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HomeMy WebLinkAboutNCS000467_OTHER_20121031NORTH CAROLINA .� Department of Environmental Qua! STORMWATER DIVISION CODING SHEET MS4 PERMITS PERMIT NO. /v � � o U c zi 6 DOC TYPE ❑FINAL PERMIT fl ANNUAL REPORT 0 APPLICATION ❑ COMPLIANCE L9'10�HER DOC DATE 00 rLb l�)—)cS3J YYYYMMDD r - Golder Associates October 23, 2012 q Mr. Hilary Thornton United States Environmental Protection Agency _ Region IV Atlanta Federal Center 4WD-SRSEB, 111h Floor 61 Forsyth Street, SW Atlanta, GA 30303-8960 Mr. Danny Smith North Carolina Department of Environment and Natural Resources Division of Water Quality 3800 Barrett Drive Raleigh, NC 27609 Mailing Address: 1628 Mail Service Center Raleigh, NC 27699-1628 RE: REACH A 2012 VISUAL AND VEGETATION MONITORING WARD TRANSFORMER SUPERFUND SITE, RALEIGH, NORTH CAROLINA Dear Mr. Thornton and Mr. Smith: 184D FIN 203 On behalf of the Ward Transformer Site Trust (Trust), Golder Associates Inc. (Golder) submits the results of the visual and vegetation monitoring of the riparian vegetation in the West Area and the constructed drainage channel of Reach A (collectively called Reach A) at the Ward Transformer Superfund Site, Raleigh, North Carolina. MONITORING PERFORMED DURING 2012 REPORTING PERIOD Reach A monitoring was conducted in 2012, as shown in the table below: Month Description May Visual Site Monitoring and Vegetation Monitorin July Visual Site Monitoring Se tember Visual Site Monitoring and Vegetation Monitoring Visual site monitoring included walking the Reach A rip rap channel and its riparian zone to identify points of potential concern and to photo -document the conditions at the site. During the May 2012 visual monitoring Golder observed rill erosion along the northern side of Step Pool #1. The erosion was repaired the same month. During the September monitoring event, the repaired area appeared to be stable with no signs of recurring erosion. Monitoring reports are provided in Attachments 1 to 3, which include photographs of the site conditions. Vegetation monitoring included counting surviving planted trees and estimating the areal coverage of herbaceous vegetation using six (6) fixed vegetation plots (each 50 feet by 50 feet, approximately 0.06 acres in size) established in September 2011. Because of low -survivability monitored in September 2011, an additional vegetation monitoring event was conducted in May 2012 as indicated in the November 14, 2011, letter to EPA and NCDENR. Locations of the monitoring plots as well as photograph locations are provided in Figure 1. Golder Associates Inc. 3730 Chamblee Tucker Road Atlanta, GA 30341 USA Tel; (770) 496-1893 Fax: (770) 934-9476 www.goider.com Golder Associates: Operations in Africa, Asia, Australasia, Europe, North America and South America t Jov r- Ward Transformer Superfund Site Reach A Monitoring October 23, 2012 Mr. Hilary Thornton and Mr. Danny Smith 2 053-3184D For the May 2012 event, the number of surviving planted trees and the areal coverage of herbaceous ground cover estimated within the monitoring plots are summarized in the table below. The table also provides the calculated surviving tree stocking density per acre. Plot No. Herbaceous Ground Cover Number of Surviving Planted Trees Number of Volunteer Trees Calculated Tree Density per Acre Percentage to Stocked Density of 500 per Acre 1 100% 16 75 500+ 100% 2 98% 6 10 279 56% 3 100% 8 - 139 28% 4 95% 17 - 296 59% 5 95% 10 - 174 35% 6 95% 6 - 105 21% Averse 97% 11 14 249 50% In May 2012 the average of the numbers of trees found in the plots was approximately 249 trees per acre, which is approximately 50 percent of the original planned density of 500 per acre. The planted bare root species that have better survivability are tulip poplar (Liriodendron tulipifera), black oak (Quercus velutina), red maple (Ater rubrum), red bud (Cercis canadensis), and sweet gum (Liquidambar styraciflua). Red maples and loblolly pines (Pinus taeda) are sprouting voluntarily. Compared to the September 2011 monitoring event, the average herbaceous ground cover increased from 68% to 97%. For the September 2012 event the number of surviving planted trees and the areal coverage of herbaceous ground cover estimated within the monitoring plots are summarized in the table below. Plot No. Herbaceous Ground Cover Number of Surviving Planted Trees Number of Volunteer Trees Calculated Tree Density per Acre Percentage to Stocked Density of 500 er Acre 1 95% 14 97 500+ 100% 2 98% 3 31 500+ 100% 3 100% 8 1 157 31% 4 95% 17 - 296 59% 5 95% 7 1 139 28% 6 95% 4 - 70 14% Averse 96% 9 22 280 55% In this monitoring event, the average of the number of trees found in the plots was approximately 280 trees per acre, which is approximately 55 percent of the original planned density of 500 per acre. The planted bare root species that have better survivability are tulip poplar, black oak, red maple, red bud, and sweet gum. Red maple, persimmon, sweet gum, and loblolly pines are sprouting voluntarily. Compared to the May 2012 monitoring event, the average herbaceous ground cover has remained approximately the same. Based on the monitoring, the upland area of Zone 2, represented by Plots 2, 3, 5, and 6, appear to have decreasing survivability for planted trees than the areas closest to Reach A, represented by Plots 1 and 4. The monitoring reports are provided in Attachments 1 to 3. ACTIONS PERFORMED Repair of rill erosion along the northern portion of Step Pool #1 was repaired in May 2012, �� i Ward Transformer Superfund Site Reach A Monitoring October 23, 2012 Mr. Hilary Thornton and Mr. Danny Smith 3 053-3184D ANTICIPATED ACTIONS Re -planting has been scheduled for November 2012, targeting the upland of Zone 2 where tree survivability is low using the following previously planted species that had the better survivability and adding black locust and loblolly pine: Common Name Scientific Name Red maple Acer rubrum Red bud Cercis canadensis Sweet gum Liquidambar styraciflue Tulip poplar Liriodendron tutipifera Black oak Quercus velutina Black locust Robinia pseudoacacia Loblolly pine Pinus taeda Black locust has nitrogen fixation characteristics and loblolly pine has been observed as a strong volunteer at the Site. Depending on available nursery stock, species substitutions may be required. Re- planting will be conducted in accordance with the specifications provided in Drawing SR-104 from the Reach A Reconstruction Plan approved by NCDENR on March 22, 2011. Should you have any questions regarding the revised planting plan or the monitoring results, please contact the undersigned at (770) 492-8209 or the Trust's Project Coordinator, Mr. William G. Weir of CONSOL Energy Inc., at (724) 485-4604. GOLDER ASSOCIATES NC, INC. Geraldine S. Monroy Associate cc: Mr. William G. Weir, CONSOL Energy Inc. (by email) Mr. Henry Lyon, Progress Energy Carolinas, Inc. (by email) Mr. Daniel M. Darragh, Cohen & Grigsby, PC (by email) Mr. Michael Brom, PCS Administration (USA), Inc. (by email) Mr. Nile Testerman, NCDENR (by email) Attachments: Attachment 1: May 2012 Reach A Monitoring Report Attachment 2: July 2012 Reach A Monitoring Report Attachment 3: September 2012 Reach A Monitoring Report GM:gm ,NIt..1 11N iw..w .­.w 1,.,..­M[rn'1-'1lN kinwY...... �?m km.* :, II..J.. W..—­k►y I•.� 1] ­3 AV..—..,,S PAat"kd . GYA=rtes -Z Ile, wT L Az ;rpm^ 7 ------ 7" C N \��\,\ \,.�11\� r `\�\\�,,_� �`\\ � �L��~-ram-� � ^ ��// � �\\\ \ ._ � '�� It����`� �� LEGEND REFERENCES MT 1.) AS -BUILT INFORMATION FROM DRAWING TMED -POST REMOVAL ACTION CONIXTIONS (2 OF 2r.PREPARED OYFLEMR4NGENGINEERING- INC. DATED 8iIlrX"l. MVLCR PEVI DAIS I ms I PEWSM 0E9CIW'V= I CAM PROAtT TURF REINFORCED MJLTTW#G WARD TRANSFORMER SUPERFUND SITE HYDROSEEDING RALEIGH, NORTH CAROLINA CUSTOM BLEW SEEDING TIRF REACH A M VISUAL AND VEGETATION StREAMSCOIR MATTING MONITORING LOCATIONS ■ VEGETATION moNr70Rb4G PLOT LOCATION Pflo'cCT N. 053-3t643 FILE H. DESIGN SCALE AS ;;Q=*NREV. do-f SEPTEMBER 2012 VISUAL MONrrORiNG PHOTOGRAPH LOCATION AND DIRECTION CADD CCP 10 1 CHECK GM I [O/11 FIGURE I Kwwl mi 10/1, FACILITY: COUNTY �tJC CITY: PERMIT NUMBER q� Permit Information that needs to be Incorporated into Future Permit Revisions DATE COMMENTS Temporary Erosion and Sedimentation Control Plan — Phase 2 Removal Action Ward Transformer Superfund Site Raleigh, North Carolina Prepared for: DeNovo Constructors, Inc. Prepared by: ENVIRON Engineers of North Carolina Date: December 2012 Project Number: 21-31284 B t j ENVIRON 1 I fl 1 11 1 1 I Erosion and Sedimentation Control Plan — Phase 2 Removal Action Contents 1 Introduction 1.1 Site Location and Definition 1 2 Overview of Removal Action 2 Site Setting 2.1 Topography and Surface Water Hydrology 2.2 Soils 2.3 Land Use 3 Erosion and Sediment Control Practices 3.1 Temporary Gravel Construction Entrance/Exit — Practice 6.06.1 32 Temporary Sediment Traps — Practice 6.60.1 3.3 Temporary Diversions — Practice 620.1 3.4 Check Dams — Practice 6.83.1 3.5 Outlet Stabilization — Practice 6.41.1 3.6 Rip -Rap and RECP Channels — Practice 6.31 1 and 6.17 1 3.7 Sediment Fence (Silt Fence) — Practice 6.62.1 3.8 Land Grading -- Practice 6.02 1 3.9 Surface Stabilization and Roughening — Practice 6.03.1 3.10 Porous Baffles — Practice 6.65 3.11 Waste Soil Stockpiling 3.12 Dust Control 4 Construction Sequence 4.1 Erosion and Sediment Control Measures Sequence 5 Vegetative Plan 51 Seedbed Preparation 5.1.1 Fill Slopes 3:1 or Steeper (Temporary Seeding) 5.1.2 Gentle or Flat Slopes 5.2 Seeding Method (SM) 5.2.1 Temporary Seeding on all slopes 5.3 Mulch (MU) 5.31 Fill Slopes 3:1 or Steeper (Temporary Seeding) 5.32 Gentle or Flat Slopes Page 1 1 1 3 3 3 3 4 4 4 4 4 5 5 5 5 6 6 6 6 7 7 8 8 8 8 8 8 9 9 9 6 Personnel Training, Inspection, Recordkeeping, and Maintenance Plan 10 