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7906_Duke_DanRiver_OpsPlan_DIN25602_20161026
Operations Plan Dan River Landfill Duke Energy – Dan River Steam Station Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 To: Duke Energy Carolinas, LLC Date December 24, 2015 From: Amec Foster Wheeler Amec Foster Wheeler Project No. 7810140065 TOC December 24, 2015 DESCRIPTION OF REVISIONS The following table provides a brief description of the revisions to the Operations Plan. The Operations Plan was originally submitted to the North Carolina Department of Environmental Quality (NCDEQ) on August 26, 2015 and modified as shown in the following table: Revisions Date of Document Description of Revisions Initial Issue August 26, 2015 Initial issuance of document. 1 December 24, 2015 Revised per NCDEQ comments Amec Foster Wheeler Project No. 7810140065 TOC December 24, 2015 Contents 1 GENERAL FACILITY OPERATIONS .................................................................................................... 1 1.1 Overview ....................................................................................................................................... 1 1.2 Contact Information ....................................................................................................................... 1 1.3 Safety ............................................................................................................................................ 1 1.4 Access and Security Requirements .............................................................................................. 1 1.5 Operating Hours ............................................................................................................................ 2 1.6 Signs ............................................................................................................................................. 2 1.7 Training ......................................................................................................................................... 2 1.8 Record Keeping............................................................................................................................. 2 1.9 Design Drawings ........................................................................................................................... 3 2 OPERATIONS MANAGEMENT ............................................................................................................ 3 2.1 Waste Handling and Landfill Sequencing ..................................................................................... 4 2.1.1 Landfill Capacity ........................................................................................................................ 4 2.1.2 Waste Acceptance, Disposal, and Screening Requirements.................................................... 4 2.1.3 Dust, Litter, Odor, and Vector Control ....................................................................................... 5 2.1.4 Fire Control ................................................................................................................................ 5 2.1.5 Landfill Sequencing ................................................................................................................... 5 2.1.6 Waste Placement ...................................................................................................................... 5 2.1.7 Compaction Requirements and Testing .................................................................................... 6 2.1.8 Cover Requirements ................................................................................................................. 7 2.2 Leachate and Stormwater Management ....................................................................................... 8 2.3 Leachate Collection System (LCS) ............................................................................................... 8 2.3.1 Use of Leachate for Dust Control .............................................................................................. 9 2.3.2 LCS Maintenance ...................................................................................................................... 9 2.3.3 LCS Record Keeping and Sampling ....................................................................................... 10 2.3.4 Leak Detection System (LDS) ................................................................................................. 10 2.3.5 Leak Detection System Maintenance ...................................................................................... 10 2.3.6 Record Keeping and Monitoring .............................................................................................. 10 2.3.7 Response Action Plan ............................................................................................................. 11 2.4 Stormwater Collection and Conveyance ..................................................................................... 12 2.4.1 Stormwater Discharge ............................................................................................................. 12 2.5 Stormwater Maintenance Requirements ..................................................................................... 13 2.6 Groundwater Monitoring Well Access Requirements ................................................................. 13 2.7 Landfill Gas Management ........................................................................................................... 13 3 EROSION AND SEDIMENT CONTROL ............................................................................................. 13 3.1 E&SC Measures Monitoring and Maintenance ........................................................................... 13 3.2 Surface Erosion Monitoring ......................................................................................................... 14 4 VEGETATION MANAGEMENT ........................................................................................................... 14 4.1 Temporary Seeding ..................................................................................................................... 14 4.2 Permanent Seeding .................................................................................................................... 15 4.3 Over-Seeding .............................................................................................................................. 15 5 LANDFILL CLOSURE .......................................................................................................................... 16 6 REQUIRED REGULATORY SUBMITTALS ........................................................................................ 17 Amec Foster Wheeler Project No. 7810140065 TOC December 24, 2015 List of Tables Table 1 Design Drawings Table 2 Landfill Capacity Table 3 Cell Area Table 4 Leakage Rate Monitoring Table 5A Temporary Seeding Table 5B Temporary Seeding Soil Amendments Table 6A Permanent Seeding Table 6B Permanent Seeding Soil Amendments Table 7 Over-Seeding Table 8 Required Regulatory Submittals List of Appendices Appendix I Dust Control Plan Appendix II Landfill Sequencing Drawings Appendix III Closure and Post-Closure Plan Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 1 of 17 December 24, 2015 1 General Facility Operations 1.1 Overview The purpose of this Operations Plan is to provide a plan for the safe and efficient operations of the Dan River Landfill at Duke Energy’s Dan River Steam Station. This Operations Plan presents the operation requirements for: 1) General Facility Operations, 2) Operations Management, 3) Erosion and Sedimentation Control, and 4) Vegetation Management along with guidance for Landfill Closure and Required Regulatory Submittals. This Operations Plan was prepared consistent with 15A NCAC 13B .0505 Operational Requirements for Sanitary Landfill rules. The Dan River Steam Station is located at 900 South Edgewood Road in Eden, Rockingham County, North Carolina. The proposed Dan River Landfill will be owned by Duke Energy Carolinas, LLC (Duke). The proposed landfill will be located largely within the footprint of existing Ash Fill 1 on the northeastern end of the property. The ash within Ash Fill 1 will be removed prior to construction of the proposed landfill. The proposed landfill will be bounded by existing overhead electrical lines to the west and north, rail lines to the east, and a natural gas pipeline to the south. 1.2 Contact Information Correspondence and questions concerning the operation of the Dan River Landfill should be directed to the appropriate entity as follows: Owner Duke Energy Carolinas, LCC Dan River Steam Station 900 South Edgewood Road Eden, North Carolina 27288 (336) 635-3160 Facility Contact: Station Sponsor for Landfill Operations or Environmental Professional State Regulatory Agency North Carolina Department of Environmental Quality Division of Waste Management, Solid Waste Section Asheville Regional Office 2090 US Highway 70 Swannanoa, North Carolina 28778 (828) 296-4500 Permitting Engineer: Mr. Larry Frost 1.3 Safety The Dan River Landfill operations were developed with the consideration to the health and safety of the facility’s operating staff. The operating staff will be provided with site-specific safety training prior to landfill operations, and on-site activities are to be conducted according to the applicable sections of Duke’s Safe Work Practices. 1.4 Access and Security Requirements The proposed Dan River Landfill is located entirely within Duke’s property limits. Security for the site is currently in place, consisting of fencing, gates, wooded buffers and security check stations. Unauthorized vehicle access to the site is prevented around the landfill property by security check stations, woods, fencing, gates and stormwater conveyance features. Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 2 of 17 December 24, 2015 The access road to the site will be of all-weather construction and will be maintained in good condition. Potholes, ruts, and debris on the road(s) will receive immediate attention in order to avoid damage to vehicles. 1.5 Operating Hours The Dan River Landfill will be operated seven days a week, as needed. 1.6 Signs A sign providing the landfill permit number and a statement reading, “NO HAZARDOUS OR LIQUID WASTE PERMITTED” will be posted at the site entrance, and shall be maintained in good condition. Edge-of-waste markers will be installed and delineate the edge of waste. These markers shall be maintained in good condition and remain visible at all times. 1.7 Training Due to the diversity and nature of job tasks required at the Dan River Landfill, personnel shall be adequately trained to handle facility operations and maintenance. The Station Sponsor for Landfill Operations shall have a general understanding of all the tasks required for site operations. Individuals performing the various tasks shall have adequate training of the site- specific tasks they are assigned. Duke shall provide a site-specific training program for facility personnel. Noteworthy operations and maintenance tasks to be addressed in training include: ► Maintaining accurate records of waste loading (quantitative and qualitative); ► Operating requirements for stormwater segregation from exposed waste areas; and ► Operating and maintaining the leachate collection system (LCS) and leakage detection system (LDS). All training will be documented and training records will be kept on-site. The Station Sponsor for Landfill Operations will conduct Operations Plan training courses in accordance with the permit requirements. 