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HomeMy WebLinkAbout20050808 ENGINEERING REVIEW TOWN OF NORTH ANDOVER PLANNING BOARD ENGINEERING REVIEW OF WATERSHED SPECIAL PERMIT j FOR CONFORMANCE WITH THE TOWN OF NORTH ANDOVER ZONING BYLAW Site Plan Title: Site Plan VHB No.: 09280.06 Site Plan Location: 249 Marbleridge Road,North Andover,MA Applicant: Belford Construction,Inc., 1049 Turnpike Street,North Andover,MA Applicant's Engineer: New England Engineering Services,Inc.,60 Beechwood Dr,North Andover,MA Plan Date: April 1,2005 Review Date: 4-28-05 The plan was reviewed for conformance to the 1972 Town of North Andover Zoning Bylaw(last amended December 2002). The Applicant has submitted the following information for VHB's review: • Application for Watershed Special Permit with Statement of Water Quality Impact from the Engineer dated April 1,2005, • Drainage Report dated March 31,2005, • Site Plan(4 sheets)dated April 1,2005. The following comments note non-conformance with specific sections of the Zoning Bylaw or questions/comments on the proposed design and VHB's recommendations/suggestions. Town of North Andover Zoning Bylaw 1. (4.136.3.c.ii.3) The Applicant states that a variance has been requested for the construction of a new structure within the non-disturbance zone. Has the variance been granted by the Zoning Board of Appeals? 2. (4.136.3.d.iii) It appears that the following proposed work is prohibited under this section: • (4.136.3.d.iii.2) The Applicant is proposing changes in topography and grade adjacent to the driveway entrance. • (4.136.3.d.iii.3) The Applicant is proposing vegetation removal to construct the proposed driveway. • (4.136.3.d.iii.5) The Applicant is proposing surface and subsurface drainage(PVC pipe and Swale)adjacent to the proposed driveway. General Comments/Standard Engineering Practice 3. The Applicant should provide a plan view of the infiltration system detail,showing all necessary materials and dimensions. 4. The Applicant should provide a detail for the proposed foundation drains. 5. The Applicant should specify the direction of runoff flow in the Erosion Control detail. 1 \C:\WINDOWS\TEMP\0928006-Mapleridge.doc i 6. The Applicant should specify the lengths of pipe on the plans. 7. The Plans do not show how the roof runoff makes its way to the infiltration systems. Drainage Comments 8. The Applicant used a time span of 5-20 hours in the Pre-development Hydrocad model. Typically, a model should have a time span that goes from zero discharge to peak discharge,and back to zero discharge(beginning and ending of storm event). VHB suggests using a minimum time span of 0-24 hours,as was used in the post-development model. 9. The Applicant should consider providing a second catch basin on the south side of the Lot 2 driveway to avoid having channel flow from the proposed swale cross the driveway. 10. The following comments refer to the Time of Concentration calculation for Post-development Area A-1/2: • It appears the Applicant should have 2 segments of shallow concentrated flow over the paved driveways. • It appears the flow path passes through the proposed Swale along Marbleridge Road and from the pipe outlet to the wetland,these segments should be considered channel flow. • Using the proposed inverts and pipe length,it appears the slope of the proposed PVC pipe should be 3.3%,the Applicant should verify. • It appears the Manning Factor(n)for the PVC pipe is high. 0.013 is typically used for reinforced concrete pipe,PVC pipe is smoother. The Applicant should justify the chosen value. 11. The Applicant should provide storage volume calculations for the infiltration systems,specifying a void ratio for the crushed stone. 12. The Applicant should justify the exfiltration rate used for the infiltration systems in the Hydrocad model. Percolation test results should be provided. 13. The infiltration system models both show a secondary outlet of 0.5"RCP. The Applicant should revise to show 6"PVC. The Manning factor should also be revised as per previous comment. 14. The Summary Table of P.45 of the Drainage Report compares Pre-vs Post-development peak flows, using a simple addition to combine Pre-development Areas Al and A2. Because of the varying times of concentration,these peak rates will not occur at the same time,therefore a"Summation Pond" should be used for this calculation. It is recommended that the Applicant provide WRITTEN RESPONSES to the issues and comments contained herein. Reviewed by: Date: Darryl Gallant Civil Engineer—Highway and Municipal Checked by: Date: Timothy B.McIntosh,P.E. Project Manager —Highway and Municipal 2 \C;\WINDOWS\TEMP\0928006-Mapleridgedoc RECEIVED JUN 14 2005 TOWN OF NORTH ANDOVER PLANNING BOARD NORTH ANDOVER ENGINEERING REVIEW OF WATERSHED SPECIAL PERMIT PLANNING DEPARTMENT FOR CONFORMANCE WITH THE TOWN OF NORTH ANDOVER ZONING BYLAW Site Plan Title: Site Plan VHB No.: 09280.06 Site Plan Location: 249 Marbleridge Road,North Andover,MA Applicant: Belford Construction,Inc., 1049 Turnpike Street,North Andover,MA Applicant's Engineer: New England Engineering Services,Inc.,60 Beechwood Dr,North Andover,MA Plan Date: April 1,2005 Original Review Date: 4-28-05 Revised Plan Date: May 26,2005 2"a Review Date: 6-08-05 The plan was reviewed for conformance to the 1972 Town of North Andover Zoning Bylaw(last amended December 2002). The Applicant has submitted the following information for VHB's second review: • Response to Comments Letter dated May 26,2005, • Drainage Report revised May 25,2005, • Site Plan(4 sheets)revised May 26,2005. The following comments note non-conformance with specific sections of the Zoning Bylaw or questions/comments on the proposed design and VHB's recommendations/suggestions. VHB's original comments are shown in normal font,the second round of comments are shown in bold. Town of North Andover Zoning Bylaw 1. (4.136.3.c.ii.3) The Applicant states that a variance has been requested for the construction of a new structure within the non-disturbance zone. Has the variance been granted by the Zoning Board of Appeals? Addressed. 