P. Derek Petersen Partner

Derek Petersen is an environmental and business litigator with over a decade of experience representing clients before both state and federal courts. He has successfully resolved disputes throughout all stages of litigation—from pre-litigation counseling to jury and bench trials to appeals.

Derek has significant experience representing clients in contaminated site litigation, including assisting clients in CERCLA, state Superfund, and multiparty cost-recovery and allocation proceedings; government enforcement actions; and toxic tort claims. His experience includes both large federal Superfund sites, as well as smaller state-lead or voluntary cleanups. 

Derek’s environmental practice also involves representing project sponsors during the federal environmental review process and defending project approvals under NEPA. He counsels clients on environmental compliance and regulatory matters under federal and state environmental laws, including RCRA and NEPA.  

Beyond his environmental practice, Derek has extensive experience representing clients in a broad range of business litigation matters, including class action defense, real estate, construction, intellectual property, employment, noncompetition, breach of contract, and business tort matters.

Maintaining an active pro bono practice, Derek has successfully helped a victim of an equity-skimming scam retain ownership of his home, and he has participated in the Bet Tzedek Holocaust Reparations Pro Bono Project—helping multiple Holocaust survivors obtain reparations.

To help develop the next generation of lawyers, Derek has served as an adjunct professor at the Arizona State University School of Law, and he also serves as the chair of Perkins Coie’s attorney development committee for the Phoenix office.