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HomeMy WebLinkAbout2001-03015 Engineer Review JAN.31.2001 5:©7PH • VHB N0.697 P.1 TOWN OF NORTH ANDOVER PLANNING BOARD ENGINEERING REVIEW OF SITE PLAN/SPECIAL,PERMIT FOR CONFORMANCE WITH THE TOWN OF NORT11 ANDOVER ZONING BYLAW&STANDARD ENGMERING PRACTICE Site Plan Title: Brook School—New Athletic Facility VM No.: 06716.27 Location: 1160 Great Pond Road Owner: Brook School, 1160 Great Pond Road,North Andover,MA 01845 Applicant: Brook School, 1160 Great Fond Road,North Andover,MA 01845 Applicant's Engineer: Rise-Frost-Shurnway Engineering,P.C.,71 Water Street,Laconia, NH 03246 Original Plan Date: 01-04-01 Revised Plan Date: 01-25-01 Review Date: 01-29-01 The Applicant submitted plans and documents to VHB for review on January 23,2001. The site plain submission was reviewed for conformance to the appropriate sections of the 1972 Town.of North Andover Zoning Bylaw amended in May,2000 and standard engineering practice.The following comments note non-conformance with specific sections and questions/comments on the proposed design, 1) Section 8.3.5.c :The revised plazas submitted have not been signed and stamped by a civil engineer and a landscape architect registered in the Commonwealth of Massachusetts.VHB recommends that the stamps and signatures be added to the revised site plans. 2) The following information is rewired by Section 8.35 and VHB offers the following comments. a) NORTH ARROW/LOCATION MAP.No location map has been provided.VHB suggests that a location map be shown at a scale of one inch equals fifteen hundred fee ,. (V= 1500'). b) SURVEY OF LOT/PARCEL:A waiver has been requested from preparing a boundary survey.As the development appears to be within the property limits of the Brooks School,VHB sees no reason why this waiver should not be granted. c) STORMWATER DRAINAGE/DRAINAGE BASIN STUDY:See comments below under the item 3)Drainage Review. d) LOCATION OF WALLS/SIGNS:The materials plan indicates that two retaining walls are proposed in the site.VHB suggests that the Applicant's engineer provide details of the retaining walls. e) REFUSE AREAS:Are there any refuse areas proposed for this site?If so,these areas should be shown on the plans. —� Post-iV Fax Note 7671 Dais�f�ii.-b t 1A eo.r v� To CIL!f C t NJFrom 1 ►'[G % Phonev AhOn@# 1 f1�TI\0671627\dou\ecpom\OM627review re"Hoc Fax# 17 "�J f Fax it JAN.31.2001 5-'a7PM VHB N0.597 P.2 f) TRAFFIC IldPACT STUDY:The Applicant's engineer has requested a waiver from this requirement.Without a traffic study,VHB cannot comment on the potential impacts to traffic on the existing public roadways(Great Pond Road). 3) DRAINAGE REVIBW. VIM has reviewed the drainage design and calculations,The proposed drainage design is a closed drainage system that includes drain basins,catch basins drain manholes,roof drains,infiltration chambers and detention basins.VHB offers the following comments regarding the proposed drainage design: a) The Applicant's engineer has provided groundwater elevation data for the infiltration system design.However,no groundwater elevation data has been provided at the proposed detention ponds.VHB recommends that groundwater elevation data be provided to verify that there is adequate cover from the bottom of the pond to the seasonal high watertable.If them will be standing water in the proposed detention basin for an extended period of time,VHB recommends that a fence be provided around the perimeter of the detention pond with an access gate for maintenance. b) There appears to be sorne errors for the pipe slopes shown on the site plans.V118 recommends that the pipe slopes be reviewed and revised.It appears that the pipe slopes should be as follows and the Applicant's engineer should confirm: • 8=0.0280FTI1 T for structure#8 • S=0.0200 Fr/FT for structure#12 * S=0.0219 FT/Fr for structure 430 c) After the review of HydroCAD®calculations,it appears that there are some discrepancies between the HydroCAD®data input by the Applicant's engineer and the information shown in the drainage notes.'VH9 offers the following comments regarding the HydxaCADO calculations: • The Applicant's engineer utilized 4-foot sumps when modeling all drain basins in HydroCAD®,however 2-foot sumps were shown in the drainage notes.The Applicant's engineer should resolve the discrepancy and revised the HydroCAD" calculation accordingly.Also,VHB suggests that sump of the drain basin be shown in the detail. • VHB recommends that the slopes for the respective structures be updated in HydroCAD.See comment b). • The slope of the outlet devices should be 0.2080 FT/FT for POND 74(equivalent to structure#1%. • According to the inverts in the drainage notes,the invert of POND 72(structure#7) should be 192.3 ft,the invert of POND 72(structure#9)should be 189.9 ft and the invert of POND 74(structure#10)should be 189.4 ft.The Applicant's engineer should review and revise accordingly. 2 •r.