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HomeMy WebLinkAbout20140957 Ver 2_Clarification from 09-29-2017 Meeting_20171013Burdette, Jennifer a From: Spencer Trichell <Spencer.Trichell@dominionenergy.com> Sent: Friday, October 13, 2017 4:42 PM To: Poupart, Jeff Cc: Burdette, Jennifer a; Higgins, Karen; 'Wade Hammer'; Robert M Bisha; Richard B Gangle Subject: [External] ACP Clarification from 09-29-17 Meeting Attachments: 20171013 Response to clarification to NCDEQ DR - Out.pdf CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you verify that the attachment and content are safe. Send all suspicious email as an attachment to report.spam@nc.gov. Mr. Poupart, In response to questions asked by your staff in a meeting on September, 29, 2017, 1 am providing the attached clarification. Please let me know if you have questions. Regards, Spencer Trichell Environmental Consultant - Atlantic Coast Pipeline Dominion Energy Services, Inc. 5000 Dominion Blvd Glen Allen, VA 23060 0:(804)-273-3472 M:(804)-263-5980 spencer.trichell@dominionenergy.com CONFIDENTIALITY NOTICE: This electronic message contains information which may be legally confidential and or privileged and does not in any case represent a firm ENERGY COMMODITY bid or offer relating thereto which binds the sender without an additional express written confirmation to that effect. The information is intended solely for the individual or entity named above and access by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution, or use of the contents of this information is prohibited and may be unlawful. If you have received this electronic transmission in error, please reply immediately to the sender that you have received the message in error, and delete it. Thank you. Dominion Energy Services, Inc. 5000 Dominion Boulevard Glen Allen, VA 23060 OominionEnergy.com October 13, 2017 ELECTRONIC MAIL Jeff Poupart Water Quality Section North Carolina Department of Environmental Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Jeff.PoWartct,ncdenr.gov Re: Atlantic Coast Pipeline — DWR Project #14-0957 v2 Response to Request for Additional Information — Meeting Follow-up 401 Water Quality Certification Review Dear Mr. Poupart: Dominion p;Wo Energye Atlantic Coast Pipeline, LLC (Atlantic) is providing the enclosed responses to the request for additional information dated September 14, 2017, from the North Carolina Department of Environmental Quality (NCDEQ) on Atlantic's Water Quality Certification application, which we also discussed during a meeting with NCDEQ staff on September 29, 2017. The enclosed responses are in addition to responses provided on September 22 and 29, 2017. Each of the items requested by NCDEQ staff during the September 29, 2017 meeting are listed below, followed by a response or updated information from Atlantic. NCDEQ requests site-specific drawings that illustrate plan views of a horizontal directional drill and conventional bore (to also include a cross sectional view) crossing of Beaverdam Swamp and Raft Swamp. Atlantic Response: Atlantic has provided drawings illustrating potential workspace layout and cross- sectional drawings for Beaverdam Swamp and Raft Swamp, included in Attachment A. The drawings illustrate the additional workspace that would be needed for a conventional bore and a horizontal directional drill, The horizontal directional drill (HDD) exhibit depicting alignment and workspace for Beaverdam Swamp presents two potential HDD options. Both options include a horizontally straight route between endpoints located adjacent to seasonally flooded wetlands. The waterbody known as Beaverdam Swamp is characterized as a 45 to 50 foot wide perennial waterbody with an estimated depth of approximately 3 to 5 feet. The attached HDD alignment traversing Beaverdam Swamp and the adjacent wetlands deviates from the pipeline route both filed with the Federal Energy Regulatory Commission (FERC) and used for right-of-way/easement acquisition. Therefore, this route was developed based on the assumption that landowners would provide consent and FERC would approve a variance for the proposed route adjustment associate with alignment. October I3, 2017 Atlantic Coast Pipeline NCDEQ Information Request Response When reviewing the exhibit please note that both alignments require workspace within an agricultural field, approximately 1100 and 1300 feet north of residential structures situated adjacent to Richneck