Proposed wastewater release into Cape Cod Bay likely to remain in bay for at least one month, study finds

Woods Hole Oceanographic Institution

 

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Pilgrim Nuclear Power Plant, Plymouth, MA

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Credit: ©Entergy Nuclear

Woods Hole, Mass. (Dec. 5, 2024) -- Scientists at the Woods Hole Oceanographic Institution (WHOI) investigating the pathways of the proposed wastewater discharge from the Pilgrim Nuclear Power Station (PNPS) find it has a high probability of remaining in Cape Cod Bay for at least one month after release. Their findings are based on a model of the circulation patterns around Cape Cod Bay and provide insight into the seasonal differences in conditions in and around the Bay.

The study, “Model-based study of near-surface transport in and around Cape Cod Bay, its seasonal variability and response to wind,” was funded by WHOI Sea Grant and published in the Journal of Physical Oceanography.

“The spreading patterns of a plume depend on the timing of a release,” said Irina Rypina, the WHOI physical oceanographer who led the study. “We found virtually no out-of-the-Bay transport in winter and fall and slightly larger, but still low, probability of some of the plume exiting the Bay in spring and summer. These seasonal differences can be linked to different wind conditions that affect the circulation in and around the Bay throughout the year.” Because activities taking place along the shores of Cape Cod Bay, such as tourism, commercial and recreational fishing, and aquaculture, are central to the region’s economy, the scientific paper focuses on investigating whether the plume water will spread toward the shoreline within the Bay or exit the Bay without approaching the inner-Bay shoreline. Based on the model, the first scenario is more likely. However, the results of the study cannot be used to draw conclusions about the environmental and human health and impacts of releasing the wastewater being stored at Pilgrim. Those impacts, as Rypina explained, depend on the specific chemistry of each isotope and the environmental conditions they may encounter.

The research team used a state-of-the-art, high-resolution ocean circulation model developed by the National Oceanic and Atmospheric Administration and applied it to look at the spreading of the wastewater plume in Cape Cod Bay. The model output was validated using observational data gathered earlier from drifters, free-floating buoys that are released in the ocean to measure currents. The research also focused on transport of wastewater released from Pilgrim in the upper 2 meters (6 feet) of the ocean, how it varies seasonally, and the role of wind as the driving force behind the spread of the wastewater plume.

“Our numerical simulations suggest it is unlikely that the bulk of plume waters will leave the Bay in less than a month,” Rypina said.

While more research would be needed to say how long it will take for the plume to leave the Bay, the researchers say it is likely to remain in the Bay for longer than a month, coming close to the shore, including coastal waters of Dennis, Wellfleet, and Provincetown. In addition, if the release were to happen in the spring and summer, a small portion of a plume might leave the Bay in less than a month, passing north of Provincetown and then flowing southward along the outer Cape.

About WHOI Sea Grant

WHOI Sea Grant supports research, education, and extension projects that encourage environmental stewardship, long-term economic development, and responsible use of the nation’s coastal and ocean resources. Based at the Woods Hole Oceanographic Institution, it is part of the National Sea Grant College Program of the National Oceanic and Atmospheric Administration, a network of 34 individual programs located in each of the coastal and Great Lakes states. Together, these programs form a national network of over 300 participating institutions involving more than 3,000 scientists, engineers, educators, students, and outreach experts. Learn more at seagrant.whoi.edu.

About Woods Hole Oceanographic Institution

Woods Hole Oceanographic Institution (WHOI) is a private, non-profit organization on Cape Cod, Massachusetts, dedicated to marine research, engineering, and higher education. Established in 1930, its mission is to understand the ocean and its interactions with the Earth as a whole, and to communicate an understanding of the ocean’s role in the changing global environment. WHOI’s pioneering discoveries stem from an ideal combination of science and engineering—one that has made it one of the most trusted and technically advanced leaders in fundamental and applied ocean research and exploration anywhere. WHOI is known for its multidisciplinary approach, superior ship operations, and unparalleled deep-sea robotics capabilities. We play a leading role in ocean observation and operate the most extensive suite of ocean data-gathering platforms in the world. Top scientists, engineers, and students collaborate on more than 800 concurrent projects worldwide—both above and below the waves—pushing the boundaries of knowledge to inform people and policies for a healthier planet. Learn more at whoi.eduworldwide—both above and below the waves—pushing the boundaries of knowledge to inform people and policies for a healthier planet. Learn more at whoi.edu.

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Journal

Journal of Physical Oceanography

DOI

10.1175/JPO-D-24-0023.1 

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

Model-Based Study of Near-Surface Transport in and around Cape Cod Bay, Its Seasonal Variability, and Response to Wind

Article Publication Date

4-Dec-2024