Date:  Oct. 25, 2013




Policy Decisions Related to Tank Barge Oil Transport in Buzzards Bay and Cape Cod Canal
Should Not Be Based on Flawed Risk Assessment


WASHINGTON -- A recent risk assessment of safety measures intended to reduce the likelihood of tank barge oil spills in the Buzzards Bay and Cape Cod Canal regions of Massachusetts has "significant limitations" that "bring into question the value and usefulness of its conclusions" and should not be used to formulate policy decisions, says a new letter report from the National Research Council.


The Research Council committee that wrote the report was asked to review the technical merits of the risk assessment, which was commissioned by the Massachusetts Department of Environmental Protection and the U.S. Coast Guard and completed last year.  The committee did not evaluate policy options.


Over the past seven decades, eight maritime incidents in Buzzards Bay and the Cape Cod Canal, most recently in 2003, have resulted in significant oil spills and environmental damage.  In 2004, Massachusetts passed a state law requiring a tugboat escort for barges transporting 6,000 barrels of oil or more in the region and, for single-hull tankers, an additional licensed deck pilot to serve as a lookout during transport.  However, major parts of the law were challenged in court by the federal government.  The purpose of the risk assessment -- performed by the independent Homeland Security Systems Engineering and Development Institute, a federally funded research and development center of the MITRE Corp. -- was to help resolve differences between the Coast Guard and the state about potential safety measures, particularly the use of tug escorts and additional licensed pilots.  The Coast Guard is now in the process of formulating new regulations.


However, a number of serious problems in how the risk assessment was designed and executed undermine its conclusions, the Research Council report says.  The risk assessment does not factor in the causes of accidents and does not include important "base case" information about existing practices such as the percentage of operations that occur during adverse weather conditions.  Without this information, it is difficult to evaluate how the different safety measures would reduce risk.  The risk assessment uses only local data to determine the probability of a spill and does not account for changes in oil transportation -- such as the use of double-hull tankers, which have greatly improved barge safety.  As a result, the report says, assumptions about the probability and size of potential spills are significantly overestimated.  The assessment also relied on experts who were neither independent nor representative of the expertise needed.


The Research Council study was sponsored by the Massachusetts Department of Environmental Protection.  The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies.  They are private, independent nonprofit institutions that provide science, technology, and health policy advice under a congressional charter granted to NAS in 1863.  The Research Council is the principal operating agency of the National Academy of Sciences and the National Academy of Engineering.  For more information, visit  A committee roster follows.



Molly Galvin, Senior Media Relations Officer

Chelsea Dickson, Media Relations Associate

Office of News and Public Information

202-334-2138; e-mail

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Copies of Letter Report: Technical Peer Review of the Buzzards Bay Risk Assessment are available from the Transportation Research Board online bookstore at or by calling tel. 202-334-3213.  Reporters may obtain a copy from the Office of News and Public Information (contacts listed above).


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Transportation Research Board


Committee to Review the Buzzards Bay Maritime Risk Assessment


Paul S. Fischbeck (chair)


Center for the Study and Improvement of Regulation

Social and Decision Sciences

Carnegie Mellon University



William L. Hurley Jr.

Principal and Chairman of the Board

The Glosten Associates



Thomas M. Leschine
Rabinowitz Professor of Human Dimensions of the Environment, and
School of Marine and Environmental Affairs
University of Washington


Milton Levenson


Menlo Park, Calif.


R. Keith Michel


Webb Institute

Glen Cove, N.Y.


Ali Mosleh

Nicole J. Kim Professor of Engineering, and


Center for Risk and Reliability

University of Maryland

College Park


Malcolm Spaulding

Senior Adviser

Ocean Engineering

University of Rhode Island





Beverly Huey

Study Director