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.F <br /> Transit Mix Concrete Co. <br /> Changes to the aquifers, faults, and known connected fractures could devastate the entire <br /> residential area's water supply. Operations at nearby quarries, construction of NORAD, and <br /> recent earthquakes impacted water levels and water quality in nearby wells. At least one well <br /> was not shown on the water well map. <br /> Response: Bishop-Brogden Associates includes a detailed discussion, with references cited, of <br /> potential impacts to groundwater in their response to comments report included in Exhibit G of <br /> the July 14, 2016 submittal. <br /> The Bishop-Brogden Associates report demonstrates construction of NORAD is expected to have <br /> different impacts to groundwater than mining at the quarry. NORAD is an underground facility <br /> constructed deep inside a mountain where groundwater was likely encountered. The NORAD <br /> construction likely would have drained the groundwater or grouted it off, and either of these <br /> would impact the groundwater conditions in that area. The Hitch Rack Ranch Quarry will only <br /> have surface operations that will remain above the water table, and no impacts to groundwater <br /> are anticipated. <br /> Blasting operations will be monitored so that peak particle velocities do not exceed permit <br /> threshold limits. These limits are established to protect structures on the surface, because <br /> subsurface structures are less impacted than surficial structures (Society of Explosive Engineers, <br /> Inc., "The World of Explosives", 2015). Therefore, maintaining blasting operations below the <br /> permit threshold limits will protect structures on the surface and subsurface. Blasting operations <br /> are also conducted to fracture a localized amount of rock. Larger blasts require additional <br /> explosive material and greater costs. New fractures from blasting activities will not extend <br /> through granitic material into wells or the aquifer system. A Pre-Blast Survey will be offered to <br /> all homes within one-half (1/2) mile of the permitted disturbance boundary, and the survey will <br /> include structure evaluation as well as testing the water quality and well production. The <br /> proposed Pre-Blast Survey is included in Exhibit D of the July 14, 2016 submittal. Additional <br /> details on the impacts of blasting on wells and groundwater flow are included in the Bishop- <br /> Brogden Associates report. <br /> The Bishop-Brogden Associates report also demonstrates that earthquakes transmit vibrations <br /> at much larger magnitudes and different frequencies than blasting, and that earthquakes are <br /> capable of impacting groundwater aquifers under certain conditions. The comments suggest that <br /> one well was found to be damaged following an earthquake in 2008. There have been three <br /> earthquakes since 2008, and there have been no additional reports of well failures associated <br /> with these earthquakes. <br /> Hitch Rack Ranch Quarry Permit Application M-2016-010 <br /> Responses to Objection Letters <br /> July 28, 2016 7 <br />