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Home My WebLink About20060761 Ver 2_More Info Received_20120726N W E i BURDETTE LAND CONSULTING, INC 10212 Creedmoor Road Raleigh North Carolina 27615 Telephone (919) 841 9977 — Fax (919) 841 9909 S July 25 2012 Ms Lauren Witherspoon & Annette Lucas c/o Wetlands, Buffers, Stormwater Compliance and Permitting Unit NC Division of Water Quality 512 N Salisbury Street Raleigh North Carolina 27604 RE Additional Information Response Oaks of Sippahaw Phase 4 Fuquay Varma Wake County, North Carolina DWQ Project # 06 0761 v 2 BLC Project # 11411 Dear Ms Witherspoon and Ms Lucas We received your agency s letter dated July 3, 2012 requesting additional information regarding the application submitted for the subject project Each request is restated and addressed below The PCN application and impact maps were revised accordingly and are attached Level spreader Please provide all of the required items in the Required Items Checklist section of the LS VFS Supplement Form at the requested scales Some of the items that were omitted include a depiction of the drainage area and plan view details at a scale of I " = 30' or larger that show the forebay high flow bypass system one foot proposed topo lines and proposed drainage easement The attached LS VFS Supplement Form and Stormwater Management Plan sheets (SWM 1 3) have been revised to include the drainage area and plan view details at a scale of 1" = 10' showing the forebay, high flow bypass system, one foot proposed topo lines, and proposed drainage easement A photograph of the VFS showing that no draws are present is also attached Ms Witherspoon & Ms Lucas BLC Project # 11411 July 25 2012 2 Stormwater wetland Please provide the Required Items Checklist section of the Stormwater Wetland Supplement Form with all of the required items at the requested scales Some of the items that were omitted include a depiction of the proposed drainage easement and the soils test documenting the level of the Seasonal High Water Table In addition please show proposed one foot contours within the Stormwater wetland treatment area The attached Stormwater Wetland Supplement Form and Stormwater Management Plan sheets (SWM 1 3) have been revised to include all of the required items at the requested scales drainage easement and proposed one foot contours within the stormwater wetland treatment area Please see the original application (page 3 of the SMP attachment) for the Soils Report and Map provided by Central Carolina Soil Consulting PLLC Please do not hesitate to call Mr John Tucker at (919) 567 0483 if you have any questions about the stormwater plans or documentation provided Sincerely Burdette Land Consulting, Inc t Jenmf A Burdette Environmental Specialist Attachments Horace Tart John A K Tucker PE d LT�� O�OF W Te9VG NCDENR °ttil STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM LEVEL SPREADER VEGETATED FILTER STRIP (LS VFS) SUPPLEMENT This form must be completely filled out printed initialed and submitted I PROJECT INFORMATION Project name The Oaks of Sippihaw Phase 4 Contact name Phone number Date Drainage area number 2 II DESIGN INFORMATION The purpose of the LS VFS Buffer Rule Diffuse Flow Stormwater enters LS VFS from The drainage area Type of VFS Protected riparian buffer (slope < 5 / ) Explanation of any Other" responses above If Stonnwater Enters the LS VFS from the Drainage Area Drainage area Impervious surface area Percent impervious Rational C coefficient Peak flow from the 1 in /hr storm Time of concentration Rainfall intensity 10 yr storm Peak flow from the 10 yr storm Design storm Maximum amount of flow directed to the LS VFS Is a flow bypass system going to be used? Explanation of any Other" responses above If Stormwater Enters the LS VFS from a BMP Type of BMP Peak discharge from the BMP during the design stone Peak discharge from the BMP dunng the 10 year storm Maximum capacity of a 100 -foot long LS VFS Peak flow directed to the LS VFS Is a flow bypass system going to be used? Explanation of any Other" responses above LS VFS Design 38 415 fe 23 339 fe 6075 / 060 053 cis 500 min 72 in/hr 381 cis 1 inch /hour stone 053 cis Y (Y or N) Do not complete this section of the form cis