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HomeMy WebLinkAboutWPO201400084 Plan - Stormwater 2014-12-168 3 € tj . wi- r. ✓l, J✓ it ; ; .f VIRGINIA GLENMORE GROUND STORAGE TANK VSMP APPLICATION OWNER: COUNTY OF ALBEMARLE & EAST RIVANNA VOLUNTEER FIRE COMPANY DEVELOPER: ALBEMARLE COUNTY SERVICE AUTHORITY TAX MAP & PARCEL: 093A1-00-00-00200 LIST OF PARCELS AFFECTED: 093A1-00-00-0400 07900-00-00-025AO 07900-00-00-025BO ZONING DISTRICT: NEIGHBORHOOD MODEL DISTRICT THE PROPERTY IS SUBJECT TO PROFFERS ASSOCIATED WITH ZMA 2001-8 RIVANNA VILLAGE AT GLENMORE AND A CODE OF DEVELOPMENT MAGISTERIAL DISTRICT: SCOTTSVILLE EXISTING USE: FIRE STATION PROPOSED USE: WATER STORAGE TANK, PUMP STATION, AND FIRE STATION 010 TH. op k CHARLES FRANK VOTAVA Lic. No. 034916 W ION�1L�� PREPARED BY: 9 PUMP STATION, AND WATER MAIN PROJECT AT EAST RIVANNA FIRE STATION ACSA PROJECT NUMBER 2013=04 CD PROJECT NUMBER: SDP 2014=54 MAJOR SITE PLAN AMENDMENT TO SDP 1992=4 WPO 201400084 ; i E �j } r +, € ' ... +. h t ' , < : X11 : it i'` r �j I o „ j '' %;2 f✓ft�rJ "`f... � � � --.:f� � 't, f /k'c Oi✓ ; r '%, P,, � � hhyf 'h,� f}.% ti 'h. 'y, ,.... � f f ,...... ..,� � ... i � �i, O �,✓/'�`y ...• � y. J.�_. �f O ✓,,ty ✓r,J �y 'h,h J J v...� 250 tf r Cc i f,. rrJ r✓ /i �h i a y;f/, � } T � RsTq �. ;,l r Q /f ; a :,ff. _ t Oi' s r ^i [� f rt , ,:,: y ° tr.., fr' ❑ ` ..f J Q "'` Q Qy ty.::.....:... 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V O� .......... t , r ` r' �Jh, : ✓ J r ......, r 0 1(4 ft € r H k� 1 Q o i4 f ! ��f ,//Jp h. ;•`:,:.. # �� ; .,yr s h '; ✓J � ` 'a • �, .1 ' % i/ y h , LOCATION MAP SCALE: 1 " = 750' GLENMORE SUBDIVISION TAX MAPS: 093A1 8c 079 NOVEMBER 2014 INDEX OF DRAWINGS CUCOVER SHEET SWM1 STORM WATER MANAGEMENT NOTES SWM2 STORM WATER MANAGEMENT PLAN CALCULATIONS (S%V)M3 STORM WATER MANAGEMENT PLAN CALCULATIONS APPROVED by the Albemarle County Community D velo, mfjnt Department Date_____�i �i l�-iY File Wk t�"�ifl (Yr STORM WATER MANAGMENT PLAN GUIDELINES - INSTALLATION, CONSTRUCTION AND MAINTENANCE BIORETENTION COMPONENTS 1. BIORETENTION FACILITY TO CAPTURE AND INFILTRATE STORMWATER; AREA IS APPROXIMATELY 472 SQUARE FEET. 2. BIORETENTION FACILITY UNDERDRAIN SYSTEM; THE PERFORATED PIPE UNDER THE BIORETENTION AREA IS APPROXIMATELY 30 LINEAR FEET AND THE SOLID PIPE THAT TRANSPORTS WATER FROM THE BIORETENTION AREA TO THE OUTFALL LOCATION IS APPROXIMATELY 46 FT. BOTH PIPES ARE 6—INCHES IN DIAMETER. 3. GRASS SWALES TRANSPORTING RUNOFF TO THE BIORETENTION FACILITY; THE SWALES ARE APPROXIMATELY 240 LINEAR FEET. DEFINITIONS • BIOSOIL MEDIA — A SPECIALLY BLENDED STATE —APPROVED BIORETENTION MIXTURE OF SAND, TOP SOIL AND COMPOST DESIGNED TO SUPPORT CONTINUAL PLANT LIFE, RETAIN AN INFILTRATION RATE OF PREFERABLY 2 INCHES PER HOUR, AND FILTER KEY POLLUTANTS FROM TYPICAL URBAN STORMWATER RUNOFF. KEY POLLUTANTS INCLUDE PHOSPHORUS, NITROGEN, METALS, AND PETROLEUM PRODUCTS. • BMP — STORMWATER BEST MANAGEMENT PRACTICE THAT IS DESIGNED TO CONTROL STORMWATER QUANTITY AND/OR QUALITY. • UNDERDRAIN — SLOTTED OR PERFORATED PIPING THAT LIES BENEATH AN INFILTRATION BMP DRAIN FIELD AND IS DESIGNED TO DRAIN WATER FROM THE BMP AFTER IT HAS BEEN FILTERED BY OVERLYING MATERIALS. UNDERDRAINS CAN BE PLACED TO RAPIDLY REMOVE ALL INFILTRATED STORMWATER OR TO ALLOW SOME STORMWATER TO MIGRATE TO A LOWER CHAMBER THEREBY FORCING A CERTAIN QUANTITY TO INFILTRATE TO NATIVE SOILS, SUCH AS FOR GROUNDWATER RECHARGE. CONSTRUCTION AND INSTALLATION A DESCRIPTION OF THE COMMON MATERIALS REQUIRED TO CONSTRUCT AND INSTALL BIORETENTION FACILITIES IS PRESENTED