The URL can be used to link to this page

Home My WebLink About210401_2nd Peer Review Beechwood Drive - final - - 25 Beechwood Drive %�. Horsley Wiften Group 0 SUStainable, Ehvirownental Solutions 112 W'at r `tr t-61 Floor-Boston,MBA 02109 .......... 5 -2 1 ho,r 1 ten April 1, 2021 Ms. Jean Enright, Planning Director Planning Department Town of North Andover 120 Main Street North Andover, Massachusetts 01845 Ref: Second Stormwater Peer Review Climate-Controlled Self-Storage Beechwood Drive North Andover, Massachusetts Dear Ms. Enright and Board Members: The Horsley Witten Group, Inc. (HW) is pleased to provide the North Andover Planning Board with this letter report summarizing our second review of the Stormwater Management Report and Site Plans for the proposed Climate-Controlled Self-Storage development on Beechwood Drive, North Andover, MA. The plans were prepared for The Stubblebine Company (Applicant) by TFMoran, Inc. The project proposes the construction of a 3-story, climate controlled self- storage facility, including 23 parking spaces and two driveway entrances on a 2.86-acre lot. The stormwater management includes deep sump catch basins and subsurface infiltration chambers. There is a wetland resource area in the southeastern corner of the site. There is no disturbance proposed within the 25-foot buffer of the resource area and no building proposed within the 50-foot buffer. The proposed development is within the jurisdiction of the North Andover Conservation Commission and will require an Order of Conditions. The following documents and plans were received by HW in response to our February 25, 2021 initial peer review letter: • Stormwater Management Report for Self-Storage, 0 Beechwood Drive, North Andover, MA, prepared by TFMoran Inc., revised March 22, 2021 (151 pages); • Letter to the North Andover Planning Department, responding to North Andover Municipal Comments in early March, prepared by TFMoran Inc., dated March 18, 2021 (2 pages); • Letter to the North Andover Planning Department, responding to The Horsley Witten Group Comments on February 25, prepared by TFMoran Inc., dated March 11, 2021 (6 pages); • Letter to the North Andover Planning Department, requesting a waiver in connection to the proposed climate controlled self-storage site plans, prepared by TFMoran Inc., dated March 22, 2021 (2 pages); • Photos of example storage facilities (9 pages); ors ilt mu. @H,ors1eyW1tfenGrouPii t iren G,ro.0 P, Inc. Town of North Andover April 1, 2021 Page 2of8 • Architectural Schematic Plans, Norwood Self Storage, Beechwood Drive, North Andover, MA, Prepared by Dennis Mires, P.A. The Architects, dated February 16, 20217 which include: o Elevations A201 —A202 o Renderings A901 • Site Development Plans, Climate-Controlled Self-Storage Beechwood Drive, North Andover, Massachusetts, prepared by TFMoran, Inc., dated February 10, 2021, revised March 18, 2021, which include: o Cover C-1 o Notes & Legend C-2 o Existing Conditions Plan 1 of 1 o Site Preparation Plan C-3 o Site Layout Plan C-4 o Drainage Schedule C-5A o Grading & Drainage Plan C-5 o Utility Plan C-6 o Landscape Plan C-7 o Stormwater Management Plan C-8 o Lighting Plan L-1 o Drainage & Sewer Profiles P-1 o Detail Sheet C-9— C-15 o Truck Turning Movements Plan T-1 o Wetlands Buffer Impact Plan W-1 • Presentation version of the Landscape Plan from page C-7 of Site Development Plans, Climate-Controlled Self-Storage Beechwood Drive, North Andover, Massachusetts, prepared by TFMoran, Inc., dated February 10, 2021, revised March 18, 2021. Stormwater Management Design Peer Review HW offers the following overall comments concerning the stormwater management design as per the Massachusetts Stormwater Handbook (MSH) dated February 2008, the North Andover Stormwater Management and Erosion Control Regulations (Stormwater Regulations) adopted February 15, 2011, and the North Andover Stormwater Management and Erosion Control Bylaw (Bylaw). The comments below correlate with the HW initial peer review letter, follow up comments are provided in bold font. 1. Standard 1 states that no new stormwater conveyances (e.g. outfalls) may discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. a. There appears to be a discrepancy on the number of outfalls proposed, the Grading & Drainage Plan indicates two outfalls and the Post-Development Drainage Plan +n�� cc i� ....i. �'' ' �,,�. 