Road. Since the HDD construction method requires significantly more time to construct as compared to conventional cut and cover (open cut) methods, utilizing the HDD to install the pipeline beneath a small and shallow waterbody would subject the occupants of the residential structures to unnecessary impacts above and beyond those generated by the faster open cut method. If Option A was selected, the entry side would be placed in the agricultural field located between 1100 and 1300 feet from the previously discussed residential structures. HDD operations are initiated from the entry side, meaning large diesel engine driven equipment, such as: the HDD rig, drilling fluid pumps, fluid cleaning system and other ancillary support equipment; will be positioned less than 1300 feet from two residential structures. This option would unnecessarily position the HDD equipment near residences, resulting in significant noise exposure for the occupants of the residences during the 1-3 month HDD construction period. Additionally, the landowner with the agricultural field in which the HDD equipment would be placed would lose the ability to utilize the portion of the field encumbered by the HDD construction for agricultural purposes during HDD construction. Furthermore, a much larger footprint would be required to accommodate the HDD methods on the side where the HDD would exit on the north side of the waterbody. The additional workspace needed at the exit of the HDD would require an additional approximately 10,000 fece of land clearing above what would be necessary for conventional pipeline construction. If Option B was selected, the exit point and carrier pipe fabrication workspace will be positioned within two agricultural fields and across Richneck Rd. Similar to Option A, the landowner would lose the ability to cultivate two large fields during the estimated 1-3 month HDD construction period. Additionally, Richneck Rd would need to be closed during carrier pipe installation ("HDD Pullback") resulting in road closure and local traffic detours for 12-24 hours. An additional concern associated with the HDDs at Beaverdam Swamp and Raft Swamp is the potential for inadvertent drilling fluid returns within the waterbodies and adjacent wetlands. The use of the HDD construction method carries with it the potential for inadvertent returns of drilling fluid, or surface releases, at these locations. Should a surface release occur, there could be significant additional impact associated with clearing a path in to where the release occurred for clean-up equipment to access the release, space for building containment structures to contain the release, and additional disturbance related to equipment need to remove the drilling fluid and remediate the area. These impacts could potentially cause greater impact than the more minor and temporary effects of open cut construction. Prior to specifying the HDD method at any location, Atlantic carefully weighs technical constraints, site conditions and potential effects to ensure the HDD method is the best and least impactful construction technique. When the relatively small width and depth of Beaverdam Swamp and Raft Swamp is considered in conjunction with impacts and potential detrimental effects on the local population, residential occupants, wildlife, and adjacent habitat, Atlantic has determined that the HDD method is the least suitable method to construct the pipeline through these areas. The bore method has technical limitations, relating to the ability to hold line and grade in soft soils such as would be expected at these two crossings (Beaverdam and Raft Swamps). Because of these limitations a bore at either location will need to be as short as possible. For this reason, the pits on the attached figures (Attachment A) were placed such that the Iengths of the bores are within technically achievable parameters for this construction method, which necessitates the bore pits be placed within wetlands adjacent to these waterbodies. The distance across the wetlands adjacent to Raft Swamp at 2 October 13, 2017 Atlantic Coast Pipeline NCDEQ Information Request Response the proposed crossing location is approximately 3,445 feet, which far exceeds the limitation of the bore method, thus requiring bore entry and exit pits to be Iocated within the wetlands and requiring additional workspace footprint within the wetlands. In addition, the conventional bore is expected to take 