2. (4.136.3.d.iii) It appears that the following proposed work is prohibited under this section: • (4.136.3.d.iii.2) The Applicant is proposing changes in topography and grade adjacent to the driveway entrance. • (4.136.3.d.iii.3) The Applicant is proposing vegetation removal to construct the proposed driveway. • (4.136.3.d.iii.5) The Applicant is proposing surface and subsurface drainage(PVC pipe and swale)adjacent to the proposed driveway. Addressed. General Comments/Standard Engineering Practice 3. The Applicant should provide a plan view of the infiltration system detail,showing all necessary materials and dimensions. Addressed. 1 rr. na,un nr. .��,.<�...,......<,nn,�rvv:.�,,,,,,,,,,,,,,,,c..n,....r•...,,.. 4. The Applicant should provide a detail for the proposed foundation drains, Addressed. 5. The Applicant should specify the direction of runoff flow in the Erosion Control detail. Addressed. 6. The Applicant should specify the lengths of pipe on the plans. Addressed. 7. The Plans do not show how the roof runoff makes its way to the infiltration systems. Addressed. Drainage Comments 8. The Applicant used a time span of 5-20 hours in the Pre-development Hydrocad model. Typically,a model should have a time span that goes from zero discharge to peak discharge,and back to zero discharge(beginning and ending of storm event). VHB suggests using a minimum time span of 0-24 hours,as was used in the post-development model. Addressed. 9. The Applicant should consider providing a second catch basin on the south side of the Lot 2 driveway to avoid having channel flow from the proposed swale cross the driveway. Addressed. 10. The following comments refer to the Time of Concentration calculation for Post-development Area A- 1/2: • It appears the Applicant should have 2 segments of shallow concentrated flow over the paved driveways. • It appears the flow path passes through the proposed swale along Marbleridge Road and from the pipe outlet to the wetland,these segments should be considered channel flow. • Using the proposed inverts and pipe length,it appears the slope of the proposed PVC pipe should be 3.3%,the Applicant should verify. • It appears the Manning Factor(n)for the PVC pipe is high. 0.013 is typically used for reinforced concrete pipe,PVC pipe is smoother. The Applicant should justify the chosen value. Addressed. It. The Applicant should provide storage volume calculations for the infiltration systems,specifying a void ratio for the crushed stone. Addressed. 12. The Applicant should justify the exfiltration rate used for the infiltration systems in the Hydrocad model. Percolation test results should be provided. Addressed. 13. The infiltration system models both show a secondary outlet of 0.5"RCP. The Applicant should revise to show 6"PVC. The Manning factor should also be revised as per previous comment. Not addressed. Device#1 of the Outlet Devices for both Infiltrator models is still shown as a 0.5" x 401/45' long culvert. The Applicant should revise the model to be a 6"x 40'or 45'long culvert. 14. The Summary Table of P.45 of the Drainage Report compares Pre-vs Post-development peak flows, using a simple addition to combine Pre-development Areas A I and A2. Because of the varying times 2 \'1'•\119)R(111/.\irvc\n�rn�rw�f 147Af1�M\1.arhlrriilvr-Fnllrn.'I�n.�nr r of concentration,these peak rates will not occur at the same time,therefore a"Summation Pond" should be used for this calculation. Addressed. It is recommended that the Applicant provide WRITTEN RESPONSES to the issues and comments contained herein. e Reviewed by: 1 1 Ail Date: Darryl Gallant Civil Engineer—Highway and Municipal Checked by: t7 . Date: Timothy B.AlIntosh,P.E. Project Manager —Highway and Municipal 3 \T\09?HII 06\d«c\mrmnc\092!20116-\tarhlvridee-Follmvl 4r.da- TOWN OF NORTH ANDOVER PLANNING BOARD ENGINEERING REVIEW OF WATERSHED SPECIAL PERMIT FOR CONFORMANCE WITH THE TOWN OF NORTH ANDOVER ZONING BYLAW Site Plan Title: Site Plan , VHB No.: 09280.06 Site Plan Location: 249 Marbleridge Road,North Andover,MA Applicant: Belford Construction,Inc., 1049 Turnpike Street,North Andover,MA Applicant's Engineer: New England Engineering Services,Inc.,60 Beechwood Dr,North Andover,MA Plan Date: April 1,2005 Original Review Date: 4-28-05 Revised Plan Date: May 26,2005 2n4 Review Date: 6-08-05 Revised Plan Date: --- 3rd Review Date: 6-21-05 The Applicant has adequately addressed VHB's comments and no further engineering review is required at this time. Please refer to the final report below for additional details. The plan was reviewed for conformance to the 1972 Town of North Andover Zoning Bylaw(last amended December 2002). The Applicant has submitted the following information for VHB's final review: • Drainage Report revised June 15,2005, • Response to comment letter dated June 16,2005. VHB's original comments are shown below in normal font. VHB's second round of comments are shown in italic font immediately following the original comment and final comments are shown in bold font. Drainage Comments 13. The infiltration system models both show a secondary outlet of 0.5"RCP. The Applicant should revise to show 6"PVC. The Manning factor should also be revised as per previous comment. Not addressed. Device#1 of the Outlet Devices for both Infiltrator models is still shown as a 0.5"x 40'145'long culvert. The Applicant should revise the model to be a 6"x 40'or 45'long culvert. Addressed. 1 \T:\09280.06\dots\memos\0928006Marbleridge-Final.doc