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HomeMy WebLinkAboutStormwater Report - 1780 OSGOOD STREET 7/19/2011 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report A. Introduction Important: A Stormwater Report must be submitted with the Notice of Intent permit application to document farms onfilling out compliance with the Stormwater Management Standards. The following checklist is NOT a substitute for computer,use the Stormwater Report(which should provide more substantive and detailed information) but is offered only the tab key here as a tool to help the applicant organize their Stormwater Management documentation for their to move your Report and for the reviewer to assess this information in a consistent format. As noted in the Checklist, cursor-do not the Stormwater Report must contain the engineering computations and supporting information set forth in use the return p 9 9 p pp g key. Volume 3 of the Massachusetts Stormwater Handbook. The Stormwater Report must be prepared and certified by a Registered Professional Engineer(RPE) licensed in the Commonwealth. The Stormwater Report must include: • The Stormwater Checklist completed and stamped by a Registered Professional Engineer(see page 2) that certifies that the Stormwater Report contains all required submittals.' This Checklist is to be used as the cover for the completed Stormwater Report. • AppIicant/Project Name • Project Address • Name of Firm and Registered Professional Engineer that prepared the Report • Long-Term Pollution Prevention Plan required by Standards 4-6 • Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan required by Standard 82 • Operation and Maintenance Plan required by Standard 9 In addition to all plans and supporting information, the Stormwater Report must include a brief narrative describing stormwater management practices, including environmentally sensitive site design and LID techniques, along with a diagram depicting runoff through the proposed BMP treatment train. Plans are required to show existing and proposed conditions, identify all wetland resource areas, NRCS soil types, critical areas, Land Uses with Higher Potential Pollutant Loads (LUHPPL), and any areas on the site where infiltration rate is greater than 2.4 inches per hour. The Plans shall identify the drainage areas for both existing and proposed conditions at a scale that enables verification of supporting calculations. As noted in the Checklist, the Stormwater Management Report shall document compliance with each of the Stormwater Management Standards as provided in the Massachusetts Stormwater Handbook. The soils evaluation and calculations shall be done using the methodologies set forth in Volume 3 of the Massachusetts Stormwater Handbook. To ensure that the Stormwater Report is complete, applicants are required to fill in the Stormwater Report Checklist by checking the box to indicate that the specified information has been included in the Stormwater Report. If any of the information specified in the checklist has not been submitted, the applicant must provide an explanation. The completed Stormwater Report Checklist and Certification must be submitted with the Stormwater Report. 'The Stormwater Report may also include the Illicit Discharge Compliance Statement required by Standard 10. If not included in the Stormwater Report,the Illicit Discharge Compliance Statement must be submitted prior to the discharge of stormwater runoff to the post-construction best management practices. 2 For some complex projects,it may not be possible to include the Construction Period Erosion and Sedimentation Control Plan in the Stormwater Report. In that event,the issuing authority has the discretion to issue an Order of Conditions that approves the project and includes a condition requiring the proponent to submit the Construction Period Erosion and Sedimentation Control Plan before commencing any land disturbance activity on the site. swcheck.doc•04/01/08 Stormwater Report Checklist-Page 1 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater B. Stormwater Checklist and Certification The following checklist is intended to serve as a guide for applicants as to the elements that ordinarily need to be addressed in a complete Stormwater Report. The checklist is also intended to provide conservation commissions and other reviewing authorities with a summary of the components necessary for a comprehensive Stormwater Report that addresses the ten Stormwater Standards. Note: Because stormwater requirements vary from project to project, it is possible that a complete Stormwater Report may not include information on some of the subjects specified in the Checklist. If it is determined that a specific item does not apply to