1.8 Record Keeping An operating record is to be maintained on-site and include the following records: ► Leachate Collection Systems (LCS) – Periodic Maintenance Documentation; ► Leak Detection System (LDS) Monitoring Information and Periodic Maintenance Documentation; ► Leachate Monitoring ► Erosion and Sedimentation Control Inspection Logs; ► Periodic Landfill Inspection Reports; ► Dust Control Plan Monitoring Worksheets (included in the Dust Control Plan); ► Groundwater Monitoring (and Sampling) Documentation; and ► Operations Plan. The above records are to be kept in the operating record for the active life of the landfill and the post- closure care period. Information contained in the operating record must be furnished upon request to the North Carolina Department of Environmental Quality Division of Waste Management, Solid Waste Section (Division) or be made available for inspection by the Division. Additional records kept on-site should include: Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 3 of 17 December 24, 2015 ► Solid waste facility permits; ► Site Suitability Study; ► Permit to Construct Application; ► Landfill drawings and specifications; ► Record of the amount of solid waste received summarized on a monthly basis based on scale records; ► Vacuum truck waste logs; ► Regulatory agency inspection reports; and ► Employee training program and records. 1.9 Design Drawings A list of landfill design drawings is provided in Table 1. The design drawings provide the location of landfill features, landfill construction details, and technical design and construction notes. Drawing No.Title Drawing No.Title C-0.0 Cover Sheet C-6.1 Landfill Closure Grades C-1.1 Site Aerial C-6.2 Landfill Closure Stormwater C-1.2 Site Existing Conditions C-7.1 Potential Stockpile Areas C-2.1 Ash Fill 1 Existing Conditions C-8.1 Bedrock Surface Map C-2.2 Ash Fill 1 Estimated Excavation Grades C-8.2 Groundwater Surface Map C-3.1 Landfill Cell 1 Compacted Soil Liner Subgrade C-9.1 Cross Sections C-3.2 LandfilL Cell 1 Geosynthetic Liner Subgrade D-1.1 General Details 1 C-3.3 Landfill Cell 1 Top of Protective Cover D-1.2 General Details 2 C-3.4 Landfill Cell 1 Leak Detection System D-2.1 LCRS Details 1 C-3.5 Landfill Cell 1 Leachate Collection System D-2.2 LCRS Details 2 C-4.1 Landfill Cell 2 Compacted Soil Liner Subgrade D-2.3 LCRS Details 3 C-4.2 LandfilL Cell 2 Geosynthetic Liner Subgrade D-2.4 LCRS Details 4 C-4.3 Landfill Cell 2 Top of Protective Cover D-3.1 Stormwater Details 1 C-4.4 Landfill Cell 2 Leak Detection System D-4.1 Operations Details 1 C-4.5 Landfill Cell 2 Leachate Collection System D-4.2 Operations Details 2 C-5.1 Landfill Cell 3 Compacted Soil Liner Subgrade D-4.3 Operations Details 3 C-5.2 LandfilL Cell 3 Geosynthetic Liner Subgrade D-5.1 Closure Details 1 C-5.3 Landfill Cell 3 Top of Protective Cover D-5.2 Closure Details 2 C-5.4 Landfill Cell 3 Leak Detection System D-5.3 Closure Details 3 C-5.5 Landfill Cell 3 Leachate Collection System D-5.4 Closure Details 4 D-5.5 Closure Details 5 Table 1: Design Drawings 2 Operations Management The primary objective of operations management at the Dan River Landfill is to dispose of waste material in compliance with permit conditions while operating in a safe manner. The Dan River Landfill will generally be operated from northwest to northeast to south as receipt of Permit to Operate for Landfill Cells 1, 2, and 3 are obtained in general accordance with the Landfill Sequencing Drawings in Appendix II. Waste will be placed in approximate 10-foot lifts. During operations, diversion berms and other features will be utilized to separate leachate from non-contact water. Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 4 of 17 December 24, 2015 The exterior side slopes of the landfill will be constructed to slopes of 3H:1V and will be periodically covered with approximately 12-inches of interim soil cover. Intermediate cover and dust control measures will be implemented as described in the Dust Control Plan. During operations, tack-on benches will be located along exterior side slopes at intervals of approximately 30 vertical feet (90 horizontal feet) to intercept surface water flows and decrease erosion potential. The tack-on benches will convey flow to downdrains which will consist of HDPE pipes installed perpendicular to the landfill side slope contours. The downdrains will convey flow to the channel system located around the perimeter of the landfill and ultimately to the Dan River. 2.1 Waste Handling and Landfill Sequencing 2.1.1 Landfill Capacity The proposed Dan River landfill will be constructed as one phase with three cells. The Dan River Landfill is anticipated to receive waste at a rate of approximately 10,000 cubic yards (cy) per day during closure of on-site coal combustion residual (CCR) units. Assuming an in-place dry density of CCR materials of 1 ton per cubic yard, the disposal rate is approximately 10,000 tons per day. The estimated capacity of the landfill is presented in the following table: Phase Cell Area (ac) Estimated Airspace Volume (cy) Dry Density of CCR (tons/cy) Estimated Disposal Rate (tons/day) Estimated Lifetime (days) Estimated Lifetime1 (years) 1 5.1 179,229 1.0 10,000 18 0.07 2 7.4 522,887 1.0 10,000 52 0.20 3 10.8 1,443,990 1.0 10,000 144 0.56 23.3 2,146,106 --- --- 215 0.83 Table 2: Landfill Capacity 1 TOTALS Notes: 1. Lifetime in years assumes operations occur 5 days per week. The actual quantity of material disposed in the landfill may vary pending CCR unit closure requirements. 2.1.2 Waste Acceptance, Disposal, and Screening Requirements The Dan River Landfill is permitted for the acceptance of the following on-site waste types: ► Coal combustion residuals (CCRs) (including fly and bottom ash, pyrites, and coal mill rejects) generated at Duke facilities; ► Wastewater treatment sludge generated at Dan River Steam Station; ► Vacuum truck waste generated at Dan River Steam Station; ► Waste soils (i.e. from ash removal activities or soil that has contacted petroleum); and ► Small quantities of inert debris from CCR unit decommissioning activities. The Dan River Landfill will not be open for public disposal. The landfill owner or operator shall notify the Division within 24 hours of attempted disposal of any wastes the landfill is not permitted to receive. At a minimum, hazardous waste, yard trash, liquid wastes, regulated medical waste, sharps not properly packaged, polychlorinated diphenyl (PCB) waste as defined in 40 Code of general regulations (CFR) 761, and wastes banned from disposal in North Carolina by General Statute 130A-309.10(f), must not be accepted at the landfill. Asbestos waste will not be disposed of in the landfill. Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 5 of 17 December 24, 2015 The removal of waste from the landfill is prohibited without owner or operator approval. Waste will be hauled and disposed of by dedicated and consistent operators from the waste source to the landfill. Access to the interim waste storage location(s) (i.e. existing ash basins and ash fills), haul routes and landfill are restricted; therefore, no screening of waste is recommended. 2.1.3 Dust, Litter, Odor, and Vector Control Litter, odors, and vectors are not anticipated to be concerns at the Dan River Landfill. The waste placed in the landfill does not attract vectors, and windblown material is not anticipated to be a problem. Odors are typically not a problem at CCR waste landfills. Dust control is addressed in the Dust Control Plan included as Appendix I. Generally, dust control measures will be implemented when necessary, and will include at a minimum, watering of dusty roads and exposed work areas. Other measures include physical measures such as fencing and/or berms, temporary covers (like tarps), spraying dust suppressants, and modifying the active work area. Leachate may be used as a dust suppressant in areas that drain to the leachate collection system (i.e. active face of the landfill) in accordance with the Dust Control Plan. Additionally, interim cover will be vegetated as soon as practical in order to minimize the blowing of dust on-site. 2.1.4 Fire Control No open burning shall be permitted at the Dan River Landfill. There are no explosive gas concerns with ash waste, waste soils, and inert debris from CCR unit decommissioning activities; therefore, the threat of fire is considered to be minimal. Although it is unlikely, if a fire occurs at the landfill, the Station Control Room (phone number: 336-635- 3160) shall be notified, and equipment and stockpiled soil shall be provided to control accidental fires. Dan River Steam Station will notify the local fire department, which will be immediately dispatched to assist with fire control. Any fire that occurs at the landfill shall be reported to the Division within 24 hours, and a written notification will be submitted within 15 days by the Station Sponsor for Landfill Operations. 2.1.5 Landfill Sequencing The Dan River Landfill will be constructed as one phase with three cells as shown in the Landfill Sequencing Drawings in Appendix II. The landfill sequencing drawings illustrate possible sequences of landfill operations. The actual filling sequence, fill heights, and grades may be modified at the Owner’s discretion. 2.1.6 Waste Placement 2.1.6.1 Bottom Ash and Fly Ash Material Bottom ash and fly ash material at the Dan River Station is transported from the interim waste storage areas to the landfill by using on-road or off-road dump trucks. Upon reaching the active face of the landfill, the waste is dumped from the dump trucks onto the active face of the landfill. After the waste is dumped, the dump trucks exit the landfill and return to the interim waste storage areas. The interim waste storage areas, haul roads, and landfill are located within the secured Dan River Steam Station facility. No truck washes are proposed at this time because the haul paths and ash units drain to the existing ash basin. Upon completion of disposal of on-site CCR materials, the haul roads will be remediated by removing the top several inches of road material or as necessary and disposing in a lined facility permitted to receive CCR materials. The landfill surface shall be graded to promote surface water drainage to the leachate collection system (i.e. chimney drains). No waste shall be placed in standing water. Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 6 of 17 December 24, 2015 2.1.6.2 Wastewater Sludge, Pyrites, and Coal Mill Rejects Wastewater sludge, pyrites, and coal mill rejects will be spread in 6-inch lifts in the center of the operational area and shall not be placed within 25 feet of the exterior slopes. Wastewater sludge shall be blended with the other waste (i.e. ash) prior to placement of the next fill lift. Wastewater sludge, pyrites, and coal mill rejects shall be compacted as densely as practical and specific monitoring. In-place density testing of these materials is not required. 