14 to 20 days while the open cut crossing is expected to take 1 day. Please note, due to landowner restrictions, these tracts are currently not accessible, therefore these durations are based upon assumptions developed via desktop study. Actual durations may vary and are heavily dependent upon local conditions such as groundwater level, precipitation, temperature, soil types, vegetation and topography. Additionally, being able to install a bore at this location is dependent upon water level. If the area where the bore pit is to be located is inundated (e.g. standing surface water) it may be impossible to remove enough water to successfully install the bore pit, thereby eliminating the ability to utilize the bore method at this crossing. The distance across the wetlands adjacent to Beaverdam Swamp at the proposed crossing location is approximately 605 feet, which far exceeds the limitation of conventional bore, thus requiring bore entry and exit pits to be located within the wetlands and requiring additional workspace footprint. A recent site visit at this area indicates a very high water level (3-5 ft. above ground surface); thereby effectively eliminating the bore option for this crossing. Provide additional explanation focused on why waterbodies that occur within the boundaries of wetlands are not planned as dry crossings (i.e., dam and pump or flume). Atlantic has noted that this is required for inundated wetlands, but where datasheets or photos do not document inundated conditions, why does Atlantic continue to plan open cut crossings of waterbodies within the boundaries of wetlands? Atlantic Response: The U.S. Army Corps of Engineers (USACE) Wetlands Delineation Manual defines inundation as a condition in which water either temporarily or permanently covers a land surface. Saturated soils are defined by the USACE Wetlands Delineation Manual as a condition in which all easily drained voids (pore spaces) between soil particles are temporarily or permanently filled with water to the soil surface at pressures above atmospheric. As can be ascertained by the definitions presented above, the sites in question can go from saturated to inundated and vice a versa over short periods of time depending upon local conditions such as precipitation, temperature, soil types, vegetation and topography. At the time of delineation, the areas in question were characterized as saturated wetlands, meaning water was present at least to the soil surface over the majority of the delineated area. Whether inundated or saturated, soils in these areas will be characterized by low shear strength and high compressibility, due to water occupying the pore spaces. Water in the pore spaces is not only easily displaced leaving unstable air filled voids, it also reduces friction between the individual soil grains or particles, reducing shear strength. In order to ensure stability, any areas where equipment will be required to maneuver will need to be covered with load dispersing wooden mats. If these steps are not taken, heavy equipment will sink into the soil and significantly damage underlying strata requiring excessive habitat damaging remediation. Most of the waterbodies in question are less than 20 feet in width (with a few ranging between 25 feet to 45 feet). From a technical or construction perspective, waterbodies of this size are not large enough to warrant the use of dry construction techniques; given that an open cut simplifies the installation, minimizes disturbances, and significantly reduces the duration of the crossing. Additionally, due to the saturated nature of these areas it would be very difficult to achieve a dry ditch condition. Furthermore, in order to configure these sites for a dry crossing significant disturbance, above and beyond what is necessary for a conventional open cut crossing, would be required. For example in October 13, 2017 Atlantic Coast Pipeline NCDEQ Information Request Response order to configure the site for a dam and pump dry crossing method, the disturbance footprint would need to be expanded from the standard construction workspace width needed for an open cut crossing. The additional work space is needed to provide room for heavy equipment to support dam installation, position and maintain pumps, pipes and/or hoses, and support dewatering structures and operations. All of this additional area will need to be matted so heavy equipment does not sink into the soil. The extra