6.1 Personnel Training 10 6.2 Inspection and Maintenance Practices and Schedule 10 6.3 Record Keeping and Internal Reporting 11 7 References 12 Contents i ENVIRON Erosion and Sedimentation Control Plan — Phase 2 Removal Action List of Figures Figure 1: Site Location Map Figure 2: Disturbance Areas Figure 3: Existing Topography and Surface Drainage Areas Figure 4: Soil and Riparian Buffer Map Figure 5: Erosion and Sedimentation Control Plan - Estes Property Figure 6: Erosion and Sediment Control Plan - RDU Reach 1 Figure 7: Erosion and Sedimentation Control Plan - RDU Reach 2 and 3 Figure 8: Erosion and Sediment Control Details (1 of 3) Figure 9: Erosion and Sediment Control Details (2 of 3) Figure 10; Erosion and Sediment Control Details (3 of 3) List of Appendices Appendix A: NCDENR Inspection and Maintenance Report Form Appendix B: Erosion and Sedimentation Control Plan Preliminary Review Checklist Appendix C: Supporting Calculations C.1: Time of Concentration C.2: Rainfall Intensity Appendix D: Erosion Control Standard Specifications Contents ii ENVIRON F] 1 Erosion and Sedimentation Control Plan -- Phase 2 Removal Action 1 Introduction This Temporary Erosion and Sediment Control Plan (E&SC Plan) has been developed by ENVIRON Engineers of North Carolina, Professional Corporation (EENCPC) on behalf of DeNovo Constructors, Inc. (DeNovo) for use during the Phase 2 Removal Action at the Ward Transformer Superfund Site (the "Site"). The Phase 2 Removal Action will be conducted in accordance with the United States Environmental Protection Agency (USEPA)-approved Removal Action Plan (RAP) dated April 2006 with the specific scope for Phase 2 in the RAP, Addendum No. 2, Revision 7 (the "Phase 2 RAP") dated October 12, 2012. The Temporary E&SC Plan has been prepared in accordance with the requirements of the North Carolina Department of Environment and Natural Resources (NCDENR) Erosion and Sediment Control Design Manual. The permanent E&SC measures will be presented in the Stream Reconstruction Plan that will be submitted at a later date. 1.1 Site Location and Definition The Site is located in a predominantly industrial area of Wake County, North Carolina, on and adjacent to the Raleigh International Airport (RDU). The Site location is illustrated on Figure 1. The boundaries of the Site fall within the Estes Express Line (Estes) terminal located on ' property owned by Denovo Morrisville, LLC (Denovo Morrisville), property owned by Raleigh - Durham Airport Authority (RDU) located south of the Estes property, North Carolina Department of Transportation right of way along portions of 1-540 adjacent to the RDU property and portions of Lumley Road, which cuts through RDU Property, and property owned by Ward Ventures LLC between Lumley Road and 1-540. 1 1 The Phase 2 RAP for the Ward Transformer Superfund Site provides the estimated extent of polychlorinated biphenyl (PCB) -impacted areas based on the results of sampling, to date. Additional sampling to be conducted during the Removal Action may extend and/or identify further PCB -impacted areas. Consequently, the term Site as used in this E&SC Plan incorporates those areas now defined in the RAP, those areas that may be defined during the Removal Action, and associated disturbance areas including construction laydown areas and new access roads. The total area of disturbance is 12.5 acres The Site boundaries based on currently available information are shown on Figure 2. 1.2 Overview of Removal Action The Phase 2 Removal Action of the Ward Transformer Superfund Site will include excavation and off -site disposal of soil, sediment, and debris (collectively the "soil") with PCB concentrations above 1.0 milligrams per kilograms (mg/kg). Because the potential for PCB migration is via sediment transport in surface water, the removal action at the Estes property, RDU, and Ward properties will be from upstream areas to downstream areas. The removal action at the Estes property will generally be completed prior to initiating work at the other two properties, and rights -of -way. Given the terrain on the RDU property, small tracked equipment and mini -excavators are expected to be used to excavate the soil and remove other materials from portions of this property, as appropriate. Excavated material from the shallow excavations around the Estes I Introduction 1 ENVIRON Erosion and Sedimentation Control Plan — Phase 2 Removal Action property will be direct loaded for off -site disposal. Excavated material from all other excavation areas will be temporarily staged on site prior to loading for off -site disposal. The stockpile areas will be located in the laydown areas on the RDU property south of Estes and south of Lumley ' Road (later referred to in this document as RDU Reach 1 and RDU Reach 2). Loading and transportation of excavated soil for off -site disposal will be accomplished in a manner that minimizes the potential for release of the soil during the loading and transportation activities. For dust control, water may be sprayed on the soil and/or other approved dust control measures. E&SC controls as described in Section 3 will be implemented prior to beginning disturbance and excavation activities in a removal area. The excavated area will be backfilled with clean fill and returned to pre -removal grade and surface; re -vegetation will be accomplished in accordance with the Vegetation Plan in Section 5. Portions of the streams located within the various reaches within the Neuse River Riparian Buffer will be reconstructed in accordance with the approved Stream Reconstruction Plan. I 1 1 1 Introduction 2 ENVIRON 1 1 Erosion and Sedimentation Control Plan — Phase 2 Removal Action 2 Site Setting 2.1 Topography and Surface Water Hydrology The Estes property is generally flat with a very gradual slope from northeast to southwest. A storm water pipe directs water from the Mt Herman Road ditch under the Estes property. The RDU removal areas are located within and adjacent to an intermittent creek which slopes gradually from northeast to the southwest flowing through culverts under Lumley Road at two locations and then joining Reach A before flowing through a culvert under Interstate 1-540 into Reach B (an unnamed tributary to Little Brier Creek), Figure 3 shows the Site topography. The Removal Action will not change the total run-off from the site. Excavations made during the Removal Action will be backfilled to approximately the same grades and surface conditions as before excavation. ' 2.2 Soils Based on information from the City of Raleigh and Wake County MAPS website, soils on the Estes property are identified as Creedmore sandy loam in the B and C slope classes; the surface of the Estes property is general compacted gravel fill with low permeability. The soils in RDU Reach 1 are primarily Creedmore sandy loam with B (2%-6%) and E (10%-20%) slopes. The soils in Reach 2 and 3 are primarily Chewacla fine sandy loam and silt loam soils. Chewacla soils are found in lowland floodplain areas and have slopes of 0%-2%. Figure 4 shows soils present at the Site. 2.3 Land Use The Estes property is zoned as TD (thoroughfare district) and the RDU property is zoned for airport use. The TD zoning district permits land use for retail, office, and industrial uses. Properties adjacent to the Phase 2 Removal Action area include the Phase 1 Removal Action area to the north, private airport parking to the east, the RDU airfield and undeveloped woodland to the south, and 1-540 to the west. Based on information from the City of Raleigh and Wake County MAPS website, the majority of the intermittent creek running through the Site is associated with the Neuse River Basin. These portions of the intermittent creek are subject to the Neuse River Basin Buffer Rules. Figure 4 shows the location of the Neuse River Buffer zone. 1 1 ISite Setting 3 ENVIRON Erosion and Sedimentation Control Plan — Phase 2 Removal Action 3 Erosion and Sediment Control Practices Erosion and sediment control devices have been designed and will be implemented during construction in accordance with the E&SC Manual. The implementation of the measures will minimize the potential for soil erosion and sedimentation during and after project implementation. The erosion and sediment control measures that will be implemented during project construction are presented in the drawings provided in Figures 5, 6, and 7. The proposed erosion control measures are outlined in the following sections. 3.1 Temporary Gravel Construction Entrance/Exit — Practice 6.06.1 Temporary gravel construction entrances will be installed near the southeast corner of the Estes property, and at the east end of the RDU Reach 2 laydown area. The stabilized entrance will consist of a ramp of crushed stone extending a minimum distance of 50 feet installed at the point of ingress and egress from the construction area. The purpose of the device is to minimize the potential of tracking sediment off -site. Temporary gravel entrances/exits are shown on Figures 5, 6, and 7, details are provided on Figure 8, and the standard specification is provided in Appendix D-1. 