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HomeMy WebLinkAbout6403_NashCDLF_PTOapplicPh5_20210721GARRETT / & MOORE� Engineering for the Power and Waste Industries July 20, 2021 Donna Wilson North Carolina Department of Environment and Natural Resources Division of Waste Management Solid Waste Section 1646 Mail Service Center Raleigh, North Carolina 27699-1646 RE: Nash County C&D Landfill Phase 5 Expansion Permit No. 6403-CDLF-2000 CQA Certification Ms. Wilson: Please find the attached Construction Quality Assurance Report for the Phase 5 portion of the Nash County C&D Landfill. The required Limit of Waste markers will be placed prior to operation of Phase 5. Additionally, Nash County is currently installing a 4'-high protective soil berm between adjacent access roads and the Phase 5 excavation as a safety precaution. We are requesting immediate approval to operate Phase 5 since available capacity at Nash County is severely limited at this time. Thank you for your assistance and consideration. Please do not hesitate to let me know if you need anything to facilitate your review. Sincerely, GARRETT & MOORE, INC. Craig M. Fortner, P.E. Project Manager 1029 W. South Street, Raleigh, North Carolina 27603 • O: 919-792-1900 • F: 866-311-7206 Construction Quality Assurance Report Phase 5 of the Nash County C&DLF Permit No. 6403-CDLF-2000 July 21, 2021 GAPLRETT ZAF & MOORE ffl!221 Engineering for the Power and Waste Industries 1029 W. South Street Raleigh, North Carolina 27603 • O: 919-792-1900 • F: 866-311-7206 NC FIRM C-2910 This page intentionally left blank CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF Project Certification: Based on the observations and results of the CQA program documented herein, it is our professional opinion that the construction of the Phase 5 expansion of the Nash County C&DLF was completed in accordance with the following: The conditions of the Permit to Construct for Phase 5 ii. The approved CQA Plan iii. The requirements of 15A NCAC 13B .0540 iv. Accepted Engineering practices ``,�►11111i1111110 a SEAL e 129929 Craig M. Fortner, P.E. July 20, 2021 Garrett & Moore, Inc. NC Firm C-2910 Page i CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF CONTENTS 1.0 INTRODUCTION....................................................................................................... 1 2.0 RESPONSIBILITIES AND AUTHORITIES................................................................ 1 2.1 OWNER................................................................................................................. 1 2.2 ENGINEER/CQA ENGINEER................................................................................ 1 2.3 CONTRACTOR ........................................ ERROR! BOOKMARK NOT DEFINED. 2.4 SURVEYOR........................................................................................................... 1 3.0 INSPECTION ACTIVITIES........................................................................................ 1 3.1 EROSION AND SEDIMENT CONTROL................................................................2 3.2 LANDFILL CELL SUBGRADE CONSTRUCTION ................................................. 2 4.0 RECORD DRAWINGS.............................................................................................. 