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6.4.4 Exhibit D <br />Mining Plan <br /> <br /> Rock Pit #2 (RP2) was initially permitted in 2003 with an amendment approved in <br />2004 that increased the total permitted area to 930 acres including the interior haul/access <br />road. Pioneer has held the lease and mined the site since 2004. This Technical Revision <br />(TR-01) and updated exhibit is submitted as a compliance item from the 2004 amendment <br />to identify future mining phases. <br /> <br />The target deposit is the gravel located in the top 60 ft. of a bluff composed of Kim, <br />Manvel, Penrose, Minnequa, Wiley and river wash soil series. Clay lenses lie within the <br />gravel deposit that, depending on thickness, impact mining viability. Extensive clay, as in <br />the case of Phase 2, will result in not mining a particular area or will stop mining, forming <br />the mine floor. Manageable clay layers will be removed and stockpiled as overburden to be <br />used to rebuild slopes during final reclamation. <br /> <br />Existing Conditions <br /> Pioneer has operated RP2 since 2004. Surface facilities and development are all <br />temporary structures and/or portable equipment. The scales, scale house, storage shed <br />and fuel tank are located south of the Phase 3 footprint. Trucks follow a circular interior <br />road through the scale area. <br /> <br /> Existing mine disturbances include reclaimed areas as well as the current active mine <br />area. Phase 1 is mined out and reclaimed. Phase 2 was not mined due to an extensive clay <br />layer that prohibit economic extraction of the gravel. Phase 3, approximately 20 acres, is <br />mined out, graded and topsoiled; ready for seeding Fall 2022. Phase 4 is the stockpile area <br />while mining progresses into Phase 5 for a total of less than 40 acres. <br /> <br />Mining Operation <br />Mining proceeds from the north and east to the south and west through the phases <br />through the bluff. Reclamation occurs contemporaneously with mining. The active mine <br />area that includes the stockpile area and active mine area is limited to 40 acres. <br />Approximately 20 additional acres are backfilled, graded and topsoiled. This results in a <br />total mine footprint of 60 acres. As mining progresses, the stockpile area moves with <br />mining and the stockpile area is then backfilled, graded and topsoiled in preparation for <br />seeding during the appropriate season. The anticipated mining depth is 60 ft. at a <br />maximum. Mining may stop, as in the case of Phase 2, if an extensive clay layer is <br />encountered. <br /> <br />The mine area is marked by a perimeter native material berm. The perimeter berm <br />is constructed and maintain as a safety measure and stormwater BMP. The berm is <br />constructed in accordance with MSHA berm safety criteria for equipment operating safety. <br />The berm also serves as a stormwater berm, segregating on-site precipitation from off-site <br />precipitation. Precipitation that falls inside the berm pools and either infiltrates or <br />evaporates within 72 hours. <br /> <br />Material is processed by a third party contractor. Two to three times each year for <br />eight to 12 weeks, depending on market demand, Pioneer secures the services of a <br />crusher/screen contractor. Raw material is removed from the working face with a loader <br />and placed in the feed hopper using a loader. Material is pushed with a bulldozer, <br />maintaining a 3H;1V slope during mining, or may be extracted with a loader forming a <br />maximum of a 20 ft. highwall. The highwall will be limited to 500 linear feet. Processed