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Andy Zdon, PG, CHG, CEG

Andy Zdon has nearly 30 years of experience in a variety of hydrogeology-related projects. He is a Professional Geologist, Certified Hydrogeologist, and Certified Engineering Geologist in California, and a Registered Geologist in Arizona. He is a recognized subject matter expert in the area of numerical groundwater flow modeling and has been an instructor at California State University, Los Angeles in Groundwater Models and Management.

In 2013, Mr. Zdon was appointed by the Inyo County Superior Court as Watermaster for a surface water system in the Owens Valley. He specializes in basin analyses and relationships with spring systems, contaminant transport, and dual-phase flow in both basin fill and fractured rock environments. He also possesses expertise in numerical groundwater modeling which includes flow, groundwater/surface water interactions, and spring flow.

As an expert witness, Mr. Zdon has served on a number of cases and provided both depositions and court testimonies. He was appointed to serve on the first Technical Advisory Committee for the newly-combined California Board for Engineers, Land Surveyors, and Geologists. He also received Certificates of Commendation and Appreciation for his volunteer service as Subject Matter Expert for the former California Board for Geologists and Geophysicists.


State of California, Professional Geologist (No. 6006)
State of California, Certified Engineering Geologist (No. 1974)
State of California, Certified Hydrogeologist (No. 348)
State of Arizona, Registered Geologist (No. 33683)


BS, Geology, Northern Arizona University