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HomeMy WebLinkAboutCorrespondence - 180 MARBLERIDGE ROAD 12/17/2002 IMMER ENVIRONMENTAL CONSULTING 21 Pine Island Road Newbury, MA 01951 Tel 978-463-9226 Fax 978-463-8716 October 18,2002 Town of North Andover Planning Department 27 Charles Street North Andover,MA 01845 Re: Watershed Special Permit 180 Marbleridge Road Property of William J.McDermott Dear Planning Board Enclosed please find two sets of mailing labels and stamps for notification to abutters,as requested. Also, enclosed are ten(10)copies of a revised site plan depicting a revised layout discussed at the Planning Board's meeting on October 15. This layout,presented on the sketch prepared by K.J. Savoie Architecture, has been added to the site plan prepared by Clipper City Surveying,Engineering&Mapping,Inc.The change includes a reduced building footprint to meet the requirements of the Watershed Special Permit. The building footprint as shown on the original plan submitted was 743 square feet.The revised footprint is 583 square feet representing a 24.8%increase in gross floor area. We look forward to discussing this project with you at your next public meeting on November 12,2002. In the meantime,if you should have any questions or require additional information,please contact me at 978- 463-9226. Very truly, RIMMER ENVIRONMENTAL CONSULTING Mary t0 '" i mer Principal E Cc: Mary Ellen Fennessy McDermott n(.T 4 2002 NOHS T H ANbbVEA PLArvMNO Q[�PAMTMC--N i Grogg area of proposed addition= 563 5q, ft. I' � Percentage Increased floor area p 24.8% (Allowable increase Special permit i5 : 25% ) Z�4 i "p a. LAI,aoupt � :... . fM I4 h•�4.�+c.Mnsv� f1°•0Yf V :uvrwa �, � t Gb•.f4 � t S I r i j W/J Porch 1//- -- Su-.P up rat nrcn Pono Kw, i FR i r dmly RO�rn Lmnq(WYM CIYy 11NWG ••••� �.TNS".vt vl sd 1 yc rwvq Firm Floor Plan Addition and RenovatJon to the i aCHITBCTUAE �1 c Permot t Residence sc Id 1/811=1' 180 Marble Ridge Rd,, N. Andover, MA pa 10 Oct. 02 TOTAL P,02 ,. IMMER ENVIRONMENTAL CONSULTING 21 Pine Island Road • Newbury, MA 01951 Tel 978-463-9226 • Fax 978-463-8716 October 11,2002 Planning Department Town of North Andover 27 Charles Street North Andover, MA 01845 Re: Request for Amendment—Watershed Special Permit 180 Marbleridge Road Property of William J. McDermott Dear Planning Board: On behalf of William and MaryEllen McDermott, Rimmer Environmental Consulting requests that the Planning Board consider amending the Special Pennit granted for the above referenced property to allow for the construction of a 583 square foot addition to an existing single family home within the Watershed Protection District. We request that this request be addressed at your forthcoming meeting on October 15, 2002. This site received a Watershed Special Permit in 1994, prior to the construction of the original house. At that time, drywells were installed to accommodate runoff from the roof and driveway areas. Enclosed is documentation provided by Milestone Engineering addressing the infiltration of the additional impervious surfaces created by the addition. We believe that by incorporating these changes,there will be no adverse impact to the water quality of runoff entering the Lake Cochichewick watershed. The addition will not exceed 25%of the gross floor area of the existing structure,as required under the Special Permit. If you should have any questions or require additional information,please feel free to contact me. Very truly, RIMMER ENVIRONMENTAL CONSULTINC 7m&j��IM'_---- Mary Rimmer Wetland Ecologist 52 Washington Street '< Newburyport, Massachusetts 01950 Voice : (978)462-4171 o N E Fax : (978)499-2117 Civil/Site and Environmental