Heather M. Palmer

HEATHER PALMER is an award-winning environmental and energy partner who has been recognized for her work on environmental, social, and governance (ESG) matters. She serves as a co-leader of the firm’s ESG and Sustainability and climate change practices. Heather plays a strategic role in advising clients on a broad range of ESG and sustainability issues and related risks, including the disclosure of ESG-related risks in SEC filings, the review of shareholder proposals relating to ESG topics, the development of corporate ESG programs and policies, the establishment of sustainability targets and goals, the preparation of sustainability and corporate impact reports, supply chain management, and the sustainable sourcing of products and raw materials.

“Strong technical expert on environmental issues.”
Chambers USA 2024

Heather’s practice also focuses on environmental law, counseling clients on regulatory requirements, assisting them in the evaluation and negotiation of corporate and real estate transactions, supporting them in the development of environmental management systems (EMS), and advising them on environmental disclosure requirements. Her energy industry experience includes advising clients in the oil and gas, refining, chemicals, manufacturing, power, and renewables sectors on environmental compliance and the allocation of environmental liabilities in mergers and acquisitions. Heather also advises clients on carbon capture, utilization, and sequestration (CCUS) matters.

Heather has been named an “Outstanding Business Leader in Law” as part of the Houston Business Journal’s 2024 Women Who Mean Business Awards, which recognizes women who have demonstrated excellence in their career and community. Heather was recognized in Chambers USA for Texas Environment (2006–2012 and 2016–2025) and Texas Environment: Mainly Transactional (2022–2025). Best Lawyers acknowledged her for Environmental Law (2009–2025). In 2025, she was recommended by Legal 500 United States for Environment: Litigation, Environment: Regulatory, and Environment: Transactional. Furthermore, Heather was awarded the “Lawyer of the Year” distinction in the 2021 and 2025 editions of The Best Lawyers in America for her work in Environmental Law. She was featured in Texas Super Lawyers (2010–2015, 2019–2020) and was listed among the Lawdragon “Green 500: Leaders in Environmental Law” (2023), and the Lawdragon 500 “Leading Environmental Lawyers” (2025). Heather was named to the 2021 National Association of Corporate Directors Directorship 100 in recognition of her significant impact on boardroom practices and performance. She was also part of the Sidley team named as the winner of the Financial Times 2021 “Innovation in Sustainability and ESG” award for its work in helping aviation and airlines industry clients to reduce greenhouse gas (GHG) emissions.

Clients in the 2025 edition of Chambers USA describe Heather as “excellent” and that she is “commercial, sophisticated and she knows how to get transactions to the finish line without complicating.”

Heather’s representative matters include:

ESG and Sustainability

• A major global airline in its efforts to reduce its GHG emissions by 100% by 2050, including representing the company in making investments in emerging technologies that combat climate change and advising on updates to its corporate impact report.
• A global information technology company in enhancing its ESG and Sustainability practice, implementing its ESG and sustainability strategies, and preparing its ESG- and sustainability-related disclosures.
• Advising Fortune 100 and 500 companies on how to navigate the SEC’s evolving focus on climate disclosures, the appropriate language and tone for ESG and sustainability disclosures in SEC filings and voluntary sustainability reports, and best practices in aligning those disclosures with global regulatory requirements, including the EU’s Corporate Sustainability Reporting Directive (CSRD), the EU’s Corporate Sustainability Due Diligence Directive (CS3D), and the International Sustainability Standards Board (ISSB) standards.
• Advising multiple global public companies on the mitigation of regulatory enforcement and litigation risks associated with the modification or elimination of sustainability-related targets and goals, or relating to sustainability or “green” claims.
• Providing strategic advice and counsel to public and private companies across industrial sectors on compliance with the California climate disclosure laws (SB 253 and SB 261, as amended by SB 219) and AB 1305.
• A Fortune 100 company on creation of a reporting and governance framework for ESG matters and on the setting of ESG goals and metrics, including assisting with the preparation of its ESG report in alignment with the Sustainability Accounting Standards Board (SASB) and the Task Force on Climate-related Financial Disclosures (TCFD).
• Assisted one of the world’s largest private companies in a comprehensive review of its ESG and sustainability programs and policies, governance of sustainability-related risks and opportunities, and strategies for achieving its sustainability targets and goals.
• A Fortune 500 company and leader in property and casualty reinsurance and insurance and investments in middle-market businesses on its inaugural ESG report and related metrics and disclosures.
• A subsidiary of a Fortune Global 10 automobile manufacturer in connection with the procurement of 100% renewable power for its network of electric vehicle charging stations throughout the United States, including strategic advice on setting goals for net-zero carbon emissions, third-party verification of renewable power sources, and negotiating power purchase agreements with renewable energy providers.
• Advised a Fortune 100 company with respect to sustainable sourcing of products and development of ESG goals.
• Invitation Homes in its US$3.5 billion sustainability-linked senior unsecured credit facility and the first U.S. REIT syndicated credit facility to both link an ESG score to a pricing grid and to name a sustainable agent and coordinator.