area needed to facilitate this configuration would not be disturbed if the crossing was made using the open cut method. Additionally, since in most of these areas would require installation of sheet piling for trench stabilization and more time would be required to configure the site for a dry crossing, which may also necessitate the installation of well points and/or several large pumps to unnecessarily remove large volumes of ground water, the preparation for a dry crossing at these sites will take several days. This additional time will exacerbate the impacts on local wildlife as compared to the open cut method, given the open cut crossing would be completed in a fraction of the time of a dry crossing. Provide a typical drawing that illustrates the differences in workspace for an open cut versus a dry crossing where waterbodies are planned for open cut within wetlands to illustrate differences in workspace and impacts described by Atlantic. Atlantic Response: Atlantic has provided typical drawings illustrating the differences in workspace layout for dam and pump, flume, and open cut crossings of both dry and wet crossing locations, included in Attachment B. Provide additional details regarding the pump volume thresholds used to determine when a dam and pump method will be used versus a flume method. Atlantic Response: The decision whether to use a flume or pump around is largely dependent upon the width and depth of the stream, flow rates, flow velocities, weather forecasts and anticipated time required to install the crossing. As such, this decision is typically made just before the installation begins with significant consideration given to the above factors. With regards to pump volume, there are numerous factors that influence pump output capacities, including size of the pump, pump power source (e.g. electric, gas or diesel driven), head being pumped against and distance the fluid is pumped. Currently there are portable diesel driven pumps on the market that can pump 16500 GPM; however it is unlikely that pumps this large will be utilized. Pump choice is based upon site access, availability of workspace, waterbody width, waterbody depth, and flow conditions. The decision as to which pump to use is typically made just before the installation begins with significant consideration given to the above factors. Provide more specificity on where hydrostatic test water will be discharged, and provide typical drawings and/or additional explanation for the construction of discharge structures that will be utilized to dissipate the energy to prevent scour and erosion during discharge. Atlantic Response: Large volume discharges from the tested portions of the pipeline will be piped to dewatering structures. Dewatering structures will be constructed solely for dewatering at selected test manifold sites. Typically, dewatering structures are constructed of straw bales and take the shape of two large circular, concentric, fully enclosed structures. The inner circle is typically a minimum of one straw bale in height and the outer circle being a minimum of two bales in height. The straw bales will be laid out with each layer staggered, to avoid a single joint from top to bottom, See Attachment C. M October 13, 2017 Atlantic Coast Pipeline NCDEQ Information Request Response The structure is built by placing straw bales in a circular configuration; the bales are then secured in place with wooden stakes which are driven through the bales. Typically dewater structures are 36 to 42 feet in diameter; however based upon site conditions, the actual size may be modified by the Environmental Inspector. Dewatering structures will be built in well vegetated areas. To minimize erosion and sediment transfer, the bottom of the inner ring will be covered with thick plastic, wooden mats, steel plates or geotextile fabric, or as otherwise directed by the Environmental Inspector. Sediment logs will be placed and secured on the inside of the structure at the juncture between the erosion control bottom preparation and the inner straw bale circle. The actual configuration of the discharge pipe and energy dissipating baffle will be provided by the contractor and reviewed and approved by the Project Team (including the Environmental Inspector). Typically, the discharge pipe and the energy dissipating tee -baffle consist of a 20 inch diameter by 10 feet long section of pipe with overflow and underflow steel plates welded