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HomeMy WebLinkAbout4.0 Memo to BOCC 11.13.20062,1 - MEMORANDUM TO Board of County Commissioners FROM Building and Planning Department, Fred Jarman DATE November 13, 2006 RE To consider a referral of a Special Use Permit request for Extraction, Storage and Processing of Natural Resources in the Agricultural / Industrial Zone District for a Gravel Pit. I. BACKGROUND The County received a Special Use Permit (SUP) application for "Extraction, Processing and Material Handling of Natural Resources" for a sand and gravel extraction operation to be known as the Grand River Park Project in the Agricultural / Industrial (AI) zone district. More specifically, the proposed operation intends to mine sand and gravel from approximately 110 -acres of a 168 -acre property located south of the Colorado River and I-70 just west of Silt, CO. (The Map below identifies the property.) isuS II. BOCC AUTHORITY Section 9.03.04 of the Zoning Resolution of 1978, as amended requires that Special Use Permit applications be initially brought to the Board so that the Board may determine if a recommendation from the Planning Commission is necessary. III. STAFF RECOMMENDATION Due to the significant size of the extraction operation, environmental issues associated with wetlands and the riparian / floodplain areas of the Colorado River, significant visual impacts, as well as impacts to the Town of Silt's general planning areas identified in the their Comprehensive Plan, Staff recommends the Board direct Staff to schedule a public hearing before the Planning Commission in order to obtain a recommendation to the Board of County Commissioners. I. 2 Banks and Gesso, LLC 2.0 Introduction Silt Sand & Gravel LLC is submitting this application for a Special Use Permit to operate a sand and gravel mine to be called the Grand River Park Project. Silt Sand & Gravel LLC seeks to permit 168.85 acres. Of that permit area, approximately 110 acres will be mined for construction materials. Gypsum Ranch Co., LLC is the owner of the property that is to be included in the permitted area. Silt Sand & Gravel LLC has a lease agreement with Gypsum Ranch Co., LLC to mine on the property, we well as a surface use agreement with Antero Resources to mine in the vicinity of oil and gas equipment.. The current land use at the Grand River Park Project site is rangeland. Historically, the site was used for pasture and some hay production. Due to economic and practical conditions, the site proved difficult to maintain as a viable ranch or farm. The Grand River Park Project would be mined in phases, progressing generally from the east to the west of the site. The operation would involve dewatering to expose and dry out aggregate materials, on-site sorting and processing, and asphalt and/or concrete manufacturing as appropriate to market conditions and subject to other applicable environmental permitting. Presently, the applicant has installed three monitoring wells on the site to determine baseline ground water levels to provide a basis for determining potential ground water impacts on the property. The applicant proposes to reclaim the land in a manner that will be suitable for hunting, fishing, passive enjoyment of wildlife, and other potential recreational uses. Accordingly, the applicant will reclaim the land in accordance with Mined Land Reclamation bond standards. Concurrent reclamation techniques will be used to make previously mined areas suitable for post -mining use as soon as possible while mining activities progress westerly across the site. Installation of additional recreational infrastructure and detailed planning are not an operator responsibility and will occur following release from applicable land use and reclamation permits. There are two ditches that run across the site, the Last Chance Ditch and the Rising Sun Ditch. There are also overhead power lines running adjacent to and through the property boundaries, and an underground phone line running along the western edge of the property. As part of application for a reclamation permit from the Division of Reclamation, Mining and Safety Grand River Park Project Silt Sand & Gravel LLC 2 September 29, 2006 05021 • • Banks and Gesso, LLC (DRMS), structure agreements have been or will be obtained from structure owners prior to mining within 200 feet of these structures. Grand River Park Project Silt Sand & Gravel LLC 3 05021 September 29, 2006 • Banks and Gesso, LLC 3.0 Site Narrative 1. Structure and Processing Equipment to be Located On Site For the duration of mining, the applicant will convert the existing residence located on the property into an office for site employees. A parking area and truck scale will be located next to the site office, which will be located at the entrance to the site. A processing plant and standard mining equipment will be located on site, which may include conveyor belts, screens, crushers, excavators, backhoes, loaders, and haul trucks. 