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HomeMy WebLinkAbout5803_MadisonCounty_CDLF_ClosurePlan_DIN26261_20160603.pdfPage 1 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 CLOSURE AND POST-CLOSURE PLAN Madison County Landfill Construction & Demolition Landfill–Unit 2 Madison County, North Carolina Chapter 1 Overview The final cap system for Unit 2 of the Construction and Demolition Landfill (CDLF) located at the Madison County Landfill Facility will be constructed in a progressive manner. As substantial areas of the landfill are brought to final grade, the cap system will be constructed in order to minimize infiltration of stormwater, control erosion, and establish and maintain a vegetated cap. The proposed CDLF Unit 2, which covers a total area of approximately 4.3 acres, is estimated to reach capacity in 2029. 1.1 Cap Construction A detail of the final cap is shown in Figure 2. The post-settlement slopes of the final cap will be at a minimum of five percent and a maximum of 25 percent. The cross-section will consist of an 18-inch low permeable layer and a vegetative supportive layer with a minimum thickness of 18 inches, constructed as follows:  An 18-inch thick low permeability soil placed directly on top of the waste or intermediate cover. This soil layer shall have a permeability less than or equal to the original soils underlying the landfill or a permeability no greater than 1.0 x 10-5 cm/sec, whichever is less.  An eighteen (18)-inch thick minimum vegetative\erosion layer capable of sustaining native plant growth. 1.2 Methane Gas Removal System A methane venting system will be constructed in the final cap of CDLF, Unit 2. The locations of the methane vents and a detail describing the construction of the vents are shown on Figures 1 and 2. 1.3 Final Vegetative Layer The final vegetative layer will be a total of 18-inches thick. The soil cover will provide support for native vegetation and protect the low permeability barrier. 1.3a - Materials Required A grass cover is proposed for the Landfill to provide the required cover while minimizing cap maintenance. The surface will be prepared by fertilizing and placing seed in accordance with the North Carolina Erosion and Sediment Control Standards. The final cover will be constructed of native soils. Although the material will not be required to have a specific classification or Page 2 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 permeability, it should be a cohesive soil capable of supporting native vegetation. The upper 6 inches of the final cover should be topsoil. i. Fertilizer: The final cover material shall be tested prior to spreading to determine the amount of fertilizer that should be added to achieve optimum growth potential of the required vegetative cover. The quality of fertilizer and all operations in connection with the furnishing of this material shall comply with the requirements of the North Carolina Fertilizer Law and regulations adopted by the North Carolina Board of Agriculture. Fertilizer shall be 10-10-10 grade. Upon written approval of the Engineer a different grade of fertilizer may be used, provided the rate of application is adjusted to provide the same amounts of plant food. During handling and storing, the fertilizer shall be cared for in such a manner that it will be protected against hardening, caking, or loss of plant food values. Any hardened or caked fertilizer shall be pulverized to its original conditions before being used. ii. Lime The final cover material shall be tested prior to spreading to determine the amount of lime that should be added to achieve optimum growth potential of the required vegetative cover. The quality of lime and all operations in connection with the furnishing of this material shall comply with the requirements of the North Carolina Lime Law and regulations adopted by the North Carolina Board of Agriculture. During the handling and storing, the lime shall be cared for in such a manner that it will be protected against hardening and caking. Any hardened or caked lime shall be pulverized to its original condition before being used. Lime shall be agriculture grade ground dolumitic limestone. It shall contain not less than 85% of the calcium and magnesium carbonates and shall be of such fineness that at least 90% will pass a No. 10 sieve and at least 50% will pass a No. 100 sieve. Page 3 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 ii. Seed: The quality of seed and all operations in connection with the furnishing of this material shall comply with the requirements of the North Carolina Seed Law and regulations adopted by the North Carolina Board of Agriculture. Seed shall have been approved by the North Carolina Department of Agriculture