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HomeMy WebLinkAboutNC0004961_RBSS_SARP_Rev0_Appx F_20161219Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Duke Energy Coal Combustion Residuals Management Program Riverbend Steam Station Site Analysis and Removal Plan Revision 0 APPENDIX F: RIVERBEND CONSTRUCTION QUALITY ASSURANCE PLAN CONSTRUCTION QUALITY ASSURANCE PLAN RIVERBEND STEAM STATION REVISION 0 Prepared for Duke Energy 400 South Tryon Street Charlotte, North Carolina 28202 December 2016 Prepared by Amec Foster Wheeler Environment & Infrastructure, Inc. Project 7810-16-0625 Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 i TABLE OF CONTENTS 1. INTRODUCTION ................................................................................................................. 1 2. BACKGROUND ................................................................................................................... 1 3. PROJECT TEAM AND RESPONSIBILITIES ..................................................................... 2 3.1. Owner ............................................................................................................................................... 2 3.2. Design Engineer of Record (Engineer) ....................................................................................... 2 3.3. Construction Quality Assurance Engineer .................................................................................. 2 3.4. Engineering Technicians ............................................................................................................... 3 3.5. Prime Contractor ............................................................................................................................ 3 3.6. Regulatory Agency ......................................................................................................................... 3 4. DOCUMENTATION AND REPORTING ............................................................................. 3 4.1. Record Documentation .................................................................................................................. 3 4.2. Design, Specification, and Drawing Changes ............................................................................ 4 4.3. Non-Conformances ........................................................................................................................ 4 4.4. Record Drawings ............................................................................................................................ 4 4.5. Certification Report ........................................................................................................................ 5 5. QUALITY ASSURANCE PROGRAM ................................................................................. 5 5.1. Fill Density Testing ......................................................................................................................... 5 5.2. Instrumentation ............................................................................................................................... 6 5.3. Verification of Ash Removal .......................................................................................................... 7 5.4. Surveying ......................................................................................................................................... 7 Figures Figure 1 – Site Location Map Figure 2 – Instrumentation Locations Tables Table 1 – Instrumentation Table 2 – Testing Frequency Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 1 1. INTRODUCTION This document presents the Construction Quality Assurance Plan (CQA) Plan for the Riverbend Steam Station Ash Pond Coal Combustion Residual (CCR) Removal Grading Plan project in Gaston County, North Carolina. The purpose of the CQA Plan is to identify the quality assurance procedures, standards, and methods that will be employed during the project to provide assurance that the requirements of the drawings, specifications, regulatory permits, and owner specified health, safety and environmental requirements are met. The CQA Plan is specific to the referenced project and is prepared in compliance with the North Carolina Coal Ash Management Act of 2014. The primary objective of the scope of work for the Ash Pond CCR Removal Grading Plan project at Riverbend Steam Station (hereafter referred to as Riverbend) includes excavation and removal of CCR materials currently stored in the areas known as the Cinder Pit, Dry Stack, and the Primary and Secondary Ash Basins. The scope of work includes all ancillary activities such as dewatering, grading, fill placement, erection and maintenance of erosion and sediment control, and all other activities required to achieve the primary objective. The scope of work also includes obtaining and complying with regulatory permits required for performing the work. The project will be performed with highest regards to safety and environmental standards in compliance with local, state, and federal regulations as included in the site specific environmental, health and safety program. 