Wehrum was most recently with the U.S. Environmental Protection Agency where for almost two years he served as the Acting Assistant Administrator for Air and Radiation supervising a national staff of over 1200 professionals.  In his capacity as EPA's senior official on air issues, Wehrum worked closely with state agencies, with EPA Regional offices, with other federal agencies and with foreign environmental ministers and agencies.  Before accepting this position, Wehrum served for four years as the chief counsel to the Assistant Administrator.

Key initiatives during his tenure included development and implementation of the Clean Air Interstate Rule and the Clean Air Mercury Rule, reform of EPA's New Source Review permitting program, review and revision of the National Ambient Air Quality Standard for particulate matter, implementation of federal fuel and emissions standards for heavy duty highway vehicles, and development of proposed emissions standards for locomotives and marine engines.  Wehrum was also instrumental in formulating Agency positions on a variety of permitting, air toxics, and climate change issues.

"With Bill’s experience at EPA, he brings a unique perspective to the problems companies face," said Hunton & Williams partner F. William Brownell, co-head of the firm’s Resources, Regulatory, and Environmental Law Practice.  "He will be an invaluable resource for our clients seeking to navigate an increasingly complex regulatory process."

Wehrum started his career as an environmental engineer and environmental supervisor for a major U.S. chemical manufacturer.  He also worked as an attorney in private practice for several years before joining EPA.  Wehrum graduated with distinction from Purdue University with a B.S. in Chemical Engineering, and earned his J.D. from Widener University.  He is a registered Professional Engineer and is admitted to practice law in the District of Columbia.