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Home My WebLink AboutSW5220201_Design Calculations (NSW)_20220517Tar -Pamlico Stormwater Rule 15A NCAC 28.0258 Piedmont of the Tar -Pamlico River Basin: Last Modified 5/17/2022 Includes Oxford, Henderson, Rocky Mount and Tarboro as well as Franklin, Nash and Edgecome Counties Total Nitrogen and Total Phosphorus Loading Calculation Worksheet (Automated) Project Name: Bryson's Ridge - Phase I Date: 511012022 By: E. Averette Checked By: Directions (same for pre -development and post -development tables): > Enter the acres of each type of land cover in the green boxes. The spreadsheet will calculate all of the values in light blue. > Compare total areas of development in pre- and post- tables for consistency (bottom of column (2)), and also for consistency witli the site plans. If all of these values are not the same, there is an error that must be corrected. > Unless drainage onto the development from offsite is diverted around or through the site, offsite catchment area draining in must be included in the acreage values and treated. Pre -development: 1 ::................. 4" : . [ It : i?f>�; t d Covri :: i.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:....:.:.:..:.:.:.:.:.:.:.:.:.:.:.:.::.:.:.:.:.:.:.:.:.:.:.:.:.:.::.:.:.:.:.:.:. .....................................:..........................:...:................................... ::::A:rea :::::S°lt o_zttit#la:: Avera e 1 I..fi .... .:.:.:.:.:.:.:.::.:.:.:.:.:.:.:.:.:.:.:.:..:.:.:.:.:.:.:.(:.:.:.:.:.:.:.:..;.;.:.:;;.:.;.;.:.;.:.:.: e5 .. . >tm .. acres ..::. Q 46.i 8 31 ..:ofTN m II ::::. 2; ;.;. 3 .;.; :.:;:o€:l?: :h :: :. ... . ..•:.. 3 :.: isp..... i......i eev i sj i i 0.55 2.60 0.30 0.19 0.02 a :vof peruiops 0.55 1.95 0.00 0.11 0.00 ge [ewioiii3 €€€ I.... ......cfl ied ........ E.:.:..) U i-, 0.55 1.42 0.00 0.28 0.00 siggepivu'.u5_ jer'.oEilanil)' _ 0.5.5 4.23 13.90 1.23 4.04 I rai►iAged p i viitiis 0.55 2.04 0.00 0.62 0.00 pai)': �Voodei€(erii'nis': ' 0.55 0.94 6.98 0.14 1.04 .......... . . .' . CN ::::::::::.:: OAcc7111 I�r action Irtperviaits (I) 0.01 ............ ............ ............ .. bl .... 21.17 .... (fib. y...... 5.10 ACe�:of Iaevelii smerrt _ 19.74 :..:off" l'I,.cp C;:;.ff. 1.07 ;'''`{ ]P..,xp.:::p€.. `_ 0.26 th 161ac:: r: Post -development: ............................:.:.:.::.: 11Jiit}dovi rAea F `iiilieKe ` `'e E 11ICa►iiiri ` ea'. e ICTG Ave ........ . .::: 2. 3. ;.;. Trasvaus 3.40 2.60 24.15 0.19 1.76 Raoiiiipeiviois 3.40 1.95 28.27 0.11 1.59 3.40 1.42 60.49 0.28 11.93 \VootlrlperliiiS_;`: 3.40 0.95 0.74 0.14 0.11 ............ ::.:.x:pFt.ro.e"n...I.l.n.�._ 0.35 ......I...............-..:..:...:.:..:...:..:... ........ TNL,oiiii . TPI .'...'..'..- 15.40 _g.. :. ........I..b..c .ifoTtF ti►.aA.l..c.t. 19.74 Coef . .. 0�aloFUem8 .i.w...i..a..y.s . .'/...:. .