May 10, Nathaniel N. Strosberg Town Planner/Director of Community Development Town of Ashland 101 Main Street Ashland, Massachusetts 01721

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1 Nathaniel N. Strsberg Twn Planner/Directr f Cmmunity Develpment Twn f Ashland 101 Main Street Ashland, Massachusetts Re: 73 Olive Street Definitive Subdivisin Plan Dear Mr. Strsberg and Members f the Bard: Prfessinal Services Crpratin, PC (PSC) cmpleted the peer review f the Definitive Subdivisin Plans fr prperty at submitted 73 Olive Street. This letter is prvided t summarize findings, cmments and recmmendatins. BASIS OF REVIEW PSC is in receipt f the fllwing dcuments dated March 25, 2016 and prepared by Engineering & Land Surveying/The Jillsn Cmpany, Inc. which will serve as the basis f the review: Mem entitled Waiver Request fr Definitive Subdivisin Submissin dated April 1, 2016 Ashland Planning Bard Definitive Subdivisin Applicatin dated April 13, 2016 Plans (10 Sheets) entitled N. 73 Olive Street Definitive Subdivisin Plan dated March 25, 2016 Plans (1 Sheet) entitled N. 73 Olive Street Prpsed Cnditins Hydrlgic Sub Area Map dated March 25, 2016 Plans (1 Sheet) entitled N. 73 Olive Street Existing Cnditins Hydrlgic Sub Area Map dated March 25, 2016 Plans (1 Sheet) entitled N. 73 Olive Street Ltting Plan dated March 25, 2016 Plans (1 Sheet) entitled N. 73 Olive Street Subdivisin Lcus Map dated March 25, 2016 Reprt entitled Strmwater & Ersin Cntrl Reprt prepared by The Jillsn Cmpany, Inc. fr Suresh Rajakumar dated March 25, 2016 Existing Cnditins Prpsed Cnditins HydrCAD Prpsed Cnditins Printuts Strmwater Summary Existing Cnditins HydrCAD Printuts Sil Infrmatin Ersin Cntrl Management Estimated Cnstructin Phasing Review by PSC will include the abve items alng with the fllwing: Twn f Ashland Chapter 282 Zning as amended thrugh May 6, 2015 Twn f Ashland Chapter 343 Strmwater Management dated May 28, Twn f Ashland Chapter 344 Subdivisin f Land dated April 29, Ten Lincln Rad, Suite 201 Fxbr, Massachusetts T: F:

2 Page 2 f 7 SITE AND PROJECT OVERVIEW The prject parcel is lcated n the westerly side f Olive Street apprximately 230 feet suth f Mrey Drive and cntains apprximately 5.34 acres. The parcel supprts a single family residential structure lcated n the frnt prtin f the parcel clsest t Olive Street. The huse is served by a hrseshe shaped driveway with curb cuts t Olive Street. The land slpes generally suth t nrth with wetland areas at bth the nrthwest and nrtheast prtin f the parcel. These tw wetland areas cnnect t the nrth f the site and are tributary t an intermittent streams that flws under Olive Street in a culvert t the nrth f the site. The site is zned Residence A which requires 30,000 sq. ft. f area and feet f frntage. There is a FEMA Zne A fldplain within the prperty bundaries. FEMA Zne des nt have a determined elevatin fr the 100 year fld. WAIVER REQUEST The applicant has requested waivers frm a number f requirements. 1. Waiver t allw elevatins t refer t NAVD88 were United States Gelgical Survey Datum is required (344 8.B.(11)(h)). 2. Waiver frm pen space (park) requirement (344 16). 3. Waiver t prvide 20 ft wide pavement where 26 feet are required ( H.(1)). 4. Waiver frm grass strip requirement ( F). 5. Waiver t allw PVC pipe at less than 12 inches where reinfrced cncrete pipe a minimum f 12 inches in diameter are required ( B.(4)). 6. Waiver frm street lamp requirement ( D.(1)). 7. Waiver f buffering requirement f detentin basin adjacent t Olive Street ( E). 8. Waiver t allw limited mnumentatin (344 25). 9. Waiver frm requirement t plant street trees (344 29) W1. Prvide justificatin fr each waiver and hw it is in the best interest fr the Twn t grant it. W2. PSC recmmends the applicant request a waiver frm the traffic impact reprt (344 8.D.) CHAPTER 282 ZONING District and Use Regulatins ( 2.0 & 3.0) The prject site is lcated within a Residence A (RA) District and the Fldplain Overlay District (FPOD). Dimensinal Requirements ( 4.0) The prject lts meet the minimum lt area, frntage, frnt and rear yard requirements. Z1. Prvide dimensins t demnstrate that the existing huse will meet the dimensinal setback requirements. Z2. The tw (2) existing sheds shuld be shwn t be demlished.

