Loading...
HomeMy WebLinkAboutNC0002468_SARP_Rev0_Appx A_20161201December 2016Amec Foster Wheeler Environment & Infrastructure, Inc. Duke Energy Coal Combustion Residuals Management Program Dan River Steam Station Site Analysis and Removal Plan Revision 0 APPENDIX A: ASH INVENTORY CALCULATION Ash Inventory Calculation Dam Decommissioning Plan Duke Energy - Dan River Steam Station Amec Foster Wheeler Project No. 7810-14-0065 1 of 4 12/06/2016 Calculation Title: Ash Inventory Calculation Summary: The estimated quantity of ash at Dan River Steam Station is approximately 2,480,000 cubic yards (2,210,000 dry tons). Note that these estimates may be updated as new information becomes available. Notes: Revision Log: No. Description Originator Verifier Technical Reviewer 0 Initial Submittal - 12/6/16 Chris Jordan Stephanie Stanwick Cedric Ruhl Ash Inventory Calculation Dam Decommissioning Plan Duke Energy - Dan River Steam Station Amec Foster Wheeler Project No. 7810-14-0065 2 of 4 12/06/2016 OBJECTIVE: The objective of this calculation is to estimate the in-situ volume and tonnage of coal combustion residuals (CCR) located in the Primary and Secondary Ash Basins, Ash Fill 1, and Ash Fill 2 at the Dan River Steam Station. METHOD: Historical and current topographic and bathymetric data was utilized to estimate top of ash and bottom of ash grades for the Primary and Secondary Ash Basins, Ash Fill 1, and Ash Fill 2, and quantity of soil stockpile on Ash Fill 1. AutoCAD Civil 3D 2013 was used to estimate in-situ volumes of ash and soil stockpile. CALCULATIONS: 1.0 Site Summary In 1948, construction on the Dan River Steam Station began and units 1-3 came online between 1949 and 1956. In 1956, the first ash basin was constructed with a crest elevation of 525 feet. From 1968-1969, the ash basin was expanded to its current footprint and the crest elevation was raised to 530 feet. From 1976-1977 an intermediate dike was constructed separating the primary and secondary basins and raising the Primary Ash Basin crest to 540 feet. In 1980, dredge dikes were constructed north of the ash basins to support construction of Ash Fills 1 and 2. The coal units were retired on April 1, 2012 and the production of CCR at the site has stopped. Refer to Figure 1 for the location of existing CCR units. 2.0 Quantity of Material in Ash Fills 1 and 2 The material in Ash Fills 1 and 2 includes ash placed as fill, cover soils, and additional soil stockpiled on top of Ash Fill 1. The quantity of material within Ash Fills 1 & 2 was estimated using AutoCAD Civil 3D software. The extents of ash were delineated based on topographic features, test pits performed in 2014, and our understanding of the site. The topography of the bottom of Ash Fills 1 & 2 was estimated based on Drawing D-1037M-5 dated June 5, 1983, provided by Duke Energy and included as Figure 2.1. This drawing indicates that soil was excavated within the footprints of Ash Fills 1 and 2 for dredge dike construction. The bottom of ash grades from Drawing D-1037M-5 were digitized in AutoCAD Civil 3D for surface comparison purposes as shown in Figure 2.2. The bottom of ash grades are consistent with recent geotechnical boring information. The current topography of Ash Fills 1 and 2 was based on aerial photogrammetric survey flown February 7, 2014 and acquired by LDSI as shown in Figure 2.3. An isopach (i.e. cut/fill map) comparing current topography and bottom of ash grades is presented in Figure 2.4, and a cross-section of the ash fill CCR units is presented in Figure 2.5. Refer to the discussion section of this calculation for estimated quantities. Ash Inventory Calculation Dam Decommissioning Plan Duke Energy - Dan River Steam Station Amec Foster Wheeler Project No. 7810-14-0065 3 of 4 12/06/2016 3.0 Quantity of Soil Stockpile and cover soils on Ash Fills 1 and 2 The material in Ash Fills 1 and 2 includes ash placed as fill, cover soils, and additional soil stockpiled on top of Ash Fill 1. The quantity of soil stockpile material within Ash Fill 1 was estimated using