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Home My WebLink About20091105 Ver 1_More Info Received_20101105ffiZEN AND SAWYER Environmental Engineers & Scientists 4011 WESTCHASE BLVD., SUITE 500 RALEIGH, INC 27607 (919) 833-7152 FAX: (919) 833-1828 To: Raleigh Regional Office NCDENR-DWQ-401 Oversight Permitting Unit 2321 Crabtree Blvd, Suite 250 Raleigh, NC 27604 WE ARE SENDING YOU: ® ATTACHED ? SHOP DRAWINGS ? SAMPLES LETTER OF TRANSMITTAL DATE: 11/5/2010 H&S JOB No.: 32039 ATTENTION: Mr. Ian McMillan RE: 401 Water Quality Certification Application - Additional Information Big Buffalo Creek Wastewater Treatment Plant 12 MGD Expansion Project City of Sanford, North Carolina - Itz)S THE FOLLOWING ITEMS: ? SPECIFICATIONS ? COPY OF LETTER ? UNDER SEPARATE COVER VIA ? PRINTS ? PLANS ? CHANGE ORDER ? COPIES DATE NO. DESCRIPTION 1 11/5/2010 1 Request for more information response letter Li 2 11/5/2010 2 Revised full sized (22"x 34") Sheet C21 1 11/5/2010 3 Revised full sized (22"x 34") Sheet D1 ' ?Uin DENR- THESE ARE TRANSMITTED AS CHECKED BELOW: ® FOR APPROVAL ? FOR YOUR USE ? AS REQUESTED ? FOR REVIEW AND COMMENT ? FURNISH AS SUBMITTED ? FURNISH AS CORRECTED ? REVISE AND RESUBMIT ? PRINTS RETURNED AFTER LOAN TO US ? RESUBMIT COPIES FOR APPROVAL ? SUBMIT COPIES FOR DISTRIBUTION ? RETURN CORRECTED PRINTS ? FORBIDS DUE ? REMARKS As requested within the "Request for More Information" letter dated Oct., 28, 2010, please find the information provided within. COPY T0: SIGNED: MICHAEL SANTOWASSO, PE] IF ENCLOSURES ARE NOT AS NOTED, KINDLY NOTIFY US AT ONCE. r. HAZEN AND SAWYER Environmental Engineers & Scientists November 5, 2010 Mr. Ian McMillan Acting Supervisor N.C. Department of Environment and Natural Resources Division of Water Quality - 401 Oversight/Express Permitting Unit 1650 Mail Service Center Raleigh, North Carolina 27699 Hazen and Sawyer, P.C. 4011 WestChase Blvd. Suite 500 Raleigh, NC 27607 (919) 833-7152 (919) 833-1828 (Fax) 7 r ?U V C3§ W RA D AND ST?Rl41Nq?R BQ Re: Big Buffalo Creek Wastewater Treatment Plant 12 MGD Expansion Project City of Sanford, North Carolina DWQ Project # 09-1105 H&S Project No. 32039 Request for More Information Dear Mr. McMillan: Please find following our response to your letter of "Request for More Information" dated October 28, 2010, which followed an email from Annette Lucas of your office sent on October 