the project under review, please note that the item is not applicable (N.A.) and provide the reasons for that determination. A complete checklist must include the Certification set forth below signed by the Registered Professional Engineer who prepared the Stormwater Report. Registered Pro€esston l-E ngineers Certi#!catfon I have reviewed the Stormwater Report, including the soil evaluation, computations, Long-term Pollution Prevention Plan, the Construction Period Erosion and Sedimentation Control Plan (if included), the Long- term Post-Construction Operation and Maintenance Plan, the Illicit Discharge Compliance Statement(if included)and the plans showing the stormwater management system, and have determined that they have been prepared in accordance with the requirements of the Stormwater Management Standards as further elaborated by the Massachusetts Stormwater Handbook. I have also determined that the information presented in the Stormwater Checklist is accurate and that the information presented in the Stormwater Report accurately reflects conditions at the site as of the date of this permit application. Registered Professional Engineer Block and Signature tN OF M4SS�c O� �G OLUKt J.ROY U CIVIL N No.47356 A90 9�GIS1 EP� ONO-CG , Signature a d Date 1 Checklist Project Type: Is the application for new development, redevelopment, or a mix of new and redevelopment? ❑ New development ❑ Redevelopment Mix of New Development and Redevelopment swcheck.doc•04/01/08 Stormwater Report Checklist-Page 2 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for r r Report Checklist (continued) LID Measures: Stormwater Standards require LID measures to be considered. Document what environmentally sensitive design and LID Techniques were considered during the planning and design of the project: M No disturbance to any Wetland Resource Areas ❑ Site Design Practices (e.g. clustered development, reduced frontage setbacks) ❑ Reduced Impervious Area (Redevelopment Only) ❑ Minimizing disturbance to existing trees and shrubs El LID Site-Design Gredit Requested: ❑ Credit 1 ❑ Credit 2 ❑ Credit 3 ® Use of"country drainage"versus curb and gutter conveyance and pipe ❑ Bioretention Cells(includes Rain Gardens) ❑ Constructed Stormwater Wetlands(includes Gravel Wetlands designs) ❑ Treebox Filter ❑ Water Quality Swale ❑ Grass Channel ❑ Green Roof ❑ Other(describe): Standard 1: No New Untreated Discharges No new untreated discharges ❑ Outlets have been designed so there is no erosion or scour to wetlands and waters of the Commonwealth Supporting calculations specified in Volume 3 of the Massachusetts Stormwater Handbook included. swcheck.doc•04/01/08 Stormwater Report Checklist-Page-3 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Checklist (continued) Standard 2: Peak Rate Attenuation ❑ Standard 2 waiver requested because the project is located in land subject to coastal storm flowage and stormwater discharge is to a wetland subject to coastal flooding. ❑ Evaluation provided to determine whether off-site flooding increases during the 100-year 24-hour storm. Calculations provided to show that post-development peak discharge rates do not exceed pre- development rates for the 2-year and 10-year 24-hour storms. If evaluation shows that off-site flooding increases during the 100-year 24-hour storm, calculations are also provided to show that Post-development peak discharge rates do not exceed pre-development rates for the 100-year 24- hour storm. - 1JUa11dard 3: Recharge ` Soil Analysis provided. [ Required Recharge Volume calculation provided. ❑ Required Recharge volume reduced through use of the LID site Design Credits. Sizing the infiltration, BMPs is based on the following method: Check the method used. Static ❑Simple Dynamic ❑ Dynamic Field, ❑ Runoff from all impervious areas at the site discharging to the infiltration BMP. Runoff from all impervious areas at the site is not discharging to the infiltration BMP and calculations are provided showing that the drainage area contributing runoff to the infiltration BMPs is sufficient to generate the required recharge volume. Recharge BMPs have been sized to infiltrate the Required Recharge Volume. ❑ Recharge BMPs have been sized to infiltrate the Required Recharge Volume only to the maximum extent practicable for the following reason: ❑ Site is comprised solely of C and D soils and/or bedrock at the land surface ❑ M.G.L. c. 21E sites pursuant to 310 CMR 40.0000 ❑ Solid Waste Landfill pursuant to 310 CMR 19.000 ❑ Project is otherwise subject to Stormwater Management Standards only to the maximum extent practicable. Calculations showing that the infiltration BMPs will drain in 72 hours are provided. ❑ Property includes a M.G.L. c. 21E site or a solid waste