IN TABLE 1. THE SPECIFICATIONS FOR THE BIOSOIL MEDIA ARE PRESENTED IN TABLE 2. ADDITIONAL GUIDELINES CONCERNING BIORETENTION FACILITY MATERIALS AND PLACEMENT ARE GIVEN BELOW: • BIORETENTION FACILITIES SHOULD BE CONSTRUCTED AFTER THE DRAINAGE AREA TO THE FACILITY IS COMPLETELY STABILIZED. EROSION AND SEDIMENT CONTROLS FOR • ALL MATERIALS ARE TO BE INSPECTED AND COMPARED TO THE PLAN SPECIFICATIONS PRIOR TO INSTALLATION. ANY MATERIALS NOT MEETING PLAN SPECIFICATIONS SHOULD BE REJECTED AND REPLACED WITH SUITABLE MATERIALS. • STONE AND GRAVEL SHALL BE WASHED UNTIL LESS THAN 1 PERCENT PASSES THE #200 SIEVE. • EXCAVATION OF THE BIORETENTION FACILITY SHOULD BE COVERED WITH PLASTIC SHEETING OR OTHER MATERIAL AT THE END OF THE WORK DAY, OR WHEN IT RAINS, TO INHIBIT THE COLLECTION AND INFILTRATION OF PRECIPITATION. THIS REQUIREMENT MUST BE MET UNTIL AT LEAST THE GEOTEXTILE AND STONE ARE INSTALLED PROPERLY AND IS FULLY FUNCTIONAL AS DESIGNED. TABLE 1: BIORETENTION FACILITY COMPONENTS Component Material Additional Information Planting Sall Homogeneous ® Mixture must be State approved mixture of sails « The components of the soil ,should be mixed at a batch cell prior to delivery to the site. 0 The soil media should be slightly moistened, as necessary, to prevent Separation during installation • See additional design guidelines for soil media in the narrative below. Plants 0 Plants must be able to tolerate highly variable moisture conditions, generally dry, with brief periods of inundation. Plants must be able to tolerate exposure to Wind and sun, as Well as salt and toxins in runoff from roads; parking lots, and driveways. Use of native plant species is preferred. • See additional E sidelines for �l 8 ants below. Mulch fine shredded Mulch is well aged when it has been stockpiled hardwood mulch or stored for 6 to 12 months. Mulch should be uniform in color and free of foreign material , including lent material. Underdrain System and 6 inch, Schedule 40; 3/8 inch perforations with each row of Cleanout or better polyvinyl perforations containing at least 6 holes. perforated and solid • Max spacing between rows of perforation shall pipe be 6-inches and the minimum slope of the pipe should be 1 . Low Permeability Needled, non-- Must meet the fallowing specifications Geotextile woven, o Grab Tensile Strength (ASTM D4632): polypropylene >120 lbs geotextile meeting o Mullen Burst Strength (ASTM D3786); criteria in Additional >225 lbs/in2 Information o Apparent Opening Size (ASTM D4751): US #100 sieve Lines the outside of the bioretention facility to block migration of native files (material that can pass the #200 sieve) into the facility Filter Media VDOT #3, #8, or #89 Material between soil media and dnderdrain Pea Gravel stone layer Stone VQOT #57 Stone • Homogeneous stank layer with stone at least 6 inches above and 6 inches below the u nd erd ra in 5 Service A , uth6rity 'i SEQUENCE OF CONSTRUCTION ROUGH EXCAVATION OF THE BIORETENTION AREA MAY BE SCHEDULED WITH THE ROUGH GRADING OF THE PROJECT TO PERMIT USE OF THE EXCAVATED MATERIAL AS FILL ELSEWHERE ON THE SITE. HOWEVER, THE BIORETENTION AREA MUST NOT BE CONSTRUCTED OR PLACED IN SERVICE UNTIL THE ENTIRE CONTRIBUTING DRAINAGE AREA HAS BEEN STABILIZED. THE LOCATIONS OF BIORETENTION AREAS MUST NOT BE USED FOR SEDIMENT AREAS FOR EROSION AND SEDIMENT PROTECTION DURING SITE CONSTRUCTION. THE SEQUENCE OF CONSTRUCTION SHALL BE AS FOLLOWS: 1. INSTALL THE EROSION AND SEDIIMENT CONTROL MEASURES FOR THE SITE. 2. GRADE EACH SITE TO ELEVATIONS SHOWN ON PLAN. INITIALLY, THE FLOOR MAY BE EXCAVATED TO WITHIN ONE FOOT OF ITS FINAL ELEVATION. EXCAVATION TO FINISHED GRADE SHALL BE DEFERRED UNTIL ALL DISTURBED AREAS WITHIN THE WATERSHED HAVE BEEN STABILIZED AND PROTECTED. 