9 iiiii d.� ill�...:, m�.n� '11",� .i6..:rm ..,i M.,�i �I 1.:� mil is -,.11";r 'Ili :� M.,.�r�.� i,„ „�.,�,,,. � ., III a ,,, m �,�,, m� ail Town of North Andover April 1, 2021 Page 3of8 indicates three outfalls. HW recommends that the Applicant verify that the number of outfalls are consistent between the design plans and the Post-Development Drainage Plan. HW (4/01/21): The Applicant has clarified that there are two outfalls on the Grading and Drainage Plan. HW has no further comment. b. HW recommends that the Applicant provide riprap apron sizing calculations for all riprap at proposed outfalls to confirm no erosion will occur. HW (4/01/21): The Applicant has provided riprap apron sizing calculations for the proposed outfalls to confirm no erosion will occur. HW has no further comment. 2. Standard 2 requires that stormwater management systems shall be designed so that post- development peak discharge rates do not exceed pre-development peak discharge rates. a. In accordance with the North Andover Stormwater Management and Erosion Control bylaw, Chapter 240, Section 27 the following amendments are recommended: i. Addition of a summary table including peak discharge rates and total volume of discharge for all modelled storm events to easily evaluate the pre- and post- development values. HW (4101/21): The Applicant has added a table summarizing the pre- and post-development peak runoff discharge rates and peak volumes for all modelled storm events. HW has no further comment. ii. Amendment of the rainfall data for all modelled storm events to match the values provided in Section B (a). HW (4/01121): The Applicant has adjusted the rainfall data utilized in the HydroCAD model as requested. HW has no further comment. iii. Amendment of the Time of Concentrations to include no more than 50 feet of sheet flow for both pre- and post-development conditions as stated in Section B (11). HW (4101/21): The Applicant has adjusted the sheet flow length as requested. HW has no further comment. b. There appears to be a discrepancy on the number of infiltration chambers for Stormtech System #1 between the HydroCAD model and the design plans, Sheet C- 19. HW recommends that the Applicant verify the number of chambers and update the plans or calculations accordingly. HW (4/01/21): The Applicant has revised the plans to be consistent with the HydroCAD model. HW has no further comment. c. HW recommends that the Applicant verify the chosen flow path for Drainage Area (DA) 2 in the pre-development conditions as the flow path for DA 201 in the post- development conditions appears to be longer and is within the same area as Pre- development DA 2. „ ,,, ,�,„..., W "N �' °�� r�,, » "4 r� x.�,�, � :." ,,, � R III �, � .��i�� :�, +�� i hi r �� d..... h .I -� li ili? �i� i'l" I I m '� �qi Mi, �,., ,..„,,poll,. �, m�� .��_�'� .....�'��..��.� ..�. .III.�_��I �� A ��.ii� ��L��..��_��'�,�.....� �� .ii��_��_�� m M�'�� .�_�� '�,...,�.�. ..� ..��.� ��.�a �".��.��.�� .�� .��... � �.�� ,,. Town of North Andover April 1, 2021 Page 4 of 8 HW (4/01/21): The Applicant has adjusted the flow path as requested. HW has no further comment. d. Catch Basin Nodes 214 and 215 in the HydroCAD model do not appear to exist in the design plans. HW recommends that the Applicant verify where these two catch basins are proposed and update the plans or calculations accordingly. HW (4/01/21): The Applicant has adjusted the post development plan accordingly. HW has no further comment. e. HW recommends that the Applicant confirm the upper boundary of the catchment area and that the property to the west is not flowing onto the site. HW (4/01/21): The Applicant has adjusted the watershed boundary accordingly. HW has no further comment. f. For documentation purposes of the Post-Development Drainage Plan HW recommends that the area of DA 212 match the area modelled in HydroCAD as well as specifying the location of Pond Node 1. HW (4/01/21): The Applicant has revised the HydroCAD model accordingly. HW has no further comment. g. To verify that the paved area within DA 212 is draining toward CB 5, HW recommends that the Applicant provide spot grades at the end of the turnaround area in the southeastern driveway. HW (4/01/21): The