3 5.0 CONCLUSION..........................................................................................................4 ATTACHMENTS: 1. CONSTRUCTION QUALITY CONTROL RECORDS 2. AS -BUILT SURVEY 3. PHOTOGRAPHS Page i This page intentionally left blank CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF 1.0 INTRODUCTION The Nash County C&DLF is located at 3057 Duke Road, Nashville, North Carolina. A Permit to Construct for Phase 4-9 of the Nash County C&DLF was issued by the North Carolina Division of Waste Management (NCDWM) on May 3, 2017. This Construction Quality Assurance (CQA) Report documents CQA activities performed during construction of Phase 5 of the Nash County C&DLF. Nash County staff performed the excavations associated with establishing the Phase 5 base grades during ongoing C&DLF disposal operations. Figure 1 presents the current topography of Phase 5 with cross sections illustrating deviation from the permitted Phase 5 base grades. The Phase 5 area of the Nash County C&DLF as certified herein consists of 2.3 acres and provides approximately 207,800 cubic yards of airspace. 2.0 RESPONSIBILITIES AND AUTHORITIES The following parties were involved in the construction and CQA of Phase 4. 2.1 OWNER Nash County PO Box 849 Nashville, NC 27856 Contact: William Hill, Nash County Health Director Phone: (252) 459-9823 2.2 ENGINEER/CQA ENGINEER Garrett & Moore, Inc. 1029 W. South Street Raleigh, NC 27603 Contact: Craig M. Fortner, P.E. Phone: (919) 815-4221 2.3 SURVEYOR Sorrell Land Surveying, Inc. 107 Union Drive, Suite 101 Washington, NC 28586 Contact: Hugh Sorrell, PLS Phone: (252) 948-2464 3.0 INSPECTION ACTIVITIES Inspection activities for Landfill Cell Subgrade Construction included the following: Page 1 of 4 CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF 3.1 EROSION AND SEDIMENT CONTROL The construction of the erosion and sediment control measures took place in conjunction with project activities and under the site permits issued by North Carolina Depart of Environmental Quality (NCDEQ), Division of Energy, Mineral and Land Resources during Phase 4 C&DLF development. No additional stormwater infrastructure and erosion and sedimentation controls are required for the operation of the Phase 5 C&DLF. 3.2 LANDFILL CELL SUBGRADE EXCAVATION Inspection activities for Landfill Cell Subgrade Construction included: • Craig Fortner, PE of Garrett & Moore visited the site periodically during excavation of Phase 5 for the purpose of inspecting disposal cell subgrade conditions. Mr. Fortner visited the site on the following dates: o May 20, 2019 o June 17, 2019 o February 11, 2020 o June 24, 2020 o July 9, 2020 o March 4, 2021 o April 29, 2021 o July 7, 2021 • Proof rolling of excavated portions of the cell was observed and documented by Garrett & Moore staff on July 7, 2021. • Subgrade soils within 2-feet below the constructed Phase 5 floor were confirmed to be USCS soil type ML and characterized as dense clayey silt with isolated '/2" rock fragments by the visual -manual classification method. • Craig Fortner, PE reviewed the as -built survey point prepared by Sorrell Land Surveying, Inc. and confirmed the following with respect to the permitted Phase 5 C&DLF base grades: o Phase 5 floor elevation is higher than the permitted Phase 5 floor, thereby providing additional separation from the approved seasonal high water table. See additional discussion in Section 4. Page 2 of 4 CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF o Phase 5 sideslopes on the southern edge have been excavated beyond the horizontal extent of the permitted Phase 5 base grades as illustrated in Figure 1. See additional discussion in Section 4. Photographs of the Phase 5 base grades are included as Attachment 2 to this report. No backfill was required to establish Phase 5. 