Patrick W. Dennis is a partner in the Los Angeles office of Gibson, Dunn & Crutcher.  He Chairs the Environment and Natural Resources practice group for the Firm and in that capacity works with and helps lead nine other partners and approximately twenty associates who practice full time in the environmental law area in four different offices within the United States.  He is a graduate of the University of California Law School in 1982, and also received a BS ('76) and MS ('78) from the UCLA School of Engineering and Applied Science.  Mr. Dennis has practiced exclusively in the environmental law area since graduating from law school.

Mr. Dennis has spent a substantial portion of his practice representing clients in cases involving exposure to chemicals and has developed expertise in the science and legal standard of medical causation and exposure reconstruction, among other issues.  The following is a representative list of matters he has lead or co-lead regarding toxic tort exposure cases:

• Lead counsel for Occidental Chemical in toxic tort case pending in Los Angeles County Superior Court involving claims by school teachers and students regarding exposure to hexavalent chromium from nearby industrial facility.  Case is still in early stages of discovery.
• Member of trial team for the In re Redlands Tort Litigation, involving allegations of exposure to trichloroethylene and ammonium perchlorate.  Lead the defense team of epidemiologists including scientists who studied the community and published their findings regarding cancer incidence in adults and children and prevalence of congenital hypothyroidism in newborns in the community at issue.  Responsibilities at trial include the examination of key plaintiff and defense experts on medical causation.
• Lead counsel for Occidental Petroleum in toxic tort case in Los Angeles County involving community claims of exposure to crude oil and various derivatives from production operations in West Los Angeles.  Successfully defended action resulting in voluntary dismissal of case by all plaintiffs.
• Member of team that represented Lockheed Martin in the Burbank toxic tort litigation involving trichloroethylene and hexavalent chromium.  Had responsibility for the epidemiological and toxicological experts on hexavalent chromium.  Assembled team of international specialists in hexavalent chromium and successfully presented the medical causation case through the development of their opinions and defense of their depositions, then took the key plaintiff experts' depositions on chromium toxicology and epidemiology.  Plaintiffs’ experts subsequently disqualified through motion practice and case settled.
• Member of team that represented major Los Angeles law firm in defense of $200 million malpractice case regarding the Belmont Learning Center.  The core allegation was the claim of alleged unsafe conditions for the school children due to hydrogen sulfide and methane gas.  Handled the expert portion of the defense of the case regarding the safety of the school site.  Case won on defense motion for summary judgment. 
• Lead counsel to major property developer in toxic tort claims regarding exposures of multiple tenants in commercial building.  Case settled with summary judgment motion pending, and none of the settlement money was paid for by client.

Pat has also been lead or co-counsel in a number of high profile environmental litigation matters involving disputes over the clean up costs and other damages associated with environmental contamination.  Representative examples of those matters include:

• Lead counsel representing Kerr McGee Corporation in Newhall v. Kerr-McGee, brought in Los Angeles County Superior Court.  There, major landowner/developer in Southern California alleged contamination of some 4,000 acres of former crude oil production property by Kerr McGee.  Case successfully settled after summary judgment motions brought. 
• Lead counsel representing Solar Turbines (a Caterpillar subsidiary) in Solar Turbines v. Navistar, brought in United States District Court for the Southern District of California.  Case involved the clean up of the former aircraft manufacturing site where the Spirit of St. Louis was built in San Diego.  Contaminants included heavy metals, including cadmium and lead, volatile organic compounds including TCE and PCE, and semi-volatile organic compounds.  Case settled with defendant paying the majority of clean up costs for the site.
• Lead counsel representing Atlantic Richfield Company (Arco) in the precedent setting case that established the scope of CERCLA's petroleum exclusion.  Successfully argued before the Ninth Circuit that the petroleum exclusion in CERCLA prevents the use of CERCLA for cost recovery associated with refined motor vehicle fuel leaks, including gasoline.  Published decision is at Wilshire Westwood Associates v. Atlantic Richfield Company, 881 F. 2d 801 (9th Cir. 1988).
• Lead counsel representing GNB, in GNB v. NL Industries, Inc., involving the clean up of one of the largest secondary lead smelters in the Western States.  Case settled after GNB brought successful summary judgment motion challenging the contractual defenses of NL Industries.  Major compound at issue was lead.
• Co-counsel to Goodrich Corporation in the series of actions brought by the City of Rialto and the State of California against various entities for the estimated $200 million + cleanup of perchlorate and TCE in the Rialto and Colton groundwater basins.