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• velocity expected from each contributing watershed during the 100-yeaz,_ hour storm event. The <br />applicant will need to verify that all permanent spillways and drainage channels are designed to withstand <br />the peak velocity expected from such an event. For those applications where riprap installation will be <br />necessary, the applicant will need to provide the details for riprap sizing such as the riprap D 50 and <br />thickness of application. Please provide. <br />19. The March 15, 2004 Memo from Mike McDemrid to Alex Schatz references the 10-yeaz, 24-hour <br />storm event as the design storm event for temporary drainage structures. Please provide an assessment of <br />the 10-yeaz, 24-hour storm; l0-yeaz, 6 hour storm; and ] 0-yeaz, 2-hour storm event for the watershed <br />encompassing the proposed MMRR quarry and indicate which storm event produces the highest peak flow <br />and corresponding peak flow velocity. The applicant will need to verify which of these storm events <br />produces the highest peak flow and velocity, and then provide the coaesponding peak flows and flow <br />velocities for each contributing watershed used in the design of temporary spillways and/or drainage <br />channels. The applicant will also need to verify that any new drainage culverts (24" or 48'~ to be <br />installed are designed to convey the peak flow expected from either a 10-year, _ hour or 100-year, <br />hour storm event, whichever is more appropriate. <br />20. The March 15, 2004 Memo from Mike McDermid to Alex Schatz references 4 attachments, ie: <br />hydrology calculations, pit slope report, diversion channels design, road design parameters. Please <br />provide these 4 attachments. <br />21. Blasting Plan -The applicant has indicated that a blast vibration analysis and the on-going blast <br />monitoring plan covering all affected azeas and structures will be submitted to the Division prior to <br />commencement of blasting. It is the Division's position that the blast vibration analysis and blasting plan, <br />per Rule 6.4.4(1), is an integral component of this application and must be provided with all of details <br />• outlined in Allen Sorenson's January 25, 2005 Memo (see attached copy). The blast vibration analysis and <br />blasting plan must also include a detailed assessment of the possible surface and subsurface impacts, a <br />monitoring plan that will be used to detect the presence or absence of offsite impacts, and proposed <br />mifigation measures that will be implemented in the event a peak particle velocity of 0.75 ips is detected at <br />any structure not owned or controlled by the quarry operation, or a peak particle velocity of 0.50 ips is <br />detected at any older structure with plaster-on-lath walls that maybe within the zone of influence of quarry <br />blast ground vibrations. Please provide. <br />Uranium MineraBzation <br />22. The applicant has proposed a Monitoring, Containment, and Control Plan to address the potential for <br />adverse impacts to human health, and the environment from uranium mineralization resulting from <br />quarrying activities and to ensure the operator's compliance with all applicable Federal, State, and local <br />regulations. During the previous review period, the Division met with representatives from the Air Quality <br />Control Division and Radiation Management Program of the Colorado Depaztment of Health (CDH) to <br />discuss the concerns expressed by I.L. Turner in reference to uranium mineralization from quarrying <br />activities. As a result of our discussion, it has come to the Division's attention that it may be more <br />appropriate for the Monitoring, Containment, and Control Plan to address the presence and impacts of <br />radioactivity rather than uranium The Division has asked for more input and assistance from the CDH <br />specialists to assess appropriate monitoring requirements and protocol. We anticipate a response from the <br />CDH specialists by July 29, 2005 and will forwazd their comments to the applicant as soon as they become <br />available. <br />• 23. The applicant has proposed to "collect drill cuttings from at least one (1) representative sample point <br />and promptly perform assay work for uranium content" The Division has asked the CDH to advise <br />