3. COMPLETE CONSTRUCTION ON THE WATERSHED AND STABILIZE ALL AREAS DRAINING TO THE BIORETENTION AREA. 4. REMOVE ALL ACCUMULATED SEDIMENT AND EXCAVATE BIORETENTION AREA TO PROPOSED DEPTH. USE RELATIVELY LIGHT, TRACKED EQUIPMENT TO AVOID COMPACTION OF THE FLOOR. AFTER FINAL GRADING IS COMPLETED, DEEPLY TILL THE FLOOR WITH ROTARY TILLERS OR DISC HARROWS TO PROVIDE A WELL —AERATED, HIGHLY POROUS SURFACE TEXTURE. 5. INSTALL THE LOW PERMEABILITY GEOTEXTILE IN ACCORDANCE WITH THE PLANS. 6. INSTALL THE PERFORATED UNDERDRAIN, INFILTRATION STONE, AND PEA GRAVEL IN ACCORDANCE WITH THE SPECIFICATIONS AND DIRECTIONS. LIGHTLY COMPACT WITH A LANDSCAPING ROLLER. 7. AFTER CONFIRMATION THAT SOIL MEETS SPECS BY PERFORMING THE REQUISITE GRADATION AND CHEMICAL TESTS, FILL BIORETENTION AREA WITH PLANTING SOIL, AS SHOWN IN THE PLANS AND DETAILED BELOW. THE BIORETENTION SOIL SHOULD NOT BE COMPACTED. 8. INSTALL THE MULCH AND VEGETATION SPECIFIED IN THE PLANTING PLAN FOR BIORETENTION AREA. 9. PLACE SOD IN UPSTREAM GRASS SWALE AND THE DOWNSTREAM EMBANKMENT. 10. UPON AUTHORIZATION FROM DESIGNATED INSPECTOR, REMOVE ALL SEDIMENT CONTROLS AND STABILIZE ALL DISTURBED AREAS. BIORETENTION AREA SOIL SPECIFICATIONS PLANTING SOIL • THE SOIL MUST BE A STATE APPROVED MIX. • THE BIORETENTION AREAS SHALL CONTAIN A PLANTING SOIL MIXTURE OF 50% SAND, 30% LEAF COMPOST (FULLY COMPOSTED, NOT PARTIALLY ROTTED LEAVES), AND 20% TOPSOIL. TOPSOIL SHALL BE SANDY LOAM OR LOAMY SAND OF UNIFORM COMPOSITION, CONTAINING NO MORE THAN 5% CLAY, FREE OF STONES, STUMPS, ROOTS, OR SIMILAR OBJECTS GREATER THAN ONE INCH, BRUSH, OR ANY OTHER MATERIAL OR SUBSTANCE WHICH MAY BE HARMFUL TO PLANT GROWTH, OR A HINDRANCE TO PLANT GROWTH OR MAINTENANCE. • THE TOP SOIL SHALL BE FREE OF PLANTS OR PLANT PARTS OF BERMUDA GRASS, QUACK GRASS, JOHNSON GRASS, MUGWORT, NUTSEDGE, POISON IVY, CANADIAN THISTLE OR OTHERS AS SPECIFIED. IT SHALL NOT CONTAIN TOXIC SUBSTANCES HARMFUL TO PLANT GROWTH. • THE BIORETENTION SOIL SHALL BE TESTED AND MEET THE FOLLOWING CRITERIA: TABLE 2: BIORETENTION SOIL CRITERIA SOURCE: VIRGINIA STORMWATER MANAGEMENT HANDBOOK 1.y w:ss tiLy[{pp { '0- g C0 8 KK h "y �;<Fb.e {.0. i£&�'o::i-r. Tv,faY4✓'k 3�44 F:,YH. {.. ff MO+ kf n.a°< �6g55.5 �Eb %pYh3k 1 0- 1_ h i rf;a"i�{,lb,a3,?:gs fa1..t to s.'v`.s SH n% � .✓ i e� tiik fh K ff�.Y'.S k.13�9f..b:4� wv f% 9 3IL.f: �,L� "•i3' •,$:i L�45 { A+A.: zxk�:"kFha; ..°3'��,�. K 4. THE FOLLOWING TESTING FREQUENCIES SHALL APPLY TO THE ABOVE SOIL CONSTITUENTS: PH, ORGANIC MATTER: 1 TEST PER 90 CUBIC YARDS, BUT NO LESS THAN 1 TEST PER BIORETENTION AREA MAGNESIUM, PHOSPHORUS, POTASSIUM, SOLUBLE SALTS: 1 TEST PER 500 CUBIC YARDS, BUT NO LESS THAN 1 TEST PER BORROW SOURCE ONE GRAIN SIZE ANALYSIS SHALL BE PERFORMED PER 90 CUBIC YARDS OF PLANTING SOIL, BUT NO LESS THAN 1 TEST PER BIORETENTION AREA. SOIL TESTS MUST BE VERIFIED BY A QUALIFIED PROFESSIONAL. MULCH • AREAS SHOULD BE MULCHED ONCE TREES AND SHRUBS HAVE BEEN PLANTED. ANY GROUND COVER SPECIFIED AS PLUGS MAY BE INSTALLED ONCE MULCH HAS BEEN APPLIED. • THE MULCH LAYER SHOULD CONSIST OF STANDARD LANDSCAPE FINE SHREDDED HARDWOOD MULCH. • MULCH SHALL BE FREE OF WEED SEEDS, SOIL, ROOTS, OR ANY OTHER SUBSTANCE NOT CONSISTING OF EITHER BOLE OR BRANCH WOOD AND BARK. • THE MULCH SHALL BE UNIFORMLY APPLIED APPROXIMATELY 2.5 INCHES IN DEPTH. • INSTALLATION SHOULD BE PERFORMED BY A PROFESSIONAL LANDSCAPE CONTRACTOR. PLANT