landfill and a mounding analysis is included. ' 80%TSS removal is required prior to discharge to infiltration BMP if Dynamic Field method is used. swcheck.doc•04/01/08 Stormwater Report Checklist•Page 4 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist Stormwater Checklist (continued) Standard 3: Recharge (continued) ❑ The infiltration BMP is used to attenuate peak flows during storms greater than or equal to the 10- year 24-hour storm and separation to seasonal high groundwater is less than 4 feet and a mounding analysis is provided. Documentation is provided showing that infiltration BMPs do not adversely impact nearby wetland resource areas. Standard 4: Water Quality The Long-Term Pollution Prevention Plan typically includes the following: • Good housekeeping practices; Provisions for stoi inn materials and waste products inside or under cover; • Vehicle washing controls; • Requirements for routine inspections and maintenance of stormwater BMPs; • Spill prevention and response plans; • Provisions for maintenance of lawns, gardens, and other landscaped areas; • Requirements for storage and use of fertilizers, herbicides, and pesticides; • Pet waste management provisions; • Provisions for operation and management of septic systems; • Provisions for solid waste management; • Snow disposal and plowing plans relative to Wetland Resource Areas; • Winter Road Salt and/or Sand Use and Storage restrictions; • Street sweeping schedules; • Provisions for prevention of illicit discharges to the stormwater management system; • Documentation that Stormwater BMPs are designed to provide for shutdown and containment in the event of a spill or discharges to or near critical areas or from LUHPPL; • Training for staff or personnel involved with implementing Long-Term Pollution Prevention Plan; • List of Emergency contacts for implementing Long-Term Pollution Prevention Plan. EJ A Long-Term Pollution Prevention Plan is attached to Stormwater Report and is included as an attachment to the Wetlands Notice of Intent. ❑ Treatment BMPs subject to the 44% TSS removal pretreatment requirement and the one inch rule for calculating the water quality volume are included, and discharge: ❑ is within the Zone II or Interim Wellhead Protection Area ❑ is near or to other critical areas Q is within soils with a rapid infiltration rate (greater than 2.4 inches per hour) ❑ involves runoff from land uses with higher potential pollutant loads. ❑ The Required Water Quality Volume is reduced through use of the LID site Design Credits. ❑ Calculations documenting that the treatment train meets the 80%TSS removal requirement and, if applicable, the 44% TSS removal pretreatment requirement, are provided. swcheck.doc•04/01/08 Stormwater Report Checklist• Page 5 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist Checklist (continued) Standard 4:Water Quality(continued) ❑ The BMP is sized (and calculations provided) based on: ❑ The Y2"or 1°Water Quality Volume or ❑ The equivalent flow rate associated with the Water Quality Volume and documentation is provided showing that the BMP treats the required water quality volume. ❑ The applicant proposes to use proprietary BMPs, and documentation supporting use of proprietary BMP and proposed TSS removal rate is provided. This documentation may be in the form of the propriety BMP checklist found in Volume 2, Chapter 4 of the Massachusetts Stormwater Handbook and submitting copies of the TARP Report, STEP Report, and/or other third party studies verifying performance of the proprietary BMPs. ❑ A TMDL exists that indicates a need to reduce pollutants other than TSS and documentation showing that the BMPs selected are consistent with the TMDL is provided. Standard 5: Land Uses With Higher Potential Pollutant Loads (LUHPPLs) ❑ The NPDES Multi-Sector General Permit covers the land use and the Stormwater Pollution Prevention Plan (SWPPP) has been included with the Stormwater Report. ❑ The NPDES Multi-Sector General Permit covers the land use and the SWPPP will be submitted prior to the discharge of stormwater to the post-construction stormwater BMPs. ❑ The NPDES Multi-Sector General Permit does not cover the land use. ❑ LUHPPLs are located at the site and industry specific source control and pollution prevention measures have been proposed to reduce or eliminate the exposure of LUHPPLs to rain, snow, snow melt and runoff, and been included in the long term Pollution Prevention Plan. ❑ All exposure has been eliminated. ❑ All exposure has not been eliminated and all BMPs selected are on MassDEP LUHPPL list. ❑ The LUHPPL has the potential to generate runoff with moderate to higher concentrations of oil and grease(e.g. all parking lots with >1000 vehicle trips per day)and the