cis Do not complete this section of the form 2 cis cis Do not complete this section of the form (Y or N) Forebay surface area 47 sq It Depth of forebay at stormwater entry point 18 in Depth of forebay at stormwater exit point 6 in Feet of level lip needed per cis 50 ft/cfs Computed minimum length of the level lip needed 27 it Length of level lip provided 30 ft Width of VFS 50 It Elevation at downslope base of level lip 39698 fmsl Elevation at the end of the VFS that is farthest from the LS 39648 fmsl Slope (from level lip to the end of the VFS) 100 / Are any draws present in the VFS? N (Y or N) Forebay is adequately sized Depth is appropriate OK Form SW401 LS-VFS 27Ju12011 Rev 9 page 1 of 3 Is there a collector swale at the end of the VFS? Bypass System Design (if applicable) Is a bypass system provided? Is there an engineered flow splitting device? Dimensions of the channel (see diagram below) M B W y (flow depth for 10 -year stone) freeboard (during the 10 year storm) Peak velocity in the channel during the 10 yr storm Channel lining material Does the bypass discharge through a wetland? Does the channel enter the stream at an angle? Explanation of any Other responses above N (Y or N) Y (Y or N) Y (Y or N) Please provide plan details of flow splitter & supporting calcs ft ft ft It ft ftlsec Pick one Y (Y or N) Redesign channel to discharge to a dissipator pad adjacent to the wetlar (Y or N) W 9d » ♦ B Ill REQUIRED ITEMS CHECKLIST EDIT Please Indicate the page or plan sheet numbers where the supporting documentation can be found An incomplete submittal package will result in a request for additional information This will delay final review and approval of the project initial in the space provided to indicate the following design requirements have been met If the applicant has designated an agent the agent may initial below If a requirement has not been met attach justification Requned Item 1 Plans (1 50 or larger) of the entire site showing Design at ultimate build -out, Off site drainage (if applicable) Delineated drainage basins (Include Rational C coefficient per basin) Forebay (If applicable) High flow bypass system Maintenance access Proposed drainage easement and public right of way (ROW) and Boundaries of drainage easement 2 Plan details (1 30 or larger) for the level spreader showing Forebay (If applicable) High flow bypass system One foot topo lines between the level lip and top of stream bank Proposed drainage easement and Design at ultimate build -out 3 Section view of the level spreader (1 20 or larger) showing Underdrain system (if applicable) Level lip Upslope channel and Downslope filter fabric IJTIs Page or plan sheet number and any notes Sheet SWM1 - JT Sheet SWM3 JT Sheet SWM3 Form SW401 LS-VFS 27Ju12011 Re 9 page 2 of 3 4 Plan details of the flow splitting device and supporting calculations (if applicable) I Sheet SW3 5 A construction sequence that shows how the level spreader will be protected from JT Sheet SW 3 sediment until the entire drainage area is stabilized 6 If a non - engineered VFS is being used then provide a photograph of the VFS showing See attached that no draws are present 7 The supporUngcalculations JT See original Submittal 8 A copy of the signed and notarized operation and maintenance (08M) agreement JT See original s ubmi t t a 1 Form SW401 L-1-VFS 27Ju12011 Rev 9 page 3 of 3 Oaks of Sippahaw Phase 4 Photo 1: Photograph of area down slope of Level Spreader #1. Permit No (to be provided by DWQ) Ill � REQUIRED ITEMS CHECKLIST Please Indicate the page or plan sheet numbers where the supporting documentation can be found An Incomplete submittal package will result in a request for additional Information This will delay final review and approval of the project Initial in the space provided to Indicate the following design requirements have been met If the applicant has designated an agent the agent may initial below If a requirement has not been met attach justification Initials Page/ Plan JT Sheet No SWM1 1 Plans (1 50 or larger) of the entire site showing Design at ultimate build out Off site drainage (if applicable) Delineated drainage basins (include Rational C coefficient per basin) Wetland dimensions (and length to width