MATERIAL GUIDELINES PLANT MATERIAL SOURCE • THE PLANT MATERIAL SHOULD CONFORM TO THE CURRENT ISSUE OF THE AMERICAN STANDARD FOR NURSERY STOCK PUBLISHED BY THE AMERICAN ASSOCIATION OF NURSERYMEN. • PLANT MATERIAL SHOULD BE SELECTED FROM CERTIFIED NURSERIES THAT HAVE BEEN INSPECTED BY STATE OR FEDERAL AGENCIES. • THE BOTANICAL (SCIENTIFIC) NAME OF THE PLANT SPECIES SHOULD BE IN ACCORDANCE WITH A STANDARD NOMENCLATURE SOURCE SUCH AS BIRR, 1975. • TREES SHOULD BE A MINIMUM OF ONE INCH CALIPER. SHRUBS SHOULD BE A MINIMUM OF TWO —GALLON CONTAINER SIZE AND HERBACEOUS PLANS SHOULD BE A MINIMUM OF SIX INCH DIAMETER CONTAINER SIZE. • ALL PLANT MATERIALS SHOULD BE TAGGED FOR IDENTIFICATION WHEN DELIVERED. INSTALLATION • BALLED AND BURLAPPED AND CONTAINERIZED TREES AND SHRUBS SHOULD BE PLANTED DURING THE FOLLOWING PERIODS: MARCH 15 THROUGH JUNE 30 AND SEPTEMBER 15 THROUGH NOVEMBER 15. • THE PLANTING OF TREES AND SHRUBS SHOULD BE PERFORMED BY FOLLOWING THE PLANTING SPECIFICATIONS SET FORTH IN MS 3.05, LANDSCAPING. MS 3.05 SPECIFICATIONS PROVIDE GUIDELINES THAT INSURE THE PROPER PLACEMENT AND INSTALLATION OF PLANT MATERIAL. DESIGNED: ZMC VSMP APPLICATION DRAWN: JLB ACSA PROJECT No. 2013-04 CD PROJECT No. SDP 2014-54 CHECKED: CFV No. DATE REVISION MAJOR SITE PLAN AMEND. TO SDP 1992-4 Michael Baker Jr., Inc. A Unit of Michael Baker International '�' T 272 Bendix Road, Suite 400 Virginia Beach, Virginia 23452 INTERNATIONAL hon757-4636 050370 Fa WARRANTIES • THE CONTRACTOR SHALL MAINTAIN A ONE (1) CALENDAR YEAR 80% CARE AND REPLACEMENT WARRANTY FOR ALL PLANTING. • THE PERIOD OF CARE AND REPLACEMENT SHALL BEGIN AFTER INSPECTION AND APPROVAL OF THE COMPLETE INSTALLATION OF ALL PLANTS AND CONTINUE FOR ONE CALENDAR YEAR. • PLANT REPLACEMENTS SHALL BE IN ACCORDANCE WITH THE MAINTENANCE SCHEDULE. BIORETENTION AREA PLANTING SPECIFICATIONS • ROOT STOCK OF THE PLANT MATERIAL SHALL BE KEPT MOIST DURING TRANSPORT FROM THE SOURCE TO THE JOB SITE AND UNTIL PLANTED. • WALLS OF PLANTING PIT SHALL BE DUG SO THAT THEY ARE VERTICAL. • THE DIAMETER OF THE PLANTING PIT MUST BE A MINIMUM OF SIX INCHES (6") LARGER THAN THE DIAMETER OF THE BALL OF THE TREE. • THE PLANTING PIT SHALL BE DEEP ENOUGH TO ALLOW 1 /8 OF THE OVERALL DIMENSION OF THE ROOT BALL TO BE ABOVE GRADE. LOOSE SOIL AT THE BOTTOM OF THE PIT SHALL BE TAMPED BY HAND. • THE APPROPRIATE AMOUNT OF FERTILIZER IS TO BE PLACED AT THE BOTTOM OF THE PIT. • THE PLANT SHALL BE REMOVED FROM THE CONTAINER AND PLACED IN THE PLANTING PIT BY LIFTING AND CARRYING THE PLANT BY ITS BALL (NEVER LIFT BY BRANCHES OR TRUNK). • SET THE PLANT STRAIGHT AND IN THE CENTER OF THE PIT SO THAT APPROXIMATELY 1 /8 OF THE DIAMETER OF THE ROOT BALL IS ABOVE THE FINAL GRADE. • BACKFILL PLANTING PIT WITH EXISTING SOIL. • MAKE SURE PLANT REMAINS STRAIGHT DURING BACKFILLING PROCEDURE. • NEVER COVER THE TOP OF THE BALL WITH SOIL. MOUND SOIL AROUND THE EXPOSED BALL. • TREES SHALL BE BRACED BY USING 2" BY 2" WHITE OAK STAKES. STAKES SHALL BE PLACED PARALLEL TO WALKWAYS AND BUILDINGS. STAKES ARE TO BE EQUALLY SPACED ON THE OUTSIDE OF THE TREE BALL. UTILIZING HOSE AND WIRE THE TREE IS BRACED TO THE STAKES. • BIORETENTION AREA PLANTS SHOULD NOT REQUIRE CHEMICAL FERTILIZATION. MAINTENANCE/INSPECTION GUIDELINES REGULAR INSPECTIONS SHOULD BE COMPLETED ON A MONTHLY BASIS FOR THE FIRST SIX MONTHS AFTER INSTALLATION. THEREAFTER, THE FACILITY SHOULD BE INSPECTED EVERY 6 MONTHS. A SAMPLE MAINTENANCE SCHEDULE CAN BE FOUND IN TABLE 3. THIS OR A SIMILAR PLAN SHOULD BE IMPLEMENTED FOR THE PROJECT. PLANTING SOIL • IT IS RECOMMENDED THAT THE APPLICATION