treatment train includes an oil grit separator, a filtering bioretention area, a sand filter or equivalent. Standard 6: Critical Areas ❑ The discharge is near or to a critical area and the treatment train includes only BMPs that MassDEP has approved for stormwater discharges to or near that particular class of critical area. Critical areas and BMPs are identified in the Stormwater Report. swcheck.doc o 04/01/08 Stormwater Report Checklist•Page 6 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Li Checklist Checklist (continued) Standard 7: Redevelopments and Other Projects Subject to the Standards only to the maximum extent practicable ❑ The project is subject to the Stormwater Management Standards only to the maximum Extent Practicable as a: ❑ Limited Project ❑ Small Residential Projects: 5-9 single family houses or 5-9 units in a multi-family development provided there is no discharge that may potentially affect a critical area. ❑ Small Residential Projects: 2-4 single family houses or 2-4 units in a multi-family development with a discharge to a critical area ❑ Marina and/or boatyard provided the hull painting, service and maintenance areas are protected from exposure to rain, snow, snow melt and runoff Bike-Path-andtor Foot Path ❑ Redevelopment Project im Redevelopment portion of mix of new and redevelopment. ❑ Certain standards are not fully met(Standard No. 1, 8, 9, and 10 must always be fully met)and an explanation of why these standards are not met is contained in the Stormwater Report. The project involves redevelopment and a description of all measures that have been taken to Improve existing conditions is provided in the Stormwater Report. The redevelopment checklist found in Volume 2 Chapter 3 of the Massachusetts Stormwater Handbook may be used to document that the proposed stormwater management system (a)complies with Standards 2, 3 and the pretreatment and structural BMP requirements of Standards 4-6 to the maximum extent practicable and (b) improves existing conditions. Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan must include the following information: • Narrative; • Construction Period Operation and Maintenance Plan; ® Names of Persons or Entity Responsible for Plan Compliance; ® Construction Period Pollution Prevention Measures; • Erosion and Sedimentation Control Plan Drawings; • Detail drawings and specifications for erosion control BMPs, including sizing calculations; o Vegetation Planning; • Site Development Plan; 0 Construction Sequencing Plan; • Sequencing of Erosion and Sedimentation Controls; Y Operation and Maintenance of Erosion and Sedimentation Controls; • Inspection Schedule; ® Maintenance Schedule; • Inspection and Maintenance Log Form. °r A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan containing the information set forth above has been included in the Stormwater Report. swcheck.doc•04/01/08 Stormwater Report Checklist•Page 7 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program iL.A­, Checklist (continued) Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control (continued) ❑ The project is highly complex and information is included in the Stormwater Report that explains why it is not possible to submit the Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan with the application. A Construction Period Pollution Prevention and Erosion and Sedimentation Control has not been included in the Stormwater Report but will be submitted before land disturbance begins. ❑ The project is not covered by a NPDES Construction General Permit. ❑ The project is covered by a NPDES Construction General Permit and a copy of the SWPPP is in the Stormwater Report. --The-project is covered by a-NPDES Construction General Permit but no SWPPP been submitted. The SWPPP will be submitted BEFORE land disturbance begins. Standard 9: Operation and Maintenance Plan [ ` The Post Construction Operation and Maintenance Plan is included in the Stormwater Report and includes the following information: ❑ Name of the stormwater management system owners; ❑ Party responsible for operation and maintenance; ❑ Schedule for implementation of routine and non-routine maintenance tasks; ❑ Plan showing the location of all stormwater BMPs maintenance access areas; ❑ Description and delineation of public safety features; ❑ Estimated operation and maintenance budget; and ❑ Operation and Maintenance Log Form. ❑ The responsible party is not the owner of the parcel where the BMP is located and the Stormwater Report includes the following submissions: ❑ A copy of the legal instrument(deed, homeowner's association, utility trust or other legal entity) that establishes the terms of and legal responsibility for the operation and maintenance of the project site stormwater