3 Page 3 f 7 CHAPTER 344 SUBDIVISION OF LAND GENERAL G1. The prpsed subdivisin street is prpsed t be private. The applicant shuld submit Hmewners Assciatin dcuments t the Bard fr review. PSC recmmends that all streets be cnstructed t meet public street standards. Article III Submissin and Apprval f Plans Definitive Plan S1. Prvide prf f filing f Determinatin f Applicability with the Cnservatin Cmmissin (A (2). S2. Prvide riginal stamp and signature and seal f the engineer and surveyr f recrd n plans. S3. Prvide tw cpies f clsed traverse fr the whle subdivisin, each individual lt and the street. (B (2)). S4. Prvide the prpsed name f the street in pencil (B (4)). S5. Prvide suitable space fr the Twn Clerk certificatin (B (8)). S6. Prvide ne prpsed (centerline) prfile with elevatins n vertical curves at 25 ft intervals (B (11) c)). Prvide prpsed grades and vertical curves n prfile. S7. Shw drainage facilities including lcatins, size, elevatins and slpes n prfile and prvide capacity and velcity calculatins (B (11)(e). S8. Shw water supply systems including lcatin, size and elevatins f all pipes, including gate valves and hydrants (B (11)(f). S9. Prvide elevatins n USGS datum r request a waiver (B (11)(h)). S10. Update typical sectin t shw finished surface fr full width f prpsed right f way (B (14)) Article IV Design Standards Streets The prject includes cnstructin f a 485 feet lng, 20 feet wide dead end rad with sidewalk n ne side a cul de sac. D1. Prvide t the Bard the depsitin f Parcel A (A (4)). D2. Prvide vertical curves when the algebraic differences in grade between centerline tangents is 2.0% r mre. (C (3)). D3. Prvide evidence that frward sight distances are 150 feet r greater fr the subdivisin street. (D). Prvide sight distances at intersectin with Olive Street. D4. Prvide the intersectin sight distance fr the subdivisin radway and Olive Street using ASSHTO standards. (A (1))

4 Page 4 f 7 D5. Design requires Planning Bard apprval f a requested waiver t cnstruct a 20 feet wide in lieu f 26 feet. The reduced pavement is cnsistent with LID techniques. Prvide crrespndence frm the public safety fficer that this is acceptable. Easements The prject includes easements fr strmwater management facilities. D6. Prvide easements with a minimum width f 30 feet. (A) Drainage See cmments belw under B and Strmwater Management. Water Supply The prject includes a waterline in the radway and hydrant n far end f cul de sac. D7. Prvide in writing the apprval f the water system design frm the Department f Public Wrks Water and Sewer Divisin. Prtectin f Natural Features D8. Prvide a prpsed tree line fr the entire prject t indicate cmpliance and fr the Bard s review. Curbs, inlets and berms D9. Prvide type VA 4 granite curbing at the entering radii f the subdivisin rad and Olive Street. Granite curbing shuld be prvided fr three (3) feet n each end f the end f the curbing and granite inlet blcks shuld be prvided fr catch basins lcated within granite curbing limits. (A (1)) D10. It is nt clear as t the type f ht mix asphalt curbing is t be prvided at all ther lcatins. The drawings prvide details fr tw different types f ht mix asphalt curbing. The regulatins specify Type I 1, class I bituminus cncrete mdified Cape Cd style berm. (Subsectin C) Sidewalks A 5 ft ht mix asphalt sidewalk has been prvided alng the westerly edge f the street pavement and has been extended t include virtually the entire cul de sac. A waiver has been requested t allw fr the sidewalk t be cnstructed starting at edge f the radway. D11. The Typical Radway Crss Sectin n the plans shuld be mdified t specify cnstructin details fr the sidewalk such as fundatin materials, ht mix asphalt curses and thicknesses and sidewalk crss slpes. (Subsectin B&C) D12. Prvide wheelchair ramps fr the sidewalk at Olive Street and at the terminus pint at the radway cul de sac. (Subsectin E)