AutoCAD Civil 3D software. The extents of soil were delineated based on topographic features and our understanding of the site. Ash Fill 1 contains two soil stockpiles built on top of the ash. The bottom elevation of the northern soil stockpile (Soil area 1A) was estimated to be at elevation 628 feet and the bottom elevation of the southern soil stockpile (Soil area 1B) was estimated to be at elevation 578 feet, based on recent geotechnical boring information. A cross-section of the ash fill CCR units showing the soil stockpiles on Ash Fill 1 is presented in Figure 2.5. Soil cover over Ash Fills 1 and 2 is assumed to be approximately 2 feet thick. For the purposes of this calculation it was assumed that 1.5 feet of soil cover will be removed prior to ash excavation. Refer to the discussion section of this calculation for estimated quantities. 4.0 Quantity of Material in the Primary and Secondary Ash Basins The material in the Primary and Secondary Ash Basins generally consists of sluiced fly ash and bottom ash. The quantity of material within the Primary and Secondary Ash Basins was estimated using AutoCAD Civil 3D software. The extents of ash were delineated based on topographic features and our understanding of the site. The topography of the bottom of the Primary and Secondary Ash Basins was estimated based on Drawing D-1039-M dated May 11, 1994. This drawing was provided by Duke Energy and included as Figure 3.1. The bottom of ash grades were digitized in AutoCAD Civil 3D for surface comparison purposes as shown in Figure 3.2. The top of ash in the Primary Ash Basin is shown on Figure 3.3 and was obtained from aerial photogrammetric survey flown February 7, 2014 and acquired by LDSI, and bathymetry performed by LDSI July 29-30, 2014. An isopach (i.e. cut/fill map) comparing current topography and bottom of ash grades is presented in Figure 3.4, and a cross-section of the ash basin CCR units is presented in Figure 3.5. Refer to the discussion section of this calculation for estimated quantities. Ash Inventory Calculation Dam Decommissioning Plan Duke Energy - Dan River Steam Station Amec Foster Wheeler Project No. 7810-14-0065 4 of 4 12/06/2016 DISCUSSION: Based on data gathered from several coal burning plants, the following typical CCR properties are assumed: Material Dry Unit Weight (tons/cy) Moisture Content (percent) Moist Unit Weight (tons/cy) CCR in Ash Basins 0.8 50%1.2 CCR in Ash Fills 1.0 20%1.2 Table 1: Assumed CCR Properties Estimated in-situ volumes are presented in the following table: Location Total Quantity of Material (cy) Quantity of Soil Stockpile (cy) Quantity of Cover Soil (cy) Quantity of CCR (cy) Ash Fill 1 959,658 116,554 47,698 795,406 Ash Fill 2 380,096 0 34,606 345,490 Subtotal 1,339,754 116,554 82,304 1,140,896 Primary Ash Basin 1,012,267 0 0 1,012,267 Secondary Ash Basin 323,871 0 0 323,871 Subtotal 1,336,138 0 0 1,336,138 TOTAL 2,675,892 116,554 82,304 2,477,034 Table 2: Estimated In-Situ Volume of Material Estimated in-situ tonnages are presented in the following table: Location Quantity of CCR (cy) Estimated Dry Unit Weight (tons/cy) Estimated Dry Weight (tons) Estimated Moisture Content (percent) Estimated Moist Unit Weight (tons/cy) Estimated Moist Weight (tons) Ash Fill 1 795,406 1.0 795,406 20%1.2 954,487 Ash Fill 2 345,490 1.0 345,490 20%1.2 414,588 Subtotal 1,140,896 N/A 1,140,896 N/A N/A 1,369,075 Primary Ash Basin 1,012,267 0.8 809,814 50%1.2 1,214,720 Secondary Ash Basin 323,871 0.8 259,097 50%1.2 388,645 Subtotal 1,336,138 N/A 1,068,910 N/A N/A 1,603,365 TOTAL 2,477,034 N/A 2,209,806 N/A N/A 2,972,440 Table 3: Estimated Quantities of CCR Material The estimated quantity of ash at Dan River Steam Station is approximately 2,480,000 cubic yards (2,210,000 dry tons). Figures 1 Ash Areas Aerial Imagery 2.1 Ash Fill 1 & 2 Original Topography 2.2 Ash Fill 1 & 2 Digitized Base Contours 2.3 Ash Fill 1 & 2 Recent Topography 2.4 Ash Fill 1 & 2 Isopach 2.5 Ash Fill 1 & 2 Cross Section 3.1 Primary and Secondary Ash Basins Original Topography 3.2 Primary