or any agency approved by the Engineer before being sown, and no seed will be accepted with a date of test more than nine (9) months prior to the date of sowing. Such testing however, will not relieve the Contractor from responsibility for furnishing and sowing seed that meets these specifications at the time of sowing. When a low percentage of germination causes the quality of the seed to fall below the minimum pure live seed specified, the Contractor may elect, subject to the approval of the Engineer, to increase the rate of seeding sufficiently to obtain the minimum pure live seed contents specified, provided that such an increase in seeding does not cause the quantity of noxious weed seed per square yard to exceed the quantity that would be allowable at the regular rate of seed. During handling and storing, the seed shall be cared for in such a manner that it will be protected from damage by heat, moisture, rodents, or other causes. Seed shall be entirely free from bulblets or seed of Johnson Grass, Nutgrass, Sandbur, Wild Onion, Wild Garlic, and Bermuda Grass. The specifications for restricted noxious weed seed refers to the number per pound, singly or collectively, of Blessed Thistle, Wild Radish, Canada Thistle, Corncockle, Field Bindwee, Quackgrass, Dodders, Dock, Horsenettle, Bracted Plantain, Buckhorn or Wild Mustard; but in no case shall the number of Blessed Thistle or Wild Radish exceed 27 seeds of each per pound. No tolerance on weed seed will be allowed. iv. Mulch: Straw mulch shall be threshed straw of oats, rye or wheat free from matured seed of obnoxious weeds or other species which would grow and be detrimental to the specified grass. 1.3b - Construction Requirements Final cover shall be placed according to the following requirements: i. The final 6 inches of final cover shall be spread by utilizing small equipment with a relatively low ground pressure. This will reduce the potential of the underlying layers of the final cap being damaged. Prior to placing final soil layer, shape the underlying soil layer to graded lines and cross sections to provide for 6 inches of vegetative supportive soil. Clear the underlying soil layer of materials larger than 2” in diameter. Page 4 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 ii. After alignment of the underlying soil, loosen and till to a depth of 6 inches by disking, harrowing, rototilling, or other approved methods to assure that the final soil layer properly adheres to the underlying soil layer. iii. After the condition of the underlying soil layer has been approved by the on-site CQA personnel, place and spread final layer to achieve required depth after compaction; rake and remove materials larger than 2 inches. Compact with approved roller equipment, grade to finished tolerances, and prepare the seedbed in accordance with the approved CDLF Unit 2, Technical Specifications. Seed, fertilizer and lime shall be applied according to the following: Seed shall be applied by means of a hydro-seeder or other approved methods. The rates of application of seed, fertilizer and limestone shall be as stated below, unless pre- construction testing is contrary to these rates and can be documented. All rates are in pounds per acre: Fertilizer - 1000 lbs. per acre Lime - 4,000 lbs. per acre KY-31 Fescue - 100 lbs. per acre Straw mulch – 60 to 80 bales For summer seeding the following shall be added:  German Millet - 10 lbs. per acre  Sudangrass – 15 lbs. per acre For winter seeding the following shall be added:  Rye grain – 15 lbs. per acre For steep slopes the following shall be added:  Sericea Lespedeza – 40 lbs. per acre Equipment to be used for the application, covering or compaction of limestone, fertilizer, and seed shall have been approved by the Engineer before being used on the project. Approval may be revoked at any time if equipment is not maintained in satisfactory working condition, or if the equipment operation damages the seed. Limestone, fertilizer, and seed shall be applied within 24 hours after completion of seedbed preparation unless otherwise permitted by the Engineer, but no limestone or fertilizer shall be distributed and no seed shall be sown when the Engineer determines that weather and soil conditions are unfavorable for such operations. Limestone may be applied as a part of the seedbed preparation, provided it is immediately worked into the soil. If not so applied, limestone and fertilizer shall be distributed Page 5 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 uniformly over the prepared seedbed at the specific rate of application and then harrowed, raked, or otherwise thoroughly worked or mixed into the seedbed. Seed shall be distributed uniformly over the seedbed at the required rate of