Cal ISO is a not-for-profit public-benefit corporation charged with operating the majority of California’s high-voltage wholesale power grid servicing more than 30 million consumers. Youngdahl completed environmental engineering, geotechnical engineering and geologic hazards evaluations for various phases of project design and development.

Our studies have included detailed geotechnical and geophysical investigations for site characterization.  Both surfical and down-hole geophysical studies were performed to evaluate rippability of the underlying bedrock materials and to optimize the seismic design criteria for speciof this critical structure.

Since the site had been impacted by historic mining activities, both by gold dredging and hard rock mining, detailed historical research and subsurface exploration was performed. An evaluation for the presence of contaminants relating to former mining activities was performed as well as an assessment for naturally occurring asbestos.   

Once construction of the critical service structure was complete, Youngdahl continued our engineering services by providing complete earthwork, special inspection and materials testing observation and testing services during project construction. Our full range of capabilities has provided holistic support for the project minimizing construction scheduling delays and enabling a timely response to unanticipated field conditions.

Project involvement during construction included materials testing and inspection of earthwork, underground improvements, paving, structural concrete, pre-cast concrete, shotcrete, masonry, fireproofing, structural steel welding observation and non-destructive testing.