2. BACKGROUND The Riverbend Steam Station is located on the Catawba River near Mt. Holly in Gaston County, North Carolina, approximately 13 miles northwest of Charlotte. Historically, the primary ash management facilities included the Primary and Secondary Ash Basins which have served as the main ash storage component for plant operations. The site has three regulated impoundment structures, the Primary Ash Basin Dam (State ID GASTO-097), the Secondary Ash Basin Dam (State ID GASTO-098), and Intermediate Dam (State ID GASTO-099). Two additional ash storage areas at the station include the Dry Ash Stack and Cinder Pit Storage Area. Power production at the plant was discontinued in 2013. The closure of the ash management facilities at the station is a part of the overall station decommissioning plan. The CCR materials in the storage areas at Riverbend will be excavated and removed from the site using conventional excavation equipment. The materials will be transported and placed in approved lined landfills and structural fills. Upon establishing final grades, the site will be seeded to establish grassy ground cover per approved grading plan drawings and specifications. In addition to establishing vegetative ground cover, relatively gentle slopes will be established during final grading to control runoff velocities. After ash and dam removal, the ash basin area will be stabilized with permanent vegetation (consisting of grasses) and will be maintained throughout the post-closure period. Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 2 3. PROJECT TEAM AND RESPONSIBILITIES The following identifies the roles and responsibilities for the primary parties associated with the project, including the anticipated duties and expectation s each party will fulfill in execution of the work associated with implementation of the project. 3.1. Owner The Owner of the site and project is Duke Energy Carolinas, LLC (Duke). The Owner is ultimately responsible for oversight and authorization of the work and assuring that the work is performed in general accordance with the specifications, drawings, permits, this CQA Plan, and other contractual documents. The Owner has the right to delegate its oversight authority to third parties contracted with the Owner but will maintain ultimate responsibility for the successful implementation of the project. The Owner will maintain the authority to make final decisions regarding all aspects of the project in compliance with local, state, and federal regulations. For this project, the Owner will have sole authority to suspend or stop work if, in their opinion, the work is being performed in an unsafe manner, the work is not meeting quality standards, or changes to the scope of work must be enacted to comply with the spirit of the objectives of the project. 3.2. Design Engineer of Record (Engineer) The Design Engineer of Record (Engineer) is the engineer who signs and seals the Issued for Construction Drawings and Specifications. The Engineer is delegated limited and selected authority at the discretion of the Owner. The Engineer acts in a consultant role to the Owner on aspects of the project for which the Owner seeks direction in the decision making process. The Engineer has no authority to stop or suspend work at the site, only the authority to recommend remedial actions for the Owner’s consideration. 3.3. Construction Quality Assurance Engineer The Construction Quality Assurance Engineer (CQA Engineer) will be experienced in quality assurance testing and monitoring. The CQA Engineer will report to the Owner and can be employed by the same entity as the Design Engineer of Record. The CQA Engineer may be a Duke employee. The CQA Engineer serves as the on-site representative of the Owner and is responsible for the field implementation of the approved quality assurance program as follows:  Monitor the quality assurance activities of the field testing and document conformance with test procedures and the Technical Specifications  Inform the Engineer of quality assurance activities and non-conformance to the approved CQA program, if any  Observe that sample handling procedures are in accordance with the appropriate guidelines for the testing to be conducted Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 3  Organize, assign, and direct engineering technicians  Maintain an awareness of the overall field testing operations to identify conditions that may jeopardize the quality of testing. 3.4. Engineering Technicians The engineering technicians (technicians) are responsible for field observations and testing at the direction of the CQA Engineer. Technicians will be assigned to the project as deemed necessary by the CQA Engineer. The CQA Engineer may perform and conduct field observations and testing himself. Technicians will be under the direct supervision of the CQA Engineer. 