� ..Y)�ba . Note: The nutrient loading goals are 4.0 Ib/ac/yr for TN and 0.4 lb/ac/yr for TP. If the post -development nutrient loading is below these levels, then no BMP is necessary. Otherwise, the next worksheet calculates post -development TN and TP loadings after BMPs are installed. Tar -Pamlico Stormwater Rule 15A NCAC 28 .0258 Piedmont of the Tar -Pamlico River Basin: Last Modified 5/23/03 Includes Oxford, Henderson, Rocky Mount and Tarboro as well as Franklin, Nash and Edgecome Counties BMP Removal Calculation Worksheet (Automated) Project Name: Bryson's Ridge - Phase 1 Date: 511012022 By: E. Averette Checked By: Directions: > It may be advantageous to split the development into separate catchments to be handled by separate BMPs. The tables below allow the development to be split into as many as three catchments, and can be copied for greater than three. NOTE: Unless runoff flowing onto the development from offsite is routed separately around or through the site, the offsite catchment area draining in must be included in the acreage values of the appropriate land use(s) and treated. > Above each table: Enter the catchment acreage in the top green blank. Based on a comparison of the post -development TN and TP export coefficients you calculated above to the rule requirements of 4.0 Ib/ae/yr TN and 0.4 Ib/ac/yr TP, select BMP(s) from the list for treating the catchment runoff. Enter the chosen BMP(s) nutrient removal rates in the green blanks. If more than one BMP is to be used in series, the combined removal rates will be calculated automatically in the blue blanks. > Catchment Tables: Enter the acres of each type of land cover in the green boxes. The spreadsheet will calculate all of the light blue boxes. NOTE: Compare the Total Catchment Acreage for the Development (final table) to the value you established in the pre-BMP worksheet tables, and also to the site plans, for consistency. All of these values need to be the same ........................ ................. '•TP€`: r•.•.•.•........ lies i ii Sta... [l € ......g............................:...:..:... BMP bcrcfiogI'arid 25 40 NC BMP Manual Nutrient Stoi'ipw €ee........... 40 35 NC BMP Manual Removal !?a Cii Mlio' :: `::: 35 45 NC BMP Manual Rates Bibr�t>#ioei. 35 45 NC BMP Manual `ass'`vale 20 20 NC BMP Manual €(eetfiteiif#eiti'ip3vf 20 35 NC BMP Manual :Leuai:;'iiter: DtyDet: iiiop;E; 10 10 NC BMP Manual Catchment 1: Total acreage of catchment 1 - ac First BMP's TN removal rate = % First BMP's TP removal rate = % Second BMP's TN removal rate = % Second BMP's TP removal rate = % Third BMP's TN removal rate = % Third BMP's TP removal rate = % TOTAL TN REMOVAL RATE = 30 % TOTAL TP REMOVAL RATE = 30 % :.:.:.:::.:.:.:.:.:.:.:.:.:.:.:.:.::.:.:.:.:....:.:.:.:.:::: ....:...........:.:.::.:.::.:.:.:.:.:.:..:.:.:.:.::..:.:.:.:.:.:.:.:.:.:.:.....:.:.:.:.:.:. 1C :eofLariU4ver YP.... +Ytcliii[enjr SiM, I annul? ' cis e C.• . z�}....g..l...........a..,nn............r?ge.>&.. •.•.•. lu ' ' z4v`e : 'k ' I., ' lil .....a...m�.•.. . .:.af 3.80 2.60 23.01 0.19 1.68 3.80 1.95 24.07 0.11 1.36 : 1VINIi3i'eT1 :CE:� oiis; ;:::: 3.80 1.42 42.83 0.28 8.44 coded !ervltius; ; 3.80 0.94 0.00 0.14 0.00 Ai$tFfalieiiispliBNi? 3.80 1.95 2.74 0.11 0.15 >a'raerol.Cm eruiaus°�� p OAo I?re>S1VII? TLV 2 _�'.r` �FC'`�SMF�TP ;g ............... 11.64 asoad`lh - - - x'atTl,t1..•.a_oi'�3e.._.,v ,�?e[�t....... ..,1?..•.•.•.•.�.�.�. 13.89 . i:i�i Pre. LEP.TN _ :i`)~iorU�(W�c/'P:.' G.G7 _ �'�AY't:`Iltts��'it):� 0.8 4 P lu #'•ost=1�M . •�'`` ,4 t 'k'os . .. . s .1s tI bf r .. .as t ............... '....:T.. ...�.s..�:..:. 