Applicant has added spot grades of 81.80 at the end of the driveway as suggested, however the 81 contour does not appear accurate as shown. HW recommends that the Applicant revisit the grading in this area. h. For construction purposes, HW recommends that the Applicant list the following items on the plan set for each of the subsurface infiltration systems: • System # • Size and number of chambers • Proposed surface elevation (minimum) • Top of stone elevation • Top of chambers elevation • Bottom of chambers elevation • Bottom of stone elevation • ESHGW HW (4/01/21): The Applicant has included the requested information on Sheet C-15. HW has no further comment. 3. Standard 3 requires that the annual recharge from post-development shall approximate annual recharge from pre-development conditions. a. The Applicant has provided a Test Pit Report dated December 5, 2020. Test pits 1 and 2 were conducted within the vicinity of the proposed subsurface infiltration systems. The saturated hydraulic conductivity rate (Ksat) was determined using an Amoozemeter test at Test Pit 1, which is an acceptable method. In accordance with +n�� c c..... µ '� ' �,,� 9 ��i�i d.� ill�...:, .I m�.n� '11, II .i6..^. ..,i M.,� :: mil e ""N Iq r HIV ,.�,.�l.,.�r�.� i�,; „�.,,n �� ,� �� .,�� II �� a �, �� ,,, I �� I u, li,m�� II II Ir, ,II II, �,�,, II� m�� li ��1„� ��µ�, m��I �.�'�,.....,�'��..,� ... III..�W µ�,�� "A ��iu ��.��W��'�,� ... ��I �iul�� W�� mM�'�� :_�V u'�,:..,� .:� ..��.�� .0 �"�.�m�.�� .�u��WI�� .� Town of North Andover April 1, 2021 Page 5 of 8 Volume 3, Chapter 1, page 13 of the MSH, "When the "Dynamic Field"Method is used, the exfiltration rate for design purposes must be assumed to be no more than 50% of the in-situ saturated hydraulic conductivity rate at the actual location on site where infiltration is proposed."HW recommends that the Applicant revisit the exfiltration rate used in the HydroCAD modeling calculations to be 50% of the lowest Ksat rate determined in the field. HW (4/01/21): The Applicant has adjusted the exfiltration rate as requested. HW has no further comment. b. In accordance with the MSH, Volume 3, Chapter 1, page 28, a mounding analysis is required when the vertical separation from the bottom of an exfiltration system to seasonal high groundwater is less than four (4)feet and the recharge system is proposed to attenuate the peak discharge from a 10-year 24-hour storm or greater. HW recommends that the Applicant determine if the infiltration chamber designs require a mounding analysis and provide the same as necessary. HW (4/01/21): The Applicant has adjusted the system and confirmed that 4 feet of separation has been provided. A mounding analysis is not necessary. HW has no further comment. 4. Standard 4 requires that the stormwater system be designed to remove 80% Total Suspended Solids (TSS) and to treat 1.0-inch of volume from the impervious area for water quality. a. The Applicant has provided water quality volume calculations in the Stormwater Management Report. It appears that the Applicant will meet this criteria however it is not clear how the Applicant calculated the Provided Water Quality Volume. The volume utilized must be the total volume in the infiltration chambers below the outlet elevation. For documentation purposes HW recommends that the Applicant revisit the provided water quality volume and clarify how the values listed were determined. HW (4/01/21): The Applicant has provided additional documentation to verify the volume provided below the outlet elevation. The Applicant has provided adequate water quality volume to comply with Standard 4. HW has no further comment. b. The Applicant has included 5% of TSS removal for street sweeping. HW recommends that the Applicant confirm that the street sweeping schedule will be in accordance with the Table provided in Volume 2, Chapter 1, page 9 of the MSH. Furthermore, HW recommends that the Applicant update the Inspection & Maintenance Manual to include the applicable street sweeping schedule. HW (4/01/21): The Applicant has included the street sweeping requirements in the Inspection & Maintenance Manual as requested. HW has not further comment. c. The Applicant has proposed a stormwater management system with deep sump catch basins and two subsurface infiltration systems with isolator rows for pretreatment of the parking lot runoff. HW recommends that the closed drainage system be revised to eliminate the catch basin to catch basin configuration. According to the MSH, Volume 2, Chapter 2, page 3 to provide TSS „ ,,, ,�,„..., W "N �' °�� r�,, » "4 r� x.