2.1.6.3 Vacuum Truck Waste Vacuum trucks are used to remove waste materials from the plant areas that consist of various permitted CCRs. The origin of the vacuum truck waste materials is typically from various sumps, catch basins, wheel wash stations, and coal pile sumps located within the plant. The moisture contents of the vacuum truck waste materials may vary considerably with the waste varying in consistency from a relatively dry state to a wet, fluid-like state depending on the amount of liquid present in the sumps or vacuumed areas. CCR material transported via vacuum truck will occur in a vacuum truck dedicated to Duke Energy operations or documentation will be obtained to ensure that the vacuum truck contains no human or other non-permitted waste streams. Vacuum truck waste could also mean similar waste material transported in smaller water tight units. Vacuum truck waste shall consist of permitted waste materials. Non-permitted waste materials inadvertently included with the vacuum truck waste including but not limited to yard trash (paper, plastic, wood, aluminum, Styrofoam, etc.) shall be visually screened and immediately removed from the vacuum truck waste after the waste material is dumped in the operational area by vacuum contractor. The consistency of the vacuum truck waste may vary from a relatively dry state to a relatively wet, fluid- like state. Vacuum truck waste material shall be moisture conditioned by initial decanting excess moisture from the waste or by mixing the waste with fly ash, bottom ash, or gypsum materials depending on its consistency. The vacuum truck waste shall be placed and spread in maximum 6-inch lifts near the center of the operational area. The vacuum truck waste shall not be placed within 50 feet horizontally from exterior landfill slopes or within 50 feet of chimney drain structure locations. The vacuum truck waste material shall be thoroughly mixed with fly ash, bottom ash, or gypsum material during waste placement using a dozer or other similar grading equipment to provide additional moisture conditioning prior to compaction. In-place density testing of the vacuum truck waste materials is not required. The vacuum contractor shall coordinate vacuum truck waste placement with landfill operator personnel and the vacuum truck waste disposal will be documented. Dust control measures shall be provided for the vacuum truck waste in accordance with the Dust Control Plan outlined in Appendix I. 2.1.7 Compaction Requirements and Testing After the waste is dumped from the trucks and placed on the active face, the waste will be placed in consecutive, approximate 1-foot thick lifts that do not exceed a 10-foot operational lift. Prior to compaction of an existing lift, the existing and new material should be adequately blended. 2.1.7.1 In-Place Density and Moisture Content Testing In-place density and moisture content testing shall be performed at a minimum frequency of one test per 8,000 cubic yards (or one test per 216,000 square feet per 12-inch thick lift). Waste shall be compacted to a minimum 95 percent of its Standard Proctor (ASTM D698) maximum dry density. Compacted moisture content shall be within 5 percent of the material’s optimum moisture content as determined by ASTM D698. In-place density tests shall be performed using the Sand Cone Method (ASTM D1556), Drive-Cylinder Method (ASTM D2937), or Nuclear Method (ASTM D6938). If the nuclear method is selected, a minimum Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 7 of 17 December 24, 2015 of one comparison density test using the Sand Cone or Drive Cylinder method shall be performed for every five nuclear density tests, and correlations between the test methods shall be developed and reviewed by the Engineer. A sample of ash material shall be collected from each density test location and placed in a sealed container for subsequent field and laboratory moisture testing. A family of Proctor curves shall be developed for the on-site ash material as standard Proctor moisture- density tests are performed as a reference for the field density testing. A minimum of one (1) one-point field Proctor test shall be performed for every five field density tests. Additional one-point field Proctors shall be performed if the dry density between successive density tests varies by more than 2 pounds per cubic foot (pcf). If the estimated standard Proctor maximum dry density based on the results of one-point Proctor testing indicates that the maximum dry density varies by more than 5 pcf from the nearest representative standard Proctor moisture-density relationship, an additional bulk sample of ash material shall be obtained and standard Proctor testing shall be performed for the sample as a reference for the field density testing. Field moisture content testing shall be performed for each density test using the Direct Heating Method (ASTM D4959). The Nuclear Method (ASTM D6938) shall not be used for moisture content testing on the ash material. Comparison laboratory moisture content testing shall be performed using the Oven Method (ASTM D2216), at an oven temperature of 60 degrees Celsius. The laboratory moisture content shall control in the event of a discrepancy between laboratory moisture content and in-place moisture content. 2.1.7.2 Laboratory Testing Laboratory moisture content testing shall be performed in conjunction with the field density testing as described above. The laboratory moisture content testing shall be performed using the Oven Method (ASTM D2216), at an oven temperature of 60 degrees Celsius. Standard Proctor moisture-density relationship (ASTM D698) testing shall be performed at a minimum frequency of one test for every 50,000 cubic yards of material placed. As previously mentioned, additional standard Proctor samples shall be obtained and tested if one-point Proctor testing indicates that the estimated maximum dry density of the material varies by more than 5 pcf from the nearest representative standard Proctor moisture-density relationship. 2.1.8 Cover Requirements 2.1.8.1 Operational Cover Operational cover should be applied, as needed, for dust control and stormwater management. If needed, operational cover should be applied at a thickness suited for its purpose. For example, operational cover may be applied thinner to provide dust control and it may be applied thicker to tolerate erosion. Operational covers to provide dust control shall be as described in the Dust Control Plan in Appendix I. Downdrains, tack-on benches, and chimney drains will be installed and extended as appropriate. Soil Diversion berms will be used to direct water as appropriate. Waste will be covered with interim and final cover as applicable, in accordance with the following sections in this plan. Operational cover consisting of soil is not required, provided the Dust Control Plan included as Appendix I is followed. 2.1.8.2 Interim Cover An interim soil cover layer shall be placed at a thickness of approximately 1-foot on exterior slopes and areas where final waste grades have been reached. For areas where waste placement will be inactive for 12 months or more, interim cover will be provided in accordance with the Dust Control Plan included as Appendix I. Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 8 of 17 December 24, 2015 2.1.8.3 Final Cover The final cover system for the Dan River Landfill will be completed within 180 days following the beginning of closure activities unless otherwise approved by the Division. The proposed cover system will consist of the following components, from top to bottom: ► 6-inch thick vegetative soil cover; ► 18-inch thick final cover soil; ► Geocomposite drainage layer (or 8 oz/sy non-woven geotextile alternate); and ► 40-mil thick double-sided textured linear low density polyethylene (LLDPE) geomembrane (or 50- mil LLDPE structured geomembrane alternate); ► Interim cover. The soil components will provide a surface suitable to sustain vegetative growth while protecting the underlying geosynthetic components of the cover system. Infiltration through the cover soils will be collected by the geocomposite drainage layer, while the geomembrane will function as a hydraulic barrier to reduce infiltration into the waste mass. Interim cover shall be as needed to achieve geosynthetic cover system subgrade. The interim cover at the time of final closure may consist of ash. The cover system stormwater management structures will collect both infiltration and surface water runoff. The final cover will be vegetated with grasses within six months following closure. Refer to the Closure and Post-Closure Plan in Appendix III for final cover specifications and maintenance and operations requirements. 2.2 Leachate and Stormwater Management As previously described, the landfill has been designed to provide separation of leachate from stormwater. Leachate includes water that has percolated through the waste as well as surface water flows from the active face of the landfill that are intercepted by chimney drains. The leachate collection system and leak detection system consists of a geocomposite drainage layer and pipe network to convey leachate to sumps located in each landfill cell. Leachate will be pumped from the landfill sumps to a leachate tank storage facility and ultimately to the City of Eden publically owned treatment works (POTW) for treatment or alternative leachate treatment approach as approved by the Division. Stormwater runoff from the proposed landfill will be conveyed to the perimeter channel network via a series of tack-on benches and downdrains. No truck washes are proposed at this time. Transport of existing on-site CCR materials to the Dan River Landfill will occur on Dan River Station property and within areas that currently drain to the existing Primary and Secondary Ash Basins. Loading and unloading of CCR material will be conducted using methods to prevent excessive spillage and tracking of CCR material during transport. Upon completion of hauling on-site CCR materials, haul road surfaces will be remediated as necessary to protect the environment. 2.3 Leachate Collection System (LCS) The leachate collection system has been designed to meet the performance criteria of providing less than 1 foot of leachate head on the liner system under normal operating conditions and conveying leachate generated by the 25-year, 24-hour storm event. The leachate collection system generally consists of the following components: ► Leachate collection system pipes within the landfill; ► Sumps at the low points of each cell of the landfill; and ► Force main and appurtenant structures (pumps, valves, etc.). Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 9 of 17 December 24, 2015 Each landfill cell is equipped with leachate collection system (LCS) pipes located directly above the geocomposite drainage layer that collect infiltration and chimney drain flows. The LCS pipes convey leachate flows by gravity to collection sumps for removal. Clean-outs have been provided at the ends of the leachate header pipes in the event that the leachate collection and removal pipes become clogged. Chimney drains have been installed in each cell and shall be extended vertically along with the placement of each lift. Each chimney drain comprises a vertical, perforated HDPE riser pipe surrounded by filter aggregate. At the base of the chimney drains, the riser pipe connects to a distribution pipe which conveys the flow from the riser pipe into the LCS, via infiltration through a constructed layer of drainage material. During operations, chimney drains may be modified with pipe fittings to allow the chimney drain pipe to drain leachate from the active face. Sumps are located at the low point of the landfill cells. From the sumps, leachate is conveyed to the leachate force main via side slope risers and pumps and ultimately to the City of Eden POTW or alternative leachate treatment approach as approved by the Division. The LCS sump shall be equipped with a dedicated pump system. The pump system shall operate automatically based on level switches with a low level cutoff and high level run-start activations. Additionally, a high level alarm shall be in place which will also have a high level activation. The LCS system control panels will be equipped with visual and audible alarms programmed to activate at the programmed sump liquid level. The alarms will be equipped with a test function. It is anticipated that leachate generated at the Dan River Landfill will ultimately discharge to the City of Eden POTW for treatment or alternative leachate treatment approach as approved by the Division. Plans and specifications for a leachate storage tank facility will be provided to the Section prior to commencement of their construction. 