3.2 Temporary Sediment Traps — Practice 6.60.1 There will be five temporary sediment traps installed during the Phase 2 Removal Action; two for RDU Reach 1 and 2, and one for Reach 3. Once excavation is completed upstream of a sediment trap, the trap will be cleaned to remove collected sediments and the check dam will be used to retain clean water. The retained water will be diverted or pumped around downstream removal areas. In RDU Reach 1, there will be a sediment trap constructed south of where the access road crosses the drainage channel and then another just upstream for the Lumley Road culvert which will drain approximately 3.1 and 1.2 acres, respectively. In RDU Reach 2, there will be sediment traps at the upstream and downstream ends of the reach which will collect sediment from approximately 0.2 and 0.9 acres of disturbed land respectively. Finally, in Ward Reach 3, there will be a sediment trap located at the downstream end of the reach just upstream of the 1-540 culvert, which will collect sediment from approximately 1.0 acres of disturbed land. Sediment traps are shown on Figures 6 and 7, details are provided on Figure 9, the standard specification is provided in Appendix D-2, and the design calculations are shown in Appendix C. 3.3 Temporary Diversions — Practice 6.20.1 Temporary diversions will be used during the excavation in RDU Reach 1, 2, and 3 to control run-on from entering the disturbed areas. Diversion ditches are shown on Figures 5, 6 and 7, details are provided on Figure 8, and the standard specification is provided in Appendix D-3. 3.4 Check Dams — Practice 6.83.1 Check dams will be used for two purposes during the Phase 2 excavation. Check dams will be used to slow down water in temporary diversions and water flowing through the main channel. Additionally, in locations where large areas of undisturbed land drain to the removal area, larger diversion berms will be installed to manage run-on. The diversion berms will be constructed to retain run-on from smaller storms long enough to allow for the water to be pumped around the excavation area. In advance of forecasted larger storms, DeNovo will temporarily cease 1 1 1 1 1 1 1 1 Erosion and Sediment Conrol Practices 4 ENVIRON 1 Erosion and Sedimentation Control Plan - Phase 2 Removal Action ' additional soil removal activities and backfill all open excavations within the streams. In these cases, the water will be allowed to overtop the diversion berm. Certain check dams and diversion berms are shown on Figures 5, 6, and 7, details are provided on Figure 10, and the standard specification is provided in Appendix D-4. I3.5 Outlet Stabilization — Practice 6.41.1 Outlet stabilization, consisting of a rip -rap apron, will be installed at the discharge of diversion ditches and piping to prevent scour. Outlet Stabilization structures are shown on Figures 6 and 7, details are provided on Figure 9, and the standard specification is provided in Appendix D-5. 3.6 Rip -Rap and RECP Channels — Practice 6.31.1 and 6.17.1 A combination of rip -rap and erosion control mats (RECP) may be installed to protect the temporary diversion berm drainage channels after completion of excavation and backfill activities in RDU Reach 1, 2 and 3. Calculations provided in Appendix C indicate that the shear stress along the channel perimeter ranges from 0,48 -1.02 pounds/square feet (lb./SF). It is 1 assumed that a constant channel bed slope of 1% will be maintained for all channels. Where steeper slopes are necessary to accommodate field constraints, additional velocity control measures like check dams will be installed. RECP channel details are provided on Figure 10, and the standard specification is provided in Appendix D-6. A combination of rip -rap and RECP may be installed to protect the drainage channel after ' completion of excavation and backfill activities in RDU Reach 1, ,2 and 3. Final channel restoration will be based on the Stream Reconstruction Plan. Channels will be reconstructed to the existing cross-section; where channel side slopes are steeper than 3:1, the channel will be reconstructed with 3:1 slopes. 3.7 Sediment Fence (Silt Fence) — Practice 6.62.1 Silt fences will be installed to reduce runoff velocity and affect deposition of transported sediment load on the Estes property and the construction laydown areas. The purpose of silt ' fences is to intercept and detain sediment contained within runoff from on -site disturbed areas. Sediment fencing is shown on Figures 5, 6, and 7, details are provided on Figure 8, and the standard specification is provided in Appendix D-7. ' 3.8 Land Grading — Practice 6.02.1 Areas excavated during the Removal Action will be backfilled using clean fill from an off -site borrow source or "clean" fill from an on -site source and re -graded to a slope matching the original grade. Where the drainage channel slopes are steeper than 3:1, the slope will be graded back to a desired 11 slope or to the extent practicable based on field conditions. Soil on the slope of the Lumley Road embankment will not be removed inside a 2 horizontal to 1 vertical line extending downward from the top shoulder of the embankment in accordance with the access agreement with the North Carolina Department of Transportation (NC DOT). ' Excavation areas to be filled are shown on Figures 5, 6, and 7, and the standard specification is provided in Appendix D-8. IErosion and Sediment Conrol Practices 5 ENVIRON Erosion and Sedimentation Control Plan — Phase 2 Removal Action 1 3.9 Surface Stabilization and Roughening — Practice 6.03.1 Surface roughening will be implemented to facilitate the surface stabilization activities which will be accomplished with vegetation and mulch as specified in the Vegetative Plan, Section 5. The standard specification is provided in Appendix D-9. 3.10 Porous Baffles —Practice 6.65 Porous baffles will be used to facilitate sedimentation in temporary sediment traps. The standard specification is provided in Appendix D-10 and details are provided on Figure 9. 3.11 Waste Soil Stockpiling Material excavated during the removal action within the Reaches will be stockpiled prior to off - site disposal. These stockpiles will be placed in lined waste containment areas as specified in DeNovo's Operation Plan to be approved by the USEPA. The approximate location of the waste soil stockpiles are shown on Figures 5, 6, and 7, 3.12 Dust Control Dust control will be accomplished through the use of vegetative cover, mulch, watering, or barriers, as described in the Vegetative Plan. Construction operations will be scheduled to minimize the amount of area disturbed at one time. Water will be applied by sprinkler or water truck as necessary during grading operations to minimize sediment transport and maintain acceptable air quality conditions. 1 I I 1 1 1 1 1 Erosion and Sediment Conrol Practices ENVIRON I Erosion and Sedimentation Control Plan — Phase 2 Removal Action 4 Construction Sequence 4.1 Erosion and Sediment Control Measures Sequence Removal actions will be conducted from upstream to downstream starting at the Estes property and ending at the 1-540 culvert in Ward Reach 3. In each of the reaches, the Removal Action will be conducted in the following general sequence: • Hold preconstruction conference at least one week prior to starting construction to discuss erosion and sediment controls. Meet as necessary throughout the duration of the project to discuss continuing erosion and sediment controls. • Install temporary gravel construction entrance/exit where site traffic is expected to enter and exit the site on a daily basis. • Flag the excavation areas as work progresses. • Construct the sediment trap at the downstream end of excavation area or install the sediment fence for the Estes property removal area. • Construct temporary diversions around excavation area and outlet protection at the discharge, if required. • Install check dam(s), if required. • Install laydown area silt fence and construct laydown area. • Excavate soil in specified areas, backfill with clean soil, and stabilize backfilled areas with mulch and temporary seed as specified in the vegetation plan or filter fabric and rip -rap as specified in the plan. In general, excavation will progress from upstream to downstream. As a goal, excavated areas will be backfilled the same day so that excavations are not left open overnight and check dams will be routinely installed downstream of excavated and restored areas. To the degree practicable, excavation and backfill will not be performed during storm events. • Once the Site is stabilized with vegetation, remove all temporary erosion and sediment control measures. Construction Sequence 7 ENVIRON Erosion and Sedimentation Control Plan - Phase 2 Removal Action 5 Vegetative Plan As individual excavation areas are completed, grass seed will be applied as quickly as is practicable. The specific type of grass seed to be used will depend on the time of year that the excavation area is backfilled. Temporary grasses will be used to quickly establish a grass cover on disturbed areas except for the Reach B channel and Estes properties. The total area to be temporarily stabilized with vegetation is approximately 12 acres. Permanent grasses will be specified in the Stream Reconstruction Plan. The following sections describe the general approach for seedbed preparation, seeding and mulching methods and maintenance for the Phase 2 Removal Action. Once DeNovo's work is completed, which includes establishing permanent vegetation in accordance with the Stream Reconstruction Plan, maintenance will be the responsibility of DeNovo for a year and then the individual property owners thereafter. 5.1 Seedbed Preparation 5.1.1 Fill Slopes 3:1 or Steeper (Temporary Seeding) • Leave a loose, uncompacted surface. Remove large clods, rocks, and debris, which might hold netting above the surface. . Spread lime and fertilizer evenly at rates recommended by soil tests. • Incorporate amendments by roughening or grooving soil surface on the contour. 5.1.2 Gentle or Flat Slopes • Leave a loose, uncompacted surface. Remove large clods, rocks, and debris that might hold netting above the surface. • Spread lime and fertilizer evenly at rates recommended by soil tests. • Break up large clods and rake into a loose, uniform seedbed. • Incorporate amendments by roughening or grooving soil surface on the contour. 