inside and an appropriate sized inlet connection, typically 6 inches in diameter. During dewatering, the tee will be positioned on plywood, which will be positioned on top of the erosion control bottom preparation. Plywood will be under each end of the Tee to act as energy dissipating device and to provide an additional prevention measure to reduce erosion and sediment transfer within the dewatering structure. During discharge, the flow rate into the dewater structure will be controlled by a person manipulating a 6 inch discharge valve located on the test manifold. If the Environmental Inspector determines the water level within the dewater structure is rising too quickly, the valve will be closed down to a point to prevent water from overflowing the structure. Additionally, the water flow from the exterior of the structure will be monitored to ensure erosion is not occurring away from the structure. Should the Environmental inspector determine that water filtering through the structure is causing erosion, the discharge valve will be closed and straw bales or other erosion control devices will be placed, as directed by the Environmental Inspector, to minimize erosion and sedimentation. NCDEQ requested that Atlantic provide typical drawings for stream restoration, one example of which was restoration of an incised stream. Confirm that Atlantic does not intend to provide an incised stream restoration typical drawing and indicate why. Atlantic Response: Atlantic does not anticipate crossing incised streams in North Carolina, and therefore Atlantic is not providing a typical drawing for incised stream restoration. NCDEQ requested additional information about how Atlantic intends to monitor stream stability and potential for pipeline exposure at stream crossings in the long-term. Atlantic Response: Beyond the monitoring activities that occur during and shortly after construction (previously described in Atlantic's September 22, 2017, response to NCDEQ's September 14, 2017 request), Atlantic will also monitor the right-of-way for the life of the project. Long-term monitoring activities will include annual foot patrol inspections of the right-of-way; monthly aerial inspections; and foot patrol inspections of stream crossings following major storm events (hurricanes, tropical storms, atypical rainfall/snowmelt, etc.). The purpose of long term monitoring is to identify areas of erosion, subsidence, and encroachments that may occur along the right-of-way. Pipeline exposure concerns or issues identified during inspections would be addressed immediately. These inspections are completed as required by USDOT Pipeline and Hazardous Materials Safety Administration regulations governing natural gas transmission facilities. 5 October 13, 2017 Atlantic Coast Pipeline NCDEQ Information Request Response NCDEQ requested greater clarity regarding the applicability and willingness to comply with NCG010000 permit within four watersheds with 3034 streams impaired for benthos. Atlantic Response: Atlantic will be obtaining the General Permit NCG010000 to Discharge Stormwater under the National Pollutant Discharge Elimination System for Construction Activities (NCG010000). Atlantic submitted applications for the NCG010000 permit to the NCDEQ Raleigh and Fayetteville regions on 28 August 2017 and received comments from NCDEQ dated 15 and 26 September 2017. Atlantic is in the process of responding to these comments and will have provided revised submissions to both the Raleigh and Fayetteville regions by 13 October 2017. Accordingly, Atlantic commits to implementing the requirements in Section ILB of the NCG010000 permit (or similar additional best management practices) in these 4 watersheds. Upload revised Erosion and Sediment control sheets to NCDEQ site when final, scheduled for October 13, 2017. Atlantic Response: According to a coordination meeting with NCDEQ staff on October 12, 2017, revised erosion and sediment control sheets will be uploaded to the specified location on the NCDEQ website the week of October 16, 2017. Explain why Neuse River HDD that has recently been added was previously considered infeasible. Atlantic Response: The Neuse River HDD has never been defined as infeasible. Atlantic Coast Pipeline's position on the matter was, and is, less total environmental impacts are created with an open cut. Atlantic Coast Pipeline is in the process of developing an HDD design for this crossing. Atlantic