2. Operating Schedule and Maximum Number of Employees Aggregate extraction and processing activities will operate year-round between the hours of 6 a.m. and 8 p.m., Monday through Saturday. Concrete and asphalt production will cease during the winter months, typically December through March. There will be approximately 10 employees or less, excluding truck drivers, on-site at any given time. 3. Wet or Dry Pit The site will be fully or partially dewatered (via the use of pumps) and dry mined. A sump area will be created in the north part of the Phase 1B Mining Area to clarify water associated with dewatering activities. Clarified water will, in part, be used for recharge of wetlands on the site as well as other consumptive uses on the site. 4. County Roads Utilized County Road 346 will be utilized for access to and from the site. Haul trucks will leave the site at an existing access point on the east end of the permit boundary during Phases 1 and 2. During Phase 3, the previous entrance will be closed and a new entrance will be utilized at the southwest corner of the site, as shown on the Site Plan Map. Proposed haul routes are as follows: South -346 to 315 346 to 331 346 to 311 (Mamm Cr.) (Dry Hollow) (Divide Cr.) Grand River Park Project Silt Sand & Gravel LLC 4 05021 September 29, 2006 • • Banks and Gesso, LLC East - 346 to 311 to: River Frontage 1-70 EB USH 6 (Silt — New Castle) North - 346 to 311 to: USH 6 231 Road (First St.) 235 Road (Davis Point) 1-70 (North of Rifle) West - 346 to Mamm Creek 346 to 311 to: USH 6 1-70 WB It is estimated that 60°i° of trucks leaving the site will follow the haul route going east. Additional information regarding vehicular use is found in the Traffic Impact Study appended to this report. 5. Mining Details The site will be mined in Phases (see Phasing Table in #7 below). Disturbance of mining areas will begin with topsoil removal and placement of topsoil as screening berms. Mining of the site will generally progress from east to west. The site will be mined to an approximate depth of 25 feet, using excavators, backhoes, loaders and haul trucks. The applicant estimates excavation of material will be 500,000 tons per year, but this number may fluctuate depending on market conditions; a faster recovery of the reserve would reduce the life of the mine proportionally. Excavated material will be processed at the on-site plant facilities. The location of the processing plant will move as mining progresses with the primary crusher located in the active pit and the major plant facilities subject to location in two phases. Once mining has reached the final phase, the processing plant will be moved off-site to allow for recovery of sand and gravel in all areas of the reserve. Please see Exhibit D — Mining Plan of the DRMS Grand River Park Project 05021 Silt Sand & Gravel LLC 5 September 29, 2006 • • Banks and Gesso, LLC Application (referenced in Appendix A and included under separate cover) for more detail. 6. Size of Area and Stages to be Worked at Any One Time The total area to be mined is 110.16 acres (out of 168.85 acres). The applicant commits to not disturbing more than 60 acres at any one time. The largest of the areas to be mined (Phase 3A — see table below) consists of 39.5 acres. Backfilling and reseeding within each phase will happen concurrently with mining as much as possible. 7. Timetable for Various Stages of Operation Please refer to the attached DRMS Mining Plan Map for a graphic depiction of the following phasing plan. Phase Mined Acreage Years to mine* 1A 1.72 acres 0.10 1B 26.42 acres 2.50 2 16.86 acres 1.75 3A 39.50 acres 4.00 3B(1)** 15.36 acres 1.75 3B(2)** 10.30 acres 1.00 TOTAL 110.16 acres * Subject to market conditions ** Phase 3B includes (1) area to be mined and processed on-site and (2) area to be mined and pit run hauled after processing equipment is removed 8. Depth and Thickness of Materials to be Removed Mining areas of sand and gravel will be approximately 25 feet in depth. Topsoil to be removed ranges widely throughout the site, from almost none in some places to depths of 48 inches in others. Topsoil will be stockpiled, to serve as screening berms within the permit boundary and stockpiles will be vegetated with a cover crop (see attached DRMS Exhibit C-2) if to remain in place for more than growing season. There is no significant overburden within permit area. 9. Proposed Reclaimed Use and Explanation of Reclamation Process The site will be reclaimed to standards suitable to passive recreational use, including five groundwater lakes. Reclamation will consist of establishment of contours, re -spreading and any amendment of plant growth medium, seeding and planting, as well as Grand River Park Project Silt Sand & Gravel LLC 6 05021 September 29, 2006 • • Banks and Gesso, LLC establishment. Reclaimed slopes will range from 2H:1V to 5H:1V or shallower, according to Colorado Mined Land Reclamation Board Construction Materials Rule 3.1.5(7) (see Reclamation Plan Map for reclaimed contours) and other objectives, such as aspirational standards identified by the Colorado Division of Wildlife. The applicant has solicited input and worked diligently with experts and regulators to achieve a reclamation plan that will specifically optimize wildlife benefits. At least 4 inches of topsoil will be re -spread on disturbed areas. Please see Exhibits E & F (Reclamation Plan) of the DRMS Application for more detail. 