�,�, � :." ,,, � R III �, � .��i�� :�, +�� i hi r �� d..... h .I -� li ili? �i� i'l" I I m '� �qi Mi, �,., ,..„,,poll,. �, m�� .��_�'� .....�'��..��.� ..�. .III.�_��I �� A ��.ii� ��L��..��_��'�,�.....� �� .ii��_��_�� m M�'�� .�_�� '�,...,�.�. ..� ..��.� ��.�a �".��.��.�� .�� .��... � �.�� ,,. Town of North Andover April 1, 2021 Page 6of8 removal the catch basins must be placed offline. Providing manholes between connections is standard engineering practice in Massachusetts. HW (4/01/21): The Applicant has revised the closed drainage system to include manhole structures. HW has not further comment. 5. Standard 5 is related to projects with a Land Use of Higher Potential Pollutant Loads (LUHPPL). a. The proposed development is not considered a LUHPPL and therefore, Standard 5 is not applicable to this project. HW (4/01/21): No further comment. 6. Standard 6 is related to projects with stormwater discharging into a critical area, a Zone II or an Interim Wellhead Protection Area of a public water supply. a. The proposed development is not within a critical area, Zone II or an IWPA area and therefore, Standard 6 is not applicable. HW (4/01/21): No further comment. 7. Standard 7 is related to projects considered Redevelopment. a. The proposed development is not considered redevelopment and therefore, Standard 7 is not applicable. HW (4/01/21): No further comment. 8. Standard 8 requires a plan to control construction related impacts including erosion, sedimentation, or other pollutant sources. a. The Applicant has provided a Site Preparation Plan. Silt Fence is proposed along the down gradient limit of work. HW recommends that the Applicant add a compost sock, in addition to the siltation fence, where the limit of work is within the 50-foot wetland buffer. HW (4/01/21): The Applicant has added the compost sock as requested. HW has no further comment. b. HW recommends that the Applicant include Catch Basin Protection on all existing catch basins within 100 feet of the construction entrance. HW (4/01/21): The Applicant has added a detail for inlet protection however it is not clear which catch basins the protection should be provided on. HW recommends that a note be placed on the Site Preparation Plan. c. HW recommends that the Applicant review the required contents and controls of the Erosion and Sediment Control Plan listed in Article VIII, 250-29 and 250-30 of the North Andover Stormwater Regulations and verify all items have been addressed. HW (4/01/21): The Applicant has provided additional information on the plans in accordance with the Town of North Andover regulations. No further comment. „ ,,, ,�,„..., W "N �' °�� r�,, » "4 r� x.�,�, � :." ,,, � R III �, � .��i�� :�, +�� i hi r �� d..... h .I -� li ili? �i� i'l" I I m '� �qi Mi, �,., ,..„,,poll,. �, m�� .��_�'� .....�'��..��.� ..�. .III.�_��I �� A ��.ii� ��L��..��_��'�,�.....� �� .ii��_��_�� m M�'�� .�_�� '�,...,�.�. ..� ..��.� ��.�a �".��.��.�� .�� .��... � �.�� ,,. Town of North Andover April 1, 2021 Page 7of8 d. The property will be disturbing more than 1 acre of land and will therefore be required to develop a Stormwater Pollution Prevention Plan (SWPPP) in accordance with the Environmental Protection Agency (EPA) National Pollutant Discharge Elimination System (NPDES) Stormwater Program. HW recommends that the Applicant provide the Town of North Andover with a copy of its SWPPP prior to construction. HW (4/01/21): The Applicant agrees that the NPDES Construction General Permit will be required and is willing to provide a copy of the SWPPP to the Town prior to land disturbance. 