respectfully requests that NCDEQ continue to process its application. Please contact Spencer Trichell at (804) 273-3472 or Spencer.Trichell@dominionenergy.com, if you have questions regarding this submittal. Please direct written responses to: Richard B. Gangle Dominion Energy Services, Inc. 5000 Dominion Boulevard Glen Allen, Virginia 23060 Sincerely, eo—* 4�A Robert M. Bisha Environmental Technical Advisor, Atlantic Coast Pipeline cc: Spencer Trichell (Dominion Energy) Jennifer Burdette (NCDEQ) Attachments T Attachment A Beaverdam Swamp and Raft Swamp HDD and Conventional Boge Example Drawings M , , - Z � OPTION B - 100' AIDE TEMPORARY m WORKSPACE FOR PULL SECTION 200'X 250'TEMP17RARY PRELIMINARY 200'X 250' TEMPORARY STAGING TO EXTEND 1,700' A WORKSPACE FOR HDD HDD ALIGNMENT WORKSPACE FOR HDD BEYOND HDD ENDPOINT o OPTION A - 100' WIDE TEMPORARY b OPERATIONS PRELIMINARY PRELIMINARY OPERATIONS WORKSPACE FOR PULL SECTION HDD ENDPOINT HDD ENDPOINT STAGING TO EXTEND 1,700' - - - PROPOSED ACP � i BEYOND HDD ENDPOINT CENTERLINE i — �. i' ✓ - - - — — x / % - - - - - - - - - - - - - - - - - - - - — n b 70 WETLAND) BEAVER DAM n ( TYPICAL) SWAMP BUILDING �CTYPICAL) 0 J. D.Hair&Associates,Inc. Consulting Engineers 2424 East 21 st Street Suite 510 Tulsa, Oklahoma 74114 PLAN SCALE. 1'= 4 00' PRELIMINARY LEGEND AP -2 PIPELINE (PROFILE) ■ AP -2 PIPELINE (PLAN VIEW) 50' PERMANENT RIGHT-OF-WAY TEMPORARY RIGHT-OF-WAY m � PROPOSED ADDITIONAL EXTRA WORK AREA • —STREAM BSRF BELTED SILT RETENTION FENCE (BSRF) WBS WATERBAR (PLAN VIEW) COMPOST FILTER SOCK COIR LOG WETLAN D BORE PIT TIMBER MATTING ■ WATER PUMP IN SECONDARY CONTAINMENT 1 DEWATER STRUCTURE 0 PERMANENT WATERBAR/SLOPE BREAKER - TEMPORARY WATERBAR/SLOPE BREAKER T TRENCH BREAKER/PLUG NOTES: 1. SINCE THE BORE PITS WILL BE BUILT IN SATURATED AND/OR FLOODED WETLANDS, SIGNIFICANT GEOSTATIC/HYDRROSTATIC PRESSURES WILL BE ENCOUNTERED. BORE PITS SHALL BE DESIGNED TO WITHSTAND THESE TYPES OF PRESSURE AND TYPICALLY REQUIRE DRIVEN SHEET PILING AND SIGNIFICANT BRACING AND CONCRETE FLOORS. 2. SATURATED AND/OR SOFT SOILS THAT ARE PRESENT IN WETLANDS MAY CAUSE ALIGNMENT ISSUES THAT WILL MAKE THE CROSSING DIFFICULT TO COMPLETE. 3. IN SATURATED WETLANDS, THE BORE PITS WILL REQUIRE CONSTANT PUMPING INTO DEWATER STRUCTURES TO DEWATER THE AREA. 4. WELL POINTS MAY BE REQUIRED TO HELP REMOVE WATER FROM THE BORE PIT. 5. IF THE WETLAND IN INUNDATED WITH WATER AT THE TIME OF THE CROSSING. IT WOULD NOT BE FEASIBLE TO COMPLETE THIS BORE. PROFILE NOTE: EXISTING GRADE ELEVATIONS PROVIDED IN THE PLAN/PROFILE WILL BE RESTORED TO LIKE ELEVATIONS AFTER CONSTRUCTION; NO CHANGE TO ELEVATIONS ARE PLANNED. 140 120 100 IE 1168+74 C. L. 1169+13 C.L. 1169+62 1170+25 1170+74 C. L. 1171+13 C. L. 15° OVER BEND 15° SAG BEND 15° SAG BEND 15° OVER BEND PROFILE SCALE : 1" = 20' Horizontal & Vertical VV WAY DEWATER STRUCTURE I �/ 4, •/ I DEW!TER STRICTURE WETLAND I �� / �� • ' /� ��_�_� I ( I I ----------------- 25'x200'PROPOSEDADDITIONA,LE,XTRA WORK AREA –�--------�------� � � � � � /� / � � � � �I � I �-- \ – WETLAND � i~– --- ----25'x200' PROPOSE DADDITI.ONALEXTRA WORK AREA =--=-----------� 20' 10' 0 20' SCALE: 1"=20' 2'CONTOURS PLAN REFERENCE SYM. DATE BY REVISION INFORMATION PROJECT/TASK APP. SEAL F and Consulting, LLCAtlantic Coast Pipeline, LLC LIDAR ELEVATION DATA PROVIDED BY GAI CONSULTANTS. INTEGRITY • INITIATIVE • INNOVATION PIPELINE SURVEY INFORMATION PROVIDED BY GAI CONSULTANTS. DRAWN: RLR 10/5/17 925 White Oaks Blvd. Bridgeport, West Virginia 26330 / 681-842-8000 IFC REV 0 ALIGNMENT AND E&S UTILIZED CHECKED: DLM 10/7/17 TITLE: CONVENTIONAL BORE APP. FOR BID: PROPOSED PIPELINE AP -2 CROSSING BEAVERDAM SWAMP LAB 10/13/17 RLR ADD EQUIPMENT / MATERIAL STAGING AREAS APP. FOR CONST.: DISTRICT: COUNTY. • HALIFAX STATE: NC GROUP DWG. NO. REV. 10/9/17 RLR ADD TIMBER MATS SCALE. V. = 20' DIR/FILE. DOM/ACP/StreamBOres/Beaverdam Swamp Bore 1 of 1 B PRELIMINARY RAFT SWAMP HDD ENTRY POINT PRELIMINARY HDD EXIT POINk - ' VWETLAND 150'X 250' TEMPORARY 200'X 250' TEMPORARY PRELIMINARY (TYPICAL) WORKSPACE FOR HDD WORKSPACE FOR HDD HDD ALIGNMENT PIPE SIDE OPERATIONS RIG SIDE OPERATIONS J. D.Hair&Associates,Inc. Consulting Engineers 2424 East 21 st Street Suite 510 Tulsa, Oklahoma 74114 PROPOSED ACP CENTERLINE 1 OO o IRUILDING ( TYPICAL) � 0 100' VIDE TEMPORARY WORKSPACE FOR PULL SECTION STAGING TO EXTEND 4,350' BEYOND HDD EXIT I \ \ \ I o \ I \I PLAN SCALE. 