2.3.1 Use of Leachate for Dust Control The following operational requirements shall be followed prior to use of leachate for dust control: ► Use a water truck dedicated for use of leachate as dust control to prevent cross-contamination. ► The water truck shall be marked as dedicated for use of leachate as dust control. ► Ensure that the dedicated water truck is in good working condition and that no leaks are observed prior to filling with leachate. ► Loading of leachate into the water truck shall be performed within a contained area. ► Upon loading, the water truck shall be driven to within the landfill limit of waste of the landfill. ► The water truck shall be parked within the landfill limit of waste of the landfill or in a contained area when not in service. 2.3.2 LCS Maintenance The maintenance of the leachate management system's physical facilities (consisting of high-density polyethylene (HDPE) piping) and records will be performed by or under the direct supervision of Duke. Visual observations of the LCS system performance will be made monthly by Duke staff to verify that the LCS is performing properly. Clean-out pipes will be located on the LCS leachate lateral and header pipes. LCS pipes will be cleaned out by the use of a clean-out snake or high-pressure water flushing at least once a year, and the LCS piping will be remote-camera monitored at least once every 5 years. The frequency of clean-out and camera inspections may be modified based on consecutive inspection results and observed operating conditions. Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 10 of 17 December 24, 2015 2.3.3 LCS Record Keeping and Sampling Records will be maintained documenting the leachate line cleanout and camera monitoring. Untreated leachate shall be sampled and analyzed at least semi-annually concurrently with the groundwater water sampling as discussed in the approved Water Quality Monitoring Plan. 2.3.4 Leak Detection System (LDS) A leak detection system (LDS) has been incorporated into the design of the landfill. The LDS consists of a secondary 60 mil HDPE liner system overlain by a secondary geocomposite drainage layer connected to an LDS sump. Flow collected in the sump will be transferred to the active ash basin via the leachate force main. The LDS sump shall be equipped with a dedicated pump system. The LDS pump system contains one pump. The LDS pump system shall operate automatically based on level switches with a low level cutoff and a high level run-start activation. Additionally, a high level alarm shall be in place which will also have a high level activation. The LDS system control panels will be equipped with visual and audible alarms programmed to identify sump liquid levels. The alarms will be equipped with a test function. The LDS has been designed with an Initial Response Leakage Rate (IRLR) of 300 gallons per acre per day and an Action Leakage Rate (ALR) of 500 gallons per acre per day. Should fluid collected in the LDS exceed the IRLR or ALR based on routine flow meter readings, the owner or operator shall take steps as indicated in the facility’s leachate Response Action Plan presented in Section 2.3.6. The management of the leak detection system’s physical facilities (consisting of piping and flow meters) and monitoring records will be performed by or under the direct supervision of Duke. 2.3.5 Leak Detection System Maintenance The maintenance of the leachate management system's physical facilities (consisting of high-density polyethylene (HDPE) piping, sumps, and pumps) and records will be performed by or under the direct supervision of Duke. Visual observations of the LDS system performance will be made monthly by Duke staff to verify that the LDS is performing properly. Clean-out pipes are located on the LDS leachate lateral and header pipes. LDS pipes will be cleaned out by the use of a clean-out snake or high-pressure water flushing at least once a year, and the LDS piping will be remote-camera monitored at least once every 5 years. The frequency of clean-out and camera inspections may be modified based on consecutive inspection results and observed operating conditions. 2.3.6 Record Keeping and Monitoring Flow will be measured at the discharge of the LDS sump by a totalizing flow meter. The facility shall maintain records of monthly flow rate data from the LDS sump from the activation of the cell drainage system and until the waste height reaches approximately 40 feet. From that point, flow rate data shall be collected on a quarterly basis until landfill closure. During the post-closure care period, semi-annual monitoring is required. If the liquid level in the sump stays below the pump high level run-start (no pump flow) for more than 1 year, then flow rates can be recorded annually. However, if at any time during post-closure care the pump high level run-start level is exceeded on the semi-annual or annual schedules, the facility must return to monthly monitoring, until such time as the liquid level remains below the pump high-level run start activation level for two consecutive months. The purpose of LDS monitoring is to monitor if the leakage rates have been exceeded. Specific leakage rates are identified in Section 2.3.6. To determine if exceedances of the leakage rates have occurred, the facility must convert monitored data to an average daily flow rate for the cell (in gallons per acre per day, gpad). For example, the average daily flow rate in gpad is equal to the total monthly flow rate divided by the number of days in the month, divided by the area of the cell in acres. Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 11 of 17 December 24, 2015 Cell Area (ac) 1 5.1 2 7.4 3 10.8 Table 3: Cell Area If a leakage rate is exceeded, then the Division must be notified as set forth in the Response Action Plan presented in Section 2.3.6. 2.3.7 Response Action Plan The purpose of the Response Action Plan is to describe the necessary course of action in the event the Initial Response Leakage Rate (IRLR) and/or the Action Leakage Rate (ALR) are exceeded. If the IRLR is exceeded, steps 1 through 4 will be followed. Should the ALR also be exceeded steps 1 through 6 will be followed. The IRLR and ALR are referenced collectively as “leakage rates” in the following Response Action Plan steps. The IRLR is 300 gallons per acre per day. The ALR is 500 gallons per acre per day. The estimated monthly volume of leakage triggering an IRLR or ALR response is provided in the following table: Cell Area (ac) Initial Response Leakage Rate {IRLR} (gpad) Monthly Volume1 (gal) Action Leakage Rate {ALR} (gpad) Monthly Volume1 (gal) 1 5.1 300 45,900 500 76,500 2 7.4 300 66,600 500 111,000 3 10.8 300 97,200 500 162,000 Table 4: Leakage Rate Monitoring Initial Response Leakage Rate (IRLR) Notes: 1. Assumes a 30-day month Action Leakage Rate (ALR) If the monthly volumes exceed those for the IRLR and the ALR listed in the table above, the response action steps will include: 1. (IRLR and ALR) - Review physical equipment (pump and flow meter) function and data to confirm flow readings. Review operations to evaluate where operating equipment may have contacted the landfill liner or how landfill operations may have influenced the exceedance. If the exceedance is confirmed, the cell LDS flow shall be recorded daily. Should the daily monitored LDS flow exceed the IRLR or ALR after the initial exceedance, operational responses may include: the reduction of active face area; grading to provide improved drainage; and/or, the addition of interim soil cover. 2. (IRLR and ALR) - Within 14 days of identifying that a leakage rate has been exceeded, the facility shall contact the Division in writing. Daily LDS flow recording shall continue. Should none of the daily measured LDS flow rates exceed the leakage rate within 14 days of initial identification of the exceedance, monthly LDS flow averaging shall resume. 3. (IRLR and ALR) - Within 30 days of identifying that a leakage rate has been exceeded, the facility shall submit to the Division a written preliminary assessment which shall include at a minimum: Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 12 of 17 December 24, 2015 ► the amount of the liquid exceedance including initial measurement and daily measurements, if necessary, to date; ► likely sources of the liquids; ► the possible leak location; ► the possible leak size; ► the probable cause of the leak; and ► an outline of the short-term actions being taken and planned. 4. (IRLR and ALR) - To the extent practicable, evaluate the location, size and cause of the leak; and assess the potential for leakage escaping into the environment and its mobility. Leachate quality shall be sampled, including a chemical analysis of LDS fluids, to evaluate potential hazards (pH and RCRA metals). 5. (ALR only) - When the ALR is exceeded, establish whether or not the unit should be closed or receipt of waste should be curtailed; and conclude whether waste should be removed from the unit for inspection, engineered controls, or repair of the liner and drainage system. Evaluate and prepare to implement what other short-term or long-term measures shall be taken to mitigate or stop any leaks according to the stage (early operations, middle operations, or closed) of landfill development. 6. (ALR only) - Within 60 days of identifying that the ALR has been exceeded, submit to the Division the results of the evaluation performed in Step 4, any actions taken according to Step 5, and any further measures planned. For as long as there is an exceedance of the action leakage rate, the owner or operator shall submit monthly reports to the Division summarizing the results of the remedial actions taken and further actions planned. 2.4 Stormwater Collection and Conveyance Stormwater that does not come in contact with waste will be treated as non-contact water. Non-contact water will be managed separately from leachate and may be used for dust control or other operational purposes. The stormwater collection system has been designed to pass the 50-year, 24-hour storm event, and generally consists of the following components: ► Tack-on benches; ► Downdrains; and ► Perimeter ditches. Interim cover will be placed over waste at the exterior side slopes. Tack-on benches will be placed to convey non-contact surface water from the exterior side slopes to downdrains. The tack-on benches and downdrains will be constructed and extended as operations progress. The downdrains discharge to perimeter ditches, which in turn ultimately discharge to the Dan River via a system of culverts and channels. 