Trey Shaffer is the Vice President, Key Clients at RES, where he leads the company’s Key Client Program, an enterprise-wide effort to strengthen strategic relationships and create value for RES’ most important energy and power sector clients. He guides the integration of RES’ ecological restoration, mitigation, and water resource capabilities into cohesive offerings that support client priorities and long-term environmental outcomes. Trey focuses on aligning RES’ expertise and strategic resources to deliver exceptional client value, working closely with delivery teams to ensure coordinated and seamless execution.

Trey brings over 35 years of experience in environmental consulting, commercial leadership, and operational management. Before joining RES, he spent more than two decades as a Partner of the firm in senior leadership roles at Environmental Resources Management (ERM), a global environmental and sustainability consulting firm. Earlier in his career, he served in operational and business leadership roles with Boots & Coots Special Services, overseeing environmental services, regional operations, and field teams supporting the energy sector.

He holds a Bachelor of Environmental Design degree from Texas A&M University.