OF ALKALINE, SUCH AS LIMESTONE, BE CONSIDERED ONCE TO TWICE A YEAR. TESTING OF THE PH OF THE ORGANIC LAYER AND SOIL, SHOULD PRECEDE THE LIMESTONE APPLICATION TO DETERMINE THE AMOUNT OF LIMESTONE REQUIRED. • SOIL TESTING SHOULD BE CONDUCTED ANNUALLY SO THAT THE ACCUMULATION OF TOXINS AND HEAVY METALS CAN BE DETECTED OR PREVENTED. OVER A PERIOD OF TIME, HEAVY METALS AND OTHER TOXIC SUBSTANCE WILL TEND TO ACCUMULATE IN THE SOIL AND THE PLANTS. THE PREVENTATIVE MEASURES WOULD INCLUDE THE REMOVAL OF THE CONTAMINATED SOIL. IN SOME CASES, REMOVAL AND DISPOSAL OF THE ENTIRE SOIL BASE AS WELL AS THE PLANT MATERIAL MAY BE REQUIRED. • THE SOIL LAYER SHOULD BE INSPECTED FOR AREAS OF EROSION AND MATERIAL REPLACED AS NEEDED. PLANT MATERIALS • THE MULCH LAYER SHOULD BE INSPECTED FOR AREAS OF EROSION AND MATERIAL REPLACED AS NEEDED. • THE ENTIRE MULCH LAYER SHOULD BE REPLACED EVERY TWO TO THREE YEARS IN THE SPRING. WHEN THE MULCH LAYER IS REPLACED, THE PREVIOUS LAYER SHOULD BE REMOVED FIRST. • PLANT MATERIAL UPKEEP INCLUDES ADDRESSING PROBLEMS ASSOCIATED WITH DISEASE OR INSECT INFESTATIONS, REPLACING DEAD PLANT MATERIAL, AND ANY NECESSARY PRUNING. TABLE 3: SAMPLE MAINTENANCE SCHEDULE SOURCE: VIRGINIA STORMWATER MANAGEMENT HANDBOOK q 3 tin e�f I W a # s% 111 , o .11 5 � s6r s �.iyes.�' �y.;;c: 4„s�.:c%: �: � �m�;..,.'K'. � » o4r.: 96,r,e�< Ada k� fva-vrvrvfvnwwvunvpuwuuuuwwrrrurmwfiiiurrmrti fiiiuiirurrr�iaruiiiiiiiiiiiiiruvuuvviafvi afiiiairiiiiii ririiiauu�foevxuri rzorfffiffffi_riry u.�am�aufpu i rofiiifiuif-rf.raaaif y I' :z gx 4 z,,,. .F F y v" -- 2 £{{ ass F:. /s-: 1%s * .gB ;` s; "� sF, s� - sy b y f / s+i /.c& Y !4 f b y: ......i _ uru..rrruinwuuiuuuf 4 k mcmuuuer�...� viiuriiufiuuiuiiuuuumur,�ir 5 K �.cY"� � �'� k4.'/Fo� .fC' ..£ufuii,.uifw.0 w. 4 ..r..+- ffriffu u uuuu. fit . S um.. _ ui uufu..uuu. .vi ?wmov Pn'44 III owi w£.4:z.Sw .:5.. By' s .roa'.'. on'...e sk .» f mo to lws.,s�'Si'ii�i'iy'<.J,y."yF��=.�''�..��6�2 s 121 x. 1 2 ,x cwn s s £} G�xs,.`.-s.c!.c.."s. 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No. 034916� ICNAL GLENMORE GROUND STORAGE TANK, PUMP STATION, AND WATER MAIN PROJECT (PROJECT NO. 2013-04) STORM WATER MANAGEMENT NOTES NOVEMBER 2014 TAX MAP 00791 SWM 1 ELEV OF 363.5 BJORETENTION SOIL LAYER 2' PEA GRAVED. LAYER UNDERDRAIN CONNECTION TO 6" PVC PIPE T�H' Or CHARLES FRANK VOTAVA Lic. No. 034916 W TONAL 6' SOUD PVC PIPE. APED (PLACE V A80VE SOIL) STATE -APPROVER BIORETENTION MIX �"T" CONNECTION 6" DIAMETER PERFORATED UNDERDRAIN AT 1% SLOPE. LIMITS OF DISTURBANCE/LIMITS OF CLEARING/LIMITS OF CONSTRUCTION THE GEOTEXTILE SHOULD BE TIED INTO THE EXISTING GROUND WITH AT LEAST 2' OF GROUND ABOVE THE GEOTEXTILE VERTICAL SIOEWALLS PROP. 12" DIP WATER SUPPLY LINE ELEV OF 363.5 GEOTEXTILE (ALONG ROPOSED GROUND ELEV OF 364.0 FT ISURFACE STORAGE BIOSOIL PEA GRAVEL TOTAL STORAGE= DEPTH VOID RATIO VOLUME (FT3) 0.5 1 236 2 0.25 236 1 1 1 0.4 1 188.8 I 1 1 660.8 NOTE: THE BIORETENTION FACILITY WILL REDUCE THE FLOW RATE OF GEOTEXTILE (ALONG BIDES) STORMWATER ENTERING THE STREAM FROM "DRAINAGE AREA A" AS A RESULT OF A 1 YEAR 24 HOUR STORM EVENT FROM A PRE -DEVELOPMENT FLOW RATE OF 0.08 CFS TO A POST -DEVELOPMENT FLOW RATE OF 0.02 CFS. DIAMETER PERFORATED UNDERDRAIN - ............. ... . ...... ' -P GRAVEL TO BE GRADED AIN'ibWARD GRASS SWALE • V.11)" CRASS SWALE TYPICAL CRASS SECTION NOT TO SCALE PROP -GRASS SWALE TAX MAP 093A1-00-00-00400 SEE CROSS-S€ETION RIVANNA VILLAGE LLC L DETAIL, THIS SHEET 1 (D.B. 4375, PG. 410) 441 q, PROP.PUM� I_(4) CEPHALANTHUS '' P,-;,, .ATION \�q \a`qq„QOCCfDENTAI�IS/BUTTON BUSH ...... PROP. 30LF- C I0 R ET" N F}�1� WoW x4a e4 0 UNDERDRAI) 0 v� f STA. 1 +24 �. PROP. 18" �ONC. PROP. STORM STORM', PIPE WATER MANHOLE :t��i�� 124LF @ '2.2% TOP=370.5 ' ---� _ _.LOPE_ _ _ _ INV. IN=367.0 .. ; 94 I I -INV. OUT=3- J - - - - - - ---I----- 6 r. w STA. q+00 /- - - PROP.._. I DROP INL�T I I K TOP=�74.5 A/ / INV. QUT=369.5 i I I I / / - I I I I DRAINAGE AREIA A BOUNPARY I I I DRAINING TO blORETENTIQN FACILITY AREA=0.44 ORES I 41 I I I I � 0 "Op I I� �a 2J. 1 0 20 40 Ft. SCALE: I I TAX MAP 093A1-00-00-00200 EAST RIVANNA VOLUNTEER FIRE CO. INCORPORATED #3501 STEAMER DRIVE (D.B. 1204, PG. 201) j 1 "=20' HORZI I STORM WATER MANAGEMENT AND PLANTING PLAN PLANT AND COMPOSITION SCHEDULE BIORETENTION SIZE ( acres ) :.009 AC (399 SF/14'x28.5') OVERALL SPACING (FEET OFF CENTER) QUANTITY PER ACRE FREQUENCY (%) SPECIES QUANTITY BOTANICAL NAME COMMON NAME UNIT 10 520 17% 4 CEPHALANTHUS OCCIDENTALIS BUTTONBUSH 30" HT. 2 2600 83% 25 RUDBECKIA HIRTA BLACK-EYED SUSAN QT. NOTES: 1. CLUSTERING AND ARRANGEMENT OF THESE SPECIES TO BE COORDINATED WITH ACSA STAFF. 2. PLANT SPECIES ARE PER THE ALBEMARLE COUNTY RECOMMENDED PLANTS LIST. 3. VEGETATION SHALL ACHIEVE AT LEAST 75% COVERAGE WITHIN 2 YEARS OF THE BIORETENTION FACILITY BEING INSTALLED. PROP. 18" CONC. �6RI-iv `PtflE (20) RUBECKIA HIRTA/BLACK-EYED SUSAN PROP. 29.5'x16' BIORETENTIO FACILITY OUTLINE INV. IN=364 SEE CROSS SECTION DETAILS, THIS SHEET 20LF @ 2.2% SLOPjE STA. 1 +44 _ INV. OUT=366.5 � _ PROP. 12.2 S.Y. PROP. 6" PVC CLASS I DRY & RAP BIORETEN ON DRAIN -_-__ -- P R ��_^_ PIPE EXT ND TO DAYLIGHT UNDERLINING �` ��LF--� • 1 % SLOPE DRAINAGE SUMMARY TABLE STRUCTURE NUMBER DESCRIPTION LENGTH INVERT IN INVERT OUT SLOPE REMARKS 1 DI-7 N/A N/A 369.5 N/A 4' MANHOLE 2 18" RCP, CLASS (III 124' N/A N/A 2 N/A 3 MANHOLE N/A 366.5 366.4 N/A 4' MANHOLE 4 18" RCP, CLASS III 56' N/A 365.5 4 N/A STORMWATER COMPUTATION AND BMP CALCULATIONS OUTFALL THE NATURAL TOPOGRAPHY OF THE SITE DROPS OFF IN THE SOUTH DIRECTION. THE RELATIVELY SMALL FLOW RATES EXPECTED FROM THE UNDERDRAIN AND THE EMERGENCY SPILLWAY (DURING INFREQUENT STORM EVENTS) SHOULD NOT RESULT IN EROSION OR ANY OTHER DOWNSTREAM ISSUES. A SOLID POLYVINYL PIPE WILL CONNECT THE PERFORATED UNDERDRAIN PIPE TO THE OUTFALL LOCATION. VEGETATED EMERGENCY SPILLWAY THE PEAK FLOW RATE TO THE BIORETENTION AREA IS APPROXIMATELY 1.4 CFS DURING THE 100-YR OR 1-PERCENT-ANNUAL-CHANCE STORM EVENT. WHEN THE DEPTH OF WATER ABOVE THE BIORETENTION AREA REACHES 0.5-FT, THE EMBANKMENT ON THE WEST SIDE OF THE BIORETENTION BASIN WILL ACT AS A SPILLWAY ALLOWING WATER TO SPILL OVER THE SIDE AND DOWN THE EXISTING HILL. NO STRUCTURES ARE FOUND IN THE IMMEDIATE AREA DOWNSTREAM OF THE EMBANKMENT. GRASS SWALE ONE (MAJOR AND TWO MINOR GRASS SWALES SHALL BE CONSTRUCTED TO CONVEY WATER FROM THE IMPERVIOUS AREAS TO THE BIORETENTION AREA. THE GRASS SWALES WHICH WILL CONVEY FLOW TO THE BIORETENTION FACILITY SHALL SERVE AS THE PRETREATMENT FOR FLOWS ENTERING THE FACILITY. THE SWALES ARE SIZED USING MANNING EQUATION FOR THE 10-YR OR 10-PRECENT-ANNUAL-CHANCE STORM EVENT AND WERE ANALYZED USING THE FLOWMASTER PROGRAM. THE MINIMUM DIMENSIONS ARE AS FOLLOWS: BOTTOM WIDTH = 0.5 FT TOP WIDTH = 3.5 FT DEPTH = 0.45 FT MAX. SIDE SLOPES = 3 TO 1 Site Data Summary Total Rainfall = 43 inches Site Land Cover GLIM nary A Soils B: Soils C Sails D'Soil:s Total °I of Total Forest (acres) 0100 G.00 0.00 0100 0100 0.00 Turf (acres) 0.00 0'.00 0,00 0,34 0,34 77.27 Impervious (acres) 0.001 0.001 a001 0.20 0A0 22.73 0,44 100.00 Site Ry O.41 Post Development Treatment Volume (ft3) 653 