5.2 Seeding Method (SM) 5.2.1 Temporary Seeding on all slopes • Broadcast seed at the recommended rate with a cyclone seeder, drop spreader, or cultipacker seeder. Late Winter/Early Spring (Jan 1 to May 1) -- Rye (Grain): 120 Ibs.lacre -- Kobe lespedeza: 50 Ibs.lacre — Summer (May 1 — Aug 15) -- German Millet: 40 Ibs.lacre -- Sudangrass at 50 Ibs.lacre can be substituted 1 1 F' L F L_ 7 L Vegetative Plan 8 ENVIRON I Erosion and Sedimentation Control Plan — Phase 2 Removal Action — Fall (Aug 15 — Dec 30) -- Rye (Grain): 120 Ibs.lacre • Rake seed into the soil and lightly pack to establish good contact. 5.3 Mulch (MU) 5.3.1 Fill Slopes 3:1 or Steeper (Temporary Seeding) • In mid -summer, late fall or winter, apply 100 Ib.11,000 square feet (ft) grain straw. In spring or early fall use 45 Ib.11,000 ft2 wood fibers in a hydroseeder slurry. • Cover with jute or excelsior netting and staple to the slope per the manufacturer's specification. 5.3.2 Gentle or Flat Slopes • Apply 4,000 lb./acre grain straw • Tack immediately with 0.1-gallon per square yard (gallyd2) asphalt (11 gaI11,000 ft). Vegetative Plan 9 ENVIRQN Erosion and Sedimentation Control Plan -- Phase 2 Removal Action 6 Personnel Training, Inspection, Recordkeeping, and Maintenance Plan The following section specifies the requirements for maintaining and inspecting erosion controls during the Removal Action, DeNovo's Site Manager, Dan Felton, will be responsible for implementing the Maintenance Plan. 6.1 Personnel Training During the Removal Action, personnel will be given responsibility for inspections, maintenance and repair activities, and the corresponding documentation. Personnel selected for inspection and maintenance responsibilities will have been or will be trained in the inspection and maintenance practices necessary for keeping the erosion and sediment controls in good working order. The training program will include: • Briefings for field personnel regarding the scope and importance of erosion and sedimentation control; and • Training for the personnel authorized to perform the inspections and administrative duties of the erosion and sediment control program. The employee briefings will address the following areas: • Sedimentation and erosion prevention - a review of the purposes and goal of the Storm water Pollution Prevention Plan (SPPP), potential sources of sediment and erosion measures employed, and the role of the field personnel in sediment and erosion prevention; . Pollution control laws and regulations pertaining to sediment release; and . The importance of sedimentation and erosion prevention. 6.2 Inspection and Maintenance Practices and Schedule The following inspection and maintenance practices will be used to maintain erosion and sediment controls during construction activities. • Erosion and control measures, as well as storm water discharge points, will be inspected a minimum of twice a week because the Site discharges into a 303(d) impaired watershed. • Control measures, as well as storm water discharge points, will also be inspected within 24 hours after any precipitation of 0.5 inches or greater in any 24-hour period since the last inspection as measured at the RDU weather station. . Areas that have been permanently stabilized will be inspected at least twice weekly. • Control measures will be maintained in good working order; repairs will be initiated within 24 hours of being reported. • Sediment in sedimentation traps will be removed when it reaches one-half of the design depth. Sedimentation control structures will be inspected for erosion, piping and risk of displacement after each significant rainstorm (0.5 inches or greater), and will be repaired immediately. Personal Traning, Inspection, Recordkeeping, 10 ENVIRON and Maintenance Plan 1 I 1 Erosion and Sedimentation Control Plan — Phase 2 Removal Action • Breaches in diversion and containment dikes will be promptly repaired. • Silt fence will be inspected for: - Depth of sediment (should be less than 6 inches at the fence), - Fabric damage or tears, - Fabric is secured to fence post, and - Fence posts are firmly grounded. • Temporary and permanent vegetative cover will be inspected twice weekly for bare spots, washouts, and healthy growth. Repairs will be made, as necessary. 6.3 Record Keeping and Internal Reporting Recordkeeping and reporting for maintenance activities are a part of the E&SC Plan. A log will be kept of inspection and maintenance activities and to evaluate the effectiveness of the E&SC program, equipment, and operation. A maintenance inspection report will be made after each inspection. Inspections should be documented on the NCDENR Inspection and Maintenance Report Form, which is included in Attachment A. This form documents rainfall events, structural control inspections, and other erosion control inspections. The following techniques may also be used to generate and document the information required by the NCDENR Storm Water Inspection Form: . Field notebooks and inspection forms; • Timed and dated photographs, or video tapes; and . Drawings, sketches and/or maps. The Respondents will be provided copies of the inspection reports. These reports will be provided within one calendar week following the week of each inspection. All other required forms and reports will be forwarded with the weekly reports. Original records of inspections and maintenance activities will be retained by DeNovo throughout the Removal Action, and copies of these records will be available to EPA, if requested. At the completion of the Removal Action, original records will be transferred to the Respondents, with copies retained by the DeNovo. A summary of the E&SC activities will be included in the Construction Completion Report to be submitted to the USEPA under the terms of the Settlement Agreement. Personal Traning, Inspection, Recordkeeping, 11 ENVIRON and Maintenance Plan Erosion and Sedimentation Control Plan — Phase 2 Removal Action 7 References Golder Associates, Inc., 2005. Example Erosion and Sedimentation Control Plan For The Ward Transformer Superfund Site, Raleigh, North Carolina. Golder Associates, Inc., 2012. Addendum No. 2 — Ward Transformer Removal Action Plan, Revision 7 Phase 2 — Estes Property and RDU Property. October 12, 2012. North Carolina Department of Environment and Water Resources, North Carolina Erosion and Sedimentation Control Planning and Design Manual, 2006. References 12 ENVIRON I Erosion and Sedimentation Control Plan - Phase 2 Removal Action Figures ENVIRON I I I I I I I I I I I I I I I I I I I 112 0 200n 0 2000 4000 6000 FEET LEGEND APPROXIMATE PROPERTY BOUNDARY ' SOURCE Google Eart dated June 17, 2008. t ENVIRON 0$4AI T t 11 BY C N DATE 11120/12 SITE LOCATION MAP WARD TRANSFORMER SUPERFUND SITE RALEIGH, NORTH CAROLINA FIGURE 1 >�T 312f!nH / loop / " 1 - -% f ! .01 TEMPORARY TRAILER/ EMPLOYEE PARKING ADDITIONAL TRAILER PARKING E57ES / PROPERTY ■ 7 f LAYDO" I ACCE 1 ' ROAD SOUTH I � - I � l TEMPORARY TRAILER/ EMPLOYEE PARKING 1 _ r 0 LEGEND -- APPROXIMATE PROPERTY BOUNDARY — SURFACE WATER & DRAINAGE — PIPE LOCATION PHASE I REMOVAL ACTION ® EXISTING ACCESS ROAD AND PAD PROPOSED PIPE ALIGNMENT BELOW GROUND SURFACE IN CLEAN SOIL _ ESTIMATED EXCAVATION AREA ® 25-FT DISTURBANCE AREA BUFFER LAYDOWN AREAS oaoaaa AREA FOR ADDITIONAL INVESTIGATION oaa000 NOTE, 1 Data as of August 31 2011 2 Total area distur ed is appro i atel 12 5 acres. REFERENCES: 1 Wa a Count GIS, 1 2002 2 Weston Solutions, Inc, 2005 3 fie ing Engineering, Inc 2006, 2007 4 Projection: Nort Carolina State Plane one 3200. Datu : NAD 83 APPROX SCALE ,ft i 0 250 I I I I I I I I I I I I I I I I I I I I I 'do IJ WT 70W / WARD 't -- i rvr low — �.� �• - I WARD /WAR D I WARD .01 VENTURES.04 U / RDU 100 RDU EST 1 \ RDU UA5 3 ACRES , Gr._ ,� - 51 ACRES C_•. ,j r ' RDU � ACRES (CO201 R DAo DATI I ACRES DA14 0 7 ACRES IC 0451 , 46 ACRES kk �Dh' • i Or1C' �B \ , 1206ACRES 09 ACRES �c a 20 iC 0451 C � ' 45 ACRES \ RDU 252 ACRES / C 0 15) \/ / RDU S / l � / 1 / 1 f 1 , V O 2 %-- 000 6 s LEGEND --- APPROXIMATE PROPERTY BOUNDARY — — SURFACE WATER & DRAINAGE PIPE LOCATION PHASE I REMOVAL ACTION NOTE Data as of August 31 2011 REFERENCES 1 Wa a Count GIS, 1 2002 2 Weston Solutions. Inc. 2005 3. Fle ing Engineering. Inc_ 2006. 2007 4 Projection Nort Carolina State Plane one 3200. Datu NAD 83 APPROX SCALE(R) a 350 1 I 1 CrE _ CrC2 MfC2 f CrB2 MfB2 i P CrC2 CrC2 w CrC _ _--- MfE MfB CrC2 CrE CrB2 CrE L CrB CrE Cm , I I I I I CrE ` CrB2 -� CrC2 CrC ` CrC CrC CrE CrC CrB CrC CrB2 lei Q LEGEND Z Q APPROXIMATE SITE BOUNDARY _ NEUSE RIVER BASIN RIPARIAN BUFFER W CrE CREEDMORE SANDY LOAM \1 (10-20 PERCENT SLOPES) CrC CREEDMORE SANDY LOAM `• (6-10 PERCENT SLOPES) ? CrC2 CREEDMORE SANDY LOAM (6-10 PERCENT SLOPES. ERODED) CrB2 CREEDMORE SANDY LOAM (2-6 PERCENT SLOPES, ERODED) \ Cm CHEWACLA SOILS NOTE: The location of the riparian buffer is based an the stream segment shorn CrB on the 2010 USGS Southeast Durham 7.5' Quadrangle Map. Soils layout adapted from City of Raleigh. Wake County, #MAPS http:llmaps.ralei hnc.govrMAPSfrnda.html CrC CrC2 - CrB2 MfB2 - - - Me APPROX. SCALE (R) 0 25C 1 1 f ADDITIONAL TRAILER PAR ING ; (SEE NOTE 1) r------------------- CLEAN SOIL STORAGE rFR r�Fq rMENTp �Nr APPROY `_ALE (ft.