Engineering Land Development and Permit Acquisition October 10, 2002 Town of North Andover Community Development& Services Planning Department 146 Main Street North Andover, MA 01845 RE: 180 Marbleridge Road, North Andover, MA Mary Ellen Fennessy McDermott Required infiltration sizing for house addition Dear Board Members: Assessing compliance under the local Special Permit requirements can proceed via many pathways. Rather than prove capacity of existing systems to absorb the increase in runoff it was decided to proposed and design a new"Infiltrator" (or equivalent competitor) subsurface stormwater trench and storage system. Such a system can be sized for the net change in site runoff volume during the 100-year, 24-hour storm event incurred by the proposed addition. This system can also be constructed simply and fairly inexpensively. I have attached a construction detail and potential layout given the proposed site plan provided to me by you. Please keep in mind that so long as the construction detail remains unchanged the only deciding factors will be the approximated rooftop inflow area to be served and the calculated number of required infiltration units. Thus, changes in layout and footprint can be made in the future without compromising these calculations so long as the approximated rooftop inflow area is not exceeded or the calculated number of required units decreased. I have included a few hundred square feet extra of approximated rooftop inflow area over that calculated by measuring the proposed addition off the site plan. This extra area should more than compensate for pavers and other impervious surfaces being proposed in the landscape about the new addition. Calculate Required Infiltration Volume Given an approximated rooftop inflow area= 1,500 square feet Given a parent hydrologic soil grouping= Group D (determined by inspection of N.R.C.S. Soils Survey of Essex County Northern Part) Given an existing Cover Curve Number(CN) = 80 (Lawn, or Open Space, good condition) (See attached copy of Table 2-2a from the N.R.C.S. TR55 manual for soil group D) Given a proposed Cover Curve Number (CN) = 98 (Impervious areas) (See attached copy of Table 2-2a from the N.R.C.S. TR55 manual for soil group D) 10/10/02 Project CLP0205 Page 2 Using attached Table 2-1 from N.R.C.S. TR55 calculate existing runoff depth for 100-year 24-hour rainfall of 6.5 inches = 4.23 inches Using attached Table 2-1 from N.R.C.S. TR55 calculate proposed runoff depth for 100-year 24-hour rainfall of 6.5 inches= 6.26 inches Calculate the increased runoff depth resulting site development: 6.26 inches- 4.23 inches= 2.03 inches Calculate the increased runoff volume resulting from site development: (1,400 square feet)(2.03 inches)/(12 inches/foot) = 254 cubic feet Thus, to meet the 100-year rainfall requirement 254 cubic feet of storage must be provided in proposed trench. Calculate Provided Storage Volume Given a trench cross-section of 3.00 feet wide, 2.00 feet high and utilizing 11 infiltrator units at a length of 6.25 feet each, all as detailed on the attached pages. Calculate the total system volume proposed: (3.00 feet)(2.00 feet)(11 units)(6.25 feet) = 412 cubic feet Given an infiltrator void volume of 16.3 cubic feet per unit(See attached manufacturer's sheet) Calculate the total stone volume proposed: 412 cubic feet- (11 units)(16.3 cubic feet) = 232 cubic feet Given an approximated stone void ratio (Vv/Vt) = 0.33 Calculate the total storage volume provided: (11 units)(16.3 cubic feet) + (232 cubic feet)(0.33) = 255 cubic feet Calculate the total length of trench provided: (11 units)(6.25 feet) = 69 feet Thus, as designed the proposed infiltrator trench will