M&A—Upstream

• USA Compression Partners, LP, in its US$860 million acquisition of J-W Power Company, a large privately held provider of compression services.
• Canvas Energy in its US$550 million strategic transaction with Diversified Energy Company PLC.
• Ensign Natural Resources LLC in the sale of its Eagle Ford Shale oil and gas interests to Marathon Oil Company for US$3 billion.
• Laredo Petroleum, Inc. in its agreement to acquire approximately 20,000 net acres in western Glasscock County, Texas from Pioneer Natural Resources Company.
• Denbury Resources Inc. in its sale to and joint venture with Navitas Petroleum, involving properties in four Southeast Texas oil fields.
• Morgan Stanley Energy Partners and its portfolio company, Presidio Investment Holdings LLC, in Presidio’s acquisition of oil and natural gas-producing properties in the western Anadarko Basin of Texas, Oklahoma, and Kansas from Apache Corporation and its affiliates.
• Kimmeridge Energy Management Company, LLC in its joint venture with Desert Royalty Company, LLC to create Desert Peak Minerals, the largest Delaware Basin pure-play mineral and royalty company, with over 70,000 net royalty acres on a 1/8th royalty-adjusted basis across eight counties in West Texas and Southeast New Mexico.
• BP America Production Company in the sale of its oil and natural gas properties in Cleveland and McClain Counties, Oklahoma (the SWOOP area) to Lime Rock Resources.

M&A—Midstream

• Cenovus in the US$1.4 billion sale of its interest in joint venture WRB Refining to its joint venture partner Phillips 66.
• Amberjack Capital Partners and its portfolio company, Entegra, in its sale to NDT Global.
• Ares Management Corporation in its US$1.1 billion acquisition of Meade Pipeline Co LLC.
• A fund managed by Macquarie Asset Management in its agreement to acquire a 40% equity interest in Diamond Infrastructure Solutions (Diamond) from Dow Inc. for approximately US$2.4 billion. Diamond provides specialist infrastructure services to Dow and other industrial customers at five Dow manufacturing sites in Texas and Louisiana.
• Enbridge Inc. in its transaction with Encap Flatrock Midstream to acquire Moda Midstream Operating, LLC for US$3 billion in cash.
• The Conflicts Committee of USD Partners LP, in connection with USD Partners’ agreement to acquire entities owning the Hardisty South terminal assets from USD Group LLC, exchange USD Group’s economic general partner interest (GP interest) in the partnership for a non-economic GP interest, and eliminate USD Group’s incentive distribution rights (IDRs) in the partnership.
• NuStar Energy L.P. in the sale of eight storage terminal locations in the Northeast and Florida to Sunoco LP.
• XRI Holdings, LLC, a portfolio company of Morgan Stanley Energy Partners and the leading full-cycle water management and midstream company with fixed infrastructure owned throughout the Permian Basin, in its acquisition of the produced water infrastructure assets of Hibernia Energy III, LLC through its wholly owned subsidiary, Celtic Disposal, LLC.
• Third Coast Midstream, LLC in its sale of its Cushing, Oklahoma crude oil storage business, AMID Crude Oil Storage, to HCS Holdings, LLC, an affiliate of Hartree Partners, LP.
• I Squared Capital in the formation of a leading Delaware Basin midstream partnership with Blackstone Energy Partners and EagleClaw Midstream and the concurrent acquisition of Caprock Midstream and Pinnacle Midstream by EagleClaw, a transaction recognized as the 2019 “Energy, Power & Utilities Deal of the Year” by The Deal’s Middle Market Awards.
• The Conflicts Committee of the general partner of Andeavor Logistics LP in MPLX LP’s acquisition of Andeavor Logistics LP, a transaction with an equity value of approximately US$9 billion.
• Macquarie Infrastructure and Real Assets Inc. in its sale of 100% of the membership interests of Leaf River Energy Center LLC to a subsidiary of New Jersey Resources Corporation for US$367.5 million.
• I Squared Capital, through its ISQ Global Infrastructure Fund II, in its US$460 million investment in convertible equity securities in Venture Global LNG.
• JERA Americas Inc. in the US$2.5 billion purchase of a 25.7% equity ownership interest from Global Infrastructure Partners in Freeport LNG Development, L.P., which owns and operates a liquefied natural gas (LNG) export facility on Quintana Island, near Freeport, Texas.
• Stonepeak Infrastructure Partners in its acquisition of Oryx Midstream Services from affiliates of Quantum Energy Partners, Post Oak Energy Capital, Concho Resources, WPX Energy, and other investors, for approximately US$3.6 billion.
• OMERS Infrastructure Management Inc., the infrastructure investment manager for the Ontario Municipal Employee Retirement System, in an approximately US$1.4 billion acquisition of a 50% interest in the BridgeTex Oil Pipeline from Plains All American Pipeline, L.P. and Magellan Midstream Partners, L.P.