26, 2010 requesting the same information, for the above referenced project. Two copies of all information relevant to our response are provided herein for your use. The Additional Information Requested in this letter, and our responses to the requests, are listed below: Request 1: On Sheet D-1, please specify an appropriate species of grass for the bioretention cells. Response 1: The bioretention cell detail on Sheet D-1 has been modified to note the use of Bermuda grass in the bioretention areas. Two (2) copies of Sheet D-1 are attached to this letter. Request 2: On Sheet SMP-3, please clarify which areas in and around the dump station will be directed to the head of the WWTP. Response 2: Only drainage/stormwater runoff within the footprint of the Vacuum Truck Dump Station is collected and returned to the head of the WWTP. Runoff from all immediately surrounding paved areas drains down slope to the north and is discharged through a curb cut and flows to the bioretention cell in this location. New York, NY - Philadelphia, PA - Raleigh, NC - Charlotte, NC - Greensboro, NC - Charleston, SC - Atlanta, GA - Fairfax, VA - Hampton Roads, VA - Baltimore, MD - Cincinnati, OH - Hollywood, FL - Boca Raton, FL - Miami, FL HVEN AND SAWYER Mr. Ian McMillan November 5, 2010 Page 2 Request 3: Please provide a treatment mechanism for the stormwater runoff collected from MH-137, CI-133, and MH-B7 if practicable. Response 3: After discussion with Annette Lucas and City of Sanford personnel, it was decided the installation of two (2) structural stormwater BMPs capable of separating TSS, gross particles, floatable trash and debris, hydrocarbons, and bacteria such as Best Management Products "Snout", or approved equal, would be appropriate. Revisions have been made to Drawings C-21 to reflect these additional measures. Two (2) copies of the appropriate drawings are attached to this letter. We believe the revisions made to the attached plans, and our responses as noted above, completely address your concerns for this project. If so, we trust DWQ will complete the processing of the 401 Water Quality Application and grant approval to same for this project. Thank you for your assistance on this matter. Please call you have any questions or require any additional information. Very truly yours, HAZEN AND SAWYER, P.C. L7t{duuP,(u?D.,?eo L. Michael Santowasso, P.E. Senior