4.0 ENGINEERING DISCUSSION 4.1 DEVIATION FROM APPROVED GRADES The final constructed grades of the Phase 5 C&DLF expansion deviate from permitted grades both vertically and horizontally. As constructed, the Phase 5 grades are higher than the permitted grades. With the Phase 5 grades remaining higher than the permitted maximum excavation, additional separation from the approved seasonal high water table is provided. Figure 1 presents the constructed grades relative permitted grades and the permitted seasonal high water table. Figure 1 also illustrates the extent to which Phase 5 was over -excavated horizontally on the southern portion of Phase 5. The additional horizontal excavation is more steep relative to the permitted Phase 5 subgrade slopes of 3H:1 V. 4.2 REVISED PHASED 5 AREA AND CAPACITY Phase 5 as constructed, adds approximately 2.3 acres of disposal footprint and 207,800 CY of disposal capacity. This represents approximately +0.2 acres of disposal area and +7,800 CY of disposal capacity beyond that recognized in the Permit to Construct (PTC) for Phase 5. It is noted that the additional Phase 5 disposal area is completely within the permitted waste footprint illustrated in the approved Facility Plan. When considered in conjunction with Phase 4, the total disposal capacity provided represents a net reduction of the capacity approved in the PTC. Figure 1 presents a tabulation of the deviation from permitted areas and volumes for Phase 4 and Phase 5. 4.3 SOUTHERN EMBANKMENT STABILITY Excavation at the southern limit of Phase 5 has resulted in slopes steeper than the permitted 3H:1 V. As constructed, slopes along this embankment range from near- 0.5H:1 V (with isolated heights of up to 3-feet) to approximately 2H:1 V. The current condition of the slope is considered temporary, as the initial lift of C&D waste will buttress the slope. Page 3 of 4 CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF Stability analysis of the cut slope yields a minimum global factor of safety (FS) of 2.3, which is considered acceptable for both short-term and long-term conditions. The slope stability evaluation is included as Attachment 3. Nash County will install a 4' tall stabilized earthen berm between the access road and the cut slope as a safety measure against vehicles going off the access road and into the Phase 5 base grades. 5.0 RECORD DRAWINGS An as -built subgrade survey for Phase 5 of the Nash County C&D Landfill is shown in Attachment 1 to this report. Reference is made to Figure 1 which presents the local context for the as -built survey. 6.0 CONCLUSION Based on the observations and results of the CQA program documented herein, it is our professional opinion that the construction of the Phase 5 of the Nash County C&DLF was completed in accordance with the following: i. The conditions of the Permit to Construct for Phase 5 ii. The approved CQA Plan iii. The requirements of 15A NCAC 13B .0540 iv. Acceptable Engineering practices. Page 4 of 4 OD N OU OU O OU r OU D CD E \ CD 0 O O L_ O U) C O a X w T) CD U) s U) z C O N U) C O O_ X T) CD U) c- a c- U) z U O O � _ Q n2 �� ��� / . �/ // /� ✓ / � 1 I II l I l ll 17 o // c/lll�i � �A �/ l `t' �230 l I l /11All�i((1illy � l )/ill 17 lcu (PHASE v � II lk �2oo \ \ \ Roz GRADES SHOWN REPRESENT AN ENGINEERING SURVEY PERFORMED ON MARCH 4, 2021. \ 280 270 260 250 240 230 220 210 200 190 PHASE AND CAPACITY ANALYSIS PERMITTED FINAL COVER GRADES PERMITTED PROPOSED PERMITTED PROPOSED PHASE PHASE PHASE PHASE AREA AREA NET DISPOSAL NET DISPOSAL PHASE (AC) (AC) CAPACITY (CY) CAPACITY (CY) J to PHASE 4 3.7 3.7* 133,000 100,200* Q PERMITTED INTERMEDIATE OVER GRADES PHASE 5 2.1 2.3 200,000 207,800 IL to pES Ep�p,T� pES RM� TOTAL 5.8 6.0 333,000 308,000 PERMITTED VALUES FROM APPROVED FACILITY PLAN, TABLE 1. Lu �a 5 �N� 05E 5 O ER RM E PERMITTED PHASE 4 INTERMEDIATE COVER GRADES *DENOTES ASBUILT CONDITION °C N pa D pHpsE PERMITTED C&DLF HORIZONTAL --------- -------- -- ---- -- --- -------- -------- --------- ENGINEERING SURVEY ION BASE G ESa --_- ------ - - -_-EXPAN , MARCH 4, 2021 - _______ ASB ILT PHASE 4A/ B BASE GRADS--- PHASE 4B PHASE 5 P SE 4 PERMITrED SEASONAL. HIGH GROUN WATER 1 +00 2+00 SECTION A -Al 3+00 4+00 5+00 �.