and Secondary Ash Basins Digitized Base Contours 3.3 Primary and Secondary Ash Basins Recent Topography 3.4 Primary and Secondary Ash Basins Isopach 3.5 Primary and Secondary Ash Basins Cross Section R E V I E W E D B Y : S C A L E : D A T U M ( H O R - V E R ) : P R O J E C T I O N : T I T L E : P R O J E C T : D A T E : F I G U R E N O . R E V I S I O N N O . P R O J E C T N O . : P R E P A R E D B Y : C L I E N T : 2 8 0 1 Y O R K M O N T R O A D , S U I T E 1 0 0 C H A R L O T T E , N C 2 8 2 0 8 T E L : ( 7 0 4 ) 3 5 7 - 8 6 0 0 F A X : ( 7 0 4 ) 3 5 7 - 8 6 3 8 L I C E N S U R E : N C E N G : F - 1 2 5 3 N C G E O L O G Y : C - 2 4 7 A m e c F o s t e r W h e e l e r E n v i r o n m e n t & I n f r a s t r u c t u r e , I n c . A S N O T E D D A M B R E A C H A N D A S H R E M O V A L P L A N D A N R I V E R S T E A M S T A T I O N 7 8 1 0 1 4 0 0 6 5 0 A P R . 2 0 1 5 N A D 8 3 - N A V D 8 8 N C 8 3 F M A C R A S H A R E A S A E R I A L I M A G E R Y D A N R I V E R S T E A M S T A T I O N , R O C K I N G H A M C O . , N C 1 N 0 4 0 0 ' 2 0 0 ' S E C O N D A R Y A S H B A S I N REFERENCES1. HIGH RESOLUTION 2014 AERIAL IMAGERY WAS OBTAINED FROM ESRI.NOTES:1. ASH BOUNDARIES ARE APPROXIMATE. P R I M A R Y A S H B A S I N A S H F I L L 1 L I M I T A S H F I L L 2 L I M I T S O I L S T O C K P I L E 1 A L I M I T S O I L S T O C K P I L E 1 B L I M I T 565 565 560 555 550 545 5 5 5 570 575 585 590 610 615 620 610 580590590 58 5 58 0 555 5 6 0 565 5 7 0 5 7 5 5 9 0 5 9 0 5 8 5 5 8 0 575 5 7 0 5 6 5 5 5 5 5 5 0 5 4 5 5 4 0 5 4 5 5 4 0 550 5 6 5 5 8 0 58 5 6 0 0 5 9 0 6 0 5 6 1 0 6 1 5 6 2 0 6 2 5 5 7 5 5 8 0 5 8 5 5 9 0 5 9 5 600 5 4 0 5 3 5 5 4 5 550 5 5 0 5 4 5 535 5 3 5 57 5 570 5 6 5 5 5 0 R E V I E W E D B Y : S C A L E : D A T U M ( H O R - V E R ) : P R O J E C T I O N : T I T L E : P R O J E C T : D A T E : F I G U R E N O . R E V I S I O N N O . P R O J E C T N O . : P R E P A R E D B Y : C L I E N T : 2 8 0 1 Y O R K M O N T R O A D , S U I T E 1 0 0 C H A R L O T T E , N C 2 8 2 0 8 T E L : ( 7 0 4 ) 3 5 7 - 8 6 0 0 F A X : ( 7 0 4 ) 3 5 7 - 8 6 3 8 L I C E N S U R E : N C E N G : F - 1 2 5 3 N C G E O L O G Y : C - 2 4 7 A m e c F o s t e r W h e e l e r E n v i r o n m e n t & I n f r a s t r u c t u r e , I n c . A S N O T E D D A M B R E A C H A N D A S H R E M O V A L P L A N D A N R I V E R S T E A M S T A T I O N 7 8 1 0 1 4 0 0 6 5 0 A P R . 2 0 1 5 N A D 8 3 - N A V D 8 8 N C 8 3 F M A C R A S H F I L L 1 & 2 O R I G I N A L T O P O G R A P H Y D A N R I V E R S T E A M S T A T I O N , R O C K I N G H A M C O . , N C 2 . 1 NOTES:1. BOXED CONTOUR LABELS HAVE BEEN ADDED FOR CLARITY.2. CONTOUR ELEVATIONS ARE ASSUMED TO REFERENCE NGVD29 VERTICAL DATUM. N 0 0 2 0 0 ' 1 0 0 ' REFERENCES1.DRAWING NO. DM-1037M-5 ENTITLED “DRY ASH BASIN CONTOURS”, PREPARED BY DUKE POWER COMPANY, R E V . 0 , D A T E D 6 / 5 / 8 3 . V E R T I C A L D A T U M N O T I N D I C A T E D . N G V D 2 9 ASH FILL 2 LIMIT(BASED ON RECENT AERIAL IMAGERY,TOPOGRAPHY, AND TEST PITS) A S H F I L L 1 L I M I T ( B A S E D O N R E C E N T A E R I A L I M A G E R Y , T O P O G R A P H Y , A N D T E S T P I T S ) 550 560 570 580 590 555 565 575 585 5 5 0 5 6 0 5 7 0 5 8 0 5 9 0 5 5 5 5 6 5 5 7 5 5 8 5 580 590 6 0 0 6 1 0 6 2 0 585 59 5 6 0 5 6 1 5 590600600610610595595605605 57 0 5 8 0 5 9 0 5 7 5 5 8 5 5 9 5 55 0 560 5 7 0 5 4 5 555 5 6 5 5 7 5 5 4 0 5 5 0 5 6 0 5 4 0 5 5 0 5 6 0 B - 3 0 1 B - 3 0 2 B - 3 0 3 B - 3 0 4 B - 3 0 5 B - 3 0 6 B - 3 1 2 B - 3 1 4 B - 3 1 5 B - 3 1 6 B - 3 1 7 B - 3 1 8 B - 3 1 9 B - 3 2 0 B - 3 2 1 B - 3 2 2 B - 3 2 3 B - 3 2 4 MW-8D O W - 3 0 1 D O W - 3 0 2 D O W - 3 0 3 D O W - 3 0 4 D O W - 3 0 5 D O W - 3 0 5 S O W - 3 0 6 D O W - 3 0 6 S O W - 3 1 5 D O W - 3 1 5 S OW-317D O W - 3 1 8 D O W - 3 1 9 D O W - 3 1 9 S O W - 3 2 0 D O W - 3 2 1 D T P - 1 0 - A T P - 1 1 - A T P - 1 2 - A T P - 1 2 - A T P - 1 3 - A T P - 1 4 - A T P - 1 5 - A TP-16-A TP-17-A TP-18-A LOA T P - 1 9 - A T P - 1 - A T P - 2 0 - A T P - 2 - A L O A T P - 3 - A T P - 4 - A T P - 5 - A T P - 6 - A