� n 100 1 -- l I- TEMPORARY TRAILER/ EMPLOYEE PAR 1NG (SEE NOTE 1) j f f +. man f , + r ! t r r �t f r r r f r t r f t f r r + ! r f r 1 i 1 ; 1 � � 1 + r 1 l r f + + r ! I + I I' r 9 i- _ FIELD OFFICE EQUIPMENT STORAGE + t , 'OIL STORAGE r , t � t r`• tyO�E. til EX1STtNG ACGESS ROAD(SEE 1 LEGEND ---- APPROXIMATE PROPERTY BOUNDARY — — — SURFACE WATER & DRAINAGE � PROJECTED PIPE LOCATION PHASE I REMOVAL ACTION ® EXISTING ACCESS ROAD AND PAD PROPOSED PIPE ALIGNMENT BELOW GROUND SURFACE IN CLEAN SOIL _ ESTIMATED EXCAVATION AREA L� 25-FT DISTURBANCE AREA BUFFER LAYDOWN AREAS 9R0000 AREA FOR ADDITIONAL INVESTIGATION op0000 CONSTRUCTION ENTRANCE / EXIT LINED WASTE CONTAINMENT AREA ----- SILT FENCE ``tit` 4a1. TEMPORARY GRAVEL RAMP NOTES, 1, Existing gravel surfaces are stabilized and will not be disturbed during construction operations. Therefore. specific Sl are not proposed for these areas at this time. In the event that these stabilized gravel surfaces or adjoining areas are disturbed then appropriate l will be designed and installed as necessary 2- Only excavate areas that can be restored in the same day. 3 Water check dams will be installed upstream and downstream of the excavation area daily to slow water flow and prevent sedimentation; also used for pumping water around in the event of an emergency. 4. Once areas upstream of sediment traps are remediated. pumps will be used to pump water around remediation areas during light rain stomas (<I- nch); during larger storms water will be allowed to exit and downstream excavation areas will be protected against erosion. REFERENCES 1- Wake County GIS, 1999,2002 2. Weston Solutions, Inc., 2005 3. Fleming Engineering, Inc. 2006, 2007 4- Projection, North Carolina State Plane Zone 3200 Datum NAD 83 1 11 t r- v ,� � rye � -• � J '. .., � \ _• ` _ `- I TEMPORARY TRAILER/ I _ ~ ' EMPLOYEE PAR ING (SEE NOTE 1) ADDITIONAL _ z / - TRAILER PAR . ING (SEE NOTE 1) i~ _ r r ^ ESTES t PROPERTY 7 1 � , 1 r 1 r 1 ! r i r � 1 , ----- + r r GH2 1 1 + J ' FIELD WASTE SOIL �k ',OFFICE STORAGE r ' — ; CLEAN SOIL + SrFw�TFR� STORAGE OTE1) ,tgi1NG ACCESS ftOAO iSEE � E _ NT EQUIPMENT STORAGE ■ TS3 �J `VMS � --Nowol ROgQ � 1 APPROX. SCALE Ift + 150 � LEGEND --- APPROXIMATE PROPERTY BOUNDARY — — SURFACE WATER & DRAINAGE r+� PROJECTED PIPE LOCATION PHASE I REMOVAL ACTION ® EXISTING ACCESS ROAD AND PAD PROPOSED PIPE ALIGNMENT BELOW GROUND SURFACE IN CLEAN SOIL _ ESTIMATED EXCAVATION AREA 25-FT DISTURBANCE AREA BUFFER LAYDOWN AREAS nnnnna AREA FOR ADDITIONAL INVESTIGATION nnnono CONSTRUCTION ENTRANCE 1 EXIT LINED WASTE CONTAINMENT AREA f - TEMPORARY SEDIMENT TRAP TEMPORARY DIVERSION BERM — — — — TEMPORARY DIVERSION BERM ------- SILT FENCE ;;.` TEMPORARY GRAVEL RAMP Q TEMPORARY OUTLET PROTECTION NOTES: 1. Existing gravel surfaces are stabilized and will not be disturbed during construction operations. Therefore, specific BMPs are not proposed for these areas at this time. In the event that these stabilized gravel surfaces or ad}oining areas are disturbed, then appropriate BMPs will be designed and installed as necessary. t 2. Only excavate areas that can be restored in the same day. 3. Water check dams will be installed upstream and downstream of the excavation area daily to slow water flow and prevent sedimentation: also used for pumping water around in the event of an emergency 4. Once areas upstream of sediment traps are remediated, pumps will be used to pump water around remediation areas during fight rain storms (<1-inch), during larger storms water will be allowed to exit and downstream excavation areas will be protected against erosion REFERENCES'. 1. Wake County GIS. 1999, 2002 2. Weston Solutions, Inc., 2005 3 Fleming Engineering, Inc. 2006, 2007 4. Projection. North Carolina State Plane Zone 3200, Datum. NAD 83 1 / Ala %Y SAO TS ,1 000, r I -------- - - - - ---- - - - - -- 1 ; CH8 RDU S% ` 1 REACH 3� ♦� ♦ \ ' ... CH4 CLEAN SOIL !moat � EQUIPMENT ` GH5 � \ ^ � STORAGE �. ,STORAGE 1 RDU— . CH6 REACH 2 r �� f / WASTE SOIL - / / STORAGE .� I / - 1 f Ole � / � \ APPROX SCALE{fl} 0 150 LEGEND --- APPROXIMATE PROPERTY BOUNDARY — SURFACE WATER & DRAINAGE PROJECTED PIPE LOCATION PHASE I REMOVAL ACTION ® EXISTING ACCESS ROAD AND PAD ®PROPOSED PIPE ALIGNMENT BELOW GROUND SURFACE IN CLEAN SOIL _ ESTIMATED EXCAVATION AREA EM 25-FT DISTURBANCE AREA BUFFER LAYDOWN AREAS AREA FOR ADDITIONAL INVESTIGATION CONSTRUCTION ENTRANCE / EXIT LINED WASTE CONTAINMENT AREA l- TEMPORARY SEDIMENT TRAP TEMPORARY DIVERSION BERM — — — — TEMPORARY DIVERSION BERM ------- SILT FENCE TEMPORARY OUTLET PROTECTION NOTES. 1 Only excavate areas that can be restored in the same day. 2 Water check dams will be installed upstream and downstream of the excavation area daily to slow water flow and prevent sedimentation; also used for pumping water around in the event of an emergency. 3. Once areas upstream of sediment traps are remediated, pumps will be used to pump water around remediation areas during light rain storms (<1-inch); during larger storms water will be allowed to exit and downstream excavation areas will be protected against erosion 4. Clean soil and waste soil from RDU Reach 3 will be stockpiled in the RDU Reach 1 laydown area. REFERENCES 1 Wake County GIS, 1999. 2002 2 Weston Solutions, inc. 2005 3 Fleming Engineering, Inc 2006 2007 4 Projection North Carolina State Plane Zone 3200, Datum: NAD S1 I I I I I I I I I I I I I I I I I I I 1. THE ENTRANCE/EXIT SHALL BE MAINTAINED IN A CONDITION WHICH WILL PREVENT TRACKING OR FLOW OF SEDIMENTS ONTO PUBLIC RIGHT-OF-WAY. THIS MAY REQUIRE PERIODIC TOP DRESSING WITH 2-3 INCH STONE, AS CONDITIONS DEMAND, AND REPAIR AND/OR CLEANOUT OF ANY STRUCTURES TO TRAP SEDIMENT. ALL MATERIALS SPILLED, DROPPED, WASHED OR TRACKED FROM VEHICLES ONTO ROADWAYS OR INTO STORM DRAINS MUST BE REMOVED. UPON COMPLETION OF CONSTRUCTION, STONE AND GEOTEXTILE WILL BE REMOVED. CONSTRUCTION ENTRANCE / EXIT N-Is �LMAX. 4" III III �IL Ill W F o REG�QN SEDIMENT FENCE N TS STEEL POSTS SHALL BE 2-0 OR 1.3 LBS/FT. 2' MIN. COMPACTED SOIL LINER z FLOW VARIES 3.1 2' MIN. 6' TYP. NOTE: 1. TRENCH DEPTH VARIES FOR EACH DIVERSION, SEE APPENDIX D-3. 2. USE LINER WITH SHEAR STRESS RAIDING > 175 LB/SF. SECURE PER MANUFACTURER'S SPECIFICATIONS TEMPORARY EARTHEN DIVERSION DIKE NTS 24" MiN. NOTES: 1. SILT CONTROL SHALL BE IN EFFECT PRIOR TO ANY GRADING OR CONSTRUCTION. 2. USE WIRE -REINFORCED SEDIMENT FENCE. FILTER FABRIC FOR FENCE SHALL BE A NON-CALENDERED WOVEN FABRIC CONSTRUCTED WITH MONOFILAMENT YARNS. THE WOVEN WIRE -REINFORCEMENT FENCE SHALL BE AT LEAST 32 INCHES HIGH AND BE AT LEAST 10 GAUGE FOR THE TOP AND BOTTOM WIRES AND 12.5 GAUGE FOR THE REST OF THE WIRE. 3. SPLICED JOINTS SHALL OVERLAP 18", WITH MATCHING POST. 4. DRIVE 4 (48") MIN. POSTS 24" INTO SOIL. 5. DIG DITCH 4" WIDE, 8" DEEP. LAY FABRIC 8" DEEP, THEN BACKFILL AND COMPACT. �I 3 DETAIL DRAWINGS OBTAINED FROM GOLDER ASSOCIATES ATLANTA GEORGIA J 1 EXISTING GROUND SURFACE 2' TO 3.5' MIN, NATURAL GROUND VARIES 1 5 (SEE NOTE) M 1.5' MIN. 3` AAIfJ W IIIAI ur nrr ri are- n �N NOTES: 1. WEIR LENGTH IS 8 FEET MINIMUM FOR TS1, AND 4 FEET FOR TS2-5. 2. EXTEND RIP RAP APRON A MINIMUM OF 10 FEET PAST THE TOE OF SPILLWAY SLOPE. TEMPORARY SEDIMENT TRAP N TS DETAIL DRAWINGS OBTAINED FROM GOLDER ASSOCIATES ATLAN7r GE�)RG�A AX. Iv VL./Jv. I - lr Vlr vvw v L IN GEOTEXTILE FILTER FABRIC OVERFILL 6" FOR SETTLEMENT EMERGENCY BY—PASS 6" BELOW SETTLED TOP °L NC RIP 3. INSTALL POROUS BAFFLES AS SPECIFIED IN APPENDIX D-10. SPACE BAFFLES AS FOLLOWS: TRAP ID A B C TS 1 31 5 225 22.5 TS 2 21 15 15 TS 4. 5 17.5 125 12-5 TS 3 10.5 75 7.5 3D 10 OZ./SQ.YD. NONWOVEN GEOTEXTILE FILTER FABRIC NOTES: 1. INSTALL 10 OZ./SQ.YD. NONWOVEN GEOTEXTILE FILTER FABRIC BETWEEN SOIL FOUNDATION & RIP RAP. 2. LINE WITH NC DOT CLASS B RIP RAP. 3. MINIMUM APRON THICKENESS = 15". OUTLET STABILIZATION STRUCTURE N TS 1 1 I 1 1 1 I 1 11 1 Erosion and Sedimentation Control Plan — Phase 2 Removal Action Appendix A NCDENR Inspection and Maintenance Report Form ENVIRON SELF -INSPECTION REPORT LAND DISTURBING ACTIVITY EQU R D BY NCGS1 3 -54. PROJECT NAME: PROJECT NO.: I I i I I I I I I I I NAME OF INSPECTOR: AFFILIATION*: l I I ( I I (`Landowner, Financially Responsible Party or Agent) ADDRESS OF INSPECTOR: TELEPHONE NUMBER: j Signature: Date: (Landowner, Financially Responsible Party or Agent) j I Phase of Approved Erosion and Sedimentation Control Plan: Mark (x) Installation of perimeter erosion and sediment control measures Clearing and grubbing of existing round cover Completion of any phase of grading of slopes or fills Installation of storm drainage facilities Completion of construction or development Establishment of permanent ground cover sufficient to restrain erosion INSPECTED: EROSION AND SEDIMENTATION CONTROL MEASURES NamelNumberl Location of Measure (List all measures on Plan) Measures Installed Since Last Report Measure Operating Properly YeslNo Significant Deviation from Plan? (Yes/No) Describe Corrective Actions Needed Proposed Dimensions (feet) Actual Dimensions feet I I I _ I I I I I List actions taken to correct deviation or restore sediment damage on "Actions Taken Sheet" Page 1 Erosion and Sediment Control Measures Inspected: (Continued) Name/Number/ Location of Measure (List all measures on Plan) Measures Installed Since Last Re ort Measure operating Properly (Yes/No) Significant Deviation from Plan? (Yes/No) Describe Corrective Actions Needed' Proposed Dimensions (feet) Actual Dimensions (feet) I I I I I V l l I I 4 l I ! Ground Cover on Slopes (By Location) Date Phase of Grading Complete Date Ground Cover Provided Is Ground Cover Sufficient to Restrain Erosion?(Yes/No) Describe Corrective Actions Needed I I I I I I I Permanent Ground Cover (By Location) Date construction Complete Date Ground cover Provided Is Ground Cover Sufficient to Restrain Erosion?