5 Page 5 f 7 Utilities Water system (A) D13. The plans shuld label all water mains as cement lined ductile irn pipe (CLDI) f a class specified by the Department f Public Wrks Water Divisin. D14. Prvide the methd fr cnnecting the subdivisin radway water main t the existing Olive Street water main as apprved by the Department f Public Wrks Water Divisin. D15. Prvide lcatin f the existing fire hydrant n Olive Street ppsite huse number 78 labeled as t be remved and replaced. The Fire Department shall apprve the replacement lcatin as well as at the prpsed cul de sac. D16. Anchr tees are nt likely t be required fr water service cnnectins. The design engineer shuld cnfer with the water department t determine the crpratin stps t be prvided and revise the detail. Strm drainage system (B) See sectin n Strmwater Management Sewer system (C) D17. Sewer manhles were bserved n the G & L Enterprises prperty, which immediately abuts the subdivisin t the nrth. Recmmend the design engineer investigate if a gravity cnnectin serving the three (3) lts in the subdivisin culd be made t this sewer line. It is understd that cperatin frm G & L Enterprises wuld be necessary fr this pssible cnnectin. D18. Shuld the abve described sewer cnnectin nt be feasible, the Applicant is encuraged t investigate lw pressure frce main systems that allw frce main cnnectins frm individual dwellings t cnnect t a frce main cllectr in the street. Each f the prpsed dwellings wuld have a gravity cnnectin t a small pump chamber lcated n the lt. Frm that pump chamber a small frce main wuld be run t the cllectr frce main in the street. The cllectr frce main wuld run in the street t a design pint where a sewer manhle wuld allw a gravity cnnectin t be made t the existing sewer in Olive Street. The cnnectin at the Olive Street sewer wuld require a new manhle. D19. Prvide design f pump system and cmpnents and supprting calculatins and dcumentatin fr review and apprval. Lighting (D) The Rules & Regulatins require that street level type lamp pst lighting f apprximate 6 ft height be installed in the frnt yard f each individual building. The applicant has requested a waiver frm this requirement. Mnuments The Rules and Regulatins require 6 x 6 granite r cncrete bunds with drill hles be set at all street intersectins, at all pints f change indirectin f the layut, at easements and at frnt lt crners. In additins at all ther lt crners irn rds, pipe r ther markers are t be set. The applicant is asking