2.4.1 Stormwater Discharge The stormwater system at the landfill was designed to assist in prevention of the discharge of pollutants. Landfill operation shall not cause a discharge of pollutants into waters of the United States, including wetlands, that violates any requirement of the Clean Water Act, including but not limited to NPDES requirements, pursuant of Section 402. In addition, under the requirements of Section 404 of the Clean Water Act, the discharge of dredge or fill material into waters of the state would be a violation of the requirements and shall not be allowed by landfill operations. Operations of the landfill shall not cause the discharge of a non-point source of pollution to waters of the United States, including wetlands, that violates any requirements of an area-wide or statewide water Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 13 of 17 December 24, 2015 quality management plan that has been approved under Section 208 or 319 of the Clean Water Act, as amended. 2.5 Stormwater Maintenance Requirements All drainage features (i.e., diversion ditches, berms, risers, discharge pipes, chimney drains, etc.) will be inspected every 7 days and within 24 hours of rainfall events of 0.5 inches or greater, and documented for signs of damage, settlement, clogging, silt buildup, or washouts. If necessary, repairs to drainage control features will be made as early as possible. 2.6 Groundwater Monitoring Well Access Requirements Groundwater monitoring wells will be located around the landfill perimeter. A readily accessible, unobstructed path shall be maintained so that monitoring wells may be accessed using four-wheel drive vehicles. Care must be taken around the wells to prevent any damage to the wells. 2.7 Landfill Gas Management Because the nature of the waste to be placed in the Dan River Landfill, the Owner does not anticipate that methane or hydrogen sulfide gas will be generated or that odor will be an issue during operations. Therefore, landfill gas monitoring and management is not proposed. 3 Erosion and Sediment Control Erosion and sedimentation control (E&SC) during landfill operations will consist of monitoring and repairing E&SC stormwater conveyance features and surface erosion as defined in this Operations Plan and the active Erosion and Sediment Control Plan. 3.1 E&SC Measures Monitoring and Maintenance Erosion control principles include: ► Disturbing as little area as possible at any one time for landfilling operations. ► Seeding/mulching of disturbed areas commencing as soon as practically possible. Employing erosion control matting or seeding and mulch on steep slopes and other erosion prone areas; ► Use of earthen berms, wattles, silt fences, riprap, or equivalent devices down gradient of disturbed areas, stockpiles, drainage pipe inlets and outlets, and at intervals along grassed waterways, until such time as permanent vegetation is established. ► Placement of riprap at the inlets and outlets of stormwater piping. Erosion and sedimentation control structures include stormwater best management practice (BMP) systems, settling basins, and channels. Stormwater BMP’s shall be inspected every 7 days and within 24 hours of rainfall events 0.5 inches or greater. Sediment shall be removed from each structure when sediment accumulates to one half of the design depth. Sediment removal shall bring BMP’s to their original design depth. The BMP’s, embankments, spillways and outlets shall also be observed for erosion damage. Necessary repairs shall be made immediately. Trash or debris within the riser structures or outfalls shall be removed. Channels shall be observed for damage every 7 days and within 24 hours of rainfall events 0.5 inches or greater. Riprap-lined channels and outlet protection aprons used to prevent damage to channel vegetation shall be observed for washouts. Riprap shall be added to those areas, as needed, to maintain the integrity of the structure. Embankment slopes shall be inspected for erosion every 7 days and within 24 hours of rainfall events 0.5 inches or greater. The embankment slopes shall be mowed at least three times a year. The Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 14 of 17 December 24, 2015 embankment slopes shall be fertilized in the second year unless vegetation growth is fully adequate. Damaged areas shall be reseeded, fertilized and mulched immediately. Seeding, fertilizing, and mulching shall be in accordance with the North Carolina Erosion and Sedimentation Control Guidelines and in accordance with the active Erosion and Sediment Control Plan. Ground stabilization shall be performed within 7 calendar days on perimeter areas and slopes greater than 3H:1V. Ground stabilization shall be performed within 14 calendar days in other areas. Seedbed preparation, seeding, soil amendments, and mulching for the establishment of vegetative ground cover will be applied in accordance with North Carolina Erosion and Sedimentation Control Guidelines. 3.2 Surface Erosion Monitoring Adequate erosion control measures shall be practiced to prevent sediment from leaving the site. Channels will be observed once every seven days and within 24 hours after any rainfall event of 0.5 inches or greater. Slopes will be periodically checked for erosion and vegetative quality, fertilized, and mowed. A slope or portion thereof shall be identified as needing maintenance if it meets any one of the following conditions: ► Exposed waste on exterior slopes; ► Areas of cracking, sliding, or sloughing; and ► Areas of seepage Slopes identified as needing maintenance shall be repaired as soon as practical and as appropriate to correct deficiencies. Repair activities may include re-dressing the slope, filling in low areas, and/or seeding. 4 Vegetation Management Within six months after final termination of disposal operations at the site, the area shall be stabilized with vegetation as required by design drawings and the Closure and Post-Closure Plan included in Appendix III. Temporary seeding will be applied as required. Temporary methods of erosion control may be required until permanent cover is established. Mulching, until a vegetative cover is established, can stabilize areas where final grade has been reached. Soil mulching can be achieved using wood chips, straw, hay, asphalt emulsion, jute matting, and synthetic fibers. Mulches allow for greater water retention; reduce the amount of runoff; retain seeds, fertilizer, and lime in place; and improve soil moisture and temperature conditions. 4.1 Temporary Seeding Temporary seeding shall be applied as specified in the current Duke Vegetation Maintenance Implementation Plan (VMIP). Alternatively, temporary seeding will be applied as follows (source: NC Erosion and Sediment Control Planning and Design Manual [June 2006, Revised March 2009]): Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 15 of 17 December 24, 2015 Species Pounds per Acre Rye Grain (Secale cereale)125 Annual Rye 50 Species Pounds per Acre German Millet (Setaria italica)50 Species Pounds per Acre Rye Grain (Secale cereale)125 Table 5A: Temporary Seeding Late Winter to Early Spring - January through April Summer - May through August Fall - September through December Soil Amendment Pounds per Acre Agricultural limestone 2,000 Fertilizer (10-10-10)1,000 Mulch (straw)4,000 Table 5B: Temporary Seeding Soil Amendments Note: Soil amendments are for all-season temporary seeding applications. 4.2 Permanent Seeding Permanent seeding shall be applied as specified in the current Duke Vegetation Maintenance Implementation Plan (VMIP). Alternatively, permanent seeding will be applied as follows (source: NC Erosion and Sediment Control Planning and Design Manual [June 2006, Revised March 2009]): Species Pounds per Acre Kentucky 31 Tall Fescue (Festuca arundinacea)100 Rye Grain (Secale cereale)50 Species Pounds per Acre German Millet (Setaria italica)50 Table 6A: Permanent Seeding Fall to Early Spring - September through April Spring to Summer - May through August Soil Amendment Pounds per Acre Agricultural limestone 4,000 Fertilizer (10-10-10)1,000 Mulch (straw)4,000 Table 6B: Permanent Seeding Soil Amendments Note: Conduct North Carolina Department of Agriculture Soil Test(s). Apply fertilizer and lime pursuant to soil sampling and testing results. Apply minimum 4,000 pounds per acre of straw mulch. Protect steeper slopes (3:1 horizontal to vertical or steeper with erosion control matting. Water (if available), monitor, and maintain. 4.3 Over-Seeding Over seeding will be applied as follows (source: NC Erosion and Sediment Control Planning and Design Manual [June 2006, Revised March 2009] and the current Duke Vegetation Maintenance Implementation Plan (VMIP): Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 16 of 17 December 24, 2015 Species Pounds per Acre Kentucky 31 Tall Fescue (Festuca arundinacea)50 Rye Grain (Secale cereale)25 Species Pounds per Acre German Millet (Setaria italica)25 Species Pounds per Acre Tall Fescue (Festuca arundinacea)50 Rye Grain (Secale cereale)25 Fall - September through December Table 7: Over-Seeding Late Winter to Early Spring - January through April Summer - May through August Note: Cut the existing turf to be over-seeded to an approximate 1-inch height. Aerate the soil and turf area to be over-seeded. Apply soil amendments pursuant to prior soil sampling and nutrient testing. 5 Landfill Closure The Dan River Landfill will be closed in accordance with the design drawings and Closure and Post- Closure Plan included in Appendix III. The Closure and Post-Closure Plan outlines the sequence for closing the landfill and the post-closure maintenance activities. Closure is designed to minimize the need for long-term maintenance and control the post-closure release of contaminants. Closure activities may be revised as appropriate for materials, specifications, technology advancements, or changes in regulations at the time the landfill is closed or in post-closure. In general, the landfill development is designed so that final cover can be established as soon as practical. Operations Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 17 of 17 December 24, 2015 6 Required Regulatory Submittals Submittal Requirement Reporting/Action Frequency Groundwater Monitoring Reports Maintain a record of all monitoring events and analytical data in accordance with the Water Quality Monitoring Plan. Reports of the analytical data for each water quality monitoring sampling event shall be submitted to DENR Division of Waste Management (DWM) within 60 days of sampling event. Semiannually Annual Tonnage Reports Tons of waste received and disposed of in the landfill shall be reported to the DWM and to all counties from which waste was accepted on forms prescribed by the DWM. Refer to the Permit to Operate for annual reporting requirement information. Annually Must submit no later than August 1 each year 10-Year Waste Management Plan Per North Carolina G.S. 130A-309.09D (c): ► A 10-year waste management plan shall be developed for this landfill and submitted to DWM. ► The plan shall be updated and submitted to DWM at least every three years. ► A report on the implementation of the plan is required to be submitted to DWM by August 1 of each year. 10-year plan prepared every 10 years 10-year plan updated every 3 years Implementation report annually Table 8: Required Regulatory Submittals APPENDIX I Dust Control Plan Dust Control Plan Dan River Landfill Duke Energy – Dan River Steam Station Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 To: Duke Energy Carolinas, LLC Date August 26, 2015 From: Amec Foster Wheeler Amec Foster Wheeler Project No. 7810140065 TOC August 26, 2015 Table of Contents 1 INTRODUCTION AND SITE DESCRIPTION ........................................................................................ 1 2 DUST CONTROL METHODS ............................................................................................................... 