store the net increase in site stormwater runoff volume incurred by the proposed house addition. Given the entire above do not hesitate to contact me should you have questions or comments regarding this matter. LtM r . Very truly yours, � a .JOHN A S011CY u CIVIL y 0.39867 John Jr., Principal Milestone • 52 Washington Street, Newburyport,MA 01950 • Civil/Site and Environmental Engineering Table 24 >*Rurtoff curve zittnibcrs fot urban areas! �tarve nunbers for Cover dac ptl n hti�h is is ii: r a Average porc#nt.: - Cover type and hydroIcigic condit'ivh it env ouwa lfk- .:.: A f :. p lastly clever urban areas !t elation er-R blishvd) PRDPD:9E:b C0tJtATIbt4. Open space(lawns,parka, golf courses,cemeteries, EX15M O G, CbtJtk[1biJ Poor condition(grass cover .,....._ .. 19 86 bll _ _..:��Fair condition �a tover 56% to 75%jt El 7D :. Good Condition(ws cover.;?. 61 74 InIpez-vious areas: Paved d panting Intt,?rofs,Chi 3, etc.. (exehading rllghk--of'i ). ... 98 98 919 98 Streets and madsz PAved;ic-arbs ud storm am4ers(excluding fight-,f cvay) 98 98 98 Paved:open dit s(including riglit•of-way) ...... & b9- ti Gravel (xnclucLing relit=o-f y) ,,_.............. . i6 85 � 91 rqrt(ir eludln.g i�ght-of-iv ky) .,....._... .....,...... 72 f=9 ,.. l "- western desert urbAn areas: 1+7at 1 desert landscaping(perci are-as only)4... Art vial desert Undscap ng(impervious weed bwTier, dirt sYrzvb with 1- to 2-inch sand or gravel tvel inulch and basin borders). ,.e:.,,,.,., ... 99 96 96 Urban,districts Com.w rcial and business;,,,,,,, & ... . .._. 92 94 95 Itlttrial...... .....- .. 72 81 86 91 Residential districts average lot size: 1!9 acre or lass (to"hoes :......... ........;. 65 €5 )JA41 i7 72' 816 1 ACTT 'LQ 5} $t3 7 . i34 ..,., ......................:..,..,.. . . �� ._.... - -4 65 !i 82 .. t� rtz ttr�6rart ti�� Iti°e+vly graded areas(pervim nr only. . : - no VRgetation}� ........... 77 86 Idle lands(CN s are' determinq* Using 0DVeF types sinter to theme in table 2 ?:.. lAverage raaaf 06dit-,And-1 04a. .... .. . Me t;#etag#perCettc inpei-it)U area STIOX 71 Wrw k4,ed to tievelop the compoite<a S Qther 3�.t.ionm:tae u:feliu4x�; trntser+3+�us zit*mt VA*itlreedy cotitit.ud v)the drAinage vWem,impervious arew4 hs►qV a:.** .aYt�#_p�t�i� utk�kr ieui2lerEtl etiiiiaalu rt[�H}��r' spate in ntr��hvciroi-39 se tlQn l":t pro,kr���,i�t»tr�tt��oaf inditona t* Vpt vte_ci u;?iM gure 'N' liun are t�tlt tti itreiimp 'G't's sn:ty tte ttftiyputec#1Vr cater entitititttitt�i�+ft+*npaesvtr: e, 'G4i�pr�>ite CN';tr�r t+aisarai titn�rt istnri Capin shcttai(i be computed a:Ang Ikj� u 2-13 tw Y-4 based on-1 imp. �� pe�e�t ti�'t(:.,y )anti ttte W-ryit)w areu C,iN_The perviougs area CN'y._are ur d_sw;uir;tlent t±t Cie tt t{hY ti iii pout #!ti#iii l;urtijwlte C VL ',to we Aw the&Wgn of tempom i. cne rAvre�tiu�inkgiuu3ie �1W�ei�ittrttctki6�fi+�ii)tl be��t�t} 6�ci u;it�k bRwd on the flegw of deyeh)pm-91t limpervitputt urea pereent )anti the CN s(tw the nv lv graded peryinIM xreag. 4 texture is gives in appendix A for determining the Hydrologic condition HSG classification for disturbed s-oils. Hydrolo*:vowdition indicates the of lets of cover tV, .,e.. a nt.: ri infiltrations and runoff and is f;t�vor type generally astunated from density of plant and residue cover can rrliple areas. Good hydrologic condition Table 2,2 addresses most cover types, sueb as indicate* dial the sail usually has a low runoff vegetation, bare soil, and impervious-surfaces. There potential for that-specific hydrologic sail group, cover are a number of nmethoda for determining cover type. t�rpef:ar�d W-AA,h,.,&tie factors to conalder in The woA common are field reconnaissance, aerie e ti `tie et2-ect.:of ever �srt tit do� anti photographs, and land use maps, runoff )canopy or density of lawns, crow, or other vegeta-tive areas; (b) mount of year-round cover,,(-am-aunt of grass or close-seeded teguines in Treatment rotationap(d)percent of residue cover, and(e}degree of s u rface roughness. Treatment is a cover type modifier (wed only I+.