Associate LMS/bpr Enclosures cc: Raleigh Regulatory Field Office - US Army Corps of Engineers Victor Czar, Public Works Director, City of Sanford James A. Cramer, VP Hazen and Sawyer File 401_CoverLetter_DWQ more information NOV-5-20IO.docx _ / p ,a , N NOTES: ~s~ J__ ` / ~ti N ti_J YI-64 u~ 1. EXISTING MANHOLE TO BE ~ , _ RIM = 237.25 _ _ - r" - W _ r ~ ~ ~ RAISED FROM 249.90 TO ~ _ - ~ « w, _ ,r°'~ ~ 251.50 TO ACCOMMODATE INVERT (IN) = 233.50 ' ~w ._~_ti _ ~-v. W INVERT OUT = 233.40 ~ . _ ( ) _ r -^'a--n ....n. ~j, rt--~-~.sa_w__,. _ INCREASE IN GRADE. z N . ~ __o_._ ~ r.._ ~ i b r / ` ~J~`~"`~ ~ ! f ~ 'A.h-~ 'h / \ '1 . ,m_ _.n_._.~~-- U ~ r ~ - RIM = 251.00 ,a~", , ~ ~ s:, INVERT IN = 234.80 4~, • ;.~E ~Y~,,,......> v.. ~ INVERT OUT = 234.70 ~ n ~ 1 ! ,f ` ~ ~ ° f r........~... , ~ , __........._____.T. _......m.-_.-.~.__~,_.~ ~r a ~ s"`--~ a ` (r ~ t V'<. MH-B6 W STORMWATER BMP ' 2~~ ~_6 .~..w NEW TREE LINE, TYP RIM - 247.50 - ~ , r t , ~ ~ ~ ~ F ~ - ~ ~ tf ``t. INVERT (IN) - 233.80 ~ ~ ~ ya ; INVERT (IN) 236.00 ~~M--~ C21 i „ INVERT (OUT) = 233.70 } r~J"l YI-B3 - ; APPROXIMATE LIMITS OF RIM = 240.50 ~ _ ~~---~X°" DISTURBANCE, TYP ' INVERT (IN) = 231.10 ~ ' r FOR STRUCTURE TYPE, SIZ INVERT OUT = 230.9 t ~ 1 ` ~ ~ NEW 6 TALL CHAIN ( ) ~ AND INLET INFORMATION SEE ~ ` i i ~ f~ ~ ~ LINK FENCE, TYP CURB INLET #B3 AND ` ' ` ! - x \ , ~ ~ , a ---`'.r--°'" - .ti ~ 0244400 MANHOLE #66 ~ MH-B5 ~.w ~ ~ J I RIM = 241.50 ~ ` `'`~''ti ANTI-SIPHON DEVICE INVERT (IN) = 230.60 _ _ t v 1 h°= STALK SIZE ~ _ / " t INVERT IN 232.40 ~ ! ~ YARD INLET, TYP `I cy ~~4j I , O ACCORDING TO TOP F J 0243102 of sTRUCTURE OR INVERT (OUT) = 230.5 °~~y o ,,~r r"~'~ GRATE. 3 MIN : ~ q ~ ' ! h ~ 'j r f J ; ~ ~ a HEIGHT r` MN-B4 CLA CLARIFIER 5 - ; " RIM - 243.00 - _ f~'~ 1 - r' _ F INVERT IN = 229.95 Law O ~ , _ 240 CURB & GUTTER, TYP FLOW INVERT OUT - 229..85 , ~T 0242000 l~ ~4 / (~V~ - V/ JJ / V ~ \ ~ / i 245 BEST MANAGEMENT ~ CI-62 - ' ~ ~ ~ ~ 250 2 T ~ - ~ .~~X .0 r~. PRODUCTS SNOU ~ RIM - 243.00 OIL AND DEBRIS ~ ~ INVERT (IN) = 236.50 - ~ • STOP N ~ 4' WIDE SIDEWALK, TYP ' ~ f " ,70X INVERT OUT = 236.40 ~ ~ J ~ , MANUFACTURED BY ( ) ' 0245000 BMP,, INC.,. OR j t J,"'",,~~ r ~ ,r ~ r ~ ~r ° RAS PUMP ~gti 2 EQUAL ~ X _ ~ i ~ ~ .80X o ~ N ry, CI-B1 ~ t , ~ ~ ° STATION `RIM = 242.50 f' ~ i SUMP DEPTH a i ~ . BEST MANAGEMENT MH 66 = 7.5 INVERT (IN) = 236.00 " ~ ~t;,,,: PRODUCTS - f CI B3 - 8.0 ,INVERT (OUT) = 235.90 ° 251.2 ° CURB INLET, TYP , B10-SKIRT. f °'~;,C~ a° ~ N a ~ a 0243104 MANUFACTURED BY ~ ~ 243.25 N N BMPINC, OR E UAL ~ Q YI-B1 ' ~ - f ` ~ ~ i RIM = 241.75 N~ DENITRIFICATION N X242.25 N N ~ _ FILTERS , CI-B3 W/ STORMWATER BMP 1 ,INVERT (IN) 233.00 ~ r,.