3.5. Prime Contractor The Prime Contractor will be responsible for performing and managing construction activities required for completing the project. The Prime Contractor is responsible for performing the work in compliance with the requirements and to the quality standards of the specifications, drawings, permits, and this CQA Plan. The Prime Contractor is responsible for overseeing and managing their personnel, including the personnel of their Subcontractors such that the work is performed safely and effectively and in compliance with local, state, and federal safety and environmental regulations to include the Owner’s site specific environmental, health, and safety rules. 3.6. Regulatory Agency The Regulatory Agency having direct regulatory authority of the project is the North Carolina Department of Environmental Quality, (NCDEQ). With respect to dam decommissioning the lead agency is the NCDEQ, Division of Energy, Mineral, and Land Resources, Land Quality Section, Dams Program. The Regulatory Agency has the authority to inspect the project at any time during the course of the work, and has the authority to direct the Owner to suspend or stop the work with appropriate cause. Upon direction to suspend or stop the work, the Regulatory Agency should provide remedial measures to the Owner, that once implemented, should allow for work to continue. 4. DOCUMENTATION AND REPORTING This section provides a description of project documentation and record keeping that will be maintained during the course of the work as the project record. 4.1. Record Documentation Reports will be completed by designated Owner personnel to serve as a record of the project. The reports are intended to summarize work activities, serve as a record of important discussions and/or decisions, action items, or other information that the Owner deems important Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 4 or critical to the project record. The Owner, at their discretion, may require other entities, such as the CQA Engineer, to maintain daily records as well. The CQA Engineer and technicians will be responsible for documenting construction, monitoring, and testing activities by taking photographs. Photographs should be organized and documented in photo-logs and/or by including them in daily reports, monitoring logs, and test data sheets. Photo-logs should include a unique identifying number corresponding to the photograph file name, the date and location where the photograph was taken, and a description of the photograph subject matter. 4.2. Design, Specification, and Drawing Changes Design, specification and drawing changes may be required during construction. Proposed changes may be initiated by the Contractor, CQA Engineer, or Owner and submitted to the Design Engineer of Record for consideration. Design, specification and drawing changes may be made only with the approval of the Design Engineer of Record with consent from Owner. Changes that effect the design intent as approved by regulatory agencies will require approval of that agency. 4.3. Non-Conformances Non-conformance reports are intended to serve as a record of nonconforming items during the course of the work and as a record of the disposition of the non-conformance. Generally, the Owner will initiate the non-conformance procedure based on the recommendation or findings of a third party such as a CQA Engineer. The non-conformance will be evaluated and resolved with the disposition recorded in the non-conformance report. Sample dispositions may include rework of the nonconforming item, replacement of the nonconforming item, or accepting the nonconforming item as installed based on engineering judgment. A record of all non- conformance reports will be maintained at the site during the course of the work at all times for review by requesting representatives of the Regulatory Agency. 4.4. Record Drawings The Owner will retain a third-party surveyor registered in the state that the work is performed. The Owner shall be responsible for submitting to the Engineer the following:  Existing conditions survey (which may be a recent aerial survey not specifically performed for this project)  Existing stormwater piping elevations and locations (including piping to be removed)  Bottom of excavation grades  Installed stormwater piping elevations and locations  Final conditions survey (which may be an aerial survey) Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 5 The excavation grades survey and any other ground surveys shall be performed on a 100-foot grid with berms, toes, crests and breaks-in-slope also surveyed. Topographic ground surveys shall be performed on the same grid such that survey point locations are consistent with the survey points of the underlying layer. Surveys shall also show contours of the completed surface at two-foot contour intervals. As-built locations and details for existing and installed stormwater piping shall also be submitted to the Engineer by the Contractor. Drawings shall include pipe locations at a spacing that is adequate to identify the position of the pipe. Survey timing should be coordinated so as not to impact the construction schedule of the geosynthetics and overlying materials. 