4.67 a t i;r r r 0.59 Ibhi l Tar -Pamlico Stormwater Rule 15A NCAC 28 .0258 Last Modified 5/23/03 Catchment 2: Total acreage of catchment 2 = ac First BMP's TN removal rate = % First BMP's TP removal rate = % Second BMP's TN removal rate = % Second BMP's TP removal rate = % Third BMP's TN removal rate = % Third BMP's TP removal rate = % TOTAL TN REMOVAL RATE = 0 % TOTAL TP REMOVAL RATE = 0 % ..................................................................... ........................................ ............................. t:" E :o I ::igvi i s...........• ........... ............ :�atcli zieiit: S;lt�<Tiiiiniila ............................ : i�veia e:�11�fC ::::Colum:::::: .............. ........... #vei+ C e:ti�t:C: ............................................................................................................................................ ..of3'k ...................._............. r [:' 2 . 3 G rasjoatlatlpe+vjolis 2.45 2.60 1.97 0.19 0.14 jo'ofiuipi'aus.; 2.45 1.95 5.20 0.11 0,29 2.45 1.42 13.28 0.28 2.62 2.45 0.94 1.45 0.14 0.22 si ::Ai 1;tilicii;ip;liy ) 1P 2.45 1.95 0.00 0.11 0.00 :` I'r�.ch . t Im' ®rvious �•�� si` �.-).......... 2 0. 4 Pi-&BN4P TN 21.91 Pj e I31F4P`:TP 3. 27 .............. LonP ......{,......., lizk? f e: e t= ... ........ 5.85 Fie'-BIDIPiTh'Ei'a�i h... -. 3.7. -i N,!p.1T EV0 . 0.5G : ............................. _ ...C..1 '. ............ . . ....... ..l.... ............... .............. iisi= 21.91 .osi= 3.27 Ioiid.It).x.. (...y..... a Lo..t bf t (....3..J... 4::; : 3.75 _:..:: 0.56 :t :ltilSrJ ,j:. Catchment 3: Total acreage of catchment 3 = ac First BMP's TN removal rate = % First BMP's TP removal rate = % Second BMP's TN removal rate = % Second BMP's TP removal rate = % Third BMP's TN removal rate = % Third BMP's TP removal rate = % TOTAL TN REMOVAL RATE = 0 % TOTAL TP REMOVAL RATE = 0 % ......................................................................................................... ............................................................................................................. e:iifi}aiSil:C(lvei!:::::::; 7ttE11iileitt: ..................................................................... ::..A �'•.�'.:'.'.'.:'.'.'.'.:::::�:::�'.'.:::::'.'::::.. ........................... ............................. .................ra'e ' :: 0:4 ': t::.: ::::::.:r:' ........................................ ::4::::a :.: ''''i:•':::: ............................. ............................. ............................. ............................. ............................. iiipervidui 2.60 0.19 R4o1 tfipervi4i!SE_'E 1.95 0.11 hlAguteroFs 1.42 0.28 l.jaoded jrerWiegs 0.94 0.14 ;Ai eii'iijlieti ip'tiv B1VIP :` 1.95 0.11 is Cti ac:::o m *V-. i.. TY EFpe¢SNIP.. ! . Pt. S TP e• . MP:. . •.1;C, ,t,.X.,.(?_ ,q.,...f};.; oa0ia.n)... d.(...ty. �... _ i:i:�•at ' :'�'iie; : ' :� �' vel ' ' ' ' ' ' :�:i: �,.,r'1,),t�,.,.'[,0},�,4',.,.,9I?P?C?��,:._._. .....ieBl4IPE FiS Ee'iort t.,.,..,.. ... ;:;:;:; P.te 3� P... E b1Y .•. EiEi:�t�'�'`'�'`•`= :�:��lih`.`ii�= .:.:.:.:.:.:.:.:.:.:.:. PTN 4S .,.,.,.,..., t i j'P iiij!S•.•}}...... r . .... il( Tar -Pamlico Stormwater Rule 15A NCAC 28.0258 Last Modified 5/23/03