1 3 MONITORING AND CORRECTIVE ACTION RESPONSE .................................................................. 2 3.1 Monitoring ...................................................................................................................................... 2 3.2 Corrective Action Response .......................................................................................................... 2 List of Figures Figure 1 Dust Control Monitoring Grid List of Attachments Dust Control Monitoring Worksheet Dust Control Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 1 of 3 August 26, 2015 1 Introduction and Site Description This Dust Control Plan is for the Dan River Landfill at Duke Energy’s Dan River Steam Station. This Plan provides dust control methods for managing dust emissions at the landfill. The Plan also provides a monitoring program and corrective action responses to contain coal combustion residuals (CCR’s) on site and to prevent dust nuisances to employees and the public. The monitoring program will aid Duke Energy and the landfill operator in evaluating the dust control methods, or combination of dust control methods, that prove effective with site specific conditions. The Dan River Landfill is principally used for CCR management. CCR’s disposed of in the Dan River Landfill will predominantly consist of fly and bottom ash and is defined in Section 2.1.2 of the Operations Plan. This Plan is included as an Appendix to the Dan River Landfill Operations Plan. Please refer to the Operations Plan for a description of revisions as necessary. 2 Dust Control Methods The primary potential source of dust emissions in the landfill is the top deck area and active area of waste placement. These areas are at a higher risk for producing dust due to vehicular and equipment traffic and earthworks like construction. Exterior landfill slopes are less of a dust control concern, as they have intermediate or operational soil covers which are vegetated as required in the Operations Plan. Dust emissions from the landfill can be controlled through a variety of dust control methods. Possible dust control methods are identified herein. Dust control methods may be characterized as products and/or applications, structural wind breaks and/or covers, and operational methods. Dust control methods for the landfill area include: ► Watering; ► Potable or non-potable water (all areas); ► Leachate (areas within the limit of waste footprint that drain to the leachate collection system only i.e. active face); ► Establishing vegetative cover; ► Mulching; ► Structural controls consisting of: ► Wind breaks (i.e. fencing and/or berms); and ► Temporary coverings (i.e. tarps); ► Spray applied dust suppressants consisting of, and not limited to: ► Anionic asphalt emulsion; ► Latex emulsion; ► Resin in water; ► Polymer based emulsion; and ► Mineral mortar coatings (i.e. posi-shell); ► Calcium chloride; ► Soil stabilizers (i.e. soil cements); ► Operational soil cover; ► Modifying the active working area; and ► Modifying operations during dry and windy conditions. Dust Control Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 2 of 3 August 26, 2015 The operator may use, and is not limited to, combinations of these dust control methods or any method that is technically sound to control dust for specific site conditions. If the operator intends to use a dust control method not presented above, the proposed dust control method will be evaluated on a case by case basis to assess the effectiveness with specific site conditions. For the purposes of this Plan, operational soil cover will be defined as soil material applied at a suitable thickness to provide dust control. The effectiveness of the dust control methods implemented should be evaluated through a dust monitoring program outlined in Section 3. Operational equipment generally consists of dump trucks, vibratory smooth drum rollers, sheepsfoot compactors, bulldozers, water trucks, spray trailers, track hoes, and service trucks. Operational equipment will be used to construct, install, apply, and/or repair dust control methods. The operator will make provisions to alleviate any on-site issues that arise when primary equipment is being maintained or is inoperable. In the event that the landfill site contains multiple facilities in the future, the landfill operator will make provisions to have the necessary equipment to control multiple fugitive CCR dust emission events. 3 Monitoring and Corrective Action Response This section describes the dust monitoring program and suggests corrective action responses should fugitive emissions be observed. 3.1 Monitoring During landfill operations, a dust monitoring program will be implemented to evaluate the dust control measure performance and observe the areas for dust emissions. The dust monitoring program will consist of performing visual observations of dust prone areas, dust control measures, and monitoring existing and forecasted weather conditions. Dust emissions can occur under many conditions. For the purposes of this Plan, dust emissions are characterized as fugitive emissions, where CCR dust may be transported outside the limit of landfill waste. This is most likely to occur during windy, dry, and hot weather conditions. Therefore, the operator will monitor both existing and forecasted weather conditions and use dust control measures accordingly. The dust control measures shall be implemented prior to the forecasted weather conditions. Equipment operators shall continuously observe the active face and other areas within the landfill limit for dust emissions. In addition, preventative dust control measures should be observed and documented at least twice daily (morning and afternoon) when the landfill is in operation, to evaluate the dust control measure performance. Additional observations may be necessary as site and weather conditions dictate. Observations will be documented on the attached “Monitoring Worksheet,” or online database/worksheet, etc. Due to the continual maintenance necessary on moisture conditioned and spray-applied areas, the operator shall pay particular attention to these areas. Structural controls shall be observed to monitor that they are achieving their intended purpose. Observations in the landfill area may be made with reference to the Operations Grid system shown in the attached Figure 1. Monitoring will be conducted during times when the landfill is in operation. The operator shall continue to provide necessary dust control measures during periods when operations are inactive (i.e. outages, weekends, and holidays). Operators are to establish appropriate measures so that dust emissions are not reasonably likely to occur during inactive operation periods when monitoring is not being conducted. 3.2 Corrective Action Response If fugitive dust emissions are observed and observations indicate dust control measures are not achieving their intended purpose, then appropriate corrective actions will be taken. Dust control measures should be reapplied, repaired, or added, as necessary, to control dust emissions. The operator will construct, Dust Control Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 3 of 3 August 26, 2015 install, apply, and/or repair dust control measures prior to the end of the work day to control dust emissions during non-operating hours. The operator will implement dust control measures as preventative controls rather than in response to fugitive dust emissions. FIGURES DAN RIVER LANDFILL DUST CONTROL MONITORING GRID LANDFILL SUBGRADE REV. NO.: 0 DATE:08/26/2015 PROJECT NO: 7810-14-0065 FIGURE No. 1AS SHOWNUTM Zone 0 PROJECTION: NAD99 DATUM:DWN BY: CHK'D BY: SCALE: CHR RFK PROJECT TITLE DUKE ENERGY CAROLINAS ROCKINGHAM COUNTY, NC CLIENTCLIENT LOGO 2801 YORKMONT ROAD, SUITE 100 CHARLOTTE, NC 28208 PHONE 704-357-8600, FAX 704-357-8638 LICENSURE: NC ENG: F-1253 NC GEOLOGY: C-247 Amec Foster Wheeler Environment & Infrastructure, Inc. N ATTACHMENTS Da n R i v e r L a n d f i l l Pe r m i t N o . T B D Du s t C o n t r o l M o n i t o r i n g W o r k s h e e t Dan River Steam Station Eden, North Carolina Da t e / T i m e D u s t C o n t r o l M e t h o d i n U s e Ef f e c t i v e Ye s / N o Ob s e r v a t i o n Lo c a t i o n Pr e v e n t a t i v e o r Co r r e c t i v e A c t i o n Ta k e n Y e s / N o Ob s e r v a t i o n s / c o m m e n t s i n c l u d i n g : w e a t h e r co n d i t i o n s , w i n d s p e e d s , p r e c i p i t a t i o n , fo r e c a s t , p r e v e n t a t i v e o r c o r r e c t i v e a c t i o n s ta k e n ( i f n e e d e d ) , a d d i t i o n a l o p e r a t i o n a l no t e s Name of Observer APPENDIX II Landfill Sequencing Drawings DAN RIVER LANDFILL LANDFILL OPERATIONS SEQUENCE 1 CELL 1 PROTECTIVE COVER GRADES REV. NO.: 0 DATE:08/26/2015 PROJECT NO: 7810-14-0065 FIGURE No. 1AS SHOWNUTM Zone 0 PROJECTION: NAD99 DATUM:DWN BY: CHK'D BY: SCALE: CHR CSJ PROJECT TITLE DUKE ENERGY CAROLINAS ROCKINGHAM COUNTY, NC CLIENTCLIENT LOGO 2801 YORKMONT ROAD, SUITE 100 CHARLOTTE, NC 28208 PHONE 704-357-8600, FAX 704-357-8638 LICENSURE: NC ENG: F-1253 NC GEOLOGY: C-247 Amec Foster Wheeler Environment & Infrastructure, Inc. N DAN RIVER LANDFILL LANDFILL OPERATIONS SEQUENCE 2 CELL 1 INTERIM WASTE, CELL 2 INITIAL CONDITIONS REV. NO.: 0 DATE:08/26/2015 PROJECT NO: 7810-14-0065 FIGURE No. 2AS SHOWNUTM Zone 0 PROJECTION: NAD99 DATUM:DWN BY: CHK'D BY: SCALE: CHR CSJ PROJECT TITLE DUKE ENERGY CAROLINAS ROCKINGHAM COUNTY, NC CLIENTCLIENT LOGO 2801 YORKMONT ROAD, SUITE 100 CHARLOTTE, NC 28208 PHONE 704-357-8600, FAX 704-357-8638 LICENSURE: NC ENG: F-1253 NC GEOLOGY: C-247 Amec Foster Wheeler Environment & Infrastructure, Inc. N DAN RIVER LANDFILL LANDFILL OPERATIONS SEQUENCE 3 CELLS 1 AND 2 INTERIM WASTE, CELL 3 INITIAL CONDITIONS REV. NO.: 0 DATE:08/26/2015 PROJECT NO: 7810-14-0065 FIGURE No. 3AS SHOWNUTM Zone 0 PROJECTION: NAD99 DATUM:DWN BY: CHK'D BY: SCALE: CHR CSJ PROJECT TITLE DUKE ENERGY CAROLINAS ROCKINGHAM COUNTY, NC CLIENTCLIENT LOGO 2801 YORKMONT ROAD, SUITE 100 CHARLOTTE, NC 28208 PHONE 704-357-8600, FAX 704-357-8638 LICENSURE: NC ENG: F-1253 NC GEOLOGY: C-247 Amec Foster Wheeler Environment & Infrastructure, Inc. N DAN RIVER LANDFILL LANDFILL OPERATIONS SEQUENCE 4 FINAL COVER GRADES REV. NO.: 0 DATE:08/26/2015 PROJECT NO: 7810-14-0065 FIGURE No. 4AS SHOWNUTM Zone 0 PROJECTION: NAD99 DATUM:DWN BY: CHK'D BY: SCALE: CHR CSJ PROJECT TITLE DUKE ENERGY CAROLINAS ROCKINGHAM COUNTY, NC CLIENTCLIENT LOGO 2801 YORKMONT ROAD, SUITE 100 CHARLOTTE, NC 28208 PHONE 704-357-8600, FAX 704-357-8638 LICENSURE: NC ENG: F-1253 NC GEOLOGY: C-247 Amec Foster Wheeler Environment & Infrastructure, Inc. N APPENDIX III Closure and Post-Closure Plan Closure and Post-Closure Plan Dan River Landfill Duke Energy – Dan River Steam Station Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 To: Duke Energy Carolinas, LLC Date December 24, 2015 From: Amec Foster Wheeler Amec Foster Wheeler Project No. 7810140065 TOC December 24, 2015 Table of Contents 1 INTRODUCTION ................................................................................................................................... 1 1.1 Project Information ........................................................................................................................ 1 2 CLOSURE PLAN ................................................................................................................................... 1 2.1 Description of Cover System ......................................................................................................... 