``Pe �N CAg04 eeeeeeeee O e � e 4 SEAL e 029929 _ i r 0a `I 9 JULY 20, 2021 J 0) co E �N 0 �co cq� �m 0V� c� r— � z0 `ts 0 o� T .cm W L0 q W CW n U a0 J a �� Z UDC W d 0 280 z a v, 270 z WL O 260 250 z W 240 230 Y ♦ cn 0 220 w a� 210 200 En GRAPHIC SCALE 1' = I W 0 100 200 FIGURE 1 CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF ATTACHMENT AS -BUILT SURVEY CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF ATTACHMENT PHOTOGRAPHS CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF Photo 2 — Proofroll, northwest view Photographs Page 1 of 3 CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF Photo 3 — Phase 5, northern view from access road Photographs Page 2 of 3 CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF _ r - a Mir Ww ,� tY Photo 4 — Aerial of Project (March 2021) Photographs Page 3 of 3 CONSTRUCTION QUALITY ASSURANCE REPORT PHASE 5 OF THE NASH COUNTY C&DLF ATTACHMENT STABILITY ANALYSIS Nash Co. C&DLF P5 Excavation Global Stability v:\nash\projects\phase 5 - operations\nash ph5 input.p12 Run By: Craig Fortner, Garrett & Moore, Inc 7/20/2021 02:30PM # FS Soil Soil Total Saturated Cohesion Friction Piez. Load Value a 2.30 Desc. Type Unit Wt. Unit Wt. Intercept Angle Surface L1 250psf b 2.45 No. (pcf) (pcf) (psf) (deg) No. c 2.48 Silt 1 110.0 110.0 0.0 26.0 0 d 2.49 PWR 2 120.0 120.0 200.0 34.0 0 e 2.51 C&D 3 60.0 60.0 500.0 25.0 0 f 2.55 g 2.73 h 2.77 i 2.82 2.88 280 240 200 160 120 80 40 0L 0 GARRETT q &MOORS / E�gioseri�g io�ths Power and Waste Industries :j 40 80 120 160 200 240 280 320 PCSTABLSM/si FSmin=2.30 Safety Factors Are Calculated By The Modified Bishop Method 360 400 440 ** PCSTABLSM ** by Purdue University --Slope Stability Analysis -- Simplified Janbu, Simplified Bishop or Spencer's Method of Slices Run Date: 7/20/2021 Time of Run: 02:30PM Run By: Craig Fortner, Garrett & Moore, Inc Input Data Filename: V:Nash Ph5 Input.in Output Filename: V:Nash Ph5 Input.OUT Unit: ENGLISH Plotted Output Filename: V:Nash Ph5 Input.PLT PROBLEM DESCRIPTION Nash Co. C&DLF P5 Excavation Global Stability BOUNDARY COORDINATES 9 Top Boundaries 10 Total Boundaries Boundary X-Left No. (ft) 1 0.00 2 68.60 3 73.90 4 90.30 5 96.70 6 113.20 7 121.40 8 123.00 Y-Left X-Right Y-Right Soil Type (ft) (ft) (ft) Below Bnd 208.40 68.60 209.00 2 209.00 73.90 209.70 2 209.70 90.30 209.80 2 209.80 96.70 211.10 2 211.10 113.20 217.50 2 217.50 121.40 223.80 2 223.80 123.00 227.00 2 227.00 123.60 228.12 1 V:\Nash\Projects\Phase 5 - Operations\nash ph5 input.OUT Page 2 9 123.60 228.12 141.90 229.60 1 10 123.00 227.00 141.90 227.00 2 ISOTROPIC SOIL PARAMETERS 3 Type(s) of Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 110.0 110.0 0.0 26.0 0.00 0.0 0 2 120.0 120.0 200.0 34.0 0.00 0.0 0 3 60.0 60.0 500.0 25.0 0.00 0.0 0 BOUNDARY LOAD(S) 1 Load(s) Specified Load X-Left X-Right Intensity Deflection No. (ft) (ft) (psf) (deg) 1 124.00 140.00 250.0 0.0 NOTE - Intensity Is Specified As A Uniformly Distributed Force Acting On A Horizontally Projected Surface. A Critical Failure Surface Searching Method, Using A Random Technique For Generating Circular Surfaces, Has Been Specified. 100 Trial Surfaces Have Been Generated. 10 Surfaces Initiate From Each Of 10 Points Equally Spaced Along The Ground Surface Between X = 30.00 ft. and X = 90.00 ft. Each Surface Terminates Between X = 123.00 ft. and X = 140.00 ft. Unless Further Limitations Were Imposed, The Minimum Elevation At Which A Surface Extends Is Y = 0.00 ft. 10.00 ft. Line Segments Define Each Trial Failure Surface. Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Examined. They Are Ordered - Most Critical First. * * Safety Factors Are Calculated By The Modified Bishop Method Failure Surface Specified By 7 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 90.00 209.80 2 99.65 207.16 3 109.64 207.49 4 119.09 210.77 5 127.14 216.69 6 133.09 224.73 7 134.58 229.01 Circle Center At X = 103.5 ; Y = 240.3 and Radius, 33.4 *** 2.302 *** Individual data on the 14 slices Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Slice Width Weight Top Bot Norm Tan Hor Ver Load No. (ft) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) (lbs) 1 0.3 1.