Michael Kazz, P.E., Principal, B.S. M.S. Agricultural and Biosystems Engineering, The University of Arizona. Mr. Kazz has a wide range of engineering experience including Process Engineering, Mechanical (Vibration and Acoustic) and Environmental Engineering. A National Science Foundation Fellow, Mr. Kazz is one of Zelenís key administrators and is the Customer Service Manager.

Dennis Krantz, B.S. Geology, University of Wisconsin., M.S. Geology, Southern Illinois University. Mr. Krantz has a background as a mining geologist with over 20 years experience and has been in environmental consulting for over 10 years. He is the senior technical lead for risk based corrective action (RBCA) projects. Mr. Krantz is also the lead in Corrective Action Plan (CAP) development, and is involved in directing field investigations.


Ray Plumb, Field Operations Manager, Prescott Office: Capt. Ray Plumb of the Central Yavapai Fire District is certified in Hazmat and Emergency Response. He is an 18 year veteran Fireman and holds certifications from paramedic through confined space entry. Mr. Plumb's work with Zelen includes maintaining free product recovery systems in Northern Arizona. He also assists in other field operations throughout Central and Northern Arizona.


Roksolana Tourkevich, Project Scientist, B.S., Molecular and Cellular Biology, The University of Arizona. Mrs. Tourkevich is responsible for report review and project co-ordination for Zelenís consulting division. She is chief financial administrator for the company. She has over seven years experience in environmental consulting and fiscal management.

W. Gerald Matlock, P.E., Ph D, Civil Engineering, The University of Arizona, M.S., B.S., Agricultural Engineering, The University of Arizona. Mr. Matlock is the Senior Engineer overseeing review of site investigations and CAPs. He has over 40 years in academia and research in groundwater hydrology, irrigation and drainage as a former Professor at the University of Arizona. He is also a Principal and founder of Desert Agricultural Technology Systems (DATS).
Walter's photo coming soon
Walter Diaz Felix received a Bachelors in Chemistry from Instituto Technologico de Sonora in 2005. He held the Zelen Graduate Fellowship in Agricultural and Biosystems Engineering (ABE) from 2005-2007. Graduating in 2007 with Masters in ABE from the University of Arizona. Walter has proven technical and hands-on skills that complement his academic abilities. He will be an Environmental Field Technician and Junior Engineer for remediation system design and a strong asset to Zelen.

Marta Terletsna: Originally hailing from Lviv Ukraine, Marta is Zelen's bookkeeper and operations management co-ordinator. She holds a Pharmaceutical degree and works for Zelen part time while raising a family.