L O A T P - 7 - A T P - 8 - A L O A T P - 9 - A 54 0 5 4 0 R E V I E W E D B Y : S C A L E : D A T U M ( H O R - V E R ) : P R O J E C T I O N : T I T L E : P R O J E C T : D A T E : F I G U R E N O . R E V I S I O N N O . P R O J E C T N O . : P R E P A R E D B Y : C L I E N T : 2 8 0 1 Y O R K M O N T R O A D , S U I T E 1 0 0 C H A R L O T T E , N C 2 8 2 0 8 T E L : ( 7 0 4 ) 3 5 7 - 8 6 0 0 F A X : ( 7 0 4 ) 3 5 7 - 8 6 3 8 L I C E N S U R E : N C E N G : F - 1 2 5 3 N C G E O L O G Y : C - 2 4 7 A m e c F o s t e r W h e e l e r E n v i r o n m e n t & I n f r a s t r u c t u r e , I n c . A S N O T E D D A M B R E A C H A N D A S H R E M O V A L P L A N D A N R I V E R S T E A M S T A T I O N 7 8 1 0 1 4 0 0 6 5 0 A P R . 2 0 1 5 N A D 8 3 - N A V D 8 8 N C 8 3 F M A C R A S H F I L L 1 & 2 D I G I T I Z E D B A S E C O N T O U R S D A N R I V E R S T E A M S T A T I O N , R O C K I N G H A M C O . , N C 2 . 2 N 0 0 2 0 0 ' 1 0 0 ' NOTES:1. (5FT) CONTOURS WERE DIGITIZED FROM HISTORICAL TOPO SHOWN IN FIGURE 2.1 (REFERENCE 1) .2. A DATUM SHIFT OF -0.75 FT WAS APPLIED TO CONVERT ELEVATIONS FROM NGVD29 TO NAVD88.3. THIS IS A REPRESENTATION OF THE CONTOURS SHOWN IN REFERENCE 1 AND IS AN APPROXIMATION OF THE B O T T O M O F A S H F I L L C O N T O U R S B A S E D O N T H E I N F O R M A T I O N AVAILABLE TO AMEC FOSTER WHEELER IN APRIL 2015.REFERENCES1. RAWING NO. DM-1037M-5 ENTITLED “DRY ASH BASIN CONTOURS”, PREPARED BY DUKE POWER COMPANY, RE V . 0 , D A T E D 6 / 5 / 8 3 . V E R T I C A L D A T U M C O N V E R T E D F R O M N G V D 2 9 T O NAVD88.ASH FILL 2 LIMIT(BASED ON RECENT AERIAL IMAGERY,TOPOGRAPHY, AND TEST PITS) A S H F I L L 1 L I M I T ( B A S E D O N R E C E N T A E R I A L I M A G E R Y , T O P O G R A P H Y , A N D T E S T P I T S ) 24 + 0 0 0+00 5 + 0 0 1 0 + 0 0 15+00 2 0 + 0 0 5 8 0 582584586 578 5 7 8 5 7 0 56 0 550 5 7 0 5 6 0 580570560 5 4 0 5 5 0 580582 590 600 610 620610 600 590 588586580 5 7 0580 570 560 550 5 5 0 5 6 0 5 7 0 5 8 0 5 9 0 6 0 0 6 1 0 6 2 0 6 3 0 6 4 0 6 2 0 6 1 0 6 0 0 5 9 0 6 0 0 6 1 0 5 8 0 580 590 6 2 0 6 1 0 6 0 0 590 5 8 0 5 7 0 5 6 0 5 4 0 5 5 0 5 6 0 5 5 0 5 4 0 5 5 0 5 5 0 5 4 0 5 4 0 5 5 0 57 0 5 4 0 5 3 0 5 2 0 530 540 550 5 6 0 5 7 0 608606 604 5 9 0 58 0 5 9 0 5 9 0 6 0 0 6 1 0 5 7 0 5 8 0 5 9 0 6 0 0 6 1 0 6 0 8 B - 3 0 1 B - 3 0 2 B - 3 0 3 B - 3 0 4 B - 3 0 5 B - 3 0 6 B - 3 1 2 B - 3 1 4 B - 3 1 5 B - 3 1 6 B - 3 1 7 B - 3 1 8 B - 3 1 9 B - 3 2 0 B - 3 2 1 B - 3 2 2 B - 3 2 3 B - 3 2 4 MW-8D O W - 3 0 1 D O W - 3 0 2 D O W - 3 0 3 D O W - 3 0 4 D O W - 3 0 5 D O W - 3 0 5 S O W - 3 0 6 D O W - 3 0 6 S O W - 3 1 5 D O W - 3 1 5 S OW-317D O W - 3 1 8 D O W - 3 1 9 D O W - 3 1 9 S O W - 3 2 0 D O W - 3 2 1 D T P - 1 0 - A T P - 1 1 - A T P - 1 2 - A T P - 1 2 - A T P - 1 3 - A T P - 1 4 - A T P - 1 5 - A TP-16-A TP-17-A TP-18-A LOA T P - 1 9 - A T P - 1 - A T P - 2 0 - A T P - 2 - A L O A T P - 3 - A T P - 4 - A T P - 5 - A T P - 6 - A L O A T P - 7 - A T P - 8 - A L O A T P - 9 - A R E V I E W E D B Y : S C A L E : D A T U M ( H O R - V E R ) : P R O J E C T I O N : T I T L E : P R O J E C T : D A T E : F I G U R E N O . R E V I S I O N N O . P R O J E C T N O . : P R E P A R E D B Y : C L I E N T : 2 8 0 1 Y O R K M O N T R O A D , S U I T E 1 0 0 C H A R L O T T E , N C 2 8 2 0 8 T E L : ( 7 0 4 ) 3 5 7 - 8 6 0 0 F A X : ( 7 0 4 ) 3 5 7 - 8 6 3 8 L I C E N S U R E : N C E N G : F - 1 2 5 3 N C G E O L O G Y : C - 2 4 7 A m e c F o s t e r W h e e l e r E n v i r o n m e n t & I n f r a s t r u c t u r e , I n c . A S N O T E D D A M B R E A C H A N D A S H R E M O V A L P L A N D A N R I V E R S T E A M S T A T I O N 7 8 1 0 1 4 0 0 6 5 0 A P R . 2 0 1 5 N A D 8 3 - N A V D 8 8 N C 8 3 F M A C R A S H F I L L 1 & 2 R E C E N T T O P O G R A P H Y D A N R I V E R S T E A M S T A T I O N , R O C K I N G H A M C O . , N C 2 . 