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25. The applicant specifies that the operator is in the process of filing an augmentation plan with the Office of the State Engineer (OSE) to replace water lost to the mining operation including evaporative losses from lakes in the reclaimed areas. Please note that prior to initiation of the vazious uses of alluvial-groundwater at the Mamm Creek Sand & Gravel Pit the operator may be required by the OSE to obtain either a gravel pit or other type of well permit and prior to obtaining such permit, an approved temporary substitute supply plan or decreed plan for augmentation will be required. Therefore, prior to exposing alluvial-groundwater at the mined pit(s), the operation must be in compliance with all requirements of the Office of [he Slate Engineer (OSE) or the operator must post sufficient bond to cover the cost of backfilling the pit with inert material to an elevation that is at least two (2) feet above the groundwater surface. The applicant will need to commit to either demonstration of compliance with all applicable OSE requirements or posting sufficient bond for backfilling prior to exposure of groundwater at the Mamm Creek Sand & Gravel Pit. 26. Based on the information provided in the Regular 112 Application ("The mining operations are expected to affect the groundwater in the alluvial deposits associated with the Colorado River") and the hydrologic concerns raised by an objector, there is potential For adverse impacts to the alluvial-groundwater system within the affected and in the surrounding area. The seriousness of this potential is unknown at this time. Therefore, in accordance with Rule 6.4.7(b), the applicant will need to identify all known aquifers within the affected area, down to the first aquitazd. Also, the applicant will need to provide a chazacterization of the aquifer(s). Also, the depth to groundwater, below the surface, will need to be provided based on actual measurements and defined as to time of yeaz when the measurements are taken. Since the applicant proposes to operate and mine within analluvial-groundwater sytem, it is likely that the water table will fluctuate significantly during various times or seasons of the yeaz. The chazacterization of the aquifer and water table to be provided by the applicant will need to define seasonal vaziations to be expected and should also include a discussion on the water levels in the adjacent Colorado River since the river and azeas to be mined aze part of an interrelated, dynamic system. (For example, it is likely that the river may recharge the surrounding alluvium during certain times of the year, and the alluvium may recharge the river at other times of [he yeaz. This dynamic should be explained or defined as much as possible by the applicant prior to a decision of recorrtmendation by the Division). Please address. 27. Please identify the direction and hydraulic gradient of groundwater flow for the alluvial- groundwater aquifer to be intercepted during mining at the Mamm Creek operation. Also, please slate the source and date of the information and any assumptions used to chazacterize the aquifer. 23. Based upon the direction and gradient of groundwater flow, hydraulic conductivity, and other pertinent aquifer characteristics, please provide an analysis of the shape, direction of travel, and rate of movement of a potential contaminant plume leaving the permit area as a result of (I) a continuous point source, such as fuel storage tank leaking over an extended period, and (2) an instantaneous point source, such as an isolated spill event. Also, please provide a map which clearly identifies and show the location of the closest (offsite) downgradient alluvial well and its assumed capture zone that is located within the projected contaminant flow path.