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Cape Wind Threats: The Environment

Cape Wind would pose threats to the rich environment of Nantucket Sound during both construction and operations. A loss of habitat, changes in tidal currents, and harm or mortality to threatened and endangered avian and marine species would likely result. Dredging, pile driving, and jet plowing to install 130 turbines and nearly 100 miles of cable in the seabed would devastate the sea floor, potentially harm marine mammals, smother bottom dwelling organisms, kill juvenile fish, and drive off adult fish.

Many respected environmental groups are concerned about the Cape Wind proposal as well. Among these organizations are the Barnstable Land Trust, Humane Society of the United States, International Marine Mammal Project, Massachusetts Society for the Prevention of Cruelty to Animals (MSPCA), the Oceans Public Trust Initiative of Earth Island Institute, Orenda Wildlife Trust, the Pegasus Foundation, Three Bays Preservation, and the Whale and Dolphin Conservation Society.

Federal Concerns
The proposed Cape Wind power plant has the potential of violating one or more federal laws, including:

  • Endangered Species Act: The power plant may adversely affect several protected species listed as federally endangered or threatened.
  • Marine Mammal Protection Act (MMPA): If the power plant construction or operation results in the killing, harming, or harassment of seals, dolphins, or   whales, the project will violate the MMPA.
  • Migratory Bird Treaty Act (MBTA): If the power plant harms migratory birds, it would be in violation of the MBTA.
  • Fisheries Conservation and Management Act (FCMA): The area is a designated Essential Fish Habitat.

Nantucket Sound Concerns
Noise and disturbance from the wind farm during construction, operation, and maintenance may result in damage to or loss of habitat, changes in species behavior and usage, increased avian mortality, and overall changes in the Sound's ecology, including water quality and species distribution.

Oil Spill Threat

Cape Wind's Electrical Service Platform (ESP), pictured below, would introduce the chance of an oil spill. In addition to the 40,000 gallons of unspecified transformer oil on the proposed 10-story ESP, the Cape Wind project would contain an additional 24,700 gallons of oil in the 130 turbines (190 gallons in each turbine).

What beaches and inlets would likely be affected if the tanks on the ESP were to rupture or if there were a vessel collision with a turbine causing oil to spill into Nantucket Sound? Cape Wind's own computer simulation of a spill reveals that oil would reach Cape Cod and Island beaches within five hours. An analysis commissioned by the Alliance showed significant adverse impacts to the Nantucket Sound ecosystem, including harmful impacts to wildlife and shellfish/fish from a spill incident.


Horseshoe Shoal is a component of the Atlantic Flyway.
As many as six million birds migrate through the area in the spring and fall, usually at heights well above the turbine blades, except in foul weather when low cloud ceiling cause the birds to fly at altitudes the same as the height of the rotors, creating the potential for an episodic catastrophic kill of migrating birds. The Sound also provides important habitat to sea and shorebirds with as many as 250,000 to 500,000 sea ducks wintering in the Sound for approximately six months of the year. Biologically important numbers of endangered roseate terns and piping plovers use the Sound as a breeding and feeding area in the summer months and are known to migrate through Nantucket Sound in spring and fall. Each August, thousands of roseates congregate on Monomoy Island prior to migration and then leave in great flocks, flying southeast, south, and southwest. How many of these birds pass through the proposed Wind site has not been verified.

Endangered species
Nantucket Sound is home to several species of endangered and protected birds and marine mammals and has been designated an Essential Fish Habitat.  Cape Wind’s construction and operations would threaten this rich and fragile environment. The project would endanger the dense population of songbirds, sea ducks, and federally protected piping plovers and roseate terns. Atlantic white-sided dolphins, striped dolphins, and common dolphins are known to occur in Nantucket Sound. Pilot whales are frequently sighted in the fall, while harbor porpoises migrate through in the spring, and large whales, such as right whales, humpback whales and minke whales, are sometimes observed. Endangered and threatened turtles such as leatherback, green, Kemps Ridley and loggerhead are present during summer.


Claims toxic chemical could threaten water supply
The Barnstable Town Council took a strong stand against the placement of potentially toxic oil-filled equipment at an NStar substation in Independence Park in Hyannis that would accommodate an offsore wind farm's electricity into the regional grid. The main concern is a potential oil spill into the town's nearby municipal wells. Link to Barnstable Patriot