3 N 0 0 2 0 0 ' 1 0 0 ' NOTES1. ASH BOUNDARIES ARE APPROXIMATE.REFERENCES1. AERIAL PHOTOGRAMMETRIC SURVEY FLOWN 2/7/2014 BY LDSI. VERTICAL DATUM NAVD88.ASH FILL 2 LIMIT(BASED ON RECENT AERIAL IMAGERY,TOPOGRAPHY, AND TEST PITS) A S H F I L L 1 L I M I T ( B A S E D O N R E C E N T A E R I A L I M A G E R Y , T O P O G R A P H Y , A N D T E S T P I T S ) A S H F I L L 1 & 2 C R O S S S E C T I O N A L I G N M E N T ( S E E F I G U R E 2 . 5 ) S O I L S T O C K P I L E 1 A L I M I T S O I L S T O C K P I L E 1 B L I M I T 24 + 0 0 0+00 5 + 0 0 1 0 + 0 0 15+00 2 0 + 0 0 4 0 2 0 5 0 6 0 70 7 0 7 2 6 0 5 0 40 3 0 2 0 1 0 1 0 2 0 3 0 4 0 4 0 5 0 6 0 5 0 4 0 3 0 2 0 1 0 0 10 1 0 2 0 10 20 1020 30 40 5 0 6 0 7 0 2 0 1 0 - 6 4 10 10 20 22 24 26 28 3 0 28 2 0 1 8 1 6 1 0 2 2 0 1 0 10100 2 R E V I E W E D B Y : S C A L E : D A T U M ( H O R - V E R ) : P R O J E C T I O N : T I T L E : P R O J E C T : D A T E : F I G U R E N O . R E V I S I O N N O . P R O J E C T N O . : P R E P A R E D B Y : C L I E N T : 2 8 0 1 Y O R K M O N T R O A D , S U I T E 1 0 0 C H A R L O T T E , N C 2 8 2 0 8 T E L : ( 7 0 4 ) 3 5 7 - 8 6 0 0 F A X : ( 7 0 4 ) 3 5 7 - 8 6 3 8 L I C E N S U R E : N C E N G : F - 1 2 5 3 N C G E O L O G Y : C - 2 4 7 A m e c F o s t e r W h e e l e r E n v i r o n m e n t & I n f r a s t r u c t u r e , I n c . A S N O T E D D A M B R E A C H A N D A S H R E M O V A L P L A N D A N R I V E R S T E A M S T A T I O N 7 8 1 0 1 4 0 0 6 5 0 A P R . 2 0 1 5 N A D 8 3 - N A V D 8 8 N C 8 3 F M A C R A S H F I L L 1 & 2 I S O P A C H D A N R I V E R S T E A M S T A T I O N , R O C K I N G H A M C O . , N C 2 . 4 N 0 0 2 0 0 ' 1 0 0 ' NOTES:1. COAL COMBUSTION RESIDUALS (CCR) VOLUME WAS CALCULATED USING AUTOCAD CIVIL 3D SOFTWARE.2. RED CONTOURS INDICATE THAT THE BASE SURFACE IS AT HIGHER ELEVATION THAN THE COMPARISON SURF A C E . T H I S M A Y B E C A U S E D B Y E X C A V A T I O N O F M A T E R I A L R E L A T I V E TO ORIGINAL TOPOGRAPHY OR BY INACCURACIES IN THE DATA USED.REFERENCES:1. DRAWING NO. DM-1037M-5 ENTITLED “DRY ASH BASIN CONTOURS”, PREPARED BY DUKE POWER COMPANY, R E V . 0 , D A T E D 6 / 5 / 8 3 . V E R T I C A L D A T U M C O N V E R T E D F R O M N G V D 2 9 T O NAVD88.2. AERIAL PHOTOGRAMMETRIC SURVEY FLOWN 2/7/2014 BY LDSI. VERTICAL DATUM NAVD88.LEGENDCONTOUR OF "CUT" THICKNESS (SEE NOTE 2)CONTOUR OF CCR THICKNESS (APPROXIMATE) M A X I M U M C C R A N D S T O C K P I L E T H I C K N E S S I S A P P R O X I M A T E L Y 7 7 F T . A S H F I L L 1 & 2 C R O S S S E C T I O N A L I G N M E N T ( S E E F I G U R E 2 . 5 ) MAXIMUM CCR THICKNESSIS APPROXIMATELY 33 FT.ASH FILL 2 LIMIT(BASED ON RECENT AERIAL IMAGERY,TOPOGRAPHY, AND TEST PITS) A S H F I L L 1 L I M I T ( B A S E D O N R E C E N T A E R I A L I M A G E R Y , T O P O G R A P H Y , A N D T E S T P I T S ) S O I L S T O C K P I L E 1 A L I M I T S O I L S T O C K P I L E 1 B L I M I T ELEVATION (FT) ELEVATION (FT) S T A T I O N S ( F T ) D A N R I V E R S T E A M S T A T I O N A S H F I L L 1 & 2 520 530 540 550 560 570 580 590 600 610 620 630 640 650 660 5 2 0 5 3 0 5 4 0 5 5 0 5 6 0 5 7 0 5 8 0 5 9 0 6 0 0 6 1 0 6 2 0 6 3 0 6 4 0 6 5 0 6 6 0 0+001+002+003+004+005+006+007+00 8+00 9+00 10+00 11+00 12+00 13+00 14+00 15+00 16+00 17+00 18+00 19+00 20+00 21+00 22+00 23+00 24+00 R E V I E W E D B Y : S C A L E : D A T U M ( H O R - V E R ) : P R O J E C T I O N : T I T L E : P R O J E C T : D A T E : F I G U R E N O . R E V I S I O N N O . P R O J E C T N O . : P R E P A R E D B Y : C L I E N T : 2 8 0 1 Y O R K M O N T R O A D , S U I T E 1 0 0 C H A R L O T T E , N C 2 8 2 0 8 T E L : ( 7 0 4 ) 3 5 7 - 8 6 0 0 F A X : ( 7 0 4 ) 3 5 7 - 8 6 3 8 L I C E N S U R E : N C E N G : F - 1 2 5 3 N C G E O L O G Y : C - 2 4 7 A m e c F o s t e r W h e e l e r E n v i r o n m e n t & I n f r a s t r u c t u r e , I n c . A S N O T E D D A M B R E A C H A N D A S H R E M O V A L P L A N D A N R I V E R S T E A M S T A T I O N 7 8 1 0 1 4 0 0 6 5 0 A P R . 2 0 1 5 N A D 8 3 - N A V D 8 8 N C 8 3 F M A C R A S H F I L L 1 & 2 C R O S S S E C T I O N D A N R I V E R S T E A M S T A T I O N , R O C K I N G H A M C O . , N C 2 . 