-~ COMPACTED CRUSH ~~I! RIM =.254.00 ~ INVERT (IN) = 228.90 ~ I STONE 'i'~ 250 INVERT (IN) = 235.95 C21 " INV RT T - 228.80 " 0 243.25 ~I 12 E (OU)- 241. i `R ~ t- ~ CLA CLARIFIER 4 2 ~ INVERT (OUT) = 235.80 UU FACILITY .y 24 ti ° a ° - TROJAN a ;:a YI-B2 r - ~4 a ~ ~s N Q ~ ~ ~ 242 ~ ~ RIM = 241.50 ~ - J ° a° ~ ° ~ ~ u, MH-68 "~~aae INVERT (OUT) = 237.00 , - ~ \ ~ ~~l r tl N Q 4 d' ~ v~ ~ ~ d- d' ~ f~ - X 242.25 N N a a N a4 ~ N a° a N a RIM 25150 a~ ;~~~~y J/+f Q a CI-B1 ~ a a ° ~ ~ J~ 1 fx r_, t ° _ ,w RIM - 243.00 ` ° INVERT (OUT) = 236.20 OCHL~RITE ,r' STORMWA R SOLIDS ~ ,~'I f I - `,.,,.INVERT (OUT) _ 237.20 r-' X _ . ~ ~ ~ ~ .r_. _ ~i SEE NOTE 1 SEPARATOR AMP y ,r ~ ~ ~I I_i. I ~-r~ " 242.25 X 247 _ , y' ~ ~ ~ NEW ASPHALT PAVEMENT TYP w. ' i 247 r'"A ° , DETAIL 1 - ' 240 - ~ _ ~ ` ` 238 _ I F ~ Q 0251301 _ a w MH B2 NTS C21 g, ~ _.t ` ti~ a - i~ ~ a Dq~It05 m RIM = 239.00 t ~ ~ - - ~ 47.5~Q} y~ ~ ~ . r ~ e.- - ~ ~ - 47.5 a ~ INVERT IN = 227.60 -r:~~ ~ ~ x ~ RESURFACED ASPHALT ~ a , F~,. - j_ Q INVERT (OUT) = 227.50 _ .a ~ Q ~ PAVEMENT TYP LABORATORY i ~ ' ~ f~ I.,~ d { i . ~ W ~4 FILTERS - ~ ~ i ~ BUILDING ,ti ~ 4 a a ° 0251301 pp o ~ J~ a~ - ~ , - MODIFICATIONS i ~ r'y~~V MODIFICATIONS , e ~ 1 ° a 0251300 <Z' y ~ - _ . o MH-B1 ~ , ~ i ~ ~ ~ ~ \ ~~~~s' p~Aa~RGtTt~r r _ _I - , . _ RIM = 237.00 ~ _ _ I 1 ~ i . . _ . a_m.._ . F ~ Q INVERT IN = 227.33 ~.r ° ~ ~ ; O , , , ~ ~ ~ ~ M~AINTENAN ~ 1~ ~ 4 r ~J DIVERT OUT = 227.23 ~ _ ~ , ( ) - BUILDING ~ ~ w ~ Q ~ $ . ~ .4.®,~1' ~ ~ ;~'f ~ ~ ._tiiJ PLAN KEY . ~_m..~ J n~? ~ ,F- / ~ T ~ o ~ ~ _ _ 4. ~ ~;~QL .m _ AREA- AREA-2 m g 3 WIDE CONCRETE ~NANNEL , ' a 1Tz , , o ° ,r11 , ~ w~ t ~f:? TO DIRECT STORMWATER FLOW ~ ` 1'; m r o --...FROM ROADWAY TO f~EW DROP ; N I ~ AREA-3 AREA-4 M INLET WEST OF UV FACILITY. ~ _ i f 1, U Z . .