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ExhibitG • Limestone. The primary recharge area for the Dakota Sandstone is in the Wet Mountains and Greenhorn Mountains that are more than 20 miles to the west of the site. A deep producing well in the Dakota Sandstone is located on the Blake Ranch, approximately one mile to the east of the site. As discussed in Appendix H, measurable amounts of meteoric water from the operation will not be exposed to this aquifer and could not cause a negative impact. Also as discussed in Appendix H, meteoric water from the operation could only contact the St. Chazles River alluvium afrer being discharged from the site sedimentation ponds. Regularly scheduled sampling of these discharges under the Stormwater permit would indicate if any off-site contamination is occurring. Nitrates from blasting will have minimal impacts, since only the limestone is blasted and it all goes into the product of the cement plant. Significant nitrate concentrations in solution are unlikely because only spillage, unshot holes, and very slight residues will have rare exposure to water. Blasted limestone will generally be loaded, crushed and conveyed (covered conveyers) to an enclosed storage area within a day or two of being blasted; therefore, only small (approximate 15,000-ton shots) quantities of blasted limestone would be exposed to precipitation events at any one time. However, to reduce the potential for nitrates to affect surface and groundwater, Rio Grande will implement the following management practices: • only use the amount of explosives per ton of limestone required for efficient fragmentation. • use only trained and licensed blasting contractors. • maintain a clean workplace with spills minimized and quickly picked up. • • sample all mine Stormwater discharges for nitrates, nitrites, and ammonia • collect at ]east five quarters of baseline water quality data by monitoring water in the St. Charles alluvium for nitrates, nitrites, and ammonia, both upstream and downstream of the point where Arroyo B discharges into the St. Charles River. • install monitoring wells immediately below the mine and plant discharge points -drilled to contact between Codell Sandstone and underlying shale. • monitor and report results from discharges as required by CDPHE discharge permit. Further discussion is included in Appendix H. WATER QUALITY GCC Rio Grande submitted a Construction Activity Stormwater Permit Reapplication to Colorado Department of Public Health and Environment (CDPHE) on March 29, 2002 to renew the existing construction Stormwater permit (COR-032453) obtained on June 2, 1997. This general permit allows the discharge of Stormwater associated with construction of the Portland cement manufacturing plant. The permit requires that a Stormwater Management Plan (SWMP) be completed prior to submission of the application and that the SWMP be implemented and updated as needed. The construction Stormwater permit does not require outfall sampling or reporting. A copy of the permit and the reapplication form are • provided in Appendix A. 1180-Mine Permit Exhibits (Iu1.05.02)FWAL.doc G-2 Iuly 8, 2002