application, and immediately harrowed, dragged, raked, or otherwise worked so as to cover the seed with a layer of soil. The depth of covering shall be as directed by the Engineer. If two kinds of seed are to be used which require different depths of covering, they shall be sown separately. When a hydraulic seeder is used for application of seed and fertilizer, the seed shall not remain in water containing fertilizer for more than 30 minutes prior to application unless otherwise permitted by the Engineer. Immediately after seed has been properly covered, the seedbed shall be compacted in the manner and degree approved by the Engineer. Mulch shall be applied according to the following: It shall be spread uniformly at the rate given above and in a continuous blanket over the areas specified. Before mulch is applied on cut or fill slopes which are 3:1 or flatter, and ditch slopes, the Contractor shall remove and dispose of all exposed stones in excess of 2 inches in diameter and all roots or other debris which will prevent proper contact of the mulch with the soil. Mulch shall be applied within 24 hours after the completion of the seeding unless otherwise permitted by the Engineer. Care shall be exercised to prevent displacement of soil or seed or other damage to the seeded area during the mulching operations. Mulch shall be uniformly spread by hand or by approved mechanical spreaders or blowers that will provide an acceptable application. An acceptable application will be that which will allow some sunlight to penetrate and air to circulate but also partially shade the ground, reduce erosion, and conserve soil moisture. Mulch shall be held in place by applying a sufficient amount of approved binding material to assure that the mulch is properly held in place. The rate and method of application of binding material shall meet the approval of the Engineer. Where the binding material is not applied directly with the mulch, it shall be applied immediately following the mulch operation. The Contractor shall take sufficient precautions to prevent mulch from entering drainage structures through displacement by wind, water, or other causes and shall promptly remove any blockage to drainage facilities that may occur. Page 6 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 1.3c - Construction Quality Assurance Requirements Madison County will ensure that the materials described above are utilized for the final cap and that their placement is done in accordance with the above detailed Construction Requirements. The project engineer will ensure that the materials and methods described above are utilized to construct the final cover system, and that all requirements of the Site Specific Construction Quality Assurance Plan are met. A Site Specific Construction Quality Assurance Plan for the construction of the final cap of Unit 2 C&DLF, dated July 2009, has been prepared in accordance with section 15A NCAC 13B .0541 of the Solid Waste Rules. Page 7 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 Chapter 2 On-Site Inventory 2.0 On-Site Waste Inventory The original disposal airspace for the C&DLF Unit 2 is 152,470 c.y. This is calculated from the record drawing elevations for the base of the landfill to the top of cap contours shown in the permit drawings. The volume of the cap is 3ft. x 187,600 sq. ft., or 20,850 c.y. Therefore, the net available airspace for disposal of construction and demolition waste and daily and intermediate cover for Unit 2 is 131,600 c.y. At the time of closure, assuming a waste compaction density of 0.5 tons per cubic yard, the amount of construction and demolition waste on site is estimated to be 65,800 tons. A ground topographic survey was conducted at the Madison County Unit 2 C&DLF on May 1, 2015 to determine the volume of airspace utilized in the C&D cell. The results of the survey show that approximately 55,900 c.y. of landfill airspace has been used at the site from the opening of Unit 2 in November 2006 through the time of the survey. Based on scale records, approximately 21,161.63 tons of waste was disposed during this time. The C&D waste stream is currently less than what was anticipated at the time of the construction of the C&D cell. Based on current waste disposal rates and a compaction rate of 0.40 tons/cy, the Unit 2 C&DLF is projected to be utilized through the Spring of 2029. Page 8 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 Chapter 3 Closure Schedule 3.0 Closure Schedule 3.1 Notification of Division of Solid Waste Prior to beginning closure of the Unit 2 Construction and Demolition Landfill at the Madison County Landfill, the County will notify the Division of Waste Management that a notice of the intent to close the unit has been