~~~f1~ "1 i. .r! 100 YEAR FLOODPLAIN TYP MATCH LINE, SEE C23 228.76 NGUD 79 ( ) , PRELIMINARY DRAWING -NOT RELEASED FOR CONSTRUCTION ~ - C - DESIGNED JPC N ARQ > ~ F AF®® SITE WORK THE SCALE BAR GATE JULY 2010 o`~ F ESSI ~ ~ ~ c JPC ~ 0 9 i N®~T C L ~ SHOWN BELOW H & S JOB 32039-00® w> DRAWN y 1~ ~ ~ i~ ~I~L MEASURES ONE NUMBER ' ~ Environmental En ineers & Scientists ~ CHECKED 9 ~ I G ~ l G ~ ~ ~ ~ ~ ~ ® INCH LONG ON CONTRACT DRAWING 0 o t' 18560 O ~ ~ 3 09 2010 401.404 PERMIT RE-SUBMITTAL LMS ~ PROPOSED CONDITIONS -AREA 1 THE ORIGINAL NUMBER NUMBER PROJ.ENGR. LMS ~ 4011 WestChase Boulevard Suite 500 2 072010 401404 PERMIT RE-SUBMITTAL LMS P ~ ASTEI~ATER TF TER TREATMENT PLANT oRawING. C21 ~i ~ XC ~w 1 102009 ~ 401404 PERMIT SUBMITTAL LMS tiq Raleigh, North Carolina 27607 EL SP WQ PANSI®N ~ ~ REV. DATE ISSUED FOR BY APPROVED x_ - ANSI T 1 FLAT FILE . 2008~09~2412:26 PM 0:\32039-RAL\32D39-600\DRAWINGS\CIVIL\PCN-C21.dwg Lastsoveby~ JCOOK SPECIFICATIONS MATERIAL SPECIFICATIONS COMPAi 1. THE BIORETENTION SOIL SHALL BE AMENDED WITH 7, MINIMIZ COMPACTION CONSTRUCTION SEQUENCING 7, MINIMIZE COMPACTION OF BOTH THE BASE ANO THE 12. CONSTRUCTION OF THE BIORETENTION CELLS SHALL NOT AS-BUILT CERTIFICATION MATERIALS IMPORTED FROM OFF-SITE TO MEET THE BIORETf BIORETENTION AREA. WHEN POSSIBLE, USE EXCAVATORS TO COMMENCE UNTIL ALL CONTRIBUTING DRAINAGE AREAS 19. THE BIORETENTION CELLS SHALL BE SUBJECT TO AS-BUILT CRITERIA OUTLINED BELOW REMOVE REMOVE ORIGINAL SOIL. IF BIORETENTION AREAS ARE HAVE BEEN STABILIZED. IF CELL IS EXCAVATED BEFORE INSPECTION AND SURVEY. ANY ELEMENTS THAT ARE NOT EXCAV~ EXCAVATED USING A LOADER, THE CONTRACTOR SHOULD WATERSHED IS STABILIZED, ADDITIONAL EXCAVATION MAY CONSTRUCTED PER THIS PLAN SHALL BE REPAIRED OR 1 BIORETEN110N SOIL USE LO USE LOW GROUND PRESSURE (LGP) EQUIPMENT 6 PSI). BE REQUIRED TO REMOVE ACCUMULATED SEDIMENTS TO REBUILT AT CONTRACTOR'S EXPENSE. CONTRACTOR SHALL 2. THE SOIL SHALL BE A UNIFORM MIX, FREE OF STONES, ENGINEI ENGINEER SHALL APPROVE EQUIPMENT IN ADVANCE. RESTORE IN-SITU PERMEABILITY. COORDINATE AS-BUILT INSPECTION AND SURVEY AND EXISTIN 1" R P@ 1.56% ~ I T AR R THAN 1 G 2 C o STUMPS, ROOTS OR OTHER SIM LAR OBJEC S L GE ~ ~ TWO INCHES. NO OTHER MATERIALS OR SUBSTANCES SHALL i ~ 8. COMPA SUPPLY INFORMATION TO OWNER AT COMPLETION OF 8. COMPACTION CAN BE ALLEVIATED AT THE BASE OF THE 13, FOLLOWING STABILIZATION, EXCAVATION OF THE PROJECT. N BE MIXED OR DUMPED WITHIN THE BIORETENTION AREA BIORETf BIORETENTION FACILITY BY USING A PRIMARY TILLING BIORETENTION CELL SHALL BE COMPLETED SO TO MINIMIZE 1 CONTRACTOR SHALL REMOVE SECTION OF THAT MAY BE HARMFUL TO PLANT GROWTH OR PROVE A OPERATION SUCH AS A