Ernest J. Guadiana

Of Counsel

Bar Admissions

State of California

State of Connecticut

State of New York


J.D., Emory University School of Law

B.A., Boston College, Mathematics and Psychology

Ernest Guadiana has extensive knowledge of environmental, energy, and land use law. He regularly advises clients in navigating federal, state, and local regulations to obtain the necessary environmental and land use approvals to develop and construct projects. His work has put him before a number of regulatory agencies and jurisdictional boards and he has, at times, pursued administrative action when entitlements have been challenged, denied, or revoked. Mr. Guadiana also regularly advises clients of the impact of new federal and state environmental and land use laws to ensure his clients’ projects to continue to operate and remain compliant. With an in-depth understanding of the operations of oil, gas, and renewable energy producers, he has assisted an array of companies in governmental enforcement actions, disputes, and transactional matters.

Career Highlights

Represented an oil company in the first formal administrative action before the Division of Oil, Gas, and Geothermal Resources regarding termination of Class II water injection permits.

Represented a Canadian mining company to evaluate water injection permitting risks of the Environmental Protection Agency and State of Arizona in preparation for an acquisition of a copper mine.

Represented a waste management company in a self-disclosure before the Department of Toxic Substances Control.

Represented an oil company in navigating Coastal Commission permit issues pertaining to offshore drilling.

Represented a local agency in a petition for writ of mandamus challenging a municipal separate storm sewer permit.

Seconded to a major oil company to support assets located within California, New Mexico, Ohio and Texas.

Represented a major exploration and production company in navigating environmental permitting in California in order to drill a test well, which included California Environmental Quality Act review and obtaining incidental take permits and drilling permits.

Represented an oil and gas company in permitting a steam-injection oil recovery operation in Kern County.

Petitioned the California Division of Oil, Gas, and Geothermal Resources to terminate a statutorily created unit.

Represented a Canadian mining company as a potentially responsible party in an action filed under the Comprehensive Environmental Remediation, Compensation, and Liability Act.

Advised an oil and gas producer in determining and resolving water injection issues with neighboring lands.

Advised a client on the development of shallow heavy oil Diatomite project and related pipeline and infrastructure construction.

Represented local agencies in their unfunded state mandate claims relating to municipal separate storm sewer system permits.

Represented a chemicals company in a land dispute regarding the placement of an oil and gas drill site within close proximity to its chemicals plant.

Represented a non-profit in developing a low-income housing project.

Represented a car wash facility in obtaining conditional use and building permits.

Represented a public agency in the drafting and enactment of a pipeline franchise ordinance.

Prosecuted numerous quiet title actions, including performing expert witness examination.

Examined title and prepared numerous drillsite title opinions.

Represented a renewable energy developer in a dispute regarding a solar project approved by the Public Utilities Commission.

Represented an oil company in a class action suit relating to payment of royalties on a townlot unit.

Represented an oil and gas company in the acquisition of producing properties in seven states.

Assisted in representation of an oil and gas operator in litigation with mineral interest owners.

Assisted in representation of an oil and gas operator in disputing the validity of a mineral joint venture.

Represented an oil company in an oil pipeline spill enforcement action brought by the City of Los Angeles.

Assisted in the due diligence required for a Chinese entity to enter into a binding letter of intent to purchase a producing oilfield in Texas valued over US$600 million.

Assisted in preparing an enforceability opinion regarding mineral interests collateralizing a loan in excess of US$1 billion.

Drafted private placement memorandums for national oil and gas ventures.

Represented a major oil company in negotiation of oil and gas leases and surface use agreements covering 50,000 acres in California.

California counsel for an oil producer on US$750 million financing to fund acquisition activities.

Performed due diligence on oil and gas assets in preparation for an energy company stock offering.

Negotiated an agreement for the development of Steam Assisted Gravity Drainage horizontal wells for an oil sands project in Oxnard, California.

Represented a mineral owner in negotiations for multiple oil and gas leases with a major oil company covering 10,000 acres in California.

Represented a local water agency in a complex litigation related to groundwater contamination.

Represented a local agency before the Regional Water Quality Control Board in defense of a notice of violation relating to underground storage tanks.

Advised iodine producer in determining its rights and obligations to pay royalty to the Bureau of Land Management.

Represented a land company in the negotiation of an oil and gas lease covering over 5,000 acres.


2015-2017, Who’s Who Legal Directory, foremost practitioner of Energy law in California and the U.S

2014-2017, Super Lawyers,Southern California Rising Star

Publications & Speaking

“What’s Underground Is Still Up For Grabs in Texas,” JD Supra, March 4, 2015

“Texas’ New (and Old) Take on Exculpatory Clauses,” Law360, April 28, 2014.

“Gas Regulations in 26 Jurisdictions Worldwide,” Getting the Deal Through, March 2013.