consisted of transformer oil, which contained PCBs in high concentrations (6,200 Parts Per million). These spills have contaminated nearby Sawins and Williams Pond, both of which are downgradient of the NSTAR facility, and possibly flowed into the Charles river, which is downstream of Sawins Pond. Many local activists lobbied for NSTAR to abide by state regulations and spend the $20–40 million required to perform a PCB remediation of the affected lands. By 1997 NSTAR was responsible for nearly 50 hazardous waste sites, and by 2006 all but 5 of these had been cleaned up. HVDC transmission NSTAR has signed on a joint venture with Hydro-Québec and Northeast Utilities to build a new High-voltage direct current (HVDC) line from Windsor, Quebec (connecting with the Quebec - New England Transmission line) to a location in central New Hampshire. It is projected that the line will either run in existing right-of-way adjacent to the HVDC line that runs through New Hampshire, or it will connect to a right-of-way in northern New Hampshire that will run through the White Mountains. This 180- to 190-mile line, projected to carry 1,200 megawatts, will carry electricity to approximately one million homes. Merger with Northeast Utilities In October 2010, Northeast Utilities and NSTAR announced they would merge, with the resulting company retaining the Northeast Utilities name. Under the terms of the transaction, NSTAR shareholders received 1.312 Northeast Utilities common shares for each NSTAR share that they own. The merger was completed in 2012. On February 2, 2015, Northeast Utilities and all its subsidiaries, including NSTAR, began to brand themselves as Eversource Energy. References External links NSTAR website. Boston Edison Company records at Baker Library Special Collections, Harvard Business School FPL Press Release on purchase of Seabrook Station nuclear power plant. Proceedings from the Boston Edison restructuring from the Massachusetts Department of Telecommunications and Energy. ISO New England Inc. ISO-NE Morning Report Daily Capacity Analysis predictions Electric power companies of the United States Natural gas companies of the United States Nuclear power companies of the United States Energy in New England Technology companies based in the Boston area 1999 establishments in Massachusetts Non-renewable resource companies established in 1999 Companies listed on the New York Stock Exchange