6 Page 6 f 7 fr a waiver frm these requirements t prvide nly irn rds (n granite r cncrete bunds) at varius pints shwn n the ltting plan. Plantings The applicant has requested a waiver frm the tree planting prvisins f the Rules & Regulatins. Strmwater Management (Chapter 343) The prject prpses t capture radway runff in catchbasins and rute it t subsurface infiltratin systems. The prject indicates that wrk assciated with the cnstructin f the subdivisin rad is utside wetland resurce areas. Resurce areas may be impacted as a result f cnstructin f hmes n the newly created lts. The prject will hwever disturb greater than 10,000 sq. ft. and therefre the prject will need t cmply with the Strmwater Management Bylaw. SW1. Prvide cmpleted Applicatin Frm with riginal signatures f all wners ( 7.6.1). SW2. Prvide areas in Fldplain District ( 7.6.2) and delineate 100 year fld zne ( b)10) SW3. Prvide earth remval/fill calculatins ( ). SW4. Prvide pipe sizing and velcity calculatins ( ). SW5. SW6. SW7. Prvide drain manhles at all changes f directin and changes f grade. Update the catch basin and duble catch basin details t specify the frame and grate, indicate frame and grate adjustment methd, indicate jinting materials fr precast sectins, indicate pipe cnnectin by flexible rubber bt, the cmpressive strength f the cncrete used, reinfrcement steel specificatins and the bedding material. Update the prpsed cnditin hydrlgy plan with the apprximate lcatin f the prpsed dwellings, driveways and lawn areas, as well as estimated lt grading. The grading at retentin basin 2 shuld als be shwn n the plan. SW8. Update the HydrCAD mdel t reflect the prpsed surface cnditins fr entire buildut and impacts t time f cncentratin calculatins. Fr instance, it is nt anticipated that the NRCS maps indicate sils within the develpment area cnsist f Mntauk fine sandy lam, with hydrlgic grup rating f C and Sci very fine sandy lam with hydrlgic grup rating f B/D. Sil testing fr the prject cnsists f nine (9) test hles taken n July 16, The sil lgs are presented n Sheet 5 f the Definitive Plans. In tw (2) f the test hles mttles were bserved at 4 ft depth as well as standing water at a greater depth. The remaining seven (7) hles were excavated t depths f 7.2 feet t 9.0 feet depth. The test hle excavated t 7.2 feet encunter bedrck. The remaining test hles did nt encunter bedrck and n ntatins were included relative t mttles r lack f mttles. Fr these test hles grundwater adjustments (Frimpter methd) will be required r excavatin t a greater depth will be necessary t cnfirm the strmwater management areas are a minimum f tw (2) feet abve estimated high grundwater. Fur (4) feet f separatin is required t waive grundwater munding calculatins.

7 Page 7 f 7 SW9. Prvide test pits sufficient t determine grundwater elevatins at BMPs ( ) & ( c)12)). Test pits shuld be lcated within the limits f the strmwater BMPs t shw sil characteristics and a minimum f tw feet f separatin between bttm f system and seasnal high grundwater. SW10. Prvide grundwater munding calculatins if separatin f infiltratin system bttm t seasnal high grundwater elevatin is less than 4 feet. SW11. The calculatins indicate an infiltratin rate thrugh the bttm f the retentin basins as 2.40 inches per hur. Withut infiltratin tests infiltratin rates based n the Rawls rates and NRCS sils data is t be used. Basins are prpsed in B and C sils. Revise HydrCAD mdel accrdingly. SW12. Recmmend cnditin be included that requires bservatin f the excavatin be bserved by Twn prir t installatin f system t verify sils are cnsistent with design data and assumptins. SW13. Catchbasins must be ffline t achieve 25% TSS remval credit, eliminate all catch basin t catch basin cnnectins. Dcumentatin indicates that the ttal disturbance exceeds 1 acre therefre the prject will require the filing f a ntice f intent with EPA and develpment f a strmwater pllutin preventin plan (SWPPP). SW14. Recmmend cnditin be included that requires submissin f the final SWPPP prir t cnstructin fr review. SW15. Lcate sedimentatin and ersin cntrl devices n plan ( b)13)). Include lcatin and prtectins fr stckpile areas. SW16. Prvide Operatin and Maintenance (O&M) plan and all required dcumentatin ( ). If there are questins r yu need additinal infrmatin regarding this review d nt hesitate in calling the undersigned. Very Truly Yurs, Prfessinal Services Crpratin, PC Philip Paradis, PE, LEED AP, CPSWQ President S:\1 PROJECTS\ALPB Ashland Planning Bard\ Olive St\Reprts\Olive Street Def Sub Plan Review dcx