Margaret Rosegay

Knows the hazardous waste law and regulations in California better than anyone.

—The Legal 500 U.S.

Margaret Rosegay is a leading environmental lawyer with nearly four decades of experience addressing solid and hazardous waste regulations and water quality issues.

Meg advises on state and federal environmental regulations and compliance; provides guidance on upstream oil and gas exploration, refining and production issues; handles RCRA corrective actions, NPDES permitting and Clean Water Act matters; and conducts environmental impact analysis. Advising on environmental aspects of transactions, Meg oversees due diligence and drafts and negotiates environmental disclosures, representations and warranties. She also provides project planning counsel. A registered California lobbyist, Meg helps shape environmental laws and policies.

Representative Experience

Negotiated a favorable settlement for an environmental services company in a federal EPA administrative enforcement action regarding implementation of an RCRA land disposal restrictions program.
Defended an oil and gas industry trade association in litigation brought by NGOs challenging ongoing production operations, including underground injection, hydraulic fracturing and well permitting.
Represented an electrical generating entity in a multi-year process to decommission and remove a natural gas-fired power plant; work encompassed interpretation of contracts and all other environmental aspects of project.

Resolution of significant contractual dispute relating to allocation of environmental liabilities associated with the sale of a petroleum refinery.

Representation of major real estate developer in connection with former industrial complex undergoing “brownfields” redevelopment.

Successful administrative challenge to NPDES permit conditions imposed by a regional water quality control board and the Environmental Protection Agency prior to the development of TMDLs.

Defense of several major hazardous waste enforcement actions brought by the Department of Toxic Substances Control.

Successful mediation and consummation of a cash-out settlement agreement in connection with one of the operable units within the San Gabriel Valley Superfund Site.

Professional Highlights

Recognized by Chambers USA for Environment – California (2007 – 2025); Best Lawyers (published by BL Rankings LLC) for Environmental Law (2006 – 2026); Litigation – Environmental (2011 – 2026); Natural Resources Law (2023 – 2026); Water Law (2021 – 2026); and The Legal 500 U.S. for Energy – Renewable/Alternative (2016) and Environment (2016, 2018 – 2019).
Named to BTI’s “Client All-Stars” list in 2015 and 2016.
Authored California Hazardous Waste Management, published by California Environmental Publications.

Honors & Awards
- Named as a Thomson Reuters Stand-out Lawyer (2025)
- Who's Who Legal, Environment—San Francisco (2010)
- Middle-Market M&A Award, Consumer and Retail Products—Finalist, M&A Advisor (2008)