MAUREEN GORSEN practices at the intersection of public policy, litigation, and regulatory advocacy with a keen sense of her clients’ business objectives. She is a member of Sidley’s Environmental practice, focusing on enforcement defense and regulatory compliance. Maureen has defended clients in both federal and state enforcement matters, including hazardous waste, emissions controls, stormwater, air quality, AB 32, Prop 65, product labeling, plastic packaging, and business and tax regulation. She develops strategies for regulatory and permit compliance for environmental, financial, tax, consumer products, and supply chain regulation issues. Maureen leads global teams in developing corporate policies to address GHG and ESG reporting across multiple jurisdictions including Europe, Canada, and California, to reduce product liability risks and meet sustainability, supply chain, plastic packaging, anti-slavery and human trafficking, and conflict minerals statutes. She has a proven track record of coordinating responses to corporate emergencies, surprise government investigations, and catastrophic events, where quick action and strategic insight are critical to protecting a company’s brand.
Maureen is the former general counsel of the California Environmental Protection Agency (CalEPA) and the California Natural Resources Agency, with broad oversight of all California state, regional, and local environmental agencies (e.g. CARB, CEC, CalGEM, RWQCBs, AQMDs, and County DAs). In both roles, she was involved in the enforcement of California’s environmental laws, including AB 32, Prop 65, the Endangered Species Act, Coastal Act, and California Environmental Quality Act (CEQA).
Maureen is the also former director of the California Department of Toxic Substances Control (DTSC), where she directed regulation of waste, soil, and water cleanups under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the Resource Conservation and Recovery Act, and brownfields laws. She spearheaded the California Green Chemistry Initiative and resulting laws governing chemicals under the California Safer Consumer Products rules and other states’ products programs and federal Toxic Substances Control Act (TSCA) reform.
Maureen is recognized by Chambers USA in Environment – California (2021–2024), with clients stating that she “is a California expert and is very helpful digging into and explaining California regulatory and legal issues and explaining how the legislative process works” and “her individual strength was decisiveness, pointing out strategy flaws and developing alternative strategies” (2024). Maureen is listed among the Lawdragon “Green 500: Leaders in Environmental Law” (2023) and in Who’s Who Legal: Environment (2023–2024). The National Law Journal named her an “Energy & Environmental Trailblazer” (2021) and highlighted her instrumental role in helping pass the Global Warming Solutions Act, which allowed California to become the first state to regulate climate change. Maureen has also been named in The Best Lawyers in America every year since 2013.