(Yes/No) Describe Corrective Actions Needed I I I 1 I I *List actions taken to correct deviation or restore sediment damage on "Actions Taken Sheet." Page 2 � I♦ � i�l � Its � v � il© � � � i�i■I. � � � � � m m m m m m ! m m M � m m M > m m m'� ",,4-m ,.Location. -of :Deviation or _ ` Sediment oama a Y:, %: : "'+ Actions Taken to Correct Deviation or Restore Sedimentation Damage Date Action Taken I l I ] I I i I I - I I I I ' ! I f I l I I I I I I I _ I I i I 1 f i I I I I Page 3 Erosion and Sedimentation Control Plan — Phase 2 Removal Action 1 Appendix B Erosion and Sedimentation Control Plan Preliminary Review Checklist ENVIRON NORTH CAROLINA DEPARTMENT OF ENVIRONMENT & NATURAL RESOURCES LAND QUALITY SECTION EROSION and SEDIMENTATION CONTROL PLAN PRELIMINARY REVIEW CHECKLIST The following items shall be incorporated with respect to specific site conditions, in an erosion & sedimentation control plan: LOCATION INFORMATION X Name and classification of receiving water course or name of municipal operator (only where stormwater discharges are to X Project location & labeled vicinity map (roads, streets, landmarks) occur) North arrow and scale X Identify River Basin. X Provide a copy of site located on applicable USGS quadrangle and NRCS Soils maps if it is in a River Basin with Riparian Buffer requirements. GENERAL SITE FEATURES (Plan elements) X Property lines & ownership ID for adjoining properties X Existing contours (topographic lines) X Proposed contours X Limits of disturbed area (provide acreage total, delineate limits, and label). Be sure to include all access to measures, lots that will be disturbed, and utilities that may extend offsite. NA Planned and existing building locations and elevations X Planned & existing road locations & elevations, including temporary access roads NA Lot and/or building numbers X Hydrogeologic features: rock outcrops, seeps, springs, wetland and their limits, streams, lakes, ponds, dams, etc. (include all required local or state buffer zones and any DWQ Riparian Buffer determinations) NA Easements and drainageways, particularly required for offsite affected areas. Include copies of any recorded easements and/or agreements with adjoining property owners. NA Profiles of streets, utilities, ditch lines, etc. X Stockpiled topsoil or subsoil locations NA If the same person conducts the land -disturbing activity & any related borrow or waste activity, the related borrow or waste activity shall constitute part of the land -disturbing activity unless the borrow or waste activity is regulated under the Mining Act of 1971, or is a landfill regulated by the Division of Waste Management. If the land -disturbing activity and any related borrow or waste activity are not conducted by the same person, they shall be considered separate land -disturbing activities and must be permitted either through the Sedimentation Pollution Control Act as a one -use borrow site or through the Mining Act. X Location and details associated with any onsite stone crushing or other processing of material excavated. If the affected area associated with excavation, processing, stockpiles and transport of such materials will comprise 1 or more acres, and materials will be leaving the development tract, a mining permit will be required. NA Required Army Corps 404 permit and Water Quality 401 certification (e.g. stream disturbances over 150 linear feet) EROSION & SEDIMENT CONTROL MEASURES (on plan X Legend (provide appropriate symbols for all measures and reference them to the construction details) X Location of temporary measures X Location of permanent measures X Construction drawings and details for temporary and permanent measures. Show measures to scale on plan and include proposed contours where necessary. Ensure design storage requirements are maintained through all phases of construction. X Maintenance requirements for measures X Contact person responsible for maintenance SITE DRAINAGE FEATURES X Existing and planned drainage patterns (include off -site areas that drain through project and address temporary and .permanent conveyance of stormwater over graded slopes) X Method used to determine acreage of land being disturbed and drainage areas to all proposed measures (e.g. delineation map) NA Size, pipe material and location of culverts and sewers X Soil information: type, special characteristics X Soil information below culvert storm outlets STORMWATER CALCULATIONS X Pre -construction runoff calculations for each outlet from the site (at peak discharge points). Be sure to provide all supporting data for the computation methods used (rainfall data for required storm events, time of concentration/storm duration, and runoff coefficients). X Design calculations for peak discharges of runoff (including the construction phase & the final runoff coefficients for the site) NA Design talcs for culverts and storm sewers (include HW, TW and outlet velocities) X Discharge and velocity calculations for open channel and ditch flows (easement & rights -of -way) _X_ Design talcs for cross sections and method of stabilization for existing and planned channels (include temporary linings). Include appropriate permissible velocity and/or shear stress data. NA Design talcs and construction details for energy dissipaters below culvert and storm sewer outlets (include stone/material specs & apron dimensions). Avoid discharges on fill slopes. X Design talcs and dimension of sediment basins (note current surface area and dewatering standards as well as diversion of runoff to the basins). Be sure that all surface drains, including ditches and berms, will have positive drainage to the basins. VEGETATIVE STABILIZATION X Area & acreage to be stabilized with vegetation X Method of soil preparation X Seed type & rates (temporary & permanent) X Fertilizer type and rates X Mulch type and rates (include mulch anchoring methods to be used) NOTE: Plan should include provisions for groundcover on exposed slopes within 21 calendar days following completion of any phase of grading; permanent groundcover for all disturbed areas within 15 working days or 90 calendar days (whichever is shorter) following completion of construction or development. FINANCIAL RESPONSIBILITY/OWNERSHIP FORM NA Completed, signed & notarized FR10 Form NA Accurate application fee payable to NCDENR ($65.00 per acre rounded up the next acre with no ceiling amount) NA Certificate of assumed name, if the owner is a partnership NA Name of Registered Agent (if applicable) NA Copy of the most current Deed for the site. Please make sure the deed(s) and ownership information are consistent between the plan sheets, local records and this form. NA Provide latitude & longitude (in decimal degrees) at the project entrance. NOTE: For the Express Permitting Option, inquire at the local Regional Office for availability. NARRATIVE AND CONSTRUCTION SEQUENCE X Narrative describing the nature & purpose of the construction activity X Construction sequence related to erosion and sediment control (including installation of critical measures prior to the initiation of the land -disturbing activity & removal of measures after areas they serve are permanently stabilized). Address all phases of construction and necessary practices associated with temporary stream bypasses and/or crossings. NA Bid specifications related only to erosion control rev. 1/7/2009 1 Erosion and Sedimentation Control Plan — Phase 2 Removal Action 0 1 1 Appendix C Supporting Calculations 1 ENVIRON r r rr r r r r r r r r �r rr rr �r r r r DESIGN OF TEMPORARY DIVERSION CHANNELS Ward Transformer Superfund Site Raleigh, North Carolina Peak Storm Intensitv (in/hri 10-Year = 4.78 2-Year = 3.74 Channel RouPhness Coefficient f n) = 0.033 Channel Freeboard ifti = 0.3 Runoff Estimation 3 Temporary Diversion Channel Design Design of Channel Lining 4 Diversion Contributing Drainage 10 - Year 2 -Year 1 2 Flow flowdepth at 2 Channel ID Aareas Total Drainage Runoff Peak Runoff Peak Runoff Bottom Side Channel Shear Stress* Depth (ft) Capacity yr Storm Area (ac.) Coefficient Width (ft) Slopes Bed Slope (lb/sq.ft.) {cfs) (ft} cfs cfs CH - 1 DA 4 + DA 1 13.02 0.35 21.83 17.08 2 1.5 3 0.01 23.92 1.03 0.64 CH - 2 DA 2 + DA 5 14.98 0.41 29.10 22.77 2 2 3 0.01 52.50 1.17 0.73 DA 1 + DA 2 + DA 3 + DA 4 CH - 3 33.77 0.38 61.24 47.92 2 IS 3 0.01 95.81 1.63 1.02 + DA 5 + DA 6 + DA 11 CH -4 DA 7 12.06 0.20 11.53 9.02 2 1.5 3 0.01 23.92 0.76 0.48 CH - 5 DA 7 + DA 8 19.51 0.20 18.65 14.59 2 1.5 3 0.01 23.92 0.96 0.60 CH - 6 DA 7 + DA 8 + DA 9 44.71 0.17 36.72 28.73 2 2 3 0.01 52.50 1.30 0.81 0.5 x (CH 3 + CH 6 + DA10) CH - 7 44.86 0.25 53.81 42.10 2 2.5 3 0.01 95.81 1.54 0.96 +DA13 0.5 x (CH 3 + CH 6 + DA10) CH 8 44.90 0.25 53.84 42.13 2 2.5 3 0.01 95.81 1.54 0.96 + DA 12 Notes: 1 Location and IDs of the Diversion Channels are presented in Figures 6 and 7 Z Delineation and hydrological properties of the of the Drainage Areas are presented in Figure 3 3 A constant time of concentration of 15 - minutes was used conservatively in the calculations. The time concentration for the smallest catchment (DA 7 for CH - 4) for only the sheet flow component was estimated as 17-minutes using Kinematic Wave Theory (sheet flow length = 300ft, slope = 0.0067, n=0.033, i = 4.78, C = 0.20), using procedure laid out in Page 8.03.2 of the NC E&SC Manual (Attachment C-1). Storm intenisty for Raleigh, NC was obtained from Page 8.03.10 of the NC E&SC Manual (Attachment C-2) 4 Shear Stress calculations indicate that a straw liner with net (at a minimum) will be sufficient for channel stability. A constant channel bed slope of 1% will be maintained for all channels. Where steeper slopes are necessary to accommodate field constraints, additional velocity control measures like check dams will be instalfed. I� IA � r a• r .