BMPs; ❑ A plan and easement deed that allows site access for the legal entity to operate and maintain BMP functions. Standard 10: Prohibition of Illicit Discharges ❑ The Long-Term Pollution Prevention Plan includes measures to prevent illicit discharges; ❑ An Illicit Discharge Compliance Statement is attached; ❑ NO Illicit Discharge Compliance Statement is attached but will be submitted prior to the discharge of any stormwater to post-construction BMPs. swcheck.doc•04/01/08 Stormwater Report Checklist•Page 8 of 8 Stormwater Management Report Project Location:1780 Osgood Street,North Andover,Massachusetts The project proposes to add a porch over the existing building entrance. The existing lower 4 feet of the siding on the North side only is being replaced with a masonry base supported on the existing foundation.. The renovation including the porch is proposed to enhance the appearance of the building.A 60'x50' garage addition is proposed to be added to the existing building and is outside the 100 Foot Buffer Zone of Bordering Vegetated Wetlands. The area of the proposed porch is proposed to be approximately 186 square feet. Standard#1 The project does not propose any new untreated discharge to the wetlands.The existing grading of the site generally grades away from the wetlands towards the rear of the property. The runoff from the porch is directed to an underground infiltration system. Standard#2 No changes are proposed to increase impervious areas other than the additional of the porch. The porch BMP has been designed for the 100year storm event. Recharge has been provided in accordance with the Massachusetts Stormwater Handbook. Standard#3 Soil testing was performed at the site to determine soil classifications, soil types, permeability and estimated seasonal high water table. Soils were found to be consistent with S.C.S. type Windsor, loamy sand with a Hydraulic Group A classification. The soil logs are shown on the site plan. In general there is approximately 5 feet of fill (including original topsoil and subsoil). Water table was established by observation of redoximorphic features in the soil profile. Observed water table was at a deeper layer. Recharge volumes were calculated from both recharge areas for the porch addition and for the addition which is outside the Buffer Zone. Both systems were sized using the "Static"method which assumes no exfiltration. Recharge areas were also sized to handle the 2 year and 10 year, 24 hour storm event for the addition outside the buffer. Calculations have been provided to show the infiltration systems will drain within 72 hours. Standard#4 Water Quality Practically all of the area including impervious pavement drains westerly on the site away from the wetlands. No new impervious areas are being created. Existing roof drainage presently drains into an existing infiltration trench along the existing building foundation. The proposed new porch is proposed to drain into an infiltration system. A long term pollution prevention plan has been attached to this report. Standard#5 Land uses with Higher Potential Pollutant Loads See land uses on the property are in areas draining away from the wetlands. Standard#6 Critical Areas There are no proposed discharges into critical areas. The site drains away from the wetlands. Roof runoff is handled by infiltration systems. Standard#7 Redevelopment and other Projects Subject to the Standards only to the maximum extent practical. The project consists of an existing structure mostly within the Buffer Zone. The new addition is outside the Buffer Zone. Roof runoff is proposed to be infiltrated into the ground through an infiltration system BMP. The proposed porch is within the 100 foot Buffer Zone and the runoff will be directed to a BMP infiltration trench. Standard#8 Construction Period Prevention and Erosion and Sedimentation Control ft-is anticipated that the construction period va be apprux i��ateiy ti months:siltation fence will be installed to prevent construction material from entering the wetlands. The only excavation on the site will be within the 100 foot Buffer Zone is for the infiltration system BMP(roughly dimensions 10'x8').After installation the disturbed areas will be loamed and seeded. The area is flat so there will be minimum erosion measures needed to protect the area until the grass has been established. Standard#9 Operation and Maintenance Plan Plan has been attached and the narrative. Standard#10 No long term pollution discharges are anticipated for the project. Stormwater Management Operation&Maintenance Plan Project Location:1780 Osgood Street,North Andover,Massachusetts 1. During construction, all BMP's shall be inspected on a monthly basis and after every storm event. Repairs shall be made as necessary. 