M&A—Renewable Energy and Sustainable Aviation Fuel (SAF)

• Represented Neste Corporation, a leading supplier of renewable diesel and sustainable aviation fuel, in the establishment of a 50/50 joint venture with Marathon Petroleum.
• Represented Brookfield Renewable, one of the world’s largest publicly traded, pure-play renewable power platforms, in its purchase of Urban Grid, one of the largest greenfield solar and battery storage project developers in the United States.
• Represented GE in its solar energy joint venture with BlackRock, a global investment management company and the world’s largest asset manager.
• Represented MAP Royalty, Inc. in connection with the sale of various wind and solar projects.

M&A—CCUS

• Represented Cresta Fund Management and Silverpeak Energy Partners in their agreement with San Joaquin Renewables to invest up to US$165 million to develop and construct a biomass-to-renewable natural gas (RNG) project near McFarland, California. The project will also sequester carbon dioxide in an EPA Class VI sequestration well located on the project site.

M&A—Chemicals and Manufacturing

• Xignux, a Monterrey, México-based leader in the energy and food industries, in the US$5.28 billion sale of its stake in Prolec GE to GE Vernova.
• Regal Beloit Corporation in its US$9.1 billion combination with the Process & Motion Control (PMC) Business of Rexnord Corporation.
• GE-Prolec Transformers, Inc., a subsidiary of a joint venture between General Electric Company and Mexico-based Xignux S.A. de C.V., in its acquisition of SPX Transformer Solutions, Inc. from SPX Corporation.
• General Electric Company in connection with its agreement to sell its intelligent environments unit, Current, powered by GE, to American Industrial Partners, a New York-based private equity firm.
• General Electric Company, in its global joint venture with Baker Hughes, for aero-derivative gas turbine engines and related transactions for GE’s separation from Baker Hughes.

M&A—Healthcare/Medical Devices

• Renaissance Lakewood, LLC, a contract development and manufacturing organization (CDMO) that manufactures nasal sprays, in its sale to LTS LOHMANN Therapie-Systeme AG.
• OMERS Private Equity, the defined-benefit pension plan for Ontario’s municipal employees, in its sale of MatrixCare Holdings Inc. to ResMed Operations Inc. for US$750 million.
• Medline Industries, Inc. in its acquisition of a significant portion of Teleflex Incorporated’s respiratory business for US$286 million.
• Athletico Physical Therapy, a leading provider of outpatient orthopedic rehabilitation services, in its acquisition of Pivot Health Solutions.
• Stryker in connection with its acquisition of HyperBranch Medical Technology, Inc. for a total equity value of approximately US$220 million in an all-cash transaction.
• RTI Surgical Holdings, Inc. in connection with the sale of the company’s original equipment manufacturer (OEM) business to Montagu Private Equity, a leading European private equity firm, for US$490 million.
• RoundTable Healthcare Partners (RoundTable) and its portfolio companies in multiple transactions, including RoundTable’sinvestment in Deerland Probiotics & Enzymes.

M&A—Telecommunications and Data Centers

• Telephone and Data Systems, Inc. in the US$4.4 billion sale of United States Cellular Corporation’s wireless operations and select spectrum assets to T-Mobile US, Inc., including a combination of cash and up to approximately US$2 billion of assumed debt.
• Stonepeak in the acquisition of a minority common equity interest and a preferred equity interest in CoreSite from American Tower for US$2.5 billion.

Regulatory Counseling

• Cheniere Energy in the construction, permitting, and operation of its LNG import/export facilities in Sabine Pass, Louisiana; Corpus Christi, Texas; and the Midship Pipeline in Oklahoma.
• Providing strategic advice and counsel to buyers in evaluating the potential risks and liabilities associated with per- and polyfluoroalkyl substances (PFAS) in M&A transactions.
• Advising an international energy company in connection with the development of environmental management systems at its refineries in the United States.

• Former Executive Committee Member and Co-Chair of the Sponsorship and Membership Committee, State Bar of Texas Environmental & Natural Resources Law Section (ENRLS)
• Sustaining Life Fellow, Texas Bar Foundation
• Past Chair, Houston Bar Association, Environmental Law Section 

Heather has handled the following matters pro bono:

• An immigrant woman seeking asylum in the United States under the Violence Against Women Act (VAWA).
• A local nonprofit organization in connection with the potential purchase of land for environmental conservation in Cape Cod, Massachusetts.
• A church in connection with the donation of land for the construction of a Chicago-area community center where young mothers can get mentoring, counseling, and education.
• A local nonprofit arts organization in the purchase of a brownfield site for redevelopment in Houston, Texas.