Post Development TP Load (lb/yr) 0.41 Post Developmcent TM Lead (lb/yr) 2.94 Total TP Load Reduction Required (Ib/yr) u3 Total R€a'noff Volume Reduction (ft) 261 0 Total TP Load Reduction Achieved (lb/yr) Total TN Load Reduction ,Achieved (lb/yr) 2.9? Adjusted Post Development TP Load (lb/yr) 0.11� Remaining Phosphorous Load Reduction (Lblyr) Required 0,04 Drainage Area Summary D.A. A D.A. B D.A. C D.A. D D.A. E Total Forest (acres) 0.00 0.00 0.00 0.00 0.00 0.00 Turf (acmes) 0.34 0100 0.00 GM 0100 0.,3.E Irnperviotus (acres) 0,10 0.00 0.001 0.001 0.00 0.10 drainag,e Area Compliance Su€r€marV D.A. A D.A. B D.A. C D.A. a D.A. E Totai TP Load Reel. (Iblyr) 0123 0100 0.00 O,aO 0100 0.23 TN Load Red. (ilia/yr) 2.93 0,00 0.00 0.00 0,00 2,93 Drainage Area A Summary Lard Cover Surr€marV A Soils a Soils C Soils D Soils Total % of Total Forest (acres,) Mo 0.00 Mo 0100 0100 0.00 Turf (acres) 0.00 0.00 0100 0.34 0,34 77.27 Impervious (acres) 0.001 0.001 0,001 0,10 0!.101 22.73 BMP Selections Practice Credit Area (acres) Downstream Practice Total Impervious Cover Treated (acres) 0.10 Total Turf .Area Treated (acres) 0,34 Total 7P Load Reduction Achieved: in D.A. A (lhjyr) 0,23 Total TN Load Reduction Achieved in D.A. A (lb/yr) 2,93 NOTE: THE ABOVE SUMMARY IS FROM THE LATEST VIRGINIA RUNOFF REDUCTION METHOD SPREADSHEET. Ot.441 F, £ f£ f DESIGNED: zMc VSMP APPLICATION GLENMORE GROUND STORAGE TANK, PUMP STATION, AND WATER MAIN PROJECT tPROJECT N0. 2013-04 NOVEMBER 2014 t ��s; .....; .L,I Service Auth6rity DRAWN: J LB ACSA PROJECT No. 2013-04 Michael Baker Jr., Inc. '� iI® A Unit of Michael Bakers International 272 Bendix Road, Suite 400 T P CD PROJECT No. SDP 2014-54 Virginia Beach, Virginia 23452 Phone: 757-463-8770 STORM WATER MANAGEMENT PLAN CALCULATIONS 093A1 W M 2 CHECKED: CFv MAJOR SITE PLAN AMEND. TO SDP 1992-4 Fax: 757-463-0503 079 rN0. DATE REVISION .13i,oretention Basit-i Design F, a 'a er: a h PrOiect at Ea tt RiV :n ha Gfenm,ore Ground Star ge Tank Pump Stati"0:1111� dW t M 11 jr a on 0 A ffi Q sildretention surtaCe. Area (SA) Calculations Existing Total Dminage AFE-a Impervious Area Percent Impervious Paruious Area - Proposed Torbeil Dfaim7tge Area- Imperviou-z. Arc�-,a - Pefcent Impervious' - Per 'Vions Arco = ft 19,166 -;5,q 4j47 sq ft. 21.6 15)0191 5q ft <rneasured from (-,AD Drwtving> <mrA-sured from CAD Dnowving> <rnp_,asurp�,d from. CAD Drwvving> <measurcad froliTiti., CAD.Dre-ming> M i n-i mum Wkd th Minimum Lengt1l) Max Pondin,g, Depth = Max PondinDepth = Surface Area _- Impearvi-ous Area= Roof Are�a D r Ivt,%va, y Bi orete ntio n: Area = Biorr--tAtn.tion Area = r6 ft 29.5 ft 0.5 ;ot_ 1 ft 472 sq ft Al 47. q ft 3,521.00 sq ft 6 026.00 sq ft Impervus Araa * 5% S,ee Runiooff Caletst, Sh4_,�t ts hhL.st'llteFor widhgreatertan 20t,, thelenghsouldaat 1eal. VICe thewidth'to aow dispersedsheeet flovv .1 Without an undndrain W n 1 t an iz.4 nderdra[n 20735 -sq ft 3.11-14;- 4,67.75 -sq, ft < - e:taaln 1.0 in of runoftt, Siting ShroWd IDS t l��;;_0[20 ft id own.shop-s from any bufflding.- Ei:hu�ijld be lace— in are- to promute p, blic: invralvement 2-4, ft requIred betuv-len: the 10-cill-tram of thefaciflity and the wab.