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I.4 I3ydroloeic Balance, Off-Site Damaee, Site Stability: After mining is complete, the large underground openings are expected to partially fill with water, then overflow at the lowest quarry portal during high nuioffperiods. Since the quarry does not generate large volumes of water, and all runoff from the quarry area eventually feeds into Yule Creek, no significant impacts are anticipated on the hydrologic balance of the azea. In June of 1999, CDMG found "areas of damage outside (CYMC's) permit boundazy, attributable to the operator's mining-related activities..." Marble waste blocks were dumped by CYMC at a point d¢ectly outside the portal. These blocks rolled down the slope and very likely have crossed the property line and the boundary of the affected area established by CYMC's permit. The blocks also filled the sediment control structure built by CYMC and may have damaged its ability to stop sediment from reaching Yule Creek. Sierra intends to conduct its operations entirely within the affected azea as defined by this application. In addition, until the CYMC off-site damage issues are resolved and corrective action taken, Sierra will not perform any activity that will impact azeas where CYMC may have caused damage that maybe a violation its permit. Specifically, Sierra will not add sediment to the waste piles or dump quarry blocks in the area where they may effect the current condition ofthe sediment control structure. If substantial delays occur in the process, Sierra will work with CDMG to reestablish the effectiveness of the sediment control structure before any fines aze added to the waste dump. Sierra specifically disclaims any responsibility for any past or future off-site damage caused by CYMC. Future off-site damage may result from the actions of CYMC, including further movement of material from the waste piles below the quarry portal or from below the quarry portal access road onto neighboring property. Sierra will not perform any activity that may cause current conditions to change where damage may have occurred or may occur in the future. Only after a solution is found to the off-site damage issue, and corrective action taken to reestablish the effectiveness of the sediment control structure, will Sierra use this azea for any purpose. Sierra plans no dumping of waste materials in the area directly east of the main quarry portal during any phase of mining or reclamation. The sediment control structure should be reestablished with its base on bedrock and constructed ofsemi-permeable materials orwith asemi-permeable liner to allow water to pass through while retaining marble fines. CYMC operating personnel have indicated that it was only until recent years that the sediment control structure built by CYMC became ineffective. Even with mazble blocks filling the pond, the pond never filled or required cleaning. The pond is approximately 20 feet across and about 6 feet in depth with a total volume of approximately 500 cubic feet. It was not until the summer of 1998, when a road was built azound the outside of the south waste pile and substantial quantities of marble fines were mobilized, that substantial sediment buildup was observed. Sierra estimates that a similarly sized pond will be sufficient to collect sediment nmoffduring quarry operations, especially since Siena does not plan to route quarry discharge water into the waste piles. Periodic cleaning of the pond is anticipated. The marble waste piles from pre-1941 operations have been left with slopes estimated at approximately 1.6:1 to 1.8:1 (horizontal:vertical). These piles have remained stable for over 50 years due to the lazge size and competent nature of the mazble blocks. Sierra plans to deposit waste so the finai slope in azeas where waste is added to existing piles is 2:1 or lower. The 21