1 2.1.1 Vegetative Soil Cover ................................................................................................................ 1 2.1.2 Final Cover Soil ......................................................................................................................... 1 2.1.3 Geocomposite Drainage Layer ................................................................................................. 2 2.1.4 Geomembrane .......................................................................................................................... 2 2.1.5 Interim Cover ............................................................................................................................. 2 2.2 Gas Management System ............................................................................................................. 2 2.3 Stormwater Management System ................................................................................................. 2 2.4 Largest Area Requiring Cover System ......................................................................................... 2 2.5 Estimated Maximum Waste Inventory........................................................................................... 2 2.6 Closure Schedule .......................................................................................................................... 2 3 POST-CLOSURE PLAN ........................................................................................................................ 3 3.1 Maintenance Activities .................................................................................................................. 3 3.2 Monitoring Activities ...................................................................................................................... 3 3.2.1 Groundwater and Surface Water Monitoring............................................................................. 4 3.3 Facility Contact Information ........................................................................................................... 4 3.4 Post-Closure Planned Use ............................................................................................................ 4 3.5 Certification ................................................................................................................................... 4 List of Figures Figure 1 Site Vicinity Map – USGS Figure 2 Site Vicinity Map – Aerial Figure 3 Post-Closure Monitoring Grid List of Appendices Appendix I Example Post-Closure Monitoring Form Appendix II Cost Estimate for Closure and Post-Closure Activities Closure and Post-Closure Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 1 of 4 December 24, 2015 1 Introduction This Closure and Post-Closure Plan is being submitted as part of the Construction Plan Application and was prepared for the proposed Dan River Landfill in accordance with Title 15A Subchapter 13B of the North Carolina Administrative Code (NCAC) to meet the requirements of .0503(2), .0504(2), and .0505 for industrial landfills; and substantive requirements of Rules .1627-.1629 for municipal solid waste (MSW) landfills. The proposed Dan River Landfill is an industrial landfill and therefore some of the requirements of Rules .1627-.1629 do not apply. The information contained in this plan will be used to assist Duke Energy Carolinas, LLC (Duke) in the closure of active waste units and the maintenance and monitoring required during the post-closure care period. 1.1 Project Information Duke Energy intends to construct an industrial landfill on Dan River Steam Station property. The proposed landfill will be located largely within the footprint of existing Ash Fill 1 on the northeastern end of the property. The ash within Ash Fill 1 will be removed prior to construction of the proposed landfill. The proposed landfill will be bounded by existing overhead electrical lines to the west and north, rail lines to the east, and a natural gas pipeline to the south. 2 Closure Plan The landfill cover system has been designed to reduce infiltration into the landfill and to resist erosion. The proposed landfill cover system components, size, and closure schedule are described in the following sections of this report. 2.1 Description of Cover System The proposed cover system will consist of the following components, from top to bottom: ► 6-inch thick vegetative soil cover; ► 18-inch thick final cover soil; ► Geocomposite drainage layer (or 8 oz/sy non-woven geotextile alternate); ► 40-mil thick double-sided textured linear low density polyethylene (LLDPE) geomembrane (or 50- mil LLDPE structured geomembrane alternate); and ► Interim cover layer. The soil components will provide a surface suitable to sustain vegetative growth while protecting the underlying geosynthetic components of the cover system. Infiltration through the cover soils will be collected by the geocomposite drainage layer, while the geomembrane will function as a hydraulic barrier to reduce infiltration into the waste mass. Interim cover shall be as needed to achieve geosynthetic cover system subgrade. The interim cover at the time of final closure may consist of ash. The cover system stormwater management structures will collect both infiltration and surface water runoff. The final cover will be vegetated with grasses within six months following closure. 2.1.1 Vegetative Soil Cover The vegetative soil layer will consist of 6 inches of soil materials capable of sustaining vegetation, which will preserve the integrity of the cover system by preventing erosion. The vegetative cover layer will not be subjected to compaction requirements. 2.1.2 Final Cover Soil The final cover soil layer will consist of 18 inches of soil materials which will be compacted as specified in the Specifications. The final cover soil layer will protect the geosynthetic components of the cover system and reduce infiltration. Closure and Post-Closure Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 2 of 4 December 24, 2015 2.1.3 Geocomposite Drainage Layer A geocomposite drainage layer will be located beneath the final cover soil layer. The geocomposite will promote veneer stability and reduce infiltration through the closed landfill by conveying infiltration to regularly spaced geocomposite outlets. The alternate cover system option includes an 8 oz/sy non-woven geotextile which will provide soil separation and allow infiltration into the underlying 50-mil LLDPE structured geomembrane. 2.1.4 Geomembrane A 40-mil thick double-sided textured LLDPE geomembrane barrier will be installed between the geocomposite drainage layer and the interim cover to prevent infiltration through the closed landfill. The geomembrane will have texturing on both sides to improve veneer stability. The alternate cover system option includes a 50-mil LLDPE structured geomembrane to prevent infiltration through the closed landfill. The structured component allows drainage and is an integral component of the geomembrane. 2.1.5 Interim Cover Interim cover will be placed during landfill operations prior to cover system construction as necessary to control fugitive dust. Interim cover will consist of soil or an approved alternative. 2.2 Gas Management System The majority of waste disposed in the Dan River Landfill will consist of CCR materials, predominantly fly ash and bottom ash. Based on the nature of CCR materials and our experience it is not anticipated that landfill gases such as methane or hydrogen sulfide gas will be generated or that nuisance odors will be an issue. Therefore, Duke does not propose monitoring for landfill gas or landfill gas management measures. In the event that methane or hydrogen sulfide gases are detected during landfill operations, appropriate actions will be taken. In the event that gases are regularly detected during active landfill operations, the final closure and post-closure plan will be modified to address gas. It is anticipated that a minimum response would be to provide a passive gas venting system with the final closure. 2.3 Stormwater Management System The proposed Dan River Landfill is designed with a network of stormwater conveyances accounting for active landfill operations, interim closure, and final closure conditions. Upon final closure, stormwater will be collected by tack-on benches and conveyed to a series of down-drain pipes which will discharge to the perimeter channel system. Plans and details illustrating the stormwater management system are provided in the Engineering Plan drawings. 2.4 Largest Area Requiring Cover System The proposed Dan River Landfill will be operated until closure, and future expansions are not anticipated at this time. The largest area requiring cover system construction is the entire footprint of the proposed landfill which is approximately 23.3 acres. 2.5 Estimated Maximum Waste Inventory The proposed landfill design provides approximately 2,150,000 cubic yards of airspace as measured from the top of the protective cover soil following subgrade construction to the bottom of the interim cover following completion of CCR placement. Assuming a compacted CCR dry density of 1.0 tons per cubic yard, the available dry tonnage capacity of the proposed landfill is approximately 2,150,000 tons. 2.6 Closure Schedule Following the completion of waste placement, a final cover system will be constructed. The primary purpose of a final cover system is to minimize infiltration into the waste. The proposed final cover system cross section is presented in the Engineering Plan Drawings. Closure and Post-Closure Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 3 of 4 December 24, 2015 Final closure of the landfill will commence when final design grades are achieved, Duke declares that no more waste will be accepted, or as directed by the North Carolina Department of Environmental Quality (NCDEQ) Division of Waste Management – Solid Waste Section (the Division). Duke may elect to close the landfill incrementally during landfill operations once an area large enough to warrant cover system construction has reached final grades. Prior to beginning closure of the proposed landfill, the Owner or Operator shall notify the Division that a notice of intent to close the landfill has been placed in the operating record. Closure activities for the landfill shall begin no later than 30 days after final receipt of waste unless otherwise approved by the Division or, if the landfill has remaining capacity and there is a reasonable likelihood that the landfill will receive additional wastes, no later than one year after the most recent receipt of wastes. Extensions beyond the one-year deadline for beginning closure may be granted by the Division if the Owner or Operator demonstrates that the landfill has the capacity to receive additional wastes and the Owner or Operator has taken and will continue to take the steps necessary to prevent threats to human health and the environment from the unclosed landfill. The final cover system will be finished within 180 days following the beginning of closure activities unless otherwise approved by the Division. Extensions of the closure period may be granted by the Division if the Owner or Operator demonstrates that closure will, of necessity, take longer than 180 days and they have taken and will continue to take the necessary steps to prevent threats to human health and the environment from the unclosed landfill unit. The final cover system for the closed phase will be certified by a professional engineer as being completed. Duke Energy shall record a notation on the deed to the landfill property stating that the property has been used as a landfill and its use is restricted under the Closure/Post-Closure Plan approved by the Division. The Division will be notified by Duke Energy of the closure completion, certification, deed notation, and placement of these records into the landfill’s operating record. Following cover system construction, the landfill will be vegetated with grass and maintained. If the landfill must be closed prior to reaching the final contours, the surface of the landfill will be sloped to a minimum grade of 5 percent and maximum grade of 33.33 percent (3H:1V). A final cover will be established over the landfill unit being closed. 