-_--r tabh-_/be---dn ck 3654.uu�� Gramp- 36150, Topof Mulch 3 62, , 2 - 5 9 o t t o IF o f M u h I T c,,� p -. of i 1 3 -0 1.25 Botto m of Soj 1,1To p of Pea G rave, 360.2'5, Bo om of Pea Grave[/Top of Underdrain Layer 3 ,3 fU L 0 To p ot. n 360:50 Bo rim of Un4erdrajn Pipe (Upstream) 3 75('�-j2 OJO-RE tc'J m : ra f U n de r 'frail . i p ge If. D o w n - s tr e.. arm.) 156.FDO 0.5 Ponding C)e.pth C�,arnponents, liVA 0C.R. Stor.m.wafer Dosign Speoftation No.. 0 611ore-tentlon rvi u I c h 3 f r, c rhes de a p, '4nsni eetp D�ee st .t:th;, ri1' om d stP, aAraln hrol �nt:Ot1U dc ( I t bA 2. ftcl)ilist ad rreerten.P-Contr-RssiitoS�eTa ) -cr-a 'llieref-bre, -the Level I.Mloret-.etit.iotit -Unfacei 'M­ea (.S is cox put'.ed as. f 5 - pe r, nt ssiand, 20 perce nt ea f c./c. mpost, an d 300. perce'-nt top: soi I oit media sho�u[d be compos:&?d o 3 9.44.43VO cubic ft cif soil Joretention Levrel 1' Design Surt�aac Area ft de-p: S 7­fhhe vlouh iazl'e rpuntttz_�e?'d tan t� irl B' �S'41 .......... .......... Geotextflle Fabric unde.rdrn � Pfa,� only a" -in V Un fdlfai Pip�e4 -dij orb;etterpol'ifOnyl pi�--rfic_'&matea-d pipp�,,3/.bl r_a.a-chrowof hengsto hul�2-s:. 6 I. n c. h, S c hee 1, e 4 0 c, u, W z"i 9" u a CM, Am Ko dftw;�PE�' rfurath-m •shall be 6-ind es anid th:e: miriimum s1ccipe c4l, the :3: ::SR.,. shc',utd b,-:-, 1%. a 171 Max spadin bet rows of p a J ;CY . ...... .. . ......... ......... Clear -�.o lit _n sol id p i pe that extends a bova-­ piand ing dep h &A 0 .. ..... ... . ... . Y . ..... . .......... - Underdmin Plae 3, ft long, . .... . ....... . .......... ........... .......... . .......... ............ ........... .......... ..... . . . ..... ......... g .... .................. ................ . . . ... ..... . ... . ..... . ........................ . . . ........ . .......... . ... . . . ...... . . ..... . . . . .................................... . . ........................................... . ..... Total Storage V o Depth -id Ratio ... ... . .. . . ........................... ... . ...... ... ................. Sur"lace; sto S U) R V 0441 *Slte Rv On tab rVir qu mary"f CO. rom VRRI.M ReOew Q. M.Phance. Spreadsheet Biosoil TV 1*0.357*18.731/12 - 6514.8:5 ft3. Giravel ,SA 54632467 (7.5 ft2 -� iot13;rCUp3 tffe_ is:[`. 5el,` f VRM ,-0)14 dP,veoj n mrar v Pp a/ :a v -o R 1_ft .9e nt tet y 8 cuft - : ta ib D, rn n560.: n r mlt Fi,Cpi .cSr dTJ 1 Calculation of Design Rainfall Intensity and Peak Storm Water Runoff Rate - U.S. units (for specified return period and storm duration) Inputs Drainage Area, A = Design Return Period = 0.430 acres 100 years Runoff Coefficient, C = Tc, Time of Concentration ( Calculation below ) 0.37 2 min Time of Concentration (Kirpich Method: ADD. 6D-5 of VDOT Drainaae Manual Tc = 0.00948*HA-0.38*LAI.13 H = 10.5 ft L = 225 ft Tc = 1.765 min Calculation of Design Rainfall Intensity, i, using the equation: i = a/( d + b (using the value for storm duratin, d, specified above) 'I' 'eaLRa.ngeftw YPI Type- of Z�rea p 1_1noff Coeily toicxtt I Concrete Pavejuent 03 0-0.95 Park or Ce�xnetary/ Do,,Ynbalffn DuAn Su'igle Fantily Residential YU-ea 0. 10-0.25 Z I I �s 0.70-0.95 0.30-U0 Design Rainfall Intensity, i = 8.80 in/hr Rational, Nlethod Runoff Coefficients Calculation of Design Peak Storm Water Runoff Rate, Q, using the equation: Q = CiA Design Peak Storm Water Runoff Rate, Q = 1.4 cfs ����,TH OF CHANCES FRANK VOTAVA Lic. No. 034916 ZONAL ... ....... MR _1 Service.Authobrity DESIGNED: zMC DRAWN: JLB CHECKED: CFV VSMP APPLICATION ACSA PROJECT No. 2013-04 CD PROJECT No. SDP 2014-54 MAJOR SITE PLAN AMEND. TO SDP 1992-4 Michael Baker Jr., Inc. M*chai� :a A Unit of Michael Baker International I I B, ker 272 Bendix Road, Suite 400 Virginia Beach, Virginia 23452 Phone: 757-463-8770 1 HTERNATIONAL Fax: 757-463-0503 GLENMORE GROUND STORAGE TANK, PUMP STATION, AND WATER MAIN PROJECT (PROJECT NO. 2013-04) STORM WATER MANAGEMENT PLAN CALCULATIONS NOVE 11 BER 2014 TAX MAP 093A1 079 SWM3 NO. DATE REVISION