5 0 0 2 0 0 ' 1 0 0 ' NOTES:1. AT THE DESIGNATED LIMIT OF ASH FILL, THE ORIGINAL GROUND SURFACE ELEVATION MAY NOT EQUAL THE " E X I S T I N G " G R O U N D S U R F A C E E L E V A T I O N D U E T O R E G R A D I N G AND/OR LIMITATIONS OF DATA QUALITY.REFERENCES:1. DRAWING NO. DM-1037M-5 ENTITLED “DRY ASH BASIN CONTOURS”, PREPARED BY DUKE POWER COMPANY, R E V . 0 , D A T E D 6 / 5 / 8 3 . V E R T I C A L D A T U M C O N V E R T E D F R O M N G V D 2 9 T O NAVD88.2. AERIAL PHOTOGRAMMETRIC SURVEY FLOWN 2/7/2014 BY LDSI. VERTICAL DATUM NAVD88.ORIGINAL GROUND SURFACE(REFERENCE 1) E X I S T I N G G R O U N D S U R F A C E ( R E F E R E N C E 2 ) ASH FILL 2(THICKNESS AND EXTENTSARE APPROXIMATE) S E E N O T E 1 E X I S T I N G G R O U N D S U R F A C E ( R E F E R E N C E 2 ) E M B A N K M E N T EMBANKMENT A S H F I L L 1 ( T H I C K N E S S A N D E X T E N T S A R E A P P R O X I M A T E ) O R I G I N A L G R O U N D S U R F A C E ( R E F E R E N C E 1 ) S O I L S T O C K P I L E 1 B ( T H I C K N E S S A N D E X T E N T S A R E A P P R O X I M A T E ) S O I L S T O C K P I L E 1 A ( T H I C K N E S S A N D E X T E N T S A R E A P P R O X I M A T E ) R E V I E W E D B Y : S C A L E : D A T U M ( H O R - V E R ) : P R O J E C T I O N : T I T L E : P R O J E C T : D A T E : F I G U R E N O . R E V I S I O N N O . P R O J E C T N O . : P R E P A R E D B Y : C L I E N T : 2 8 0 1 Y O R K M O N T R O A D , S U I T E 1 0 0 C H A R L O T T E , N C 2 8 2 0 8 T E L : ( 7 0 4 ) 3 5 7 - 8 6 0 0 F A X : ( 7 0 4 ) 3 5 7 - 8 6 3 8 L I C E N S U R E : N C E N G : F - 1 2 5 3 N C G E O L O G Y : C - 2 4 7 A m e c F o s t e r W h e e l e r E n v i r o n m e n t & I n f r a s t r u c t u r e , I n c . A S N O T E D D A M B R E A C H A N D A S H R E M O V A L P L A N D A N R I V E R S T E A M S T A T I O N 7 8 1 0 1 4 0 0 6 5 0 A P R . 2 0 1 5 N A D 8 3 - N A V D 8 8 N C 8 3 F M A C R P R I M A R Y A N D S E C O N D A R Y A S H B A S I N S O R I G I N A L T O P O G R A P H Y D A N R I V E R S T E A M S T A T I O N , R O C K I N G H A M C O . , N C 3 . 1 NOTES:1. CONTOUR ELEVATIONS ARE ASSUMED TO REFERENCE NGVD29 VERTICAL DATUM. N 0 0 2 0 0 ' 1 0 0 ' REFERENCES1.DRAWING NO. D-1039-M ENTITLED "ASH SETTLING BASIN LAYOUT”, PREPARED BY DUKE POWER COMPANY, RE V . 2 2 , D A T E D 5 / 1 1 / 9 4 . V E R T I C A L D A T U M N O T I N D I C A T E D . N G V D 2 9 B - 3 0 7 B - 3 0 8 B - 3 0 9 B - 3 1 0 B-311 B - 3 2 5 B - 3 2 7 B - 3 2 8 B - 3 2 8 A B-330B-330 REL O C T E D B - 3 3 1 B-333B-335 C - 3 0 1 C - 3 0 2 C-303 C-304 C - 3 0 5 C - 3 0 6 C - 3 0 7 C-308 C - 3 0 9 C - 3 1 0 C - 3 1 1 C - 3 1 2 D P T - 3 0 1 D P T - 3 0 2 DPT- 3 0 3 DPT-304 D P T - 3 0 6 O W - 3 0 7 D O W - 3 0 8 D O W - 3 0 9 D O W - 3 1 0 D O W - 3 1 0 S O W - 3 1 1 D O W - 3 1 2 D O W - 3 1 2 S OW-313D OW-314DOW-314SSPWA-1SPWA-2 T E M P P Z 3 3 1 TEMP PZ 333TEMP PZ 335 5 1 0 5 2 0 51 0 52 0 52 0 508 530520510 502 5 0 2 504 5 0 6 510 5 2 0 5 1 0 5 2 0 5 3 0 5 2 0 510520530 530540 520 530 5 3 0 5 0 0 5 1 0 5 2 0 5 2 0 510 510 R E V I E W E D B Y : S C A L E : D A T U M ( H O R - V E R ) : P R O J E C T I O N : T I T L E : P R O J E C T : D A T E : F I G U R E N O . R E V I S I O N N O . P R O J E C T N O . : P R E P A R E D B Y : C L I E N T : 2 8 0 1 Y O R K M O N T R O A D , S U I T E 1 0 0 C H A R L O T T E , N C 2 8 2 0 8 T E L : ( 7 0 4 ) 3 5 7 - 8 6 0 0 F A X : ( 7 0 4 ) 3 5 7 - 8 6 3 8 L I C E N S U R E : N C E N G : F - 1 2 5 3 N C G E O L O G Y : C - 2 4 7 A m e c F o s t e r W h e e l e r E n v i r o n m e n t & I n f r a s t r u c t u r e , I n c . A S N O T E D D A M B R E A C H A N D A S H R E M O V A L P L A N D A N R I V E R S T E A M S T A T I O N 7 8 1 0 1 4 0 0 6 5 0 A P R . 2 0 1 5 N A D 8 3 - N A V D 8 8 N C 8 3 F M A C R P R I M A R Y A N D S E C O N D A R Y A S H B A S I N S D I G I T I Z E D B A S E C O N T O U R S D A N R I V E R S T E A M S T A T I O N , R O C K I N G H A M C O . , N C 3 . 