Thank you for visiting the NSTAR’s Cambridge Cooling Line Reliability Project website.

In April 2012, NSTAR Electric officially began construction on the Cambridge Cooling Line Reliability Project (“Project”). The Project is an effort to enhance the reliability and efficiency of NSTAR’s underground transmission lines that supply much of the electric power to Cambridge.

The project includes the installation of heat exchangers and pumps at existing substation locations on Putnam Avenue and Alewife Brook Parkway, in addition to the installation of a 3.6 mile long underground cooling line connecting the two substations through Cambridge city streets. Cambridge will realize benefits of additional cooling capacity for the existing transmission lines, which will translate into increased electric load capacity to meet the growing power demands within the city. The project will allow for the system to operate more efficiently and ultimately improve the reliability of power to Cambridge residents and businesses.

The bulk of the construction activities visible to abutters include excavation operations, installation and welding of pipe, and roadway restoration. All of this work will be performed within city streets.

NSTAR has put in place a comprehensive Community Outreach Program to ensure that residents, businesses, public officials and other stakeholders have access to construction details of the project and that any concerns or questions are addressed in an efficient and timely fashion.

In addition to this website, which will be enhanced and updated regularly moving forward, a Community Hotline has been established that allows callers with questions or concerns to contact a member of the project team. The Community Hotline is staffed 24-hours a day to allow callers to reach a person who can address their concerns or refer them to the appropriate contact. The Hotline number is 617-571-4582.

Please refer back to this project website for regular construction updates that include detailed project schedule information as well as any travel and parking impacts associated with construction.


All the pipe installation, testing and fluid filling operations on the project have been completed.

Thank you for your cooperation and interest throughout the duration of NSTAR’s Cambridge Cooling Line Reliability Project. The projects end result is an enhancement in the reliability and efficiency of NSTAR’s underground transmission lines that supply much of the electric power to Cambridge.

Additional restoration efforts will resume in Spring 2013.

Thank you again for your support.

The Project Team

November 2012

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