9. Standard 9 requires a long-term operation and maintenance (O&M)plan shall be developed and implemented to ensure that stormwater management systems function as designed. a. The Applicant has provided an Inspection and Maintenance Manual. HW recommends that the Applicant review the requirements listed in Article IX, 250-32 of the North Andover Stormwater Regulations and verify all items have been addressed including but not limited to the following: • In accordance with the MSH Vol. 2, Ch. 2, the deep sump catch basins frequency of inspection and cleaning should be increased to four times per year and at the end of the foliage and snow-removal seasons. HW (4/01/21): The Applicant has updated the O&M Plan to reflect the inspection frequency as requested. HW has no further comment. • In accordance with the MSH Vol. 1, Ch. 1, p. 9, an estimated operations and maintenance budget should be added to the O&M Plan. HW (4/01/21): The Applicant has included an estimated operations and maintenance budget to the O&M Plan. HW has no further comment. • A simple plan that illustrates the location of each of the stormwater practices that require inspections should be included. The figure should also include the components of the septic system. HW (4/01/21): The Applicant has added a Stormwater Operation & Maintenance Map, which illustrates the locations of stormwater practices and corresponding inspection requirements, to the O&M Plan. HW has no further comment. • Locations for snow storage. HW (4/01/21): The Applicant has included locations for snow storage in the Stormwater Operation & Maintenance Map. HW has no further comment. • Signatures of property Owners. HW (4/01/21): The Applicant has included an owner signature block in the O&M Plan. HW has no further comment. „ ,,, ,�,„..., W "N �' °�� r�,, » "4 r� x.�,�, � :." ,,, � R III �, � .��i�� :�, +�� i hi r �� d..... h .I -� li ili? �i� i'l" I I m '� �qi Mi, �,., ,..„,,poll,. �, m�� .��_�'� .....�'��..��.� ..�. .III.�_��I �� A ��.ii� ��L��..��_��'�,�.....� �� .ii��_��_�� m M�'�� .�_�� '�,...,�.�. ..� ..��.� ��.�a �".��.��.�� .�� .��... � �.�� ,,. Town of North Andover April 1, 2021 Page 8of8 10. Standard 10 requires that an Illicit Discharge Compliance Statement be provided. a. The Applicant has not provided an Illicit Discharge Compliance Statement in the Drainage Report signed by the property owner. HW recommends that the Planning Board or Conservation Commission include a condition of approval requiring an Illicit Discharge Compliance Statement be signed by a representative of The Stubblebine Company prior to land disturbance. HW (4/01/21): The Applicant has requested that a condition of approval requiring a signed Illicit Discharge Compliance Statement be submitted prior to land disturbance be applied to the project. HW has no issue with requiring this condition. 11. Additional Comments: a. The retaining wall along the eastern driveway is over 4 feet high, the design of this wall requires a structural engineer. HW recommends that the Applicant verify it has adequately considered the extent of land disturbance needed to construct the wall. HW (4/01/21): The Applicant has stated that the wall is approximately 8 feet high, though at one location it appears to be 14 feet high. After further review the top of wall (TOW) elevation of 94 may not be accurate. HW recommends that the Applicant revisit the proposed wall elevations. If the installation of the wall requires additional tree clearing HW recommends that the proposed tree line be adjusted. b. HW recommends that the Applicant verify that the 18-inch drainpipe between CB1 and CB2 has adequate separation from the wastewater pipe it goes under. HW (4/01/21): The Applicant has adjusted the inverts of the drainage pipe and provided profiles verifying the separation is adequate. No further comment. c. Stormtech System #1 includes DMH4 and Inlet 4 that do not appear necessary. HW recommends that the Applicant revisit this structure and verify it is required. HW (4/01/21): The Applicant has verified that DMH4 and Inlet 4 are necessary to the structure. HW has no further comment. Conclusions HW recommends that the Planning Board require that the Applicant provide a written response to address the remaining comments as part of the Board's review process. Please contact Janet Bernardo at 508-833-6600 or at jbernardo@horsleywitten.com if you have any questions regarding these comments. Sincerely, HORSLEY WITTEN GROUP, INC. r p,y y�;;;,,��r,.r, roIVIC�II "°'v�"�.�'P°„°' !�,°duu,4d'""h; Janet Carter Bernardo, P.E. Associate Principal „ ��,„.' W �' �' i �� r::�,, � � "�x.� , „, � i� � � P III�� i� I ,, ,,,,., i, „., +�� hl 11111 d..... h r. - �1'111 v "M1i m' I m 1i ryl, M1, 1 1 �'��