2 N 0 0 2 0 0 ' 1 0 0 ' NOTES:1. (5FT) CONTOURS WERE DIGITIZED FROM HISTORICAL TOPO SHOWN IN FIGURE 3.1 (REFERENCE 1) .2. A DATUM SHIFT OF -0.75 FT WAS APPLIED TO CONVERT ELEVATIONS FROM NGVD29 TO NAVD88.3. THIS IS A REPRESENTATION OF THE CONTOURS SHOWN IN REFERENCE 1 AND IS AN APPROXIMATION OF THE B O T T O M O F A S H B A S I N C O N T O U R S B A S E D O N T H E I N F O R M A T I O N AVAILABLE TO AMEC FOSTER WHEELER IN APRIL 2015.REFERENCES1. DRAWING NO. D-1039-M ENTITLED "ASH SETTLING BASIN LAYOUT”, PREPARED BY DUKE POWER COMPANY, RE V . 2 2 , D A T E D 5 / 1 1 / 9 4 . V E R T I C A L D A T U M C O N V E R T E D F R O M N G V D 2 9 TO NAVD88. SUPPLEMENTAL BORING DATA POINTS PREPARED BY AMECFW, DATED XXXX WERE USED TO EST I M A T E T H E P R I M A R Y A S H B A S I N B O T T O M . P R I M A R Y A S H B A S I N L I M I T ( B A S E D O N H I S T O R I C A L D A T A ) ) S E C O N D A R Y A S H B A S I N L I M I T ( B A S E D O N H I S T O R I C A L D A T A ) 5 9 0 5 8 0 5 7 0 5 6 0 5 4 0 5 5 0 5 6 0 5 5 0 540 550 550 540 540 550 5 7 0 5 4 0 5 3 0 520 5 3 0 5 4 0 5 5 0 5 7 0 0+005+00 1 0 + 0 0 1 5 + 0 0 2 0 + 0 0 2 5 + 0 0 2 9 + 0 0 5 3 0 5 3 0 530 530 528 5 3 0 5 2 4 522 520 520 51 0 510 5 2 0 5 3 0 530 520530530530 530530524 540530 5 3 0 5 4 0 5 5 0 5 1 4 5 1 4 516 522 5 4 0 5 5 0 5 2 0 5 5 0 5 5 0 490500 5 1 0 5 2 0 5 3 0 530 5 3 4 5 3 4 532 534536540530520530540490500510520530 5 0 0 5 1 0 5 2 0 5 2 0 52 0 510 5 3 0 5 1 6 52 6 5 3 0 5 3 0 5 3 0 532 5 3 6 B - 3 0 7 B - 3 0 8 B - 3 0 9 B - 3 1 0 B-311 B - 3 2 5 B - 3 2 7 B - 3 2 8 B - 3 2 8 A B-330B-330 REL O C T E D B - 3 3 1 B-333B-335 C - 3 0 1 C - 3 0 2 C-303 C-304 C - 3 0 5 C - 3 0 6 C - 3 0 7 C-308 C - 3 0 9 C - 3 1 0 C - 3 1 1 C - 3 1 2 D P T - 3 0 1 D P T - 3 0 2 DPT- 3 0 3 DPT-304 D P T - 3 0 6 O W - 3 0 7 D O W - 3 0 8 D O W - 3 0 9 D O W - 3 1 0 D O W - 3 1 0 S O W - 3 1 1 D O W - 3 1 2 D O W - 3 1 2 S OW-313D OW-314DOW-314SSPWA-1SPWA-2 T E M P P Z 3 3 1 TEMP PZ 333TEMP PZ 335 R E V I E W E D B Y : S C A L E : D A T U M ( H O R - V E R ) : P R O J E C T I O N : T I T L E : P R O J E C T : D A T E : F I G U R E N O . R E V I S I O N N O . P R O J E C T N O . : P R E P A R E D B Y : C L I E N T : 2 8 0 1 Y O R K M O N T R O A D , S U I T E 1 0 0 C H A R L O T T E , N C 2 8 2 0 8 T E L : ( 7 0 4 ) 3 5 7 - 8 6 0 0 F A X : ( 7 0 4 ) 3 5 7 - 8 6 3 8 L I C E N S U R E : N C E N G : F - 1 2 5 3 N C G E O L O G Y : C - 2 4 7 A m e c F o s t e r W h e e l e r E n v i r o n m e n t & I n f r a s t r u c t u r e , I n c . A S N O T E D D A M B R E A C H A N D A S H R E M O V A L P L A N D A N R I V E R S T E A M S T A T I O N 7 8 1 0 1 4 0 0 6 5 0 A P R . 2 0 1 5 N A D 8 3 - N A V D 8 8 N C 8 3 F M A C R P R I M A R Y A N D S E C O N D A R Y A S H B A S I N S R E C E N T T O P O G R A P H Y D A N R I V E R S T E A M S T A T I O N , R O C K I N G H A M C O . , N C 3 . 3 N 0 0 2 0 0 ' 1 0 0 ' NOTES1. ASH BOUNDARIES ARE APPROXIMATE.REFERENCES1. AERIAL PHOTOGRAMMETRIC SURVEY FLOWN 2/7/2014 BY LDSI.VERTICAL DATUM NAVD88.2. BATHYMETRY INFORMATION PERFORMED BY LDSI OBTAINED ON SEPTEMBER 4, 2014. VERTICAL DATUM NAVD 8 8 . L I M I T O F B A T H Y M E T R I C S U R V E Y A R E A ( R E F E R E N C E 2 ) ASH BASIN CROSSSECTION ALIGNMENT(SEE FIGURE 3.5)PRIMARY ASH BASIN LIMIT(BASED ON HISTORICAL DATA) S E C O N D A R Y A S H B A S I N L I M I T ( B A S E D O N H I S T O R I C A L D A T A ) 0+005+00 1 0 + 0 0 1 5 + 0 0 2 0 + 0 0 2 5 + 0 0 2 9 + 0 0 20 10 10 2 0 3 0 2 0 1 0 3 0 2 2 2 4 28 2 6 26 28 3 0 3 0 2 0 1 0 3 0 20 1 0 20 30 30 30302010 30 2010 103230 20 2 0 8 1 0 2 2 2 0 30 30 20 10 1 0 2 0 1 0 1 0 20 1 0 10 1 0 1 0 1 0 34 2 8 2 2 2 6 2 4 12 14 16 - 4 R E V I E W E D B Y : S C A L E : D A T U M ( H O R - V E R ) : P R O J E C T I O N : T I T L E : P R O J E C T : D A T E : F I G U R E N O . R E V I S I O N N O . P R O J E C T N O . : P R E P A R E D B Y : C L I E N T : 2 8 0 1 Y O R K M O N T R O A D , S U I T E 1 0 0 C H A R L O T T E , N C 2 8 2 0 8 T E L : ( 7 0 4 ) 3 5 7 - 8 6 0 0 F A X : ( 7 0 4 ) 3 5 7 - 8 6 3 8 L I C E N S U R E : N C E N G : F - 1 2 5 3 N C G E O L O G Y : C - 2 4 7 A m e c F o s t e r W h e e l e r E n v i r o n m e n t & I n f r a s t r u c t u r e , I n c . A S N O T E D D A M B R E A C H A N D A S H R E M O V A L P L A N D A N R I V E R S T E A M S T A T I O N 7 8 1 0 1 4 0 0 6 5 0 A P R . 