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1 • • • <br />(Page 2) <br />MINE ID # OR PROSPECTING ID #: M-9n-n98 <br />INSPECTION DATE: 8/tn/n1 INSPECTORS INITIALS: KAP <br />OBSERVATIONS <br />1. On July 11, 2001 the Division received an application for a permit amendment for the Perry Pit. The amendment proposes <br />to increase the mined area on the permit site by approximately 10 acres resulting in a single, large water resource containment <br />structure instead of two smaller ponds. The amendment would involve installation of a slurry wall in order to isolate the water <br />resource containment feature from groundwater in the area. This inspection was conducted as part of the permit amendment <br />review. Present at the inspection were Kate Pickford, DMG, Allen Sorenson, DMG, Jeff Keller, Asphalt Paving Company, anti <br />Paul Banks, Banks and Gesso, LLC. Weather conditions at the time of inspection were sunny, clear and 75 degrees. <br />2. All operations and conditions at the site during the inspection appeared to be in compliance with regulations and within <br />the parameters of the mine plan. A permit sign was posted at the main entrance to the site off of County Road 6. Notice of the <br />permit amendment was also posted at this location. The stockpile noted in the original permit application is in place to the <br />east of the pit area to prevent any change in the characteristics of the river floodplain. Currently the operator performs an <br />annual weed control program. Topsoil piles have moderate vegetation containing a moderate amount of weeds. Submittal of <br />an additional weed control plan is not necessary for the permit amendment application. There was no dust problem apparent <br />at the time of inspection. The gravel mined from the pit is being stockpiled at the site and when an adequate amount is <br />accumulated, a crusher is brought in to process the material. Twice in the history of mining at the site, a crusher has been <br />brought in to process material. <br />3. According to the operator Asphalt Paving does currently possess a 404 permit with the U. S. Army Corps of Engineers <br />related to activities on the permit property. Multiple portions of the property are to be preserved or augmented as wetlands as <br />part of the original reclamation plan. The amendment plan will eliminate some of the wetland area planned in the original <br />permit along the southeastern portion of the site. The operator will be adding the same amount of augmented wetland area <br />located in the southwestern portion of the site in order to replace the wetland to be eliminated. A good grass mix exists in the <br />current wetland area on the site. Wildlife at the site area includes Canadian Geese, observed during this inspection, and prairie <br />dogs, whose burrows were also observed during the inspection. <br />4. According to the operator, shale bedrock occurs at between 27 and 28 feet below ground surface. The permit amendment <br />application accounts for bond calculations involving a slurry wall that reaches a depth of only 25 feet. The operator was <br />advised that the bond calculation will be based on a slurry wall reaching 30 feet in depth, deep enough to be keyed into the <br />bedrock. <br />5. The amendment indicates that dewatering of the pit will be required during portions of the remaining mining process. The <br />operator indicated that a slurry wall would be installed prior to any dewatering of the pit. The operator indicated that many of <br />the adjacent residential properties may possess shallow groundwater wells and plans to install the slurry wall prior to <br />dewatering in order to avoid impacts on neighboring residential wells during dewatering activities. This information is <br />inconsistent with the permit amendment application, which indicates that dewatering activities will be performed prior to <br />installation of the slurry wall. This issue will be further addressed during the adequacy review process. <br />6. In that the operator does not currently possess a NPDES permit for the site, he will obtain one prior to dewatering and <br />discharging activities. The operator requested that bond payment for the slurry wall be postponed until installation of the slurry <br />wall is about to commence. According to the operator's calculations, installation of the slurry wall will begin in about 3 years. <br />Mining will not occur around the gas well owned by Barrett Energy and located along [he western portion of the permit area, <br />although installation of the slurry wall will occur around the well. <br />7. The permit amendment application reclamation plan specifies a 3:1 slope above and below the water level in the water <br />resource containment structure, and 2:1 ten vertical feet below the water level. The operator was advised that currently the <br />regulations require slopes of 3:1 to 5 vertical feet above and 10 vertical feet below the expected water level. In that the buyer <br />of the water has not committed to maintaining a specific minimum water level in the pit, the slopes would have to be 3:1 to <br />the bottom of the pit in order to comply with regulations. The operator will consider his options regarding the final slope of <br />the pit wall; possibly obtaining a commitment from the buyer that water will not fall below a certain level, or sloping the wall <br />at 3:1 to the floor. There is adequate overburden stockpiled at the site to accommodate any slopes planned for the wall of the <br />pit. <br />