4.5. Certification Report The Engineer will prepare a certification report upon completion of dam decommissioning activities. The certification report will include as-built and record documents that are intended to serve as documentation of the project. For this project, the primary purpose of the record drawings is to capture final grades at the site for use in future projects. A secondary purpose is to fulfill regulatory requirements for developing as-built drawings for decommissioned ash basins. The as-built and record documents will generally include:  Record drawings detailing final grades  Record of quality assurance/control testing including compacted fill, stormwater piping information, instrumentation monitoring, and verification of CCR removal  Record of non-conformance reports  Record of erosion and sediment control inspections  Other relevant information or data at the discretion of the Owner Specific requirements for information and data to be collected as part of the as-built documents is included in Section 01 71 23 SURVEYING REQUIREMENTS. 5. QUALITY ASSURANCE PROGRAM The intent of the Quality Assurance Program is to provide observations, test data, and other recorded information at a sufficient frequency to assure that the work is completed in general accordance with the requirements of the specifications, drawings, regulatory permits, and other controlling documents. A list of the observations and testing requirements for the Quality Assurance Program is included in Table 2. 5.1. Fill Density Testing Final grades at the site will be established by placing and compacting soil materials excavated from onsite sources. The requirements for fill placement are provided in Technical Specifications Section 31 23 00 EXCAVATION AND EARTHWORK. The general requirements Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 6 for fill density testing include establishing moisture-density relationships for fill materials, visually observing placement of fill materials during construction, performing fill density tests to assess the level of compaction achieved, and recording the results of testing for project records. A specific list of the observations and testing requirements for the Quality Assurance Program associated with fill placement is included in Table 2. 5.2. Instrumentation During dewatering of the ash basins, limitations on the drawdown rate within the basins will be imposed to reduce the potential for detrimental conditions developing within the existing dams. The primary concern with regard to the drawdown rate is lowering the water level within the basin significantly faster than the embankment fill materials are able to drain, potentially reducing the overall stability of the impoundment structures. In order to evaluate the initial drawdown limitations, existing instrumentation in the embankments will be monitored to track the drawdown occurring within the embankments compared to the changing water level within the basin. The locations of the instruments to be monitored during the project are shown on Figure 2. The frequency of readings to be performed as a part of the Quality Assurance Program is included on Table 1. The water level readings will be tracked in spreadsheet format and plotted versus the dam profile such that the data can be evaluated by qualified personnel. In general, monthly readings of the instrumentation listed in Table 1 will be performed during the course of the work until the identified wells are dry or dewatering of the basins is complete. A dry well will be defined as a well that returns a “dry” reading for three consecutive readings. The frequency of reading a well that has been deemed dry may be reduced to either monthly or discontinued subject to any changing condition or data from other wells that suggest reading the dry wells should be reinstated. More frequent readings of the piezometers may be deemed necessary during the course of the project and will be implemented based on the discretion of the qualified person reviewing the data. Table 1. Instrumentation Structure Piezometer Screen Interval (ft) Screen Elevation (ft, amsl) Monitoring Frequency Primary Ash Basin Dam (GASTO-097) P-100 55 - 60 662.9 – 667.9 Monthly P-101 30 – 35 654.7 – 659.7 P-102 52 – 57 632.6 – 637.6 P-103 14 – 19 651.4 – 656.4 P-104 38 - 43 627.4 – 632.4 Secondary Ash Basin Dam (GASTO-098) P-105 29 -34 679.6 – 684.6 Monthly P-106 10 – 15 634 – 639 P-107 20 – 25 623.7 – 628.7 P-108 37 – 42 671.7 – 676.7 Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 7 P-109 25 -30 648 – 653 P-110 45 - 50 627 – 632 P-111 7 – 12 633.2 – 638.2 P-112 24 - 29 615.1 – 620.1 5.3. Verification of Ash Removal Verification and documentation that CCRs have been removed will be required during ash basin closure implementation. In order to meet the basin closure performance standard, Duke’s CCR Removal Verification Procedure will be used to verify that primary source ash has been removed from the basin. Subsequent to removal of the ash pursuant to the CCR Removal Verification Procedure, Duke Energy will implement its Excavation Soil Sampling Plan, which was developed for the purpose of closing the Ash Basins in a manner that meets the closure performance standards set out in Part II, Section 3.(c) of the Coal Ash Act and 40 C.F.R. § 257.102(c). The Excavation Soil Sampling Plan is attached to the Riverbend Steam Station Coal Ash Excavation Plan (2016 Update). 5.4. Surveying The Owner will contract to have record surveying services performed for the project as described in Section 4.4. The scope of work for surveying to be performed by the Prime Contractor is contained in Technical Specifications Section 01 71 23 SURVEYING REQUIREMENTS. Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 FIGURES UV1191UV7 UV1923 UV2093 UV1641 UV2019 UV2145 UV273 UV2110 UV1205 UV1924 UV2093 UV2209 UV2209 UV2113 UV1197 UV1641 UV1923 UV2074 UV2136 UV2003 UV273 UV279 UV1662 UV1609 UV27 UV1922 UV2136 UV1650 UV1620 UV2169 UV275 UV2108 UV27 UV27 UV1662 UV73 UV2021 UV1619UV1601 UV2050 UV2519 UV2014 UV1641 UV1644 UV16 UV2110 UV16 UV1625 UV1718 UV1662 UV2019 UV2074 UV2145 UV2040 UV2128 UV2136 UV7 UV1924 UV1191 UV273 UV1784 UV115 UV2000 UV2074 UV27 UV73 £¤29£¤29 £¤21 £¤29 §¨¦277 §¨¦277 §¨¦277§¨¦485 §¨¦485 §¨¦85 §¨¦85 §¨¦77 §¨¦77 Sources: Esri, HERE, DeLorme, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), swisstopo, MapmyIndia, © OpenStreetMap contributors, and the GIS User Community PREPARED BY SJP DATE 5/20/15 CHECKED BY BC DATE 5/20/15 JOB NUMBER FIGURE 17810-15-0384 SITE LOCATION MAPDUKE ENERGY RIVERBEND STEAM STATIONASH POND CCR REMOVAL GRADING PLANGASTON COUNTY, NORTH CAROLINA ¯ 0 10,000 20,0005,000 Feet ^_ NORTH CAROLINA Project Location SecondaryPond PrimaryPond AshStack CinderPit Copyright:© 2013 National Geographic Society, i-cubed !!!!! ! ! ! ! ! C a t a w b a R i v e r P-100P-101 P-102 P-103 P-104 P-105 P-108 P-106/P-107 P-109/P-110 P-111/P-112 Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community PREPARED BY SJP DATE 5/20/15 CHECKED BY BC DATE 5/20/15 JOB NUMBER FIGURE 27810-15-0384 INSTRUMENTATION PLANDUKE ENERGY RIVERBEND STEAM STATIONASH POND CCR REMOVAL GRADING PLANGASTON COUNTY, NORTH CAROLINA¯0 350 700175 Feet !Approximate Piezometer Location Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 TABLES Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 Table 2. Testing Frequency Field Density Testing Component Test Method Frequency Fill Placement/Compaction - Visual  Daily Soil Classification of Fill - ASTM D 2488  Daily Moisture Density Relationship - ASTM D 698  3 proctors prior to commencement of fill placement;  one per 20,000 cubic yards of fill placed or change of material classification In-Place Density Testing - ASTM D 2937 - ASTM D 6938 - ASTM D 1556  one per 8,000 cubic yards placed  minimum of once daily Index Testing - ASTM D 6913 or D 422 - ASTM D 4318  one each per 8,000 cubic yards placed Moisture Content - ASTM D 2216 - ASTM D 4643 - ASTM D 4959  one per 8,000 cubic yards placed (in conjunction with field density test)  minimum once daily or as needed to monitor fill placement Earthwork Component Test Method Frequency Aggregate - Visual  per delivery Aggregate - Quarry Certification  once at beginning of project and at Owner’s request thereafter Rip Rap - Visual  per delivery Rip Rap - Quarry Certification  once at beginning of project and at Owner’s request thereafter Amec Foster Wheeler Environment & Infrastructure, Inc. December 2016 Construction Quality Assurance Plan Riverbend Steam Station Site Analysis and Removal Plan Revision 0 Table 2. Testing Frequency (Continued) Surveying Component Test Method Frequency Contractor - Project Controls N/A  Initial site layout  At Contractor’s discretion thereafter Owner - Record Survey N/A  Per Owner’s scope of work CQA Engineer N/A  Per Owner’s scope of work Instrumentation Component Test Method Frequency Primary Ash Basin Dam (GASTO-097) P-100, P-101, P-102, P-103 P-104 - Water level meter, spreadsheet  Monthly or until “dry” Secondary Ash Basin Dam (GASTO-098) P-105, P-106, P-107, P-108 P-109, P-110, P-111, P-112 - Water level meter, spreadsheet  Monthly or until “dry” Erosion and Sediment Control Component Test Method Frequency Formal Inspection - Visual, Inspection Form  Weekly and after each 0.5” of rainfall within 24 hours Rain Gauge - Visual  Daily Informal Inspection - Visual  Daily