placed in the operating record. Probable Date of Closure: Spring 2029 3.2 Begin Closure Madison County will begin closure activities of the CDLF Unit 2 no later than 30 days after the date on which the CDLF unit receives the known final receipt of wastes or, if the CDLF unit has remaining capacity and there is a reasonable likelihood that the CDLF unit 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 CDLF unit has the capacity to receive additional wastes and the owner or operator has taken and will continue to take all steps necessary to prevent threats to human health and the environment from the unclosed CDLF unit. Probable Date: Summer 2029 3.3 Completion of Closure Madison County will complete closure activities of the CDLF Unit 2, in accordance with the closure plan within 180 days following the beginning of closure. 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 all steps to prevent threats to human health and the environment from the unclosed CDLF unit. Probable Date: Fall 2029 3.4 Recording of Closure Following closure of the CDLF Unit 2, Madison County will record a notation on the deed to the landfill facility property, or some other instrument that is normally examined during a title search, and notify the Division that the notation has been recorded. The notation on the deed must in perpetuity notify any potential purchaser of the property that: 1. The land has been previously used as a landfill facility; and Page 9 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 2. Its use is restricted under the Division of Solid Waste approved Closure Plan Probable Date: Early 2030 3.5 Engineer’s Certification Following closure, Madison County shall notify the Division of Solid Waste that a certification, signed by the project engineer verifying that closure has been completed in accordance with the closure plan, has been placed in the operating record. Page 10 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 Chapter 4 Financial Assurance 4.0 Financial Assurance The Financial Assurance provision of Section .0546 of the Solid Waste Management Rules (15A NCAC 13B) requires that owners and operators of Construction and Demolition Landfills (CDLF) must provide for certain minimum measures to insure that the funds to meet the requirements of the regulations governing closure, post-closure and corrective action activities are available in the event that these actions are not taken by the owner or operator. 4.1 North Carolina Solid Waste Rule, Section .0546 In general, Section .0546 provides that the owner and/or operator must: 1. Provide accurate third-party cost estimates for the closure, post-closure care, and potential corrective actions. 2. Select a mechanism for demonstrating financial assurance. 3. Maintain the selected mechanism in compliance with the provisions of Section .0546 throughout the period for which the owner/operator is subject to the provisions of the North Carolina Solid Waste Management Rules (15A NCAC 13B). The Rule provides for the following alternative mechanisms for demonstrating financial assurance: 1. Trust Fund. 2. Surety bond Guaranteeing Payment or Performance. 3. Letter of Credit. 4. Insurance. 5. Capital Reserve Fund. 6. Local Government Financial Test. 7. Multiple Mechanisms. Madison County has reviewed the requirements associated with each of these mechanisms and assessed the costs related to their use as the County‘s financial assurance mechanism. Although the relative cost of these mechanisms does not appear to vary significantly, there are various factors associated with their availability and practicality, which make certain of the mechanisms less attractive than others. 4.2 Local Government Financial Test Therefore, Madison County has elected to adopt the LOCAL GOVERNMENT FINANCIAL TEST. The Local Government Financial Test is attractive because the County’s excellent financial condition makes passing the test quite feasible. Madison County has not had any difficulties passing the LOCAL GOVERNMENT FINANCIAL TEST in recent years and there are not any circumstances that would indicate that this would change. Page 11 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 Chapter 5 Post Closure Plan 5.0 Post Closure Plan 5.1 Inspections Inspections of the final cover will be performed according to the table below and the condition of the facility will be recorded with notes, maps, and photographs. Madison County personnel will be on-site to perform inspections on a frequent basis. The inspection will take notice of: 1. Eroded banks 2. Patches of dead vegetation 3. Animal burrows 4. Subsidence (settlement) 5. Cracks along the cover. 