�'��CL\°�tl�-IV table 2.2b)to describe the management of cultivated Cof'1n\-C\t>0 = �,2�j I KIC�I agricultural lands. It includes mechanical practices; such as contouring; and terming,and management ..:.:.. ►f�CTe�22��-[FD �'OS� practices, such crop rotations and.reduced ed or no CD�h��- (W tillage, 7'ah)e 2-I.-Runoff depth for selected N's and ra nfall mnountei Runoff dept foF cave nut Rainfall 110 45 55 60 65: 70.-_... . .5 80 1.0 0190 0.t}{? 0, O.tf►� 0_p0 O.i 1 000 AM: O.U13: 9.17 t1.32 G.S i �ffi� w __ 1:? ,00 . ,. 00`.. .:: .E)p _€}0....._....._. ,137 j76 2 ,R W L4 .90 104 .00 '00 . A .112 _13 24 1$9 .fag ..1 .` 1.18 1.6 0E1 qp: ..... .: OI .84 .n .76 1.11.. 1. . 1. 100 <: 00 4Q 414 AA: 2{1 .0D M .OD 0� .06 .14 4 s38 56 .8p 2.5 € 00 t12 .17 .30 Z9* 1.18 1.53 1.9ts.. .2"t 3-11 (1`> ( 19 3.9 1 71 .96 .126 1.59 1.913 Z4 6 , 120 25 .63 .75 1101 1.30 1.64 2 2.45 U.4 3,2 t 4.0 A .18 AM : .:: :Aq .76 1,03 L4 ,1,47= 2,04 2.46 2-92 . 3,43. .:.. 3.t i 4.: ,14 -5-4. -74 7:4 1:67 2: 2�3f 2.91 3.4-0 3.9 4.26 BA .24 .44 169 1E8 1,30 1,�r... ..._._�,_ 2.45..._.......Z"M 437 $:fSB.. .. 4:42.. .....4:s6-- 6A .50 .1311 114 L52 1.92 US- 2,81 3,2€8 3.78 4,30 9.85 5.a1: 5.76, 10 M 114 1�$. -.212... .�1i41 ��Q....:...:_��# 4.15 4,69 5 i 5.82 fa_��` 6,7- 8.0 1-25 1.14 2L25 2.78 9.33 3:89 4 4 ....; :., ,..._ li; 621 .. 681....::...7 4€i 7.7€i 9.0 1,71 2,29 2.88 3.49 4.10 4.72 SA 5.95. 6.67 7.18 7.719, -A 4€1 R,76 10.0 2.23 Z89 3.56 4.23 4.90 5.56 ....::: .._:.:.688. ......7.52 8.16 8318 9.40 9.76 11.0 2.78 182 426 5.00 5,72 6.48 7.13:.. .... 7.81 8.48 9.13 9.77 10.39 10.761 12,11 3.34 419 U0 a79 6.56 7. :65::.:..;8 76 9,45 10.11 10.76 1139 11,76 1310 4110 4.89 5.76 f,61 142 8.21'::_:;....$:98 :...,:9;71. .. 16,42 11.10 . 11. 6 12139 12.76 19.0 4.65 6,62 6.55 7.44 8134 9.12 9,91 10=91 11.39 12.08 1 .45 _13.39.`..,33.76......_..:.:._..:..:,,.-.-._. 1510 5,.33 6130 7.36 13,29 9.19 1004 111,85 11:6a 19.37 13.67 13.74 13:39 M76 'Interpolate the vat=W shown Z ainAl rUMff tlepthb for CN's or rainfAn aifloonts not shown. (210•VITR-55,fond Ed., June 1986) �,8 1 y LLS tin U C14 x on: 0 �o CN on o '. rN 1 owo // c cr Ql Ib- V3 f v _ � N - - � , .��•FAR (' _ - X00•���F 1 l +e / z k, Ilk Ir / � is i � t i O. 1c) �i Cl) a �?tm� o KXOCnO a O D m 00 co °2m 2 m s Z 3' O o 0 D 0 _ m N NO Z w Nr D w K m o v Z r O P' ,T Dww m7wm2Tw� m ° T W 0 ;*0 (0 x7-P � T ?xc (D O � L)3 � � � O c m�wW Co 7p X 0 . p03 � > D o 05 � 0 O i �no D � � T� X.. Z `A"Eg O °o 0 Z o � -�-i--'�NAOo m O o -' T N. ao - 0 G�00w(D 0 a m TI D a Z O o E �-0 j c W D(D Dm D m o�X m W nm D ° (D t mm °' °' °' w —I 3 > �00 w c0i it O W ° D v+ m P- D cu � m < (D rnrn W r O O N O 440 0 O P+ ~N n O << m 3 0 m cn m �p .. N N = N N fD fD W O N 0 �I A W -'tD J r � Od(D � fD r• O ON Q) a O O W U r U A w tj O O (n Cl)Z Z 4 O O m� '�_ r �00 co 0 0 A O F) � � n .. — (°DO O NN0 m 3 o m x w j 03 n ;0 Dorn rn o 0 n CL m 00°o D 3 n > D U)N co CC)C D \ OW A Q co� m� n v �cNn m ® �N Zz m —j oo U -n cn Ul -4 w ccn' Z W n cDA T X a Cl) a 0 00 00o G)� ��v N :E a) ° :t1 a X D-{ W o-`� W y `Dm >(nO -i o-ZT1 w Z �v0 rn onZ n� Z E5- o� IF m G)D c 0 wa 0- Z O O N CL O E5 00 �Z <N O ETOMK to 0 0 "T7 A 9 -0 N O �(D N m O mZ = =3 O N m cn o r r in � r V 1 N =1 = o d d N N� \ L � O O N_ N O O N � o O O N (O A (O A No 0 N z D z m r O O O J i �1d4 � smote lS 31 ya--- D � M D ct m tr^ 9Wu X 3NOZ r; �b'O IY t.._I d IVAU J