CHISEL PLOW, RIPPER, OR COMPACTION OF SUBSOIL BENEATH THE CELL. IF SUBSOIL 20. AS-BUILT TESTING OF BIORETENTION SOILS SHALL BE 1 1 ° RCP FOR INSTALLATION OF NEW 15~ WIDE DEPRESSED CURB ~ OPERAI EXISTING 2 HINDRANCE TO THE PLANTING OR MAINTENANCE SUBS011 SUBSOILER. THESE TILLING OPERATIONS ARE TO BENEATH THE CELL IS COMPACTED DURING EXCAVATION, PERFORMED BY A LICENSED SOIL SCIENTIST AT YARD INLET. APPROXIMATE INVERT INTO NEW TO ALLOW OVERLAND FLOW ~ 6 OPERATIONS. THE PLANTING SOIL SHALL BE FREE OF REFRAC STRUCTURE IS 261.42. INTO BIORETENTION CELL NOXIOUS WEEDS. COMPAQ REFRACTURE THE SOIL PROFILE THROUGH THE 12 INCH COMPACTION SHALL BE ALLEVIATED USING A PRIMARY CONTRACTOR EXPENSE. SOILS SHALL MEET ALL SOIL COMPACTION ZONE. SUBSTITUTE METHODS MUST BE TILLING OPERATION TO REFRACTURE THE SOIL PROFILE SPECIFICATIONS ON THIS PLAN PRIOR TO APPROVAL OF APPRO~ APPROUED BY THE ENGINEER. ROT011LLERS ARE NOT THROUGH THE 12 INCH COMPACTION ZONE. AS-BUILT PLAN. ACCEPTABLE. 26 26 3. THE PLANTING SOIL SHALL BE TESTED AND SHALL MEET ACCEPI THE FOLLOWING CRITERIA: 14. FOLLOWING CELL EXCAVATION, THE DROP INLET SHALL BE 6~ 267 2 Ksat= 2-6 IN/HR 9, WHEN E 9, WHEN BACK FILLING THE BIORETENTION FACILITY, PLACE INSTALLED IN THE LOCATION IPJDICATED. 26 PH RANGE= 5.5 - 6.5 SOIL IN SOIL IN LIFTS 12 TO 18". WATER LIFTS LIGHTLY TO - ~ PHOSPHORUS INDEX= 10 - 30 ENCODE ENCOURAGE NATURAL SETTLEMENT. DO NOT USE HEAVY 15. ONCE THE DROP INLET ~~AS BEEN INSTALLED, THE 1 INVERT(S): 262.02 SOIL FRACTIONS (BY VOLUME): EQUIPM 4:1 MAX 26 EQUIPMENT WITHIN THE BIORETENTION BASIN. HEAVY CONTRACTOR SHALL INSTALL THE GRAVEL DRAINAGE LAYER, SAND= 85 - 88% EQUIPM SLOPE SILT AND CLAY FINES= 8 - 12% BASIN EQUIPMENT CAN BE USED AROUND THE PERIMETER OF THE UNDERDRAINS, CHOKING STONE, AND SAND LAYER, _ ORGANIC MATTER= 3 - 5% BASIN TO SUPPLY SOILS AND SAND. GRADE BIORETENTION RESPECTIVELY. MATERi~ INVERTS : 262.40 MATERIALS BY HAND OR WITH LIGHT (LGP) EQUIPMENT. 16. PRIOR TO THE SOIL MEDIA INSTALLATION, THE COMPONENTS 4. GRASS THAT IS TO BE PLANTED IN THE BIORETENTION UNDER[ UNDERDRAINS OF THE SOIL MEDIA SHALL BE THOUGHLY MIXED SO THAT CELLS SHALL BE BERMUDA SOD AND SHALL NOT CONTAIN 10.4 PER 10. 