1'= 600' PRELIMINARY LEGEND AP -2 PIPELINE (PROFILE) ■ AP -2 PIPELINE (PLAN VIEW) 50' PERMANENT RIGHT-OF-WAY TEMPORARY RIGHT-OF-WAY m � PROPOSED ADDITIONAL EXTRA WORK AREA • STREAM BSRF BELTED SILT RETENTION FENCE (BSRF) � WBs WATERBAR (PLAN VIEW) COMPOST FILTER SOCK [mass" COIR LOG WETLAN D BORE PIT TIMBER MATTING NOTES: 1. SINCE THE BORE PITS WILL BE BUILT IN SATURATED AND/OR FLOODED WETLANDS, SIGNIFICANT GEOSTATIC/HYDRROSTATIC PRESSURES WILL BE ENCOUNTERED. BORE PITS SHALL BE DESIGNED TO WITHSTAND THESE TYPES OF PRESSURE AND TYPICALLY REQUIRE DRIVEN SHEET PILING AND SIGNIFICANT BRACING AND CONCRETE FLOORS. 2. SATURATED AND/OR SOFT SOILS THAT ARE PRESENT IN WETLANDS MAY CAUSE ALIGNMENT ISSUES THAT WILL MAKE THE CROSSING DIFFICULT TO COMPLETE. 3. IN SATURATED WETLANDS, THE BORE PITS WILL REQUIRE CONSTANT PUMPING INTO DEWATER STRUCTURES TO DEWATER THE AREA. 4. WELL POINTS MAY BE REQUIRED TO HELP REMOVE WATER FROM THE BORE PIT. 5. IF THE WETLAND IN INUNDATED WITH WATER AT THE TIME OF THE CROSSING. IT WOULD NOT BE FEASIBLE TO COMPLETE THIS BORE. 1 1 PROFILE NOTE: EXISTING GRADE ELEVATIONS PROVIDED IN THE PLAN/PROFILE WILL BE RESTORED TO LIKE ELEVATIONS AFTER CONSTRUCTION; NO CHANGE TO ELEVATIONS ARE PLANNED. 9034+65 C.L. 9035+04 C.L. 15° OVER BEND 15° SAG BEND 80 9035+45 9035+86 9036+27 C.L. 9036+66 C.L. 15° SAG BEND 15° OVER BEND WATER PUMP IN SECONDARY CONTAINMENT 1 DEWATER STRUCTURE 0 PERMANENT WATERBAR/SLOPE BREAKER - TEMPORARY WATERBAR/SLOPE BREAKER T TRENCH BREAKER/PLUG NOTES: 1. SINCE THE BORE PITS WILL BE BUILT IN SATURATED AND/OR FLOODED WETLANDS, SIGNIFICANT GEOSTATIC/HYDRROSTATIC PRESSURES WILL BE ENCOUNTERED. BORE PITS SHALL BE DESIGNED TO WITHSTAND THESE TYPES OF PRESSURE AND TYPICALLY REQUIRE DRIVEN SHEET PILING AND SIGNIFICANT BRACING AND CONCRETE FLOORS. 2. SATURATED AND/OR SOFT SOILS THAT ARE PRESENT IN WETLANDS MAY CAUSE ALIGNMENT ISSUES THAT WILL MAKE THE CROSSING DIFFICULT TO COMPLETE. 3. IN SATURATED WETLANDS, THE BORE PITS WILL REQUIRE CONSTANT PUMPING INTO DEWATER STRUCTURES TO DEWATER THE AREA. 4. WELL POINTS MAY BE REQUIRED TO HELP REMOVE WATER FROM THE BORE PIT. 5. IF THE WETLAND IN INUNDATED WITH WATER AT THE TIME OF THE CROSSING. IT WOULD NOT BE FEASIBLE TO COMPLETE THIS BORE. 1 1 PROFILE NOTE: EXISTING GRADE ELEVATIONS PROVIDED IN THE PLAN/PROFILE WILL BE RESTORED TO LIKE ELEVATIONS AFTER CONSTRUCTION; NO CHANGE TO ELEVATIONS ARE PLANNED. 9034+65 C.L. 9035+04 C.L. 15° OVER BEND 15° SAG BEND 80 9035+45 9035+86 9036+27 C.L. 9036+66 C.L. 15° SAG BEND 15° OVER BEND WETLAND PROFILE SCALE : 1" = 20' Horizontal & Vertical 140 120 100 ED]= 20' 10' 0 20' SCALE: 1"=20' 2'CONTOURS PLAN GENERAL NOTES AND COMMENTS: SYM. DATE BY REVISION INFORMATION PROJECT/TASK APP. SEAL REFERENCE F and Consulting, LLC INITIATIVEINNOVATIONAtlantic Coast Pipeline, LLC LIDAR ELEVATION DATA PROVIDED BY GAI CONSULTANTS. INTEGRITY • • PIPELINE SURVEY INFORMATION PROVIDED BY GAI CONSULTANTS. DRAWN. RLR 10/5/17 925 White Oaks Blvd. Bridgeport, West Virginia 26330 / 681-842-8000 IFC REV 0 ALIGNMENT AND E&S UTILIZED CHECKED: DLM 7/12/17 TITLE: CONVENTIONAL BORE APP. FOR BID: PROPOSED PIPELINE AP -2 CROSSING RAFT SWAMP LAB 10/13/17 RLR ADD EQUIPMENT / MATERIAL STAGING AREAS APP. FOR CONST.: DISTRICT: COUNTY. • ROBESON STATE: NC GROUP DWG. NO. RREV. 10/9/17 RLR ADD TIMBER MATS SCALE: V. = 20' DIRiFILE: DOM/ACP/StreamBore/RaftSwamp 1 of 1 U NOTE R BORE F !TS 18" BELOW BOTTOM OF PIPE. 60 Raft wa EXISTING GRADE EXISTI N G GRA DE 40 36" AP -2 PIPE 15.0' 6" AP- PIPELI E3MI 3' MIN. 0.00' 20 10 WETLAND PROFILE SCALE : 1" = 20' Horizontal & Vertical 140 120 100 ED]= 20' 10' 0 20' SCALE: 1"=20' 2'CONTOURS PLAN GENERAL NOTES AND COMMENTS: SYM. DATE BY REVISION INFORMATION PROJECT/TASK APP. SEAL REFERENCE F and Consulting, LLC INITIATIVEINNOVATIONAtlantic Coast Pipeline, LLC LIDAR ELEVATION DATA PROVIDED BY GAI CONSULTANTS. INTEGRITY • • PIPELINE SURVEY INFORMATION PROVIDED BY GAI CONSULTANTS. DRAWN. RLR 10/5/17 925 White Oaks Blvd. Bridgeport, West Virginia 26330 / 681-842-8000 IFC REV 0 ALIGNMENT AND E&S UTILIZED CHECKED: DLM 7/12/17 TITLE: CONVENTIONAL BORE APP. FOR BID: PROPOSED PIPELINE AP -2 CROSSING RAFT SWAMP LAB 10/13/17 RLR ADD EQUIPMENT / MATERIAL STAGING AREAS APP. FOR CONST.: DISTRICT: COUNTY. • ROBESON STATE: NC GROUP DWG. NO. RREV. 10/9/17 RLR ADD TIMBER MATS SCALE: V. = 20' DIRiFILE: DOM/ACP/StreamBore/RaftSwamp 1 of 1 U Attachment B Typical Drawings Illustrating Workspace Layout for Dam and Pump, Flume, Open Cut at Wet Crossings, and