drainage calculations and stormwater management plan

DRAINAGE CALCULATIONS AND

STORMWATER MANAGEMENT PLAN

DRAINAGE DESIGN & CALCULATIONS

for

MULTI-FAMILY DEVELOPMENT OF 40 VINE STREET

MELROSE, MASSACHUSETTS

PREPARED FOR: Daniel Galvin 40 Vine Street

Melrose, MA 02176

Date: May 6, 2020

Prepared by GCG ASSOCIATES, INC.

84 Main Street, Wilmington, MA 01887

Proposed Multi-Family Development 40 Vine Street

Melrose, MA 02176

TABLE OF CONTENTS

Stormwater Management and Erosion Control Permit Application ATTACHMENTS:

Project Analysis Summary

Engineering Methods & Standards Selection of Storm Events Site Soils Resource Areas On-site Pre-Development Conditions On-site Post-Development Conditions Stormwater Detention Facilities & Calculations Summary of Flows at Design Points

APPENDICES

Appendix A: Existing Conditions – Pre-Development Analysis

Pre-Development Plan - Watershed Routing Diagram 2, 5, 10, 25 & 100 Year, 24 Hour Storm Event Analysis

Appendix B: Proposed Conditions – Post-Development Analysis

Post Development Plan - Watershed Routing Diagram 2, 5, 10, 25 & 100 Year, 24 Hour Storm Event Analysis

Appendix C: Soils Data

Soil Map & HSG Classifications – Middlesex Counties, MA Web Soil Survey Dated:

January 30, 2020.

1982 Rawls Rates - NRCS Hydrologic Soil Group Infiltration Rates from the Massachusetts Stormwater Handbook, Vol. 3, Ch. 1, Pg. 22 Table 2.3.3

Appendix D: Operations & Maintenance

Stormwater & Drainage Operations & Maintenance Plan for 40 Vine Street

Sample O&M Log and O&M budget.

Appendix E: Drainage Watershed Plans

Pre-Development Watershed Plan

Post-Development Watershed Plan


Melrose, MA 02176

Project Analysis Summary The applicant, Daniel Galvin proposes to demolish the existing multi-family building at 40 Vine Street, Melrose, MA and construct a new eight-unit multi-family development along with general site improvements. Based on the City of Melrose’s Assessor Database, the building was constructed in 1895 on Vine Street shown as Tax Parcel ID C8 0 40 and contains 0.259+/- acres per current tax record. The site narrative describes the property as a “TWO FAM” with a “MULTI-CONV” style building. There is no wetland resource area within 100 feet of the parcel. The site is identified by the FIRM Panel 25017C0429E, effective date 6/4/2010 located within the Zone ‘X’, area determined to be of minimal flood hazard. Existing Conditions The existing site is 11,302 square feet in total, with 3,381 square feet being impervious areas. The existing drainage system consists two drainage areas. The northwest corner of the site drains toward the catch basin located in the front of the property on Vine Street. The majority of the site drains to the low point at the back southeast corner of the property where there is existing landscaping. The existing soil consists of 603-Urban Land, Wet Substratum, Hydrologic Soil Group (HSG) not rated. Through field soil testing we have decided that the soil is of HSG A, due to the findings of loamy sand and an estimated seasonal high ground water (ESHGW) of 6.5 feet below the surface. Proposed Conditions The proposed development would increase the impervious area with a parking lot and a building footprint increased by 1,470 square feet. The proposal will create a net increase of 5,517 square feet of new impervious area. Proposed stormwater management controls will be used to mitigate stormwater runoff, provide treatment and recharge. Stormwater management controls for the proposed development include an open grate proprietary mechanical treatment unit (Stormceptor STC 450i unit) for 44% pre-treatment and a sub-surface perforated pipes embedded in stone bed infiltration system for treatment and groundwater recharge. The applicant will also provide erosion and sedimentation controls during the construction period. A long-term stormwater operation and maintenance plan is established for the project. Since the site is only 11,302 square feet, a National Pollutant Discharge Elimination System (NPDES) permit and associated stormwater pollution prevention plan (SWPPP) will not be required. Engineering Methods & Standards The drainage modeling and calculations were performed using HydroCAD Hydrology software. HydroCAD uses the Soil Conservation Service (SCS), time of concentration by TR-55 methodology, and TR-20 hydrologic analyses, reach and pond rating by the Storage Indication Method and Manning's Equation, unit Hydrograph Method and the Storage Indication Method for developing the runoff and reservoir routing hydrographs, respectively. Drainage calculations for the pre- and post-development conditions were performed for the 2, 5, 10, 25, and 100 year Type III, 24 hour storm events. All calculations generated for pre-, and post-development conditions can be found in the attached appendices. The Massachusetts Department of Environmental Protection (MassDEP) Stormwater Management Policy standards were observed in the design of the stormwater management system. These standards included limiting post-development peak discharge rates and volumes to the pre-development peak discharge rates and volumes and recharging stormwater runoff to the groundwater. The City of Melrose Stormwater Management Requirements were utilized in the design of the stormwater management system.