4° PERFORATED PVC UNDERDRAIN PIPE WILL BE INSTALLED THE MEDIA IS HOMOGENEOUS AND TESTED TO ENSURE THAT -~6 CLAY SOILS. ONCE SOD HAS BEEN INSTALLED, THE TURF IN GRA' IN GRAVEL BEDDING. UNDERDRAIN PIPE SHOULD BE THE MEDIA IS AS SPECIFIED. PRIOR TO THE MIXED SOIL SHALL BE IRRIGATED APPROXIMATELY 1/2-INCH EVERY APPROXIMATE INVERT: 261.32 COVERE COVERED AND UNDERLAIN BY A MINIMUM 2 OF GRAVEL. MEDIA INSTALLATION, THE SOIL ANALYSIS SHALL BE 26 THIRD DAY UNTIL SUBSTANTIAL ROOT DEVELOPMENT HAS SUBMITTED TO THE ENGINEER FOR VERIFICATION. ONCE 6 OCCURED. ONCE THE SODDED TURF HAS BEEN 11. UNDER[ 2 ESTABLISHED THE TURF SHALL BE IRRIGATED WITH 11. UNDERDRAIN PIPES SHALL BE CONSTRUCTED AT A MINIMUM VERIFIED, THE SOIL MEDIA SHALL BE INSTALLED TO THE " 267 ~ SLOPE 24 X 36 GRATE INLET (EL. 266.00) APPROXIMATELY 1-INCH PER WEEK TO PREVENT PIPES D SLOPE OF 0.5%. OBSERVATION WELLS AND CLEAN-OUT ELEVATION SPECIFIED. 267 DEHYDRATION. FERTILIZER SHALL NOT 8E APPLIED TO THE - PIPES. PIPES MUST BE PROVIDED AT THE END OF ALL UNDERDRAIN 17, FOLLOWING SOIL MEDIA INSTALLATION, THE CONTRACTOR PIPES. SHALL INSTALL THE GRASS SOD WITHIN THE LIMITS OF THE BIORETENTION TURF. THIS WILL RESULT IN EXCESS -26 NUTRIENTS STORED IN THE BIORETENTION CELL SOIL 4" PERFORATED PVC UNDERDRAIN TYP CELL. 26 AND/OR DISCHARGED DOWNSTREAM FROM THE UNDERDRAIN 18. ONCE ALL THE LAYERS AND VEGETATION HAS BEEN DEWATERING. INSTALLEC IN THE eIORETENTION CELL, A LICENSED SOIL 264 5. ALL BIORETENTION AREAS SHALL HAVE A MINIMUM OF ONE SCIENTIST SHALL PERFORM AN ONSITE INFILTRATION TEST 26 SOIL TEST. EACH TEST SHALL CONSIST OF STANDARD SOIL AND RESULTS PROVIDED TO THE ENGINEER TO ENSURE THE TESTS FOR SATURATED HYDRAULIC CONDUCTIVITY (Ksat), CELL WILL OPERATE AS DESIGNED. PH, PHOSPHORUS INDEX, AND ORGANIC MATTER. A ~ TEXTURAL ANALYSIS IS RE UIRED FROM THE SITE Q „ STOCKPILED TOPSOIL. IF TOPSOIL IS IMPORTED, THEN A 1 = 10 TEXTURE ANALYSIS SHALL BE PERFORMED FOR EACH LOCATION WHERE THE TOP SOIL WAS EXCAVATED. SCHEDULE OF ELEVATIONS (FT) DRAINAGE DRAINAGE 6. SINCE DIFFERENT LABS CALIBRATE THEIR TESTING AREA A AREA B EQUIPMENT DIFFERENTLY, ALL TESTING RESULTS SHALL MAXIMUM PONDING DEPTH/ COME FROM THE SAME TESTING FACILITY. INLET CREST OF DROP INLET 266.00 245.00 TOP OF BIORETENTION SOIL 265.00 244.00 ~ 24 4 TOP OF GRAVEL /SAND 263.00 242.00 -24 -24~ - BOTTOM OF GRAVEL /SAND 262.00 241.00 4:1 MAX 245- SLOPE INVERT OUT 261.32 239.50 15° RCP @ 5.0% 24 APPROXIMATE SURFACE 3,500 SF 2,600 SF INVERT: 241.25 INVERT: 239.50 AREA OF SOD REQUIRED _____________m---_________---________ ® 24° X 36° GRATE INVERT(S): 241.50 - INLET (EL. 245.00) 3~ MIN GRASS 24° X 36° GRATE INLET GRASS SOD. BIORETENTION GRAVEL INVERT: 241.25 SOD FILTER STRIP (SEE SECTION DETAILS SOIL SPECIFICATIONS NO'I"E 4. FILTER STRIP FOR INVERT ELEVATIONS) 4° PERFORATED PVC 244 UNDERDRAINS @ 0.5% 24" THICK FILL SOIL. FLOW FROM ROADWAY SEE SPECIFICATIONS SLOPE, TYP , FOR SOIL CRITERIA ' 24 ~ o INLET CREST \ i ~~i 4:1 ~ MAX , 24 ~ SLOPE_ 12 MAX ~ ~ ~ ~ ~ ~ e ~ 4~ PONDING ~ ~ ,r i' ` 4 46 ` . DEPTH ` ~ : ~ r'~4 ~'J~"~~~ , ~ - `ti - - si.~~,.c`~~ ~ ~ ~ 24 . ' . n~ V `7 247 `tip PRECAST, WATERTIGHT CONCRETE, ~ ~ 2" THICK WASHED I 1-~- 15 WIDE DEPRESSED CURB 'i,;' n_ ~ YARD INLET STRUCTURE REQUIRED. SAND LAYER \~,~'R_'f TO ALLOW OVERLAND FLOW SEE PLAN VIEW FOR LOCATION. ~ , ~trF ~ INTO BIORETENTION CELL ~ , o 2 THICK WASHED , GRAVEL FILTER STRIP II #89 CHOCKING STONE ~ (1' WIDE X THICK) TO BE 4 PERFORATED PVC UNDERDRAIN ~ PLACED BETWEEN FLOW FROM e 0.5% SLOPE WITH 3/8° HOLES 8° THICK WASHED L ~ i ASPHALT PAVEMENT TOWARDS , ~ ~ BIRORETENTION AREA SPACED 6° ON CENTER. DO NOT #57 STONE , " 1 = 10 WRAP UNDERDRAIN. / , f~~ It Y U O J CO O lr O ~ r' ~~"`,'id OBSERVATION WELL/CLEANOUT 000000000000000000000000000000000000000000000o A`~,,,~~'/''~,,1 o OUTLET PIPE ~ "ir 4 PVC PIPE WITH THREADED ~~--ems:.-. o ~ ~ ' ~ ~\;F ~ , ~ t r' , ~ F ~ ~ CAP THAT IS TO BE i ~ r ~ t f r / % /~,r r ~ / >1 % ~ ~ f / / ~ / • ~ ~,;/i ~ , i INSTALLED WITH CLEANOUT i/ r 1/~.f' ~t t' tt~~``r f ~ /j i~t\`~~,~'~~ ~ ~t J \ ~ f \ t ! i t tr f~e - f ~ n N i/',, ~ 1~~~, EXTENDING 8 ABOVE GRADE. N J U Z GRASSED BI0 EETI CELL EI d I- I d 1"= 10' H I PRELII R DR I- T RELEASED F I TI® ~ 1 > DESIGNED JPC CARS e - ~ r-. ; ~ p~ ~ ~ ~ THE SCALE BAR DATE JULY 2010 > DRAWN JPC Z o N 9 i it <:i RT C 9 L9 SITE WORK SHOWN BELOW H & S JOB 32039-000 ~ ~ ~ '.d tl MEASURES ONE NUMBER ° CHECKED ~ Environmental Engineers & Scientists p o a r 1 56 O DIG 31 F L CIVIL INCH LONG ON CONTRACT DRAWING ~ 3 09.2010 401 404 PERMIT RE-SUBMITTAL LMS c.~ PROJ.ENGR. LMS ~ 4011 WestChase Boulevard Suite 500 THE ORIGINAL NUMBER NUMBER u 2 07/2010 401/404 PERMIT RE-SUBMITTAL LMS ~ I Q T T 1 10/2009 401/404 PERMIT SUBMITTAL LMS ~y Ralei h North Carolina 27607 1 T L T TORTE TIO SECTION DETAILS DRAWING. D1 q ~ 9~ E~ SP W c I SUED FOR BY APPROVED EXPANSION ~ ~ REV. DATE S Q?N I T 1 ® FLAT FILE . x _ 2008~09~24 12:26 PM 0:~\32039-RAL\32039-000\DRAWINGS\CIVIL\PCN-D1.dwg Lastsaveby. JCOOK