ratio) Pretreatment system Maintenance access Proposed drainage easement and public right of way (ROW) Overflow device and Boundaries of drainage easement JT SWM1 2 Plan details (1 = 50 or larger) for the wetland showing Wetland dimensions (and length to width ratio) Pretreatment system Maintenance access Proposed drainage easement and public right of way (ROW) Design at ultimate build out Off site drainage (if applicable) Overflow device and Boundaries of drainage easement JT SWM2 3 Section view of the wetland (1 = 20 or larger) showing Side slopes 31 or lower Wetland layers All wetlands Shallow land depth shallow water depth deep pool depth Option 1 no clay liner SLWT depth Option 2 clay liner Depth of topsoil on top of liner liner specifications JT SWM2 4 A detailed planting P Ian ( 1 = 20 or larger) pre ared by a qualified Individual showing A variety of several suitable species (not including cattails) Sizes spacing and locations of plantings Total quantity of each type of plant specified A planting detail The source nursery for the plants and Ferblizer and watering requirements to establish vegetation JT SWM2 5 A construction sequence that shows how the wetland will be protected from sediment until the entire drainage area is stabilized JT 6 The supporting calculations (Including drawdown calculations) See original submittal 7 A copy of the signed and notarized operation and maintenance (0 &M) agreement See original submittal 8 A copy of the deed restrictions (if required) See original submittal JT attachedg A soils report that is based upon an actual field Investigation and soil bonngs County soil maps are not an acceptable source of soils information Please note this was included in the original calculations SW401 Wetland Rev 6 11/16/09 Part III page 1 of 1 i 06 216 217 1 218 121 �' I �t '2 �y221 X222 —23� I /,224 i / ► ! l_, L `_ I ` / ! 1225 `22 _ 171 - - / 1 400--- -- — — / 109 108 / Q2 _ ' ° 101 1 `170 110 107 - 104 � 169 --_._ _ i 111 _ --__ '106 01 / / f 168 / / 1 \ ✓'/ h i ACCESS FROM PUBLIC 1 -' •' � , , , ' � i_ MAINT SEMENT E3 � I ; 95 / 0 ROM- 406 96 97 - - - - - -- /' P- UBLIC ROW � _ , / � i H OW ND SHALLOW WATER ". SHALLOW WATER 0114' SHALLOW SHALOW� sHWr397si , FOREB __ � -- LAND / LAND 0snwr3973 / / MAINT EASEMENT ? - 115 / \ - -� ' - ' STORMWATER WET RAP APRON OUTLE C R IN D P POOL �ENCY-SP_ LWAY - - / _._----- I GE AREA T LEVEL SPRE R } i 0.88 AC POND • � � ! _ 1 1 " =50' GRAPHIC SCALE 1 "= 50' 0 50 100 150 WIN Ei • , /HIGILOU8Y- YPA 5`101 F6REBA j V LEVELSPRE ER j 124 r 125 VICINITY MAP NTS HORACE TART 1817 WEST ACADEMY STREET FUQUAY- VARINA, NC 27526 919- 552 -6790 VOICE 919 -552 -1611 FAX JOHN A.K. TUCKER, P.E. 30 FT CONSULTING ENGINEER 8 FT PO BOX 297 20 FT FUQUAY- VARINA, NC 27526 18 FT VOICE 919- 567 -0483 70 FT FAX 919 - 567 -3611 10,000 SF PHASE 4 SITE DATA 2.95 AC TO7AL ACREAGE 16.19 AC OPEN SPACE 9.90 AC AVERAGE LOT SIZE 11,207 SF NUMBER LOTS 39 EA LINEAL FEET STREETS 1651 LF PIN NUMBER 0667 -06 -5052 ZONING R -10 SETBACKS FRONT 30 FT SID_ 8 FT REAR 20 FT CORNER 18 FT MIN LOT WIDTH 70 FT MIN LOT SIZE 10,000 SF DIS'URBED AREA 2.95 AC 4 � r. DEEP POOLE SHALLOW LAND . . . . . . SHALLOW WATER coV DRAINAGE AREA LIMITS - ' — ' —' STORPz1 WATER ESMT LIMITS 'PPI SOIL BORING 0 SHWT 397.3 r VY • am .; am 0 N Z O fN s w y cam: O d��;•� coV cn - o N 'PPI /Pflill r VY • am .; am 0 N Z O fN s w �®e� lily N Lo ® N Co � c7 ° `? g ®® U In °- U z UJ ._ o co M wa Y >, g C6 O � .. ti � C �w o m O r VY • am .; am 0 N Z O fN s w � 00000 � 00000 i, Planting Notes Planting Window All plants within the wetland shall be planted within the following dates, Begin PlantingEnd Planting April 1July 15 Plant Source All plants should be obtained from nurseries within the coastal plain and no more than 200 miles from the site, The seed source of the plant stod ;rhould be from the coastal plain and within 200 miles of the site, The Coastal Plain Conservation Nursery located in Edenton, NC complies with these stanurds for plant stock and these plants are generally available from this nursery. This nursery is only listed for informational purposes especially for contracrs not familiar with obtaining wetland plants, The listing of this nursery should not be taken as a requirement or recommendation and the selection of a rumery will be determined solely by the contractor. e� STORMWATER Planting Zones The plants as listed in the plant tables will be planted in each designated planting zone. Each planting zone shall be clearly marked out before planting commences. The zones are defined by the permanent pool and temporary pool e!!ations and should be laid out to within +/- 0.1' of the defined elevation, If the zones deviate from the design, the engineer must be notified and no planting shall 'occur until the wetland is regraded or the plan is modified. ................ GRAPHIC SCALE 1'P= 20' 6^90 6 0 20 40 60 Plant Spacing The correct spacing of vegetation within each zone should be checked by the Planting Supervisor on a regular basis. A relatively small error in planting distance an result in large alterations in overall plant density. The preferred method of planting is to perform clump or group plantings, This involves the installation of one species of plant as a group ranging in size from 10 to 20 plants per location, The grouping should extend at a minimum of three (3) rows in each direction when possible. Erosion Control Erosion control is very important in and around the wetland. The overall site should be stabilized before allowing low into the planted wetland. Only temporary annual grass seeding should be placed within the wetland for temporary erosion control. Erosion control blanket can also be utilized if needed. Plant Health, Storage, and Installation -Plugs must be robust healthy growing plants, -The root system must be vigorous and dense enough to hold the plug shape once removed from the growing container without being root bound. -Plugs must be stored in the shade and kept moist until installation. -if soil is compacted, the area of planting shall be loosened to a depth equal to that of the root ball for a radius of one (1) foot around each plant, - Install plugs only when soil is moist and/or wet. Before installation, remove any damaged roots and loosen any circling or compacted roots. - Install plugs using an appropriate implement such that a hole is created drat will allow the plug to be inserted without any bending, binding, or breaking of roots, - Before placing the plant in the hole, drop 2 tsp. (approximately 10 grams) of Osmocote 14.14.14 slow release fertilizer into the bottom of the hole. An equivalent substitute for Osmocote may be used as long as it is a slow release 14.14.14 fertilizer of at least 3 months duration. -The plug shall be planted to a depth equal to the depth grown at the nursery, -After installation, firm the soil around the plug so that no air pockets remain, so that they will not float away, or be easily plucked by geese. Constr: tcdon Sequence 1. Al area upstream must be stabilized with stabilized prior to 4,eigfnning work on Storm Water Wetland. 2. Enrm water discharge from storm network should be temporarily &verted until wetland is complete and disturbed areas stabilized. 3. Clear and grub the work area. 4. kcavate to the desired elevation. 5. Install surrounding embankments and outlet control structure. 6. G. -rade and compact soil. 7. Apply and grade planting soil. 8. deed, plant and mulch according to the planting plan. 9. Fi low maintenance guidelines. 10. Ounce wetland is stabilized, remove temporary diversions from storm ,rater network. STORMWATER WETLAND PLANTING SPECIFICATIONJ NO SCALE Oaks of Sippihaw - Phase 4 Plant List by Zone Wake County, North Carolina (ShW): Shallow Water Scientific Name Peltan dra virginica Pontederia cordata Sagittaria latifolia Saururus cernuus Sparganium americanum (ShL): Shallow Land Scientific Name Ascleptas incarnata Carex luri da Carex lupulina Eupatortadelphus maculatus Juncus cortaceus LEGEND Spacing Spacing to Root Ball Container (ft) On- Common Name Percentage Quantity Size Type Center Arrow arum 20% 270 4 -10 iii plug 2x2 Pickerel Weed 20% 270 4 -10 iri plug 2x2 Duck Potato 20% 270 4 -10 iii plug 2x2 Lizard's Tail 20% 270 4 -10 iii plug 2x2 Bur -Reed 20% 270 4 -10 iii plug 2x2 Totals 100% 1350 Spacing SHALLOW LAND SHALLOW WATER DRAINAGE AREA LIMITS STORM WATER ESMT LIMITS SOIL BORING Conditions Necessary for Plant Installation It is important for the