Recognized in Best Lawyers since 2007 
David S. Rosenzweig is an attorney with Keegan Werlin LLP in Lexington, Massachusetts, where his practice focuses on Administrative / Regulatory Law and Energy Law. He advises utility companies, project developers, energy producers, and large institutional energy users on permitting, siting, regulatory compliance, and energy infrastructure matters throughout Massachusetts and the New England region.
Mr. Rosenzweig has extensive experience with the siting and permitting of energy infrastructure projects, including electric transmission lines (underground, aboveground, and underwater); natural gas, oil, and coal-fired electric generating facilities; interstate and intrastate natural gas pipelines; natural gas storage facilities; and solar, wind, and battery storage renewable energy projects. His work includes representing the region’s first large-scale offshore wind power project in obtaining state and local permits, licenses, and siting approvals from the Energy Facilities Siting Board, the Executive Office of Environmental Affairs under the Massachusetts Environmental Policy Act, the Department of Environmental Protection, and other state and local agencies and boards.
In addition to permitting and siting matters, Mr. Rosenzweig represents utility companies and project developers in judicial proceedings before state and federal courts, including the Massachusetts Supreme Judicial Court, involving challenges to permits and regulatory approvals.
Mr. Rosenzweig also counsels electric and natural gas distribution companies on regulatory matters before the Massachusetts Department of Public Utilities. His practice includes negotiating electric and gas supply agreements for institutional energy users, as well as power sale agreements for wholesale electric generators. He advises clients on restructurings, buydowns, and buyouts of power sale agreements between competitive wholesale generators and electric distribution companies.
He also assists clients with transmission, power delivery, and project interconnection issues involving the New England Power Pool and the New England Independent System Operator. In addition, he conducts regulatory and permitting due diligence reviews related to acquisitions of natural gas, oil, and coal-fired electric generating facilities.
Before joining Keegan Werlin LLP in 1990, Mr. Rosenzweig worked at Boston Edison Company for seven years in legal, financial, rate, and planning roles.