6. Catch basins and stormwater control facilities 7. Ground water monitoring wells Areas showing subsidence, cracking, signs of erosion or damage are to be repaired. Schedule of Inspections Years (Following closure) Minimum Yearly Inspections 0-2 4 3-30 2 5.2 Maintenance The vegetative cover will be mowed at least one time a year. In the early stages of development, fertilization will be applied annually as needed. Seeding of any patches of dead vegetation and proper filling and compaction of any portion of the cap showing subsidence, cracking, or other signs of erosion will be conducted in a timely manner. Proper repair of any potential erosion problems found to be present during inspection of catch basins, piping, pipe inlets and outlets, and other stormwater control facilities will be conducted in a timely manner. Page 12 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 5.3 Planned Use and Personal Contact Preliminary proposals for the planned use of the landfill facility, following Closure are inconclusive. No definite plan has been determined as of yet. Most likely, the area will be restricted to landfill maintenance personnel only, thus insuring little or no damage to the final cap system. The person to contact regarding the facility during the Post-Closure period is: Mr. James Harris - Manager Madison County Solid Waste Department 271 Craig Rudisill Road Marshall, North Carolina 28753 Telephone (828) 649-2311 5.4 Water Quality/Environmental Monitoring Plan A Design Hydrogeologic Report and Environmental Monitoring Plan for the Construction and Demolition Landfill Unit 2 were prepared by Bunnell-Lammons Engineering, Inc (BLE) as part of the Permit to Construct package. The environmental monitoring plan satisfies the requirements of 15A NCAC 13B .0543 (e)(1)(B) and will continue to be utilized by the Madison County Landfill Staff ground and surface water monitoring. As part of the Environmental Monitoring Report, a new down gradient monitoring well, MW-9, was installed below the Unit2 waste area. The existing monitoring well, MW-6R, will be used as the upgradient well. Groundwater monitoring wells will monitored on a semi-annual basis, in accordance with Section 15A NCAC 13B .0544(b) of the Solid Waste Rules. The post-closure care period shall be 30 years, except as provided under 15A NCAC 13B .0543(e)(2). As part of the Environmental Monitoring Plan, surface water monitoring point in the vicinity of the Unit 2 Construction and Demolition Landfill are monitored on a semi-annual basis, in accordance with Section 15A NCAC 13B .0544(c) of the Solid Waste Rules. SW-1 and SW-2 are located upstream and downstream of the waste area as shown on Figure 2 of the Environmental Monitoring Plan. Madison County will continue to monitor the surface water locations during the 30-year post-closure care period as required by the Solid Waste Rules, except as provided under 15A NCAC 13B .0543(e)(2). 5.5 Engineer’s Certification Following completion of the post-closure care period, Madison County shall notify the Division of Solid Waste that a certification, signed by the Project Engineer verifying that post-closure care has been completed in accordance with this post-closure plan, has been placed in the operating record. Page 13 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 Chapter 6 Closure and Post Closure Cost Estimates 6.0 Closure and Post Closure Cost Analysis and Summary 6.1 Closure Costs Estimate Unit 2 (4.3 ACRES) – Closure Item 1 Earthwork Unit Cost Total a. 10,340 C.Y. 18” Vegetative Cover $6.00 /C.Y. $62,040 b. 10,340 C.Y. 18” Low Permeability layer $8.00 /C.Y. $82,720 Item 2 Sedimentation and Erosion Control a. 4.3 AC. Grassing $1,800.00 /A.C. $7,740 b. 750 Tons Rip Rap $51.00 /Tons $38,250 c. 1,000 L.F. Synthetic Lined Channels $15.30 /L.F. $15,300 Item 3 Methane Gas Vents a. 17 Each Gas Vents $2,000/ Each $34,000 Item 4 Engineering a. Design $35,000 b. Construction Quality Assurance $30,000 Item 5 Permit Fee $1,500 Item 6 Contingency (10%) $31,000 Total $337.550 Page 14 Closure and Post-Closure Plan Unit 2 C&DLF Madison County Revised June 2016 6.2 Post-Closure Costs Estimate Unit 2 (4.3 ACRES) – Annual Post Closure Care Item 1 Environmental Monitoring Unit Cost Total a. 2 Wells Groundwater Monitoring $500.00/Well $2,000 (2 sampling events/year, includes final report) b. 2 Point Surface Water Monitoring $500.00/Each $2,000 (2 sampling events/year, includes final report) Item 2 Routine Annual Maintenance a. 4.3 AC. Grassing Mowing $50.00 /AC. $215 (1 cut/year) b. 1 Each Repair of Cap $2,500 /Each $2,500 (0.25 acre repair, 1 foot depth) c. 4.3 AC. Re-seeding $1,000 /AC. $4,300 Item 3 Annual Permit Fee $500 Item 4 Contingency (10%) $1,000 Total Yearly Cost $12,515 30-Year Closure Period $375,450 6.3 Potential Assessment and Corrective Action Cost Estimate Total $2,000,000