3 Post-Closure Plan The Post-Closure Plan outlines the monitoring and maintenance activities intended to maintain cover system integrity during the post-closure care period. During the post-closure period, the landfill cover system and related facilities must be monitored and maintained. 3.1 Maintenance Activities Maintenance activities will be conducted as soon as practical to address items of concern identified during monitoring events. Mowing will occur at a minimum twice per year, other maintenance activities will be performed as needed and are anticipated to include the following: ► Filling in animal burrows and re-locating the animal; ► Localized placement of fill to prevent ponding of water caused by differential settlement; ► Removal of trees or brushy vegetation within the cover system limits; ► Vegetative cover shall be amended and fertilized as needed to maintain healthy vegetation; and ► Repair of stormwater conveyance measures. Any disturbed areas will be seeded and soil amendments applied as necessary to establish a healthy vegetative cover. 3.2 Monitoring Activities Post-closure monitoring events will be conducted quarterly for the first two years and semi-annually thereafter during the post-closure care period. Post-closure monitoring will include a review of the following: ► The condition of site security features such as gates and/or fencing; Closure and Post-Closure Plan Duke Energy – Dan River Steam Station Dan River Landfill Eden, North Carolina Amec Foster Wheeler Project No. 7810140065 Page 4 of 4 December 24, 2015 ► Evidence of erosion, settlement, and/or animal burrows within the cover system; ► Type and quality of vegetation within the cover system; ► Evidence of erosion and integrity of stormwater conveyance features; and ► Integrity of the leachate collection and removal system (LCRS). Example forms that may be used to document the monitoring events are included in Appendix I. The post-closure grades, stormwater features, and grid are shown on Figure 3 which may be used to assist with post-closure monitoring. Completed post-closure forms will be maintained in the facility operating record. 3.2.1 Groundwater and Surface Water Monitoring Groundwater and surface water monitoring requirements are described in the Groundwater Monitoring Plan, submitted under separate cover. 3.3 Facility Contact Information Duke will be responsible for post-closure maintenance and monitoring. Correspondence regarding the Dan River Landfill should be directed to: Duke Energy Carolinas, LCC Dan River Steam Station 900 South Edgewood Road Eden, North Carolina 27288 (336) 635-3160 Station Sponsor for Landfill Operations or Environmental Professional The physical address of the proposed Dan River Landfill is the same as above. 3.4 Post-Closure Planned Use The Dan River Landfill will be vegetated following closure. Site access to the public will remain restricted through landfill closure and the post-closure care period. There are no current anticipated post-closure uses for the proposed Dan River Landfill. Duke Energy will obtain approval from NCDEQ if a proposed post-closure use is identified. 3.5 Certification Consistent with regulations, the end of the closure/post-closure care period must be certified by a registered professional engineer. To accomplish certification over the required 30-year duration, a registered professional engineer will prepare annual certifications. The annual certifications will document that the cover system has been monitored and maintained in accordance with the Post-Closure Plan. The annual certifications shall be based on observations and results documented on regular post-closure monitoring reports, maintenance records, and compliance monitoring reports maintained in the Operating Record. FIGURES PREPAREDBY DATE CHECKEDBY DATE JOB NUMBER FIGURE 17810-14-0065 Source: Rockingham County GIS Copyright:© 2013 National Geographic Society, i-cubed r CHR 7/20/2015 CJ 7/20/2015 SITE VICINITY MAP - USGSDAN RIVER LANDFILLDUKE ENERGYROCKINGHAM COUNTY, NORTH CAROLINA 0 2,000 4,0001,000 Feet Legend Proposed Dan River Landfill Limit of Waste Dan River Station Property Boundary PREPAREDBY DATE CHECKEDBY DATE JOB NUMBER FIGURE 27810-14-0065 Source: Rockingham County GIS Source: Esri, DigitalGlobe, GeoEye, i-cubed, Earthstar Geographics,CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP,swisstopo, and the GIS User Community r CHR 7/20/2015 CJ 7/20/2015 SITE VICINITY MAP - AERIALDAN RIVER LANDFILLDUKE ENERGYROCKINGHAM COUNTY, NORTH CAROLINA 0 2,000 4,0001,000 Feet Legend Proposed Dan River Landfill Limit of Waste Dan River Station Property Boundary APPENDIX I Example Post-Closure Monitoring Form Da t e / T i m e : Ob s e r v a t i o n P e r s o n n e l : We a t h e r / T e m p e r a t u r e : Qu e s t i o n N o Y e s I f y e s , l o c a t i o n D e s c r i p t i o n Co r r e c t i v e A c t i o n s Re c o m m e n d e d Date Corrected Is t h e r e e v i d e n c e o f e r o s i o n , se t t l e m e n t , r u t t i n g , o r p o t h o l e s ? Is t h e r e e v i d e n c e o f c o v e r s y s t e m in t r u s i o n ( r u t s , b u r r o w s , ex c a v a t i o n ) ? Is t h e r e e v i d e n c e o f s t r e s s e d ve g e t a t i o n o r b a r e s p o t s , o r ev i d e n c e o f w o o d y v e g e t a t i o n (s m a l l t r e e s a n d / o r s h r u b s ) ? Is t h e r e e v i d e n c e o f e r o s i o n o r se d i m e n t a t i o n i n s t o r m w a t e r ch a n n e l s , d o w n d r a i n p i p e s , o r ot h e r s t o r m w a t e r f e a t u r e s ? Du k e E n e r g y - D a n R i v e r L a n d f i l l Po s t - C l o s u r e M o n i t o r i n g F o r m 1 / 2 Da t e / T i m e : Ob s e r v a t i o n P e r s o n n e l : We a t h e r / T e m p e r a t u r e : Qu e s t i o n N o Y e s I f y e s , l o c a t i o n D e s c r i p t i o n Co r r e c t i v e A c t i o n s Re c o m m e n d e d Date Corrected Du k e E n e r g y - D a n R i v e r L a n d f i l l Po s t - C l o s u r e M o n i t o r i n g F o r m Is t h e r e e v i d e n c e o f p e n e t r a t i o n s (p o l e s , p o s t s , s t a k e s ) ? Is t h e r e e v i d e n c e o f h u m a n en c r o a c h m e n t ( t r a s h , f i r e p i t s , ti r e / f o o t p r i n t s ) ? Ge n e r a l N o t e s : 2 / 2 APPENDIX II Cost Estimate for Closure and Post-Closure Activities Item No.Description Estimated Quantity Units Unit Cost Total Cost 1 Mobilization / demobilization 1 EA $443,069.47 $443,069.47 2 Surveying 1 EA $147,689.82 $147,689.82 $590,759.29 3 Silt fence 4,274 LF $3.50 $14,959.81 4 Wattles 43 EA $110.00 $4,730.00 5 Sediment basins 2 EA $15,000.00 $30,000.00 6 Temporary seeding (2d quantity)11.65 AC $1,400.00 $16,310.00 7 Permanent seeding (2d quantity)23.3 AC $1,400.00 $32,620.00 $98,619.81 8 Demolition/disposal of interim stormwater measures 23.3 AC $1,000.00 $23,300.00 9 Subgrade preparation 23.3 AC $1,500.00 $34,950.00 10 Final cover soil layer (18-inch thick compacted fill)56,386 CY $5.50 $310,123.00 11 Vegetative soil layer (6-inch thick un-compacted fill)18,795 CY $11.00 $206,748.67 12 Slope access road surfacing 60,000 SF $0.85 $51,000.00 $626,121.67 13 Anchor trench (includes markers)4,274 LF $6.00 $25,645.40 14 40-mil textured LLDPE geomembrane (2d quantity)1,014,948 SF $1.11 $1,126,592.28 15 Geocomposite drainage layer (2d quantity)1,014,948 SF $0.54 $548,071.92 $1,700,309.60 16 Tack-on benches 11,616 LF $25.00 $290,400.00 17 Downdrains 1,080 LF $190.00 $205,200.00 18 Downdrain outlet structures 3 EA $2,500.00 $7,500.00 19 Geocomposite outlet at perimeter 4,274 LF $6.00 $25,645.40 $528,745.40 $3,544,555.77 20 Design, permitting, and CQA 23.3 AC $15,500.00 $361,150.00 21 Contingency (assumed 15% of construction costs)1 EA $531,683.36 $531,683.36 $892,833.36 $4,437,389.13 $190,445.89 Subtotal - Earthwork Cost Estimate for Closure and Post-Closure Activities Table 1 - Estimate of Closure Costs Duke Energy - Dan River Landfill Rockingham County, North Carolina August 26, 2015 General Erosion and Sediment Control Subtotal - General Subtotal - Erosion and Sediment Control / Stormwater Management Earthwork Subtotal - Additional Costs TOTAL ESTIMATE OF CLOSURE COSTS ESTIMATE OF CLOSURE COSTS PER ACRE Geosynthetics Subtotal - Geosynthetics Stormwater Management Subtotal - Stormwater Management Subtotal - Final Cover System Construction Costs Additional Costs Item No.Description Estimated Quantity Units Unit Cost Total Cost 1 Senior Professional (80 hours/year @ $100/hr)30 YR $8,000.00 $240,000.00 2 Technician (40 hours/year @ $70/hour)30 YR $2,800.00 $84,000.00 3 Clerical (8 hours/year @ $45/hour)30 YR $360.00 $10,800.00 $334,800.00 4 Fencing, Gates, Signs, Etc.30 YR $500.00 $15,000.00 5 Access Roads 30 YR $1,000.00 $30,000.00 6 Mowing ($100/acre per quarter over 23.3 acres)30 YR $9,320.00 $279,600.00 7 Stormwater Structures 30 YR $2,500.00 $75,000.00 8 Leachate Collection and Disposal 30 YR $1,000.00 $30,000.00 9 Final Cover System ($1,500/acre over 5.8 acres)2 30 YR $8,700.00 $261,000.00 $690,600.00 $1,025,400.00 10 $153,810.00 $1,179,210.00 $50,609.87 $39,307.00 $1,687.00 Cost Per Year (Includes 15% Contingency) Cost Per Acre Per Year (for 23.3 acres) Notes: 1. Assumes quarterly monitoring and reporting, preparation of annual report, and managing site activities. 2. Assumes erosion repair and seeding for 25 percent of the cover annually. 30 Year Total 30 Year Total per Acre (for 23.3 acres) Subtotal - Closure and Post-Closure Activities Additional Costs Contingency (assumed 15% of subtotal) Administration/Inspection/Recordkeeping1 Subtotal - Administration/Inspection/Recordkeeping Maintenance Subtotal - Maintenance Cost Estimate for Closure and Post-Closure Activities Table 2 - Estimate of Post-Closure Maintenance Costs Duke Energy - Dan River Landfill Rockingham County, North Carolina August 26, 2015 Item No.Description Estimated Quantity Units Unit Cost Total Cost 1 Senior Professional (24 hours/year @ $100/hr)30 YR $2,400.00 $72,000.00 2 Technician (16 hours/year @ $70/hour)30 YR $1,120.00 $33,600.00 3 Clerical (4 hours/year @ $45/hour)30 YR $180.00 $5,400.00 $111,000.00 4 Approx. 10 Well Pairs (20 Wells) and 4 Surface Water Samples Tested Semi-Annually for 30 Years 60 EVENT $42,000.00 $2,520,000.00 5 Leachate Sampling Semi-Annually for 30 Years 60 EVENT $500.00 $30,000.00 $2,550,000.00 $2,661,000.00 6 $399,150.00 $3,060,150.00 $131,336.91 $102,005.00 $4,377.90 30 Year Total 30 Year Total per Acre (for 23.3 acres) Cost Per Year (Includes 15% Contingency) Cost Per Acre Per Year (for 23.3 acres) Cost Estimate for Closure and Post-Closure Activities Table 3 - Estimate of Post-Closure Corrective Action Costs Duke Energy - Dan River Landfill Rockingham County, North Carolina August 26, 2015 Compliance Monitoring and Reporting Subtotal - Compliance Monitoring and Reporting Sampling and Analysis Subtotal - Sampling and Analysis Subtotal - Post-Closure Corrective Action Costs Additional Costs Contingency (assumed 15% of subtotal)