�467iG2'naas�x�pocM�a6n627-e,riew repozcdoo JAN.31.2001 5:08PN VHB N©.697 P.3 The HydroCAD®repon indicates a 27"horizontal orifice/grate is proposed at the elevation 172.7(bottom of structure)in modeling the 4-foot diameter catch basin (POND 70).The Applicant's engineer should explain. d) VHB recommends that an emergency overflow spillway be proposed in each of the detention ponds.These overflow spillways will function as a backup in case of the outlet structure fails. e) VHB recommends that the location of the outlet structures be identified in each of the detention ponds. f) It is not clear where the inlet sediment control device is proposed in the site.The Applicant's engineer should clarify. g) VHB recommends the Applicant's engineer consider proposing flared end sections•at each of the pipe outfalls to prevent erosion around the pipe, h) The proposed drainage design is a closed drainage system.However,pipe sizing calculations have not been provided in this submittal.pipe sizing calculations are necessary to determine whether the proposed pipes have adequate capacky to handle certain storm events.VHB recarranends that pipe sizing calculations be submitted for the drainage system,including roof drains.Also,VHE recommends-that the Rational method be used for drainage pipe sizing calculations. i) VHB recommends that a detail of the drain manhole be added to the plans. j) VHB reviewed the drainage design for conformance with the Department of Environmental Protection's(DEP)Stormwater Management Policy.In general the design meets the requirements.VHB offers the following comments: Standard 9:Opemdo n/Maintenance Plan No operation/maintenance plan has been provided.VHB recommends that the drain basins, catch basins,manholes and detention ponds be cleaned on a regular basis by the Applicant. 4) STANDARD ENGINEERING PRACTICE.VHB has reviewed the site plans for conformance to standard engineering practices. The purpose is to document the enginw ring and potential construction issues associated with the project. 'VHB offers the following comments: a) The combination of sharp horizontal curvature and the height of the 3:1 slope' embankment at the 7-foot service driveway located to the north of the proposed athledd, facility creates a potentially unsafe driving condition particularly,in ice/snow condition. Has the Applicant's engineer considered any safety measures(vertical curb or guard rail) to prevent errant vehicles from traversing down the embankment? b) The number of accessible parking spaces does not meet Architectural Access Hoard (AAA)requirements.The plan indicates that fifty-three(53)parking spares have been provided.According to AAB 521 CMR section 23.2.1,the required minimum number of accessible spaces should be three(3).VHB recommends that three(3) accessible spaces be provided; and one of which should be a van accessible space.The Applicant's 3 T\06AF�dot3\reports\�9i627-r¢+�ew rr�wc�da� JAN.31.3801 5:38Pri VHB NO.697 PA engineer should refer to AAB 521 CMR section 23.2.3 for more information about van accessible spaces. c) Section 8.1.2 states that I parking space per 4 persons is required for athletic fields (facilities),This requirement is based on the design capacity of the facility.What is the design capacity of the proposed athletic facility's What is the resulting required number of parldng spaces according to this section?As VHB has not reviewed the Campus Wide Parking Deport,it is difficult to comment on whether parking is adequate, d) VHB recommends that a wheelchair ramp detail conforming to AAB requirement be shown on the site plans. It is recommended that the applicant provide WRITTEN RESPONSES to the issues and comments contained herein. Reviewed by: Lul IJ Date: 1 '771 Danny H.Wang, Civil Engineer-Highway and Municipal Engineering Checked by: Timothy. B.McIntosh,P. . Project Manager/Senior Project Engineer Highway and Municipal Engineering 4 r\067262A&u\rV&-N\0671627-rtWW UpUtd X Transportation Land Development0 0 Environmental Services m Imagination I innovation cmercgy Creating rest ts for our clients and benefits for our cominunities Feburary 28,2001 Inc;. Ref: 06716.27 Ms.Heidi A.Griffin Town Planner Community Development&Services Town of North Andover 27 Charles Street North Andover,MA 01845 Re: Brooks School—New Athletic Facility Site Plan Review North Andover,MA Dear Heidi, Vanasse Hangen Brustlin,Inc. (VHB)has received Kist-Frost Shumway's written response letter(dated 2-20-01)to our Engineering Review for the above referenced project. It appears that all of VHB's comments have been adequately addressed and VHB's concerns in this matter have been satisfied. No further engineering review is required at this time. If you have any questions or concerns,please call me at your convienence. Very truly yours, VAN„ABBE HANG� � � ��� T ,I Timothy B.McIntosh,P.E. MAID 001 Project Manager—Highway&Municipal Engineering till cc: John L.Scott-Rist-Frost Shumway Engineering,P.C. I LANNIN61id tr rv11 N7° 101 Walnut Street Post Office Box 9151 Watertown, Massachalsetts 02471-9151 T:\p671627\does\letters\Brooke-athletic-approv-022601,doc 61Z924.1770 tl° FAX 617'924.2286 email: info@vhb.com www.vhb.corn