2 0 1 5 N A D 8 3 - N A V D 8 8 N C 8 3 F M A C R P R I M A R Y A N D S E C O N D A R Y A S H B A S I N S I S O P A C H D A N R I V E R S T E A M S T A T I O N , R O C K I N G H A M C O . , N C 3 . 4 N 0 0 2 0 0 ' 1 0 0 ' NOTES:1. COAL COMBUSTION RESIDUALS (CCR) VOLUME WAS CALCULATED USING AUTOCAD CIVIL 3D SOFTWARE.2. RED CONTOURS INDICATE THAT THE BASE SURFACE IS AT HIGHER ELEVATION THAN THE COMPARISON SURFACE. THI S M A Y B E C A U S E D B Y E X C A V A T I O N O F M A T E R I A L R E L A T I V E T O O R I G I N A L TOPOGRAPHY OR BY INACCURACIES IN THE DATA USED.REFERENCES:1.DRAWING NO. D-1039-M ENTITLED "ASH SETTLING BASIN LAYOUT”, PREPARED BY DUKE POWER COMPANY, REV. 22, D A T E D 5 / 1 1 / 9 4 . V E R T I C A L D A T U M C O N V E R T E D F R O M N G V D 2 9 T O N A V D 8 8 . 2. SUPPLEMENTAL BORING DATA POINTS PREPARED BY AMEC FOSTER WHEELER WERE USED TO ESTIMATE THE PRIMA R Y A S H B A S I N B O T T O M 3. AERIAL PHOTOGRAMMETRIC SURVEY FLOWN 2/7/2014 BY LDSI. BATHYMETRY INFORMATION PERFORMED BY LDSI OBT A I N E D O N S E P T E M B E R 4 , 2 0 1 4 . V E R T I C A L D A T U M N A V D 8 8 . LEGENDCONTOUR OF "CUT" THICKNESS (SEE NOTE 2)CONTOUR OF CCR THICKNESS (APPROXIMATE) M A X I M U M C C R T H I C K N E S S I S A P P R O X I M A T E L Y 2 5 F T . ASH BASIN CROSSSECTION ALIGNMENT(SEE FIGURE 3.5)MAXIMUM CCR THICKNESSIS APPROXIMATELY 39 FT. P R I M A R Y A S H B A S I N L I M I T ( B A S E D O N H I S T O R I C A L D A T A ) S E C O N D A R Y A S H B A S I N L I M I T ( B A S E D O N H I S T O R I C A L D A T A ) ELEVATION (FT) ELEVATION (FT) S T A T I O N S ( F T ) DA N R I V E R S T E A M S T A T I O N P R I M A R Y A N D S E C O N D A R Y A S H B A S I N 480 490 500 510 520 530 540 550 560 4 8 0 4 9 0 5 0 0 5 1 0 5 2 0 5 3 0 5 4 0 5 5 0 5 6 0 0+001+002+003+004+005+006+007+008+009+00 10+00 11+00 12+00 13+00 14+00 15+00 16+00 17+00 18+00 19+00 20+00 21+00 22+00 23+00 24+00 25+00 26+00 27+00 28+00 29+00 R E V I E W E D B Y : S C A L E : D A T U M ( H O R - V E R ) : P R O J E C T I O N : T I T L E : P R O J E C T : D A T E : F I G U R E N O . R E V I S I O N N O . P R O J E C T N O . : P R E P A R E D B Y : C L I E N T : 2 8 0 1 Y O R K M O N T R O A D , S U I T E 1 0 0 C H A R L O T T E , N C 2 8 2 0 8 T E L : ( 7 0 4 ) 3 5 7 - 8 6 0 0 F A X : ( 7 0 4 ) 3 5 7 - 8 6 3 8 L I C E N S U R E : N C E N G : F - 1 2 5 3 N C G E O L O G Y : C - 2 4 7 A m e c F o s t e r W h e e l e r E n v i r o n m e n t & I n f r a s t r u c t u r e , I n c . A S N O T E D D A M B R E A C H A N D A S H R E M O V A L P L A N D A N R I V E R S T E A M S T A T I O N 7 8 1 0 1 4 0 0 6 5 0 A P R . 2 0 1 5 N A D 8 3 - N A V D 8 8 N C 8 3 F M A C R P R I M A R Y A N D S E C O N D A R Y A S H B A S I N S C R O S S S E C T I O N D A N R I V E R S T E A M S T A T I O N , R O C K I N G H A M C O . , N C 3 . 5 0 0 2 0 0 ' 1 0 0 ' NOTES:1. AT THE DESIGNATED LIMIT OF ASH BASIN, THE ORIGINAL GROUND SURFACE ELEVATION MAY NOT EQUAL THE " E X I S T I N G " G R O U N D S U R F A C E E L E V A T I O N D U E T O R E G R A D I N G AND/OR LIMITATIONS OF DATA QUALITY.REFERENCES:1.DRAWING NO. D-1039-M ENTITLED "ASH SETTLING BASIN LAYOUT”, PREPARED BY DUKE POWER COMPANY, RE V . 2 2 , D A T E D 5 / 1 1 / 9 4 . V E R T I C A L D A T U M C O N V E R T E D F R O M N G V D 2 9 TO NAVD88.2. SUPPLEMENTAL BORING DATA POINTS PREPARED BY AMECFW WERE USED TO ESTIMATE THE PRIMARY ASH B A S I N B O T T O M 3. AERIAL PHOTOGRAMMETRIC SURVEY FLOWN 2/7/2014 BY LDSI. BATHYMETRY INFORMATION PERFORMED BY L D S I O B T A I N E D O N S E P T E M B E R 4 , 2 0 1 4 . V E R T I C A L D A T U M N A V D 8 8 . O R I G I N A L G R O U N D S U R F A C E ( R E F E R E N C E 1 A N D 2 ) S E E N O T E 1 EXISTING GROUND SURFACE(REFERENCE 3)EMBANKMENT A S H B A S I N D E P O S I T S ( T H I C K N E S S A N D E X T E N T S A R E A P P R O X I M A T E ) E M B A N K M E N T EMBANK M E N T A P P R O X . W A T E R S U R F A C E E L E V A T I O N 5 2 2 . 5 2 ' F E B R U A R Y 2 0 1 4 PRIMARY AS H B A S I N S E C O N D A R Y A S H B A S I N