Melrose, MA 02176

Selection of Storm Events The storm events have been compiled from the City of Melrose Rules and Regulations for Stormwater Management and Erosion Control. Values are based upon 24-hour rainfall data for Massachusetts from U.S Weather Bureau’s, Technical Paper 40, published in 1961. Rainfall frequency data has been provided as follows: Frequency (Years) Rainfall [24-Hour Event (inches)] 2 3.2

10 4.6 25 5.4 100 6.6 Site Soils Drainage classes have been established based on soil maps provided by U.S. Department of Agriculture Soil Conservation Service. Soil maps and descriptions are part of "Soil Survey Area: Middlesex County, MA: Soil Survey Data: Version 19, September 12, 2019.” On-site soils are classified as: 603 Urban land, wet substratum One deep hole soil test (TP-#1) was performed by GCG on February 25, 2020. See watershed plans for soil log and test pit location. GCG decided to use HSG A based on the sandy materials for the entire site in this analysis. On-Site Pre-Development Conditions The existing drainage system for the site consists of two drainage points that were used for our analysis. One is the catch basin on Vine Street, that the northwest portion of the site drains to. The second drainage point is the low point in the southeast corner of the existing lot. The majority of the site drains to the second analysis point by the existing contours of the site. Pre X-1 Drainage Sub-area X-1 is approximately 1,668 square feet in size. The area contains roofing, a paved walkway and lawn area. The drainage runoff discharges to a catch basin located in the curb line adjacent to the property on Vine Street (Analysis Point L-1). Pre X-2 Drainage Sub-area X-2 is approximately 9,634 square feet in size. The area contains roofing, paved walkways, paved driveway, gravel driveway and lawn areas. The drainage runoff discharges to a low point located in the southwest corner of the lot (Analysis Point L-2). Routing diagrams for these drainage areas with supporting engineering calculations and information can be found in Appendix A of this report.


Melrose, MA 02176

On-site Post-Development Conditions The Post-Development site has three separate drainage areas that are based on the proposed layout of the site. Routing diagrams for these drainage areas with supporting engineering calculations and information can be found in Appendix A of this report. Post P-1 Drainage Sub-area P-1 is approximately 7,114 square feet. The area contains the majority of the proposed paved parking lot and lawn areas. The drainage area will discharge into a new Stormceptor unit for pretreatment and through a perforated pipes stone bed system for further treatment and infiltration. (Analysis Point L-2) Post P-2 Drainage Sub-area P-2 is approximately 4,123 square feet. The area contains the roof area of the proposed building. The drainage area will discharge through a roof drainpipe directly into the underground infiltration system made up of perforated pipes and a stone bed system. Roof runoff is considered clean water per MassDEP and requires no treatments. (Analysis Point L-2) Post P-3 Drainage Sub-area P-3 is approximately 65 square feet. The area contains a small part of the proposed paved driveway in the northwest corner of the site. This area of driveway will discharge directly into the catch basin on Vine Street. (Analysis Point L-1) Stormwater Management Facilities (BMPs) & Calculations for Roadway Pavement and Roof Area This is a re-development & new-development project, the existing development consists of 3,381+/- square feet of impervious areas and 7,921+/- square feet of wood/lawn landscape area. The proposed development will have a net increase of 5,517 +/- square feet of new pavement, walkway and roofing impervious areas with a total impervious area of 8,898 +/- square feet. The proposed best management practices (BMP’s) will treat and recharge the entire impervious area to meet MassDEP requirements. The proposed infiltration system will utilize a Stormceptor 450i unit with a catch basin gate for pre-treatment to collect the surface runoff. A Stormceptor unit will provide a minimum of 44% of total suspended solids (TSS) pre-treatment and discharge to a perforated pipes/stone bed sub-surface infiltration system to achieve the 80% TSS removal requirements. A roof drain line will discharge to the infiltration system directly to prevent overtaxing on the Stormceptor unit. The following calculations demonstrate required volumes and capacity of the proposed Infiltration Basin. Groundwater Recharge Volume – (Standard 3) Recharge Volumes Required (MassDEP Stormwater Handbook)

• HSG A: Impervious area = 8,898 SF • Groundwater Recharge Volume Required = 8,898 SF x 0.6” /12” = 445 CF

• The proposed infiltration system has a storage capacity of 1,925 CF

(See HydroCAD Pond S-1 – 100-Year Storm Infiltration System Storage Volume) Drawdown Calculations (MassDEP Stormwater Handbook)

• Infiltration System Storage Volume = 1,925 CF Bottom of Infiltration System Surface Area = 1,615 SF Exfiltration Rate = 2.41 IN/HR (Rawls rate, 1982)

• Drawdown Time = 1,925 CF/1,615 SF = 1.19 FT x 12 IN/1 FT = 14.30 IN/2.41 IN/HR = 5.93 HRS < 72 HRS


Melrose, MA 02176

Water Quality Volume (WQV) – (Standard 4) • Required 1 inch of the Total Impervious Area. - (MassDEP Stormwater Handbook)

Proposed impervious area = 