� � s � � i I• � � �■s � ® � DESIGN OF TEMPORARY SEDIMENT TRAPS Ward Transformer Superfund Site Raleigh, North Carolina 10-Year Peak Storm Intensitv (in/hr) = 4.78 Runoff Estimation Sediment Trap Design3 Temporary Contributing Total in. Req. Su rtace Sediment Trap Drainage 2 Drainage Peak Top Top Surface Surface Area Min. Requ. Volume ID1 Areas Area Runoff Runoff Length Width Depth Area Area Design Volume Volume Design (ac.) Coeff. Rate (cfs) (ft) (ft) (ft) (sq. ft.) (sq. ft.) Check (cu.ft) (tuft) Check TS 1 DA 3 3.12 0.45 6.71 90 45 4.S 4,050 2,919 OK 13,487 11,232 OK TS 2 DA 6 1.19 0.45 2.56 60 30 4.5 1,800 1,113 OK 5,184 4,284 OK TS 3 DA 10a 0.23 0.45 0.49 30 15 4 450 215 OK 872 828 OK TS 4 DA 10b 0.89 0.45 1.91 SO 1 25 4.5 1,250 833 OK 3,317 3,204 OK S 5 DA 14 0.97 0.45 2.09 L 50 25 5 1,250 908 OK 3,500 3,492 OK Notes: 1 Location and IDs of the Diversion Channels are presented in Figures 6 and 7 2 Delineation and hydrological properties of the of the Drainage Areas are presented in Figure 3 3 Side slopes of the Temporary Sediment Traps shall be 1V=2H Erosion and Sedimentation Control Plan — Phase 2 Removal Action Appendix C-1 Time of Concentration 1 1 1 n 1 I ENVIRON 0 Step 3. Determine the time of concentration, TC, for the drainage area Shortcut to Time of Concentration, TC calculation: As long as a watershed's area is less than 4.6S, A("CM') < 4.6. S %, where S is the slope in percent, the total time of concentration can be taken to be 5 minutes for bare soil. This is helpful to know because it will save the time of calculating time of concentration by other methods, including the Kincnia6c Wave Theory (below) which requires an iterative solution. The Kinematic Wave Theory defines time of concentration as the "travel time of a wave to move from the hydraulically most distant point in the catchment to the outlet (Bedient and Huber, 1992)". The formula for the time of concentration for overland flow is: 5 L 1.49 * Suz I, * C 2/3 ,1 (432001 IC - — - where: 60 L = length of overland How plane (feet) S = slope (ft/ft) n = Manning's roughness li = rainfall intensity C = rational runoff coefficient Because both time of concentration and rainfall intensity are unknown variables in one equation, the solution must be found through iterations. The use of a spreadsheet is recommended. An example is shown in Table 8.03a. 8.03.2 Rev. 6/07 1 Erosion and Sedimentation Control Plan — Phase 2 Removal Action 1 I I 1 I n 1 1 1 Appendix C-2 Rainfall Intensity ENVIRON t 1 1 0 Appetutives ;Raleigh. North'Carolina) 35.8706N. 78.7864W ARI* 5 min. 10 min. 15 min. 30 min. 60 min. 120 min. 3 hr. 6 hr. 12 hr. 24 hr. (years) 5.58 4.46 3:74 2.58 1.62 0.94 0.66 0.40 0.24 0.14 10 7.08 5.66 4.78 3.46 2.25 1.33 0.95 0.58 0.34 0.021 25 7.78 6.19 5.24 3.88 2.58 1.54 1.11 0.68 0.41 0.24 100 8.64 6.86 5.78 4.43 3.05 1.85 1.36 0.84 0.51 0.30 ARI* 5 min. 10 min. 15 min. 30 min. 60 min. 120 min. 3 hr. 6 hr. 12 hr. 24 hr. (years) 2 6.11 4.88 4.09 2.83 1.77 1.04 0.74 0.44 0.26 0.15 10 7.96 6.36 5.36 3.88 2.53 1.54 1.10 0.66 0.39 0.23 25 8.94 7.13 6.02 4.46 2.97 1.83 1.32 0.80 0.47 0.28 100 10.44 8.29 6.99 5.35 3.69 2.29 1.69 1.03 0.62 0.36 ARI* 5 min. 10 min. 15 min. 30 min. 60 min. 120 min. 3 hr. 6 hr. 12 hr. 24 hr. (years) 2 7.39 5.92 4.96 3.42 2.15 1.28 0.91 0.56 0.33 0.19 10 9.70 7.75 6.54 4.74 3.08 1.94 1.39 0.87 0.51 0.30 25 10.98 8.75 7.40 5.48 3.65 2.38 1.73 1.08 0.64 0.38 100 12.92 10.27 8.65 6.63 4.56 3.18 2.37 1.49 0.89 0.53 ARI* 5 min. 10 min. 15 min. 30 min. 60 min. 120 min. 3 hr. 6 hr. 12 hr. 24 hr. (years) 2 6.41 5.12 4.29 2.96 1.86 1.10 0.78 0.47 0.27 0.16 10 8.38 6.70 5.65 4.09 2.66 1.64 1.19 0.72 0.42 0.25 25 9.48 7.55 6.38 4.73 3.15 1.99 1.46 0.88 0.52 0.31 100 11.16 8.87 7.47 5.72 3.94 2.58 1.93 1.18 0.70 0.42 ARI* 5 min. 10 min. 15 min. 30 min. 60 min. 120 min. 3 hr. 6 hr. 12 hr. 24 hr. (years) 2 6.46 5.16 4.32 2.99 1.87 1.08 0.79 0.48 0.29 0.17 10 8.47 6.77 5.71 4.14 2.69 1.62 1.20 0.74 0.44 0.27 25 9.56 7.62 6.44 4.77 3.17 1.96 1.47 0.91 0.54 0.33 100 11.26 8.95 7.54 5.77 3.98 2.54 1.95 1.21 0.73 0.44 ARI* 5 min. 10 min. 15 min. 30 min. 60 min. 120 min. 3 hr. 6 hr. 12 hr. 24 hr. (years) 2 7.20 5.75 4.82 3.33 2.09 1.29 0.94 0.58 0.34 0.20 10 9.41 7.52 6.35 4.60 2.99 1.93 1.43 0.89 0.53 0.31 25 10.66 8.49 7.18 5.31 3.54 2.33 1.75 1.09 0.65 0.38 100 12.53 9.95 8.39 6.42 4.42 3.03 2.32 1.45 0.88 0.51 8.03.10 Rev. 6106 Erosion and Sedimentation Control Plan — Phase 2 Removal Action Appendix D Erosion Control Standard Specifications ENVIRON 1 Erosion and Sedimentation Control Plan — Phase 2 Removal Action IAppendix D-1: Temporary Construction Entrance/Exit Construction Specification: • Stone size - use 2-Y washed stone, or reclaimed or recycled concrete equivalent. • Length - 50 feet minimum. • Thickness - six (6) inches minimum. • Width - 12 feet minimum. • Filter cloth - will be placed over the entire area prior to placing of stone. • Surface water - all surface water flowing or diverted toward construction entrances will be piped across the entrance. If piping is impractical, a mountable berm with 5:1 slopes will be permitted. • Maintenance - the entrance shall be maintained in a condition which will prevent tracking of sediment onto public rights -of -way or streets. All sediment spilled, dropped, or washed onto public rights -of -way will be removed immediately. If found necessary, wheels will be cleaned to remove sediment prior to entrance onto public rights -of -way. • If washing is required, it will be done on an area stabilized with stone and which drains into an approved sediment trapping device. • Periodic inspection and needed maintenance will be performed after each rain event. Construction Entrance Geotextife Fabric Specifications Fabric Properties Minimum Acceptable Value Test Method Grab Tensile Strength (lbs.) 200 ASTM D1682 Elongation at Failure (%) 50 ASTM D1682 Mullen Burst Strength (PSI) 190 ASTM D3786 Puncture Strength (Ibs.) 40 ASTM D751 (modified) Equivalent Opening Size 40-80 US Std Sieve CW-02215 IAppendix D D-1 ENVIRON Erosion and Sedimentation Control Plan — Phase 2 Removal Action Appendix D-2: Temporary Sediment Trap Construction Specification: • Clear and grub the sediment trap area - dam and crest area -- based on dimensions below measured from the spillway: - TS 1: Length 90 feet, width 45 feet, depth 4.5 feet - TS 2: Length 60 feet, width 30 feet, depth 4.5 feet - TS 3: Length 30 feet, width 15 feet, depth 4.0 feet - TS 4: Length 50 feet, width 25 feet, depth 4.5 feet - TS 5: Length 50 feet, width 25 feet, depth 5.0 feet • Use fill material free of organic matter for constructing the embankments. Place fill in lifts not to exceed 8" and machine compact. Embankments should be 2 horizontal: 1 vertical minimum slope. • Install filter fabric between the embankment and the rip -rap spillway. • Construct dam and stone spillway to height as specified above, with 2 horizontal: 1 vertical minimum side slopes, bottom width of at least 3 feet and weir length as follows: - TS 1: 8 feet minimum weir length - TS 2-5: 4 feet minimum weir length • Ensure that the spillway crest is level and at least 1.5 feet below the top of the dam at all points. • Use Class "B" erosion control stone for spillway section and DOT #5 or #57 washed stone on inside face of spillway to control drainage. • Use temporary diversions and rip -rap as necessary to prevent erosion at the inlet to the sediment trap. • Stabilize the embankment and all disturbed areas above the sediment pool and below the embankment as described in the vegetation plan. • Install porous baffles as specified in Appendix D-10 and Figure 9. • Extend apron downstream of spillway at least 10 feet past the toe of the slope. Maintenance Requirements: • Inspect sediment traps at least weekly and after each significant (0.5 inches or greater) rainfall event and repair immediately. • When sediment has accumulated to one-half the design depth of the trap, remove sediment and restore the trap to its original dimensions. Place the sediment that is removed in the designated disposal area, and replace the part of the gravel facing that is impaired by sediment. • Check the structure for damage from erosion or piping. Appendix D D-2 ENVIRON I I Erosion and Sedimentation Control Plan — Phase 2 Removal Action • Periodically check the depth of the spillway to ensure it is a minimum of 1.5 feet below the low point of the embankment. • Immediately fill any settlement of the embankment to slightly above design grade. • Any riprap displaced from the spillway must be replaced immediately. rAfter all sediment -producing areas have been permanently stabilized; remove the structure and all unstable sediment. Smooth the area to blend with the adjoining areas, and stabilize properly. 1 IAppendix D D-3 ENVIRON Erosion and Sedimentation Control Plan — Phase 2 Removal Action Appendix D-3: Temporary Diversions Construction Specification: • Clear and grub the diversion area. • Construct berm to full dimensions provided below — allow for 10% settling. Use coarse aggregate to construct berms at vehicle crossings. Diversion Channel Bottom Width (ft.) Depth (ft.) Side Slopes CH 1 2 1.5 3H: 1 V CH 2 2 2 3H: 1V CH 3 2 2.5 3H: 1 V CH 4 2 1.5 3H: 1 V CH 5 2 1.5 3H: 1 V CH 6 2 2 3H: 1 V CH 7 2 2.5 3H: 1 V CH 8 2 2.5 3H: 1 V • Compact the berm with wheels of construction equipment. • Ensure the top of the berm is on design grade or higher at all points. • Lay erosion control mat with 1.75 Ibs.ISF or greater shear stress rating along the flow channel and secure in accordance with manufacturer's specification. • Install outlet stabilization as required. • Install outlet stabilization as required. Maintenance Requirements: • Inspect temporary diversions once a week and after every rainfall. Immediately remove sediment from the flow area and repair the diversion ridge. . Carefully check outlets and make timely repairs as needed. • When the area protected is permanently stabilized, remove the ridge and the channel to blend with the natural ground level and appropriately stabilize it. 1 Appendix D D-4 ENVIRON I I Erosion and Sedimentation Control Plan — Phase 2 Removal Action Appendix D-4: Check Dams Construction Specification: Clearing and grub the check dam area as necessary. - Construct dam on filter fabric to full dimensions shown in the detail using NC DOT Class B stone lined with NC DOT #5 or #57 stone on the upstream end. Keep center stone at least 9 inches below the natural ground level