2. Following construction, all BMP's shall be inspected on a monthly basis for a period of six (6)months and on a semi-annual basis thereafter. 3. The roof runoff infiltration system shall be inspected at least 2 times per year to ensure proper operation. 4. Litter shall be collected from all grassed and parking areas on a monthly basis. 5. Snow removal operations shall not result in the storage of snow within 100 feet of the Wetland areas. Owner: Louisa& Tim Tanner I Tropeano, Inc. 1780 Osgood Street North Reading,MA 01845 Maintenance Responsibility: Same Exist. Conditions Post Dev lopment 2P A Sheet Runoff ___� (Infiltration System) (Porch Area-Exist Cond. (Porch Area Roof-Prop. Cond.) Subcat Reach on Llnk Drainage Diagram for 1780 Osgood Street,North Andover Prepared by O'Neill Associates, Printed 07/14/2011 HydroCADO 8.50 s/n 000472 0 2007 HydroCAD Software Solutions LLC 1780 Osgood Street, North Andover Prepared by O'Neill Associates Printed 07/14/2011 HydroCAD®8.50 s/n 000472 @2007 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.002 61 Grass/Soil Group B (5S) 0.069 82 Dirt/compacted gravel and bit. (1S) 0.002 98 Exist.Bit.Conc. (5S) 0.004 98 New Entrance Porch (6S) 0.069 98 Prop. 60 x 50 Garage (3S) 0.146 TOTAL AREA 1780 Osgood Street, North Andover Prepared by O'Neill Associates H droCAD®8.50 s/n 000472 ©2007 H droCAD Software Solutions LLC Printed 07/14/2011 Pa e 3 Soil Listing (all nodes) Area Soil Subcatchment (acres) Goup Numbers 0.000 HSG A 0.000 HSG B 0.000 HSG C 0.000 HSG D 0.146 Other 1 S, 3S, 5S, 6S 0.146 TOTAL AREA 1780 Osgood Street, North Andover Type Ill 24-hr Rainfall=7.00" Prepared by O'Neill Associates Printed 07/14/2011 HydroCAD®8.50 s/n 000472 @2007 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 5S: (Porch Area-Exist Cond. [49] Hint: Tc<2dt may require smaller dt Runoff = 0.02 cfs @ 12.07 hrs, Volume= 0.001 af, Depth> 4.41" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr Rainfall=7.00" Area (ac) CN Description 0.002 98 Exist.Bit.Conc. 0.002 61 Grass/Soil Group B 0.004 80 Weighted Average 0.002 Pervious Area 0.002 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 5S: (Porch Area-Exist Cond. Hydrograph 0.024 p Runoff 0.023 0.02 as 0.022 0.021 .. Type 11124-hr_ 0.02 0.019 Rain- fall-=-7.00" 0.018 _._. 0.017 Runoff_Area=0.004: ac 0.016 0.015_ __ __Runoff Volume=0.001 af- y 0.014 0.013 Runoff Depth>4.41" c 0.012. LL 0.011 Tc=5.0 min 0.0, 0.009 CN=80 0.008 0.007- 0.006 0.005 0.004 0.003 0.002 0.001- 0. 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) 1780 Osgood Street, North Andover Type Ill 24-hr Rainfall=7.00" Prepared by O'Neill Associates Printed 07/14/2011 HydroCAD®8.50 s/n 000472 @2007 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 6S: (Porch Area Roof-Prop. Cond.) [46] Hint: Tc=O (Instant runoff peak depends on dt) Runoff = 0.03 efs @ 12.00 hrs, Volume= 0.002 af, Depth> 6.24" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr Rainfall=7.00" Area (ac) CN Description 0.004 98 New Entrance Porch 0.004 Impervious Area Su c"chmentBS€-IPo h-Area-Roof-Prop.-Cond. Hydrograph 0.034 Runoff 0.032 o.os a5 0.03 y pe -24=h r 0.028 Rainfall=7.00" 0.026 0.024 Runoff Area=0.004 ac 0.022 Runoff Volume=0.002 of w 0.02- 3 0.018= Runoff Depth>6 24 0.016- Tc=0.0 m i n 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) JOB Civil Engineers and Land Surveyors 234 PARK STREET SHEET NO.- OF NORTH READING, MA 01864 CALCULATED BY ij DATE. (978) 664-8141 Fax(978) 664-8142 CHECKED BY DATE SCALE .......... ---------- ...... L .....------- .......... �7 ..........- --------------- ............. -- --------- ......... % J, 17 t J k- ............. ....... JOB Civil Engineers and Land Surveyors 234 PARK STREET SHEET NO.- 0 NORTH READING, MA 01864 o«LC»Lms»BY i� ---------' (978) 664-8141 Fax(978) e84�142 "°' CHECKED BY ov, uoxL � � � | � t }�-3 u t� e AGZ Z �� Z�.•H�. �t��F::3 \=tom i_.,L 1S Exist. C nditions Post Dev p to ment 2P A 4P Sheet Runoff (Infiltration System) ;,Subcatj Reach on Llnk Drainage Diagram for 1780 Osgood Street,North Andover Prepared by O'Neill Associates, Printed 07/05/2011 HydroCAD®8.50 s/n 000472 ©2007 HydroCAD Software Solutions LLC 1780 Osgood Street, North Andover Prepared by O'Neill Associates H droCAD®8.50 --In 000472 ©2007 H droCAD Software Solutions LLC Printed 07/05/2011 Pa e2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.069 82 Dirt/compacted gravel and bit. (1S) 0.069 98 Prop. 60 x 50 Garage (3S) 0.138 TOTAL AREA 1780 Osgood Street, North Andover Prepared by O'Neill Associates H droCAD®8.50 s/n 000472 ©2007 H droCAD Software Solutions LLC Printed 07/05/2011 Pa e 3 Soil Listing (all nodes) Area Soil Subcatchment (acres) Gout) Numbers 0.000 HSG A 0.000 HSG 8 0.000 HSG C 0.000 