The site for this new CHP building is located in the historic Grass Valley Mining District, on the western edge of the North Star group of mines. Holdrege & Kull investigated the potential for underground mine excavation by reviewing mine records and the findings of previous geophysical investigations, including aerial photographs showing suspected lineaments. H&K’s research determined that the lineaments were not likely associated with past mining activity or faults. H&K also performed a subsurface investigation at the site in order to provide geotechnical engineering design criteria for deep foundations for the proposed communication tower and parking area canopies. Other services provided by H&K included soil evaluation and design of onsite wastewater and sewage disposal.