where the dam meets the channel banks. o Extend stone at least 1.5 feet beyond the ditch bank to keep water from cutting around the ends of the check dam. - Protect the channel below the lowest check dam and ensure area above the upstream check dam is stable. Maintenance Requirements: - Inspect check dams and channels at least weekly and after each significant (0.5 inches or greater) rainfall event and repair immediately. Clean out sediment, straw, limbs, or other debris that could clog the channel when needed. - Anticipate submergence and deposition above the check dam and erosion from high flows around the edges of the dam. Correct all damage immediately. • If significant erosion occurs between check dams, additional measures can be taken, such as installing a protective liner in that portion of the channel. - Remove sediment accumulated behind the check dams as needed to prevent damage to -� channel vegetation, allow the channel to drain through the stone check dam, and prevent large flows from carrying sediment over the dam. - Add stones to check dams as needed to maintain design height and cross section. Appendix D-5: Outlet Stabilization Construction Specification: ' - Excavate to 15 inches below channel outlet. Minimum length of apron is 10 feet from the outlet. • Place filter cloth — 10 oz./SF nonwoven geotextile — between soil and rip -rap; overlap 1.0 feet at seems. • Carefully place NC DOT Class B rip -rap; rip -rap should have a zero grade level with outlet of channel. Maintenance Requirements: - Inspect riprap outlet structures weekly and after significant (0.5 inches or greater) rainfall events to see if any erosion around or below the riprap has taken place, or if stones have been dislodged. Immediately make all needed repairs to prevent further damage. Appendix D D-5 ENVIRON Erosion and Sedimentation Control Plan — Phase 2 Removal Action Appendix D-S: RECP and Rip -rap Channels RECP Construction Specification - Channel Slopes: • Install RECP capable of withstanding a minimum shear stress of 1.75 Ibs./SF and tensile strength of 75 lbs./ft. • Excavate 6-inche by 6-inch anchor trench at a location along the slope such that the erosion mat will overlap at least 1.0 feet with channel bottom filter fabric, and anchor RECP in the trench as indicated in Figure 10. • Unroll the RECP down/along the slope and overlap 1 foot with channel bottom filter fabric and adjacent RECP. • Pin RECP to ground every 3 feet in a center -to -center pattern using 11 gauge staples measuring at least 6 inches long and 1-inch wide. Maintenance Requirements: • Inspect RECP at least weekly and after each significant (0.5 inches or greater) rainfall event and repair immediately. • Good contact with the ground must be maintained, and erosion must not occur beneath the RECP. • Any areas of the RECP that are damaged or not in close contact with the ground shall be repaired and stapled. • If erosion occurs due to poorly controlled drainage, the problem shall be fixed and the eroded area protected. • Monitor and repair the RECP as necessary until ground cover is established. Rip -Rap Construction Specification -- Channel Bottom: • Excavate to 12 inches below design grade or fill up to 12 inches below design grade. • Place filter cloth - 10 oz./SF nonwoven geotextile - between soil and rip -rap; overlap 1.0 feet at seems and secure with metal pins or as specified by manufacturer. • Carefully place NC DOT Class B rip -rap so as not to puncture the filter fabric on the design grade for the channel. Maintenance Requirements: • In general, once a rip -rap installation has been properly designed and installed it requires very little maintenance. • Rip -rap should be inspected periodically for scour or dislodged stones. Control of weed and brush growth may be needed in some locations. Appendix D D-6 ENVIRQN I I 1 Erosion and Sedimentation Control Plan — Phase 2 Removal Action 0 I 11 Appendix D-7: Sediment Fence Specification Materials: Silt Fence Fabric: The fabric shall meet the following specifications unless otherwise approved by the appropriate Erosion and Sediment Control Plan approval authority. Silt Fence Geotextile Fabric Specifications Fabric Properties Minimum Acceptable Value Test Method Grab Tensile Strength (Ibs.) 90 ASTM D1682 Elongation at Failure (%) 50 ASTM D1682 Mullen Burst Strength (PSI) 190 ASTM D3786 Puncture Strength (lbs.) 40 ASTM D751 (modified) Slurry Flow Rate (gal/min/so) 0.3 (max) Equivalent Opening Size 40-80 US Std Sieve CW-02215 Ultraviolet Radiation Stability (%) 90 ASTM G-26 Fence Posts (for fabricated units): The length will be a minimum of 48 inches. Wood posts will be of sound quality hardwood with a minimum cross sectional area of 3.0 square inches. Steel posts will be standard T and U section weighing not less than 1.00 pound per linear foot. Wire Fence (for fabricated units): Wire fencing will be a minimum 14 gauge with a maximum 6 in. mesh opening, or as approved. Prefabricated Units: Envirofence, Geofab, or approved equal, may be used in lieu of the above method and the units will be installed as per manufacturer instruction and ESC Standards. Installation: . Excavate a 4-inch wide by 8-inch deep trench along the lower perimeter of the site. • Unroll a section at a time and position the posts against the back (downstream) wall of the trench (net side away from direction of flow). • Drive the posts into the ground until the netting is approximately 2 inches from the trench bottom. • Lay the toe -in flap of fabric onto the undisturbed bottom of the trench, backfill the trench and tamp the soil. Steeper slopes require an intercept trench. IAppendix D D-7 ENVIRON Erosion and Sedimentation Control Plan — Phase 2 Removal Action Maintenance Requirements: • Inspect sediment fences at least once a week and after each rainfall. Make any required repairs immediately. • Should the fabric of a sediment fence collapse, tear, decompose, or become ineffective, replace it promptly. • Remove sediment deposits as necessary to provide adequate storage volume for the next rain and to reduce pressure on the fence. Take care to avoid undermining the fence during cleanout. • Remove all fencing materials and unstable sediment deposits and bring the area'to grade and stabilize it after the contributing drainage area has been properly stabilized. Appendix D-8: Land Grading Installation: • Scarify areas to be topsoiled to a minimum depth of 2 inches before placing topsoil. • Clear and grub areas to be filled by removing trees, vegetation, roots or other objectionable material that would affect the planned stability of the fill. • Place all fill in layers not to exceed 9 inches in thickness and compact the layers as required to reduce erosion, slippage, settlement, or other related problems. • Keep diversions and other water conveyance measures free of sediment during all phases of development. • Permanently stabilize all graded areas immediately after final grading is completed on each area in the grading plan. Apply temporary stabilization measures on all graded areas when work is to be interrupted or delayed for 30 working days or longer_ Maintenance Requirements: • Periodically check all graded areas and the supporting erosion and sedimentation control practices, especially after heavy rainfalls. • Promptly remove all sediment from diversions and other water -disposal practices. If washouts or breaks occur, repair them immediately. • Prompt maintenance of small eroded areas before they become significant gullies is an essential part of an effective erosion and sedimentation control plan. Appendix D 0-8 ENVIRON I I Erosion and Sedimentation Control Plan — Phase 2 Removal Action Appendix D-9: Surface Roughening Installation: • Groove cut slopes with a gradient steeper than 3:1. • Groove soil surface using any appropriate implement that can be safely operated on the slope, such as disks, tillers, spring harrows, or the teeth on a front-end loader bucket. • Do not make such grooves less than 3 inches deep nor more than 15 inches apart. • Immediately seed and mulch roughened areas to obtain optimum seed. germination and growth. Maintenance Requirements: • Periodically check the seeded slopes for rills and washes. Fill these areas slightly above the grade, then reseed and mulch as soon as possible. Appendix D-10: Porous Baffles Installation • Grade the basin so that the bottom is level from front to back and side to side. • Install posts or saw horses across the width of the sediment trap. • Install steel posts to a depth of 24 inches, space a maximum of 4 ft. apart along the bottom and sides of the basin. The top of the fabric should be 6 inches higher than the invert of the spillway. The tops of baffles should be 2 inches lower than the top of the berms. • Install three rows of baffles as specified on Figure 9. • When using posts, add a support wire or rope across the top of the measure to prevent sagging • Wrap porous material, like jute backed by coir material over the support structure (post and wire or sawhorse). The fabric should have 5-10% openings in the weave. Attach fabric to ' support structure with zip ties, wire or staples. • Anchor the bottom of the fabric into a trench or pin with 8-inch erosion control matting staples. • Use a continuous piece of fabric across the basin; do not splice fabric together. Maintenance: • Inspect baffles at least once per week and after every rainfall. Make any required repairs immediately - Be sure to maintain access to the baffles. Replace damaged baffles or fabric immediately. • Remove sediment deposits that reach half the height of the baffle. • After the contributing drainage area has been properly stabilized, remove all baffle materials and unstable sediment deposits, bring the area to grade, and stabilize. Appendix D D-9 ENVIRON