HSG D 0.138 Other 1 S, 3S 0.138 TOTAL AREA 1780 Osgood Street, North Andover Type 111 24-hr Rainfall=3.20" Prepared by O'Neill Associates Printed 07/05/2011 H droCAD®8.50 s/n 000472 @2007 H droCAD Software Solutions LLC Pa e4 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Exist. Conditions Runoff Area=0.069 ac 0.00% Impervious Runoff Depth>1.43" Tc=5.0 min CN=82 Runoff=0.12 cfs 0.008 of Subcatchment 3S: Post Development Runoff Area=0.069 ac 100.00% Impervious Runoff Depth>2.77" Tc=5.0 min CN=98 Runoff--0.22 cfs 0.016 of Pond 2P: Sheet Runoff Inflow=0.12 cfs 0.008 of Primary=0.12 cfs 0.008 of Pond 4P: (Infiltration System) Inflow=0.22 cfs 0.016 of Primary-0.22 dc_Q,01ra of Total Runoff Area= 0.138 ac Runoff Volume= 0.024 of Average Runoff Depth =2.10" 50.00%Pervious = 0.069 ac 50.00% Impervious = 0.069 ac 1780 Osgood Street, North Andover Prepared by O'Neill Associates Type ���24-hr Rainfall=3.20" Hydro ICADO 8.so s/n 000472 ©2007 H droCAD Software Solutions LLC Printed 07/05/2011 Pa e 5 Summary for Subcatchment 1S: Exist. Conditions [49] Hint: Tc<2dt may require smaller dt Runoff = 0.12 cfs @ 12.08 hrs, Volume= „ 0.008 af, Depth> 1.43 Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr Rainfall=3.20” Area ac CN Description 0.069 82 Dirt/com acted gravel and bit . 0.069 Pervious Area Tc Length Slope Velocity Capacity Description min (feet) ( �ftlsec)- Ecfs3 - -- 50 Direct Entry, Subcatchment 1S: Exist. Conditions Hydrograph 0.13 0 Runoff 0.12 cfs 0.12- 0.11.: Type III 24-hr 0.1 Rainfall=3.20" 0.09- Runoff Area=0.069 ac 9 0.08 Runoff Volume=0.008 of °' 0 Runoff Depth>1.43" LL 0.06-. Tc=5.0 min 0.05-- 0-04 CN=82 0.03 0.02 0.01 0 5 6 8 9 10 �1. . . ,1,2. 1,3. . . .14. . .15, . , . , . 16 17 18 Time (hours) 19 20 1780 Osgood Street, North Andover Type Ill 24-hr Rainfall=3.20" Prepared by O'Neill Associates Printed 07/05/2011 HydroCAD®8 50 s/n 000472 @2007 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 3S: Post Development [49] Hint: Tc<2dt may require smaller dt Runoff = 0.22 cfs @ 12.07 hrs, Volume= 0.016 af, Depth> 2.77" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr Rainfall=3.20" Area (ac) CN Description * 0.069 98 Prop 60 x 50 Garage 0.069 Impervious Area i Tc Length 'Slope Velocity Capacity Description (min) (feet) (fittft) - (fusee) (c s)- --- - 5.0 Direct Entry, Subcatchment 3S: Post Development Hydrograph 0.247 Runoff 0.23- 0.22 cTs 0.22- _ 0.21. Type III 24-hr 0. 0.19- Rainfall=3.20" 0.18; 0.17 Runoff Area=0.069 ac 0.16 0.15. Runoff Volume=0.016 of a 0.14 0.13 Runoff Depth>2.7711 0.12 LL 0.11.. Tc=5.0 min 0.1 CN=98 0.09 0.08 0.07 0.06 0.05-: 0.04- 0.03= 0.02 0.01 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) 1780 Osgood Street, North Andover Type Ill 24-hr Rainfall=3.20" Prepared by O'Neill Associates Printed 07/05/2011 HydroCAD®8.50 s/n 000472 @2007 HydroCAD Software Solutions LLC Page 7 Summary for Pond 2P: Sheet Runoff [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.069 ac, 0.00% Impervious, Inflow Depth > 1.43" Inflow = 0.12 cfs @ 12.08 hrs, Volume= 0.008 of Primary = 0.12 cfs @ 12.08 hrs, Volume= 0.008 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Pond 2P: Sheet Runoff Hydrograph FIR—in—flow--1 0.13 _ ai< Ii��iv� �CQ—V.069 ate. 0.12, 0.11- 0.1 0.09- N 0.08 v 3 0.07- 0 u 0.06 0.05- 0.04- 0.03- 0.02- 0.01 0 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) 1780 Osgood Street, North Andover Type 11124-hr Rainfall=3.20" Prepared by O'Neill Associates Printed 07/05/2011 HydroCAD®8.50 s/n 000472 @2007 HydroCAD Software Solutions LLC Page 8 Summary for Pond 4P: (Infiltration System) [40] Hint: Not Described (Outflow=I nfl ow) Inflow Area = 0.069 ac,100.00% Impervious, Inflow Depth > 2.77" Inflow = 0.22 cfs @ 12.07 hrs, Volume= 0.016 of Primary = 0.22 cfs @ 12.07 hrs, Volume= 0.016 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Pond 41P: (Infiltration System) Hydrograph Fig Inflow 0.24-, p Primery - -- -- - - 0.23 ' / 022- a�z�rs_ Inflow Area--0.0'09 asc 0.21 0.2 0.19 0.18-: 0.17-- 0.16 0.15_ 0.14-_ 0.13- 3 0.12- ° LL 0.11 ` 0.1 0.09 0.08 0.07- 0.06 0.05 0.04-` 0.03- 0.02 0.01. 