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2 6.4 1236.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3 2.9 1452.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 4 10.0 8223.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 5 3.6 3717.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 6 5.9 7078.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 7 2.3 3133.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 8 1.6 2370.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 9 0.6 982.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10 0.4 662.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 11 3.1 4769.8 0.0 0.0 0.0 0.0 0.0 0.0 786.2 12 5.9 5560.6 0.0 0.0 0.0 0.0 0.0 0.0 1485.6 13 0.8 274.7 0.0 0.0 0.0 0.0 0.0 0.0 197.9 14 0.7 75.2 0.0 0.0 0.0 0.0 0.0 0.0 175.3 Failure Surface Specified By 8 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 83.33 209.76 2 92.63 206.08 3 102.57 204.98 4 112.45 206.54 V:\Nash\Projects\Phase 5 - Operations\nash ph5 input.OUT Page 3 5 121.58 210.63 6 129.30 216.98 7 135.09 225.13 8 136.57 229.17 Circle Center At X = 101.7 ; Y = 242.2 *** 2.448 *** Failure Surface Specified By 7 Coordinate Point X-Surf Y-Surf No. (ft) (ft) 1 90.00 209.80 2 99.57 206.90 3 109.55 207.58 4 118.64 211.73 5 125.68 218.84 6 129.75 227.97 7 129.79 228.62 Circle Center At X = 102.7 ; Y = 234.5 *** 2.483 *** Failure Surface Specified By 7 Coordinate Point X-Surf Y-Surf No. (ft) (ft) 1 83.33 209.76 2 93.19 208.09 3 103.17 208.82 4 112.68 211.90 5 121.18 217.17 6 128.18 224.31 7 130.77 228.70 Circle Center At X = 95.2 ; Y = 249.7 *** 2.487 *** Failure Surface Specified By 9 Coordinate Point X-Surf Y-Surf No. (ft) (ft) 1 76.67 209.72 2 86.12 206.47 3 96.04 205.19 4 106.02 205.94 5 115.63 208.68 6 124.50 213.31 7 132.25 219.62 8 138.58 227.37 9 139.65 229.42 Circle Center At X = 97.4 ; Y = 254.6 *** 2.505 *** Failure Surface Specified By 8 Coordinate Point X-Surf Y-Surf No. (ft) (ft) 1 90.00 209.80 2 99.07 205.59 3 109.00 204.37 4 118.82 206.27 5 127.58 211.09 6 134.43 218.37 7 138.72 227.40 8 138.98 229.36 Circle Center At X = 107.9 ; Y = 236.2 *** 2.553 *** Failure Surface Specified By 9 Coordinate Point X-Surf Y-Surf No. (ft) (ft) 1 83.33 209.76 2 91.90 204.60 3 101.59 202.12 4 111.58 202.50 5 121.04 205.74 6 129.19 211.54 7 135.32 219.44 8 138.95 228.76 9 139.00 229.37 Circle Center At X = 105.3 ; Y = 236.5 and Radius, 37.3 Points and Radius, 27.8 Points and Radius, 41.6 Points and Radius, 49.4 Points and Radius, 31.9 Points and Radius, 34.6 V:\Nash\Projects\Phase 5 - Operations\nash ph5 input.OUT Page 4 *** 2.728 *** Failure Surface Specified By 8 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 90.00 209.80 2 98.62 204.73 3 108.42 202.73 4 118.34 204.00 5 127.31 208.40 6 134.38 215.48 7 138.78 224.46 8 139.41 229.40 Circle Center At X = 109.5 ; Y = 232.8 and Radius, 30.1 *** 2.771 *** Failure Surface Specified By 10 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 70.00 209.18 2 79.13 205.11 3 88.89 202.94 4 98.89 202.74 5 108.73 204.54 6 118.01 208.25 7 126.38 213.73 8 133.48 220.77 9 139.05 229.08 10 139.17 229.38 Circle Center At X = 94.9 ; Y = 252.6 and Radius, 50.0 *** 2.816 *** Failure Surface Specified By 9 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 83.33 209.76 2 91.57 204.08 3 101.10 201.08 4 111.10 201.01 5 120.68 203.89 6 128.99 209.45 7 135.30 217.21 8 139.04 226.48 9 139.29 229.39 Circle Center At X = 106.3 ; Y = 234.3 and Radius, 33.6 *** 2.881 ***