John D.S. Gilmour
Partner
- Email Address
- email hidden; JavaScript is required
- Location
- Houston
- Phone number
- (713) 355-5005
John Gilmour is the co-chair of the firm’s Environmental practice. His practice encompasses significant environmental matters, including some of the country’s largest contaminated sites, across a wide range of U.S. jurisdictions, from Puerto Rico to Guam and many states in between.
John represents public and private sector clients in matters addressing remediation and restoration, including natural resource damages in state, territorial, and federal courts. John’s environmental focus predominantly has been contaminated groundwater, surface waterways, and industrial and mining sites, including natural resources injured from years of industrial activities; chemical and weapons manufacturing processes; and mining operations. He also handles complex commercial, tort, bankruptcy, and select IP matters for clients. In every case, John works with the client throughout the representation to determine specific goals, whether it is early settlement, alternative dispute resolution, trial through verdict, or other avenues to conclusion.
A former multiyear Texas Super Lawyers “Rising Star,” John personally enjoys learning as much as possible about each of his client’s interests and strategic goals in order to better meet their needs. Clients value John’s creative analysis and dispute resolution strategies that consistently result in successful settlements and verdicts. According to Chambers USA, clients say that he is “a strong litigator with a mastery of legal issues,” and moreover, commend his ability “to communicate complex issues in a way that is easy to understand.” A trusted advisor, John is appreciated for demystifying the litigation process and aggressively defending his client’s rights at every turn, including at trial. He regularly resolves multimillion-dollar disputes by focusing not only on what his client hopes to achieve, but also on what makes sense for them financially.
John began his litigation career clerking for one of the most well-known federal judges in Texas, Judge David Hittner, in the U.S. District Court for the Southern District of Texas. More than 25 years later, he continues to put his trial skills to work, delivering strong results for his clients.
“I effectively communicate my client’s position with judges, juries and other involved parties in even the most complex matters.”
Representing a Class I railroad in defending against potential cost recovery, contribution and natural resource damages claims arising from three contiguous Superfund sites spanning nearly 300 square miles.
Representing the state of New Jersey as special counsel in pursuing costs and other damages associated with the remediation and restoration of the Passaic River.
Representing the state of New Mexico as special counsel in pursuing costs and other damages associated with the Gold King Mine blowout near Silverton, CO, into the Animas and San Juan Rivers.
Representing the Commonwealth of Puerto Rico related to island-wide groundwater contamination.
Representing a national transportation company concerning the recovery of costs associated with the remediation of the client’s properties against former lessees that released hazardous materials.
Representing an international energy company in a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) contribution action against various potentially responsible parties arising out of a contaminated dump site and salvage yard.
Representing the city of Houston in defending against a citizen suit action under the Clean Water Act arising out of construction projects at Bush Intercontinental Airport.
Representing an international energy company in defense of Superfund litigation and other matters involving claims brought under CERCLA, Resource Conservation and Recovery Act (RCRA) and various common law theories of recovery.
Representing an oil and gas owner and operator in the defense of a groundwater contamination suit.
Representing the largest private port in Texas in litigation bringing claims against a major oil company for fraud and breach of various easements, leases and contracts.
Representing an international telecommunications company in the prosecution of a contract and fraud dispute arising out of the installation of a voice and data system at federal facilities.
Representing 62 members of the U.S. House of Representatives as amicus on a class action against the Federal Emergency Management Agency related to Hurricane Katrina.
Representing a Class I railroad in the recovery of costs and damages arising from derailments.
Representing an oil and gas royalty interest owner in a breach of contract and breach of fiduciary duty dispute.
Representing a chemical manufacturer in the defense of multiple personal injury claims related to an airborne release.
Representing a chemical manufacturer in the defense of personal injury claims arising from an incident on site.
Representing a pipe manufacturer in the defense of multiple toxic tort suits in Texas.
Representing a respirator manufacturer in the defense of multiple toxic tort suits in Texas.
Served as local counsel in various matters, including intellectual property, environmental and commercial litigation, in federal district court in the Southern District of Texas and the Western District of Texas.
Ranked as one of the leading practitioners in the Environmental area by Chambers USA in 2022-2025.
The Best Lawyers in America© “Ones to Watch” (Woodward/White, Inc.), Environmental Law, 2026.
Lawdragon 500 Leading Environmental & Energy Lawyers, 2022-2025.
Recommended in US Legal 500 for his work in the Environment Litigation area, 2019-2025.
Named a “Rising Star” by Thomson Reuters for Texas Super Lawyers in 2007, 2008 and 2009.
Selected as one of the Irish Legal 100 by Irish America Magazine, 2025.
Houston Bar Association, Environmental Section, board of directors, 2007–2009
Houston Young Lawyers Association, Special Olympics Committee, co-chair, 2007–2008
American Association of Port Authorities, member
Gulf Ports Association of the Americas, member
International Association of Defense Council, former member
Texas Association of Defense Council, former member
Texas Bar Foundation, sustaining life fellow