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An Overview of the California Permitting Process

E. Dale Trower, Geothermal Resources Development (1977)

During the more than fifteen years that it has lived with geothermal power production, California has developed, and continues to develop, a sophisticated geothermal regulatory structure. This paper will present an overview of that structure giving special emphasis to the exploration permitting process. Since AMAX Exploration, Inc. has been exploring for geothermal resources in Napa, California, the newly enacted Napa County Geothermal Ordinance1 will be a focal point for discussions of the substantial powers which California has delegated to local units of state government.


The corporate geothermal exploration program generally begins when management decides that a particular area, for one reason or another, appears permissive to the presence of a geothermal steam or hot water reservoir. Interest in the area may be evoked by the results of prospecting work done by the technical staff, it may come from an attractive land offer made by a promoter or potential joint venturer, or finally, management interest may be created simply by intense competitor activity in the area.

No matter how begun, smooth transition of the exploration project from the land acquisition and surficial examination stages (which include geochemical, seismic and magneto-telluric studies) through the drilling of temperature gradient and exploration/production wells, is no l