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) 1 ` 35- . - -- � Exist. C ndit ions f Post Dev lopment 2P 4P Sheet Runoff (Infiltration System) �Subcat Reach oh Link Drainage Diagram for 1780 Osgood Street,North Andover Hydro CAD epa 81.50 s n eilAssociate ©52007 HydroCAlDtSo�yar050 Solutions LLC 1780 Osgood Street, North Andover Prepared by O'Neill Associates H droCAD®8.50 s/n 000472 ©2007 H droCAD Software Solutions LL Printed 07/05/2011 Pacie 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.069 82 Dirt/compacted gravel and bit. (1S) 0.069 98 Prop. 60 x 50 Garage (3S) 0.138 TOTAL AREA 1780 Osgood Street, North Andover Prepared by O'Neill Associates Printed 07/05/2011 HydroCADO 8.50 s/n 000472 ©2007 HydroCAD Software Solutions LLC Page 3 Soil Listing (all nodes) Area Soil Subcatchment (acres) Goup Numbers 0.000 HSG A 0.000 HSG B 0.000 HSG C 0.000 HSG D 0.138 Other 1 S, 3S 0.138 TOTAL AREA 1780 Osgood Street, North Andover Prepared by O'Neill Associates Type Ill 24-hr 70 Year/24 hour Rainfall=4.80" H droCAM 8.50 s/n 000472 ©2007 H droCAD Software Solutions LLC Printed 07/05/2011 Pa e 4 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Reach routing by Stor I d+T ans method - Pond routing ut ng by Stor-Ind method Subcatchment IS: Exist. Conditions Runoff Area=0.069 ac 0.00% Impervious Runoff Depth>2.72" Tc=5.0 min CN=82 Runoff=0.23 cfs 0.016 of Subcatchment 3S: Post Development Runoff Area=0.069 ac 100.00% Impervious Runoff Depth>4.24" Tc=5.0 min CN=98 Runoff=0.33 cfs 0.024 of Pond 2P: Sheet Runoff Inflow=0.23 cfs 0.016 of Primary=0.23 cfs 0.016 of Pond 4P: (Infiltration System) Inflow= ,3a Gf—0.424 a€ Primary=0.33 cfs 0,024 of Total Runoff Area = 0.138 ac Runoff Volume=0.040 of Average Runoff Depth = 3.48" 50.00%Pervious =0.069 ac 60.00%a Impervious=0.069 ac 1780 Osgood Street, North Andover Type 11124-hr 10 Year/24 hour Rainfall=4.80" Prepared by O'Neill Associates H droCAD®8.50 s/n 000472 ©2007 H droCAD Software Solutions LLC Printed 07/05/2011 Pa e 5 Summary for Subcatchment 1S: Exist. Conditions [49] Hint: Tc<2dt may require smaller dt Runoff = 0.23 cfs @ 12.08 hrs, Volume= 0.016 af, Depth> 2.72" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year/24 hour Rainfall=4.80" Area (ac) CN Description 0.069 82 Dirt/compacted qrAviz1 and bit . 0.069 Pervious Area Tc Length Slope Velocity Capacity Description (rein) (feet) (#ftff� ffthser - -/Cf - -- _ 5.0 Direct Entry, Subcatchment 1S: Exist. Conditions 14wir— aph 0.26. 0.25- 0.24: 0.23 as 0 Runoff 0.22, Type III 24-hr 10 Year/24 hour 0.21 0.2-. Rainfall=4.80" 0.19 Runoff Area=0.069 ac 0.18 0.17- Runoff Volume=0.016 of 0.16-- w 0.15. Runoff Depth>2.72" —a 0.14 3 0.13 Tc=5.0 min if 0.12- CN=82 0.1 0.09-- 0.08 0.07- 0.06-- 0.05 0.04 0.03 0.02 0.01" - 8 9 10 1'1 .1'2 1'3 1'4. . . .1'5 16 17 18 19. . 20 Time (hours) 1780 Osgood Street, North Andover Type 111 24-hr 10 Year/24 hour Rainfall=4.80" Prepared by O'Neill Associates Printed 07/0512011 HydroCAD®8.50 s/n 000472 ©2007 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 3S: Post Development (49] Hint: Tc<2dt may require smaller dt Runoff = 0.33 cfs @ 12.07 hrs, Volume= 0.024 af, Depth> 4.24" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year/24 hour Rainfall=4.80" Area (ac) CN Description 0.069 98 Prop. 60 x 50 Garage 0.069 Impervious Area Tc Length Slope Velocity _Capacity _Description (min) (feet) (frlft) (ft/dev) (cfs) 5.0 Direct Entry, Subcatchment 3S: Post Development Hydrograph 0.36: Runoff 0.34-- 0.33 U5 0.32- Type.11l 24-hr 10 Year/2.4.hour 0.3 Rainfall=4.80" 0.28 0.26_1 Runoff Area=0.069 ac 0.24 Runoff Volume=0.024 of y 0.22 Runoff Depth>4.24" 0.2 0.18-_ Tc=5.0 min 3 LL 0.16= CN=98 0.14 0.12 0.1 0.08 0.06 0.04-: 0.02 �. 5 6 7 8 9 10 11 12 13 14 II 15 16 17 18 19 20 Time (hours) 1780 Osgood Street, North Andover Prepared by O'Neill Associates Type 111 24-hr 70 Year/24 hour Rainfall=4.80" H droCAD®8.50 s/n 000472 ©2007 H droCAD Software Solutions LLC Printed 07/05/2011 Pa e 7 Summary for Pond 2P: Sheet Runoff [401 Hint: Not Described (Outflow=Inflow) Inflow Area = 0.069 ac, 0.00% Impervious, Inflow Depth > 2.72" for 10 Year/24 hour event Inflow = 0.23 cfs @ 12.08 hrs, Volume= Primary = 0.23 cfs @ 12.08 hrs, Volume= 0.016 of o 0.016 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Pond 2P: Sheet Runoff Hydrograph 0.26 �`Ir3fl8vii-- 0.24. ozs cfs ! Primary 0.22 Inflow Area=0.069 ac 0.2 0.16 0.16- w 0.14- 3 -° 0.12. 0.1- 0.08- 0.06- 0.04- 0.02 - - 5 6 7 8 9 10 11 12 13 14. 15 16 17 18 19 20 Time (hours) 1780 Osgood Street, North Andover Type 111 24-hr 90 Year/24 hour Rainfall=4.80" Prepared by O'Neill Associates H droCAD®8,50 s/n 000472 ©2007 H droCAD Software Solutions LLC Printed 07/05/2011 Page 8 Summary for Pond 4P: (Infiltration System) [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.069 ac,100.00% Impervious, Inflow Depth > 4.24" for 10 Year/24 hour event Inflow = 0.33 cfs @ 12.07 hrs, Volume= Primary = 0.33 cfs @ 12.07 hrs, Volume= 0.024 of o 0.024 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Pond 4P: (Infiltration System) Hydrograph U6- I 0.34 0 Primary 0.32: ° "S Inflow Area=0.069 ac 0.3-__ 0.28 0.26 0.24- 0.22- 0.2- 0 0.18-; LL 0.16 0.14-: 0.12: 0.1- 0.08-: 0.06 0.04 0.02 0= , . t, 9 . . ,10. . , 11 .12, ,1,3 14 15 1,6 Time (hours) 17 1'81 19 20 Civil Engineers and Land surveyors cos 234 PARK STREET SHEET NO. 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