Open Cut at Dry Crossings CONSTRUCTION R.O.W. WIDTH TRENCH SPOIL PILE SEDIMENT BARRIER WATERBODY SPOIL SEE NOTE 6 WATERBODY SPOIL SEDIMENT BARRIER SPOIL PILE ADDITIONAL TEMPORARY WORKSPACE (TYP.) TOPSOIL SEDIMENT BARRIER 50' (TYP.) SBZ y I cn <<O l O p U j 0- z DRY WATERBODY W O � a I SII I v 10' (TYP.) SEDIMENT BARRIER TOPSOI L "',—PIPE WELDED, COATED AND WEIGHTED PLAN VIEW (IF NECESSARY) DRAWN BY: #W..O.E SB TEMPORARY SEDIMENT BARRIER OF CHECKED BY: SILT FENCE. SCALE: NONE FOR PERMIT DESCRIPTION Atlantic Coast Pipeline PROPOSED 36" PIPELINE TYPICAL NON -FLOWING WATERBODY CROSSING OPEN CUT TRENCHED NUMBER: DATE WATERBODY BANK 10 SPOIL PILE (TYP.) � MIN. 4Typ(TYP.) SB I o I 16" FLUME PIPE (FREE OF DENTS, 4 HOLES, AND RUST).* TRFNCH PLUG SLOPE BREAKER SANDBAGS WITH PLASTIC LINER TO FORM UPSTREAM & DOWNSTREAM DAMS INSTALL REMOVABLE SEDIMENT BARRIER OR DRIVABLE BERM ACROSS ROADWAY PLAN N.T.S. * ACTUAL NUMBER OF FLUMES REQUIRED TO BE DETERMINED BY STREAM WIDTH. DRAWN BY: #W--O-E SB TEMPORARY SEDIMENT BARRIER OF CHECKED BY: SILT FENCE. SCALE: NONE SEDIMENT BARRIER (TYP.) — TRENCH PLUG i PIPELINE TRENCH SLOPE BREAKER SLIP SLEEVE JOINT TO MAINTAIN POSITIVE FLOW (16" DIA ENTERS 20") 20" STEEL FLUME PIPE* TEMPORARY EQUIPMENT MAT BRIDGE Atlantic Coast Pipeline PROPOSED 36" PIPELINE WATERBODY CROSSING - OPEN CUT, FLUME FOR PERMIT DRAWINC NUMBER: DESCRIPTION DATE TRIEV I I SB FLUME PIPE TEMPORARY EQUIPMENT MAT BRIDGE INSTALL REMOVABLE SEDIMENT BARRIER OR BERM \\ ENERGY DISSIPATING DEVICE ACROSS ROADWAY SANDBAGS WITH PLASTIC LINER TO WATERBODY FORM UPSTREAM & PLAN DOWNSTREAM DAMS N.T.S. DRAWN BY: #W..O.E SB TEMPORARY SEDIMENT BARRIER OF CHECKED BY: SILT FENCE. SCALE: NONE FOR PERMIT DESCRIPTION Atlantic Coast Pipeline PROPOSED 36" PIPELINE WATERBODY CROSSING OPEN CUT, DAM & PUMP J DRAWING SHEET N0. RE`i NUMBER0 FILTER/SCREEN INTAKE HOSE WATERBODY BANK of SEDIMENT BARRIER (TYP.) SPOIL PILE I \\� - SPOIL PILE SB SB 1 PUMP TRENCH PLUG o TRENCH PLUG PIPELINE TRENCH o SLOPE BREAKER z 0 SLOPE BREAKER --_SB D' -)A-DISCHARGE HOSE I I SB FLUME PIPE TEMPORARY EQUIPMENT MAT BRIDGE INSTALL REMOVABLE SEDIMENT BARRIER OR BERM \\ ENERGY DISSIPATING DEVICE ACROSS ROADWAY SANDBAGS WITH PLASTIC LINER TO WATERBODY FORM UPSTREAM & PLAN DOWNSTREAM DAMS N.T.S. DRAWN BY: #W..O.E SB TEMPORARY SEDIMENT BARRIER OF CHECKED BY: SILT FENCE. SCALE: NONE FOR PERMIT DESCRIPTION Atlantic Coast Pipeline PROPOSED 36" PIPELINE WATERBODY CROSSING OPEN CUT, DAM & PUMP J DRAWING SHEET N0. RE`i NUMBER0 CONSTRUCTION R.O.W. WIDTH TRENCH SPOIL PILE SEDIMENT BARRIER WATERBODY SPOIL.`. FLOW no TRENCH PLUG WATERBODY SPOIL SEDIMENT BARRIER SPOIL PILE ADDITIONAL TEMPORARY WORKSPACE (TYP.) TOPSOIL SEDIMENT BARRIER 50' (TYP.) U v z N r' o' 0 U 0Q0'— Jaz i 0 a � I3 I 10' (TYP.) SEDIMENT BARRIER TOPSOIL PIPE WELDED, COATED AND WEIGHTED PLAN VIEW (IF NECESSARY) DRAWN BY: VO SB TEMPORARY SEDIMENT BARRIER OF CHECKED BY: SILT FENCE. SCALE: NONE FOR PERMIT DESCRIPTION Atlantic Coast Pipeline PROPOSED 36" PIPELINE TYPICAL FLOWING WATERBODY CROSSING OPEN CUT TRENCHED NUMBER: DATE Attachment C Hydrostatic Test Water Discharge Structure Typical Drawing ABSORBENT BOOMS (AS REQUIRED FOR DEWATERING) USE BACKHOE BUCKET OR DOZER BLADE TO ANCHOR DISCHARGE PIPE 30-35 FT. INSIDE DIA.(TYP. OR AS DIRECTED BY THE ENVIRONMENTAL INSPECTOR T -E PIPE SUPPORT TO ENSURE THAT PIPE DOES NOT REST ON STRAW BALES PLAN VIEW VISQUEEN, WOODEN MATS, STEEL PLATES OR GEOTEXTILE FABRIC AS DIRECTED BY THE ENVIRONMENTAL INSPECTOR MINIM WELL VEGETATED AREA (IF POSSIBLE) STRAW BALES TWO LAYERS HIGH AND STAGGERED (TYP.) TOP VIEW DRAWN BY: DATE: CHECKED BY: DATE: SCALE: NONE W.O. FOR PERMIT UKAwINC NUMBER: DESCRIPTION DATE :NCE /4" x 4' x 8' PLYWOOD ENERGY DISSIPATING DEVICES FO PREVENT SCOUR ABSORBENT BOOMS TO BE USED AND ANCHORED (AS REQUIRED FOR DEWATERING FROM EXISTING PIPELINE) NW BALES TWO LAYERS K AND STAGGERED (TYP.) PIPE Atlantic Coast Pipeline PROPOSED 36" PIPELINE DEWATERING STRUCTURE FOR HYDROSTATIC TESTING m 2 LAYERS OF 2' x 2' 2" x 2" WOODEN STAKE SECURELY TIED STRAW BALES WIRE MESH FENCE SECURED TO 2" x 2" WOODEN STAKE. WIRE TO EXTEND BENEATH BALES NATURAL GRADE 4" Z g NOTE STAKES SECURING SILT FENCE BETWEEN BALES ARE NOT SHOWN FOR CLARITY. SECTION 'A-A' (N.T.S.) Atlantic Coast Pipeline DRAWN BY: DATE: CHECKED BY: DATE: PROPOSED 36" PIPELINE SCALE: NONE W.O. DEWATERING STRUCTURE FOR HYDROSTATIC TESTING 0 ISSUED FOR PERMITDRAWING SHEET NO. RE`, NUMBER: REV. DESCRIPTION DATE O