O’Melveny Worldwide

John D. Renneisen

Senior Counsel

John D. Renneisen provides legal advice on environmental issues in the context of mergers and acquisitions (M&A), debt and equity financing, and compliance counseling. His practice spans the spectrum of environmental matters at the federal, state, and local levels, including transactional due diligence and contract negotiation, hazardous waste management, hazardous site remediation, water pollution, air pollution, and toxic substance regulation. John also conducts property and compliance diligence, drafts and negotiates transaction agreements, and monitors project progress in connection with asset purchases, underwritings, securitizations, leases, and sale-leaseback transactions.

Drawing on his technical background and knowledge of environmental law, John helps clients identify problems and craft effective solutions. On transactional matters, he remains focused on the overall size and structure of the deal in order to help resolve material issues in the most efficient manner. John represents institutional and private equity investors with interests and portfolio companies in a range of industries, including oil and gas exploration and production and renewable electricity generation. In addition to his work in conventional and alternative energy, he has experience in pharmaceuticals, biotechnology and other industrial, manufacturing and commercial sectors.

John is a member of the Firm’s Environmental Practice.

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  • Represented Constellium NV (an Apollo Management portfolio company) in its acquisition of Wise Metals Group LLC for US$1.4 billion in October 2014.
  • Represented Apollo Management in its acquisition of OM Group, Inc., for US$1 billion in August 2015.
  • Represented Apollo Global Management and its portfolio company, Taminco Corp. (Taminco), the world's largest producer of alkylamines and alkylamine derivatives, in the US$2.8 billion sale of Taminco to Eastman Chemical Company, a global producer of specialty chemicals. 
  • Represented equity investors in multiple utility-scale wind energy developments.
  • Handled the environmental due diligence and transaction documentation issues for electric power generation projects worth more than US$15 billion, including independent power production and cogeneration projects, and coal, oil, natural gas, geothermal, hydroelectric, wind, solar, and biomass generation.
  • Represented developers and institutional investors in more than 100 wind, geothermal, and utility scale and rooftop solar projects. 
  • Advised electric utilities and institutional investors with respect to all aspects of environmental compliance, including climate change, greenhouse gas emissions, conventional pollutants, and toxic pollutants.
  • Assisted clients in the analysis, preparation, and negotiation of power purchase and tolling agreements between electricity generators and off-takers, including the allocation of responsibility for emission allowance costs and capital expenditures. 
  • Advised potential investors in a proposed ethanol plant, including the analysis of certain issues relating to New Jersey renewable fuel credits. 
  • Represented developers and investors with respect to natural gas storage and pipeline facilities. 
  • Represented issuers and underwriters of registered and unregistered stocks in the energy, biotech, and other industry sectors. 
  • Developed gasoline oxygenate and sulfur compliance and trading program for, and negotiated settlement agreement with the US EPA on behalf of a refiner and importer of gasoline. 
  • Represented airport developers in contentious major development projects in New York, Connecticut, and California. 
  • Negotiated CERCLA remedial actions with the US EPA and represented potentially responsible parties in multiparty CERCLA contribution litigation. 


Bar Admissions

  • District of Columbia


  • Duke University, J.D., 1993
  • Massachusetts Institute of Technology, M.S., Mechanical Engineering, 1988
  • Williams College, B.A., Mathematics and Physics, 1986

Professional Activities


  • Hydraulic Fracturing Developments,” Pratt’s Energy Law Report (January 2017)
  • Hydraulic Fracturing Developments,” Pratt’s Energy Law Report (June 2016)
  • Hydraulic Fracturing Developments,” Pratt’s Energy Law Report (March 2016)
  • “New Cleanup Obligations for EU Industrial Facilities,” Law360, co-authored with Eric Rothenberg, (November 12, 2015)
  • “Regulatory Risk and Financing: Perspectives on Transactional Due Diligence,” American Wind Energy Association (AWEA) Wind Project Siting Seminar (2012)