/407-7536, tgri461@ecy.wa.gov). Ecology is also dedicating a portion of its sediment web site (http://www.ecy.wa.gov/programs/tcp/smu.htm) to the MUDS project.