2005-02-11_REVISION - M2000016 (2)

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M-2000-016, Lafarge West, Inc.: Riverbend Operation, AM-01 February 11, 2005 Adequacy Memo Page 4 prior to dewatering. Given this information, the applicant must demonstrate that the proposed mitigation plans could work. 19. The Groundwater Elevation Graphs in Appendix B of the "Groundwater Monitoring Plan" separate irrigation season and non-irrigation season groundwater elevations versus date onto separate plots. How were irrigation versus non-irrigation seasons determined? graphical presentation of these data more useful if the plots were overlaid as two series on one graph or integrated. The Division requests the applicant respond to these inquiries and also submit revised graphs. Water Balance (P. 28 of 81) 20. "Operational Losses, Table 3" needs to specify what years these depletions occur, or corresponding phases of the operation, including reclamation. Water projected to be consumed by the concrete batch plant, for mitigation purposes, or other uses must be included. The applicant needs to clarify how "Water Balance" is defined and calculated in this table. 21. The applicant must comply with Rule 6.4.7(4), which states that they "shall indicate the projected amount from each of the sources of water to supply the project water requirements for the mining operation and reclamation." Water Rights/SWSPs 22. The SWSP approval letter dated April 2, 2001, submitted with the application for the Fort Lupton Gravel Pit (M-1985-088) portion of the amended permit area, expired on March 31, 2003. The applicant must demonstrate current compliance with OSE requirements for this exposed ground water surface. Riverbend Operation to demonstrate current complains with OSE requirements. CDPS Permit 24. The applicant should note that the flow rates from the two discharge points in the current CDPS Permit authorization (COG-500416) are limited to 1,000 GPM each (1.44 MGD). Stormwater Management Plan (`SWMP'~ 25. In Section 4 -Table A, there appears to be a discrepancy between the Key and the table as Table A indicates that a storage method for topsoil, overburden, sand and gravel, and recyclable concrete stockpiles is " 'I,' enclosed areas;" and a management practice for diesel fuel tanks, lubricating fluids, and concrete additives is "'L; stockpile revegetation:' The applicant needs to address these discrepancies. The Division assumes that the diesel fuel tanks, etc. will be placed on impervious surfaces and requests that the applicant describe the makeup of the "impervious surface:' 26. Section 7: Preventive Maintenance, the applicant should specify an inspection frequency for all facilities listed, rather than "as-needed :' 27. The statements describing the implementation and applicability of the practices in Section 9: Best Management Practices are listed as options. Please indicate which one(s) will actually be used on site and where so the Division can calculate the applicable bond amount for removal and/or reclamation of such structures.