success of plants to time the installation of plants when seasonal and daily weather conditions are appropriate. The following are the weather and soil conditions that must be present at the site during all planting activities. -Temperature greater than 35OF and less than 85OF -Relative Humidity greater than 30% Wind less than 10 miles/hour •Soil is moist to the surface -Soil is not excessively compacted Construction Sequencing Issues It is generally advisable to construct the final grades and prepare the final soil surface of the wetland when any danger of significant sediment inputs are gone. In addition, the shallow water, the shallow land, and the buffer /upland area adjacent to the wetland should all be planted at the same time to ensure stability within and around the entirety of the wetland. Post- Planting Requirements Following planting, it is important that the soil remain at least wet to the surface. If the permanent pool takes time to establish or if no rain events occur to wet the shallow land areas, watering may need to be undertaken to ensure survival of the plants. A two year warranty shall be in place on the complete survival of the wetland plants. The survival of plants should be determined at the end of year 1 and year 2. At both times, plants shall be replanted to replace any plants that have not survived. In addition, if significant mortality is seen, other steps should be taken to find the underlying problem and to fix the problem before replanting. NO SCALE TRASH RACK 401.28 2'x2' PRECAST CONCRETE RISER 1.75" PVC ORIFICE_ __________� INV 400.28 i PORTLAND CEMENT (TYP) `10" HDPE (WATERTIGHT) INV ELEV 400.28 3" MIN. CLEAR, TYP.-/ #5 REBAR 3' -6" LONG @ 8" O.C. EACH WAY EMBED OPEN RISER IN CONC. 6" MIN. 3,000 PSI CONC. 4'X 4' X 12 "THICK SET RISER AND REBAR ON SOLID CONCRETE M.H. BLOCKS to Root Ball Container (ft) Orr Common Name Percentage Quantity Size Type Center Swamp Milkweed 15% 188 4-10 iii plug 2x2 Shallow Sedge 20% 250 4-10 in plug 2x2 Hop Sedge 20% 250 4-10 ixi plug 2x2 Spotted Trumpetweed 15% 187 4-10 in plug 2x2 Leathery Rush 30% 375 4-10 iii plug 2x2 Totals 100% 1250 SHALLOW LAND SHALLOW WATER DRAINAGE AREA LIMITS STORM WATER ESMT LIMITS SOIL BORING Conditions Necessary for Plant Installation It is important for the success of plants to time the installation of plants when seasonal and daily weather conditions are appropriate. The following are the weather and soil conditions that must be present at the site during all planting activities. -Temperature greater than 35OF and less than 85OF -Relative Humidity greater than 30% Wind less than 10 miles/hour •Soil is moist to the surface -Soil is not excessively compacted Construction Sequencing Issues It is generally advisable to construct the final grades and prepare the final soil surface of the wetland when any danger of significant sediment inputs are gone. In addition, the shallow water, the shallow land, and the buffer /upland area adjacent to the wetland should all be planted at the same time to ensure stability within and around the entirety of the wetland. Post- Planting Requirements Following planting, it is important that the soil remain at least wet to the surface. If the permanent pool takes time to establish or if no rain events occur to wet the shallow land areas, watering may need to be undertaken to ensure survival of the plants. A two year warranty shall be in place on the complete survival of the wetland plants. The survival of plants should be determined at the end of year 1 and year 2. At both times, plants shall be replanted to replace any plants that have not survived. In addition, if significant mortality is seen, other steps should be taken to find the underlying problem and to fix the problem before replanting. NO SCALE TRASH RACK 401.28 2'x2' PRECAST CONCRETE RISER 1.75" PVC ORIFICE_ __________� INV 400.28 i PORTLAND CEMENT (TYP) `10" HDPE (WATERTIGHT) INV ELEV 400.28 3" MIN. CLEAR, TYP.-/ #5 REBAR 3' -6" LONG @ 8" O.C. EACH WAY EMBED OPEN RISER IN CONC. 6" MIN. 3,000 PSI CONC. 4'X 4' X 12 "THICK SET RISER AND REBAR ON SOLID CONCRETE M.H. BLOCKS ■ to = U ',•Cn W N N N ■ to ■ N N N a `— m M 2 S e® U 6 ,.r, a. � � Z LUo cx ■ > M ®® 0 m ■ ■�' m . Cm i N � W o M O n. r- Sf