10. Vehicle type and access schedule Haul trucks will access the site throughout each working day. Approximately 175 round trips will occur each working day. Employee vehicles will add up to 10 round trips per working day. Additional detail regarding traffic is found in the attached Traffic Impact Study. 11. Wildlife Impacts A review of the Wildlife Habitat Profile Map, Garfield County, Colorado, indicates the subject site is suitable habitat for mammals and other significant species. However, the degraded condition of the forage base, the proximity of human activity, and other influences limit the value of the site for wildlife in its current condition. Please see the attached Habitat Assessment for additional detail. In general, the mining operation will have no extraordinary effect on wildlife during the proposed operation. Site disturbance will be limited and mitigated by design to areas in the immediate vicinity of sand and gravel extraction and processing. Following reclamation, the site will be suitable for wildlife uses similar to the pre -mining condition. Please see the attached Mitigation and Reclamation Plan report for discussion of extensive planning to ensure wildlife benefits in the reclamation plan. 12. Screening Plan Topsoil will be stockpiled as berms in strategic locations around the site to screen adjacent properties. Peripheral tree cover, distance, and mine topography also Grand River Park Project 05021 Silt Sand & Gravel LLC 7 September 29, 2005 • • Banks and Gesso, LLC contribute to screening. Visual impacts in the subject valley floor location will generally be below the horizon line. 13. Electricity Electricity needed on-site for operation of plant facilities and dewatering pumps will be provided by portable diesel generators. However, with electric service currently available at the site, it is anticipated that line service will be routed to both the plant facilities and pumps. Initial feasibility has been conducted to verify that line service may be appropriately extended. 14. Dust Control Blowing of dust off-site will be controlled by water spraying of disturbed areas and material stockpiles, and revegetation of screening berms to minimize erosion and material blowing off-site. 15. Sound Screening Noise impacts to surrounding properties will be mitigated by topsoil screening berms located between mining areas and surrounding properties. 16. Lighting Impacts The operator proposes have one portable light plant on site, to be used as necessary for equipment maintenance. For routine operations during the late fall and other times of year when lighting may be required, lighting will be limited to lights mounted on equipment and on structures according to building code. Grand River Park Project 05021 Silt Sand & Gravel LLC 8 September 29, 2006 • • Banks and Gesso, LLC 4.0 Water Statement Overview The Grand River Park Project is an alluvial deposit located within the floodplain of the Colorado River. Based on initial water level measurements, monitoring wells and test pits at the proposed reclamation permit site show an approximate average groundwater elevation 5 feet below the land surface across the site. By its nature, recovery of the alluvial deposit may have effects on surface and subsurface water systems. Based on standard practices, no adverse quantitative or qualitative effects to surface waters are expected to result from the proposed Grand River Park Project, Groundwater effects will be mitigated to prevent adverse impacts. Water Requirements Water demand at the proposed construction materials operation will be generated by (a) worker demands for potable water, (b) dust control, (c) revegetation establishment, (d) process water (e.g., aggregate washing), and (e) augmentation or temporary substitute supplies for depleted waters subject to appropriation. Annual water demands on the site are estimated at: Potable and sanitary uses (10 employees on site per day) Dust control and irrigation water Process water Augmentation water Total annual water demand 0.1 acre-feet 10 acre-feet 22.1 acre-feet 15 acre-feet 47.2 acre-feet Potable and sanitary water needs will be supplied by water trucked onto the site from vendors. Any consumable water required to fill other demands above will be adequately supplied by operator interests, including commitments and options through the lessor land owner, in irrigation supplies in the Last Chance Ditch or Rising Sun Ditch. The landowner has submitted an application for water rights and plan for augmentation with the Water Court of Colorado Water Division No. 5. An application for a Gravel Pit well permit and approval of a substitute water supply plan has also been submitted to the Colorado State Grand River Park Project Silt Sand & Gravel LLC 9 September 29, 2006 05021 • • Banks and Gesso, LLC Engineer's Office (see Appendix B). The pending approval of the gravel well and Substitute Water Supply Plan will ensure the adequacy of water supplies for the proposed use. Grand River Park Project 05021 Silt Sand & Gravel LLC 10 September 29, 2006 • • Banks and Gesso, LLC 5.0 Site Plan Maps The following current site maps are included with the attached state mining application: Pre -Mining Plan Map (Exhibit C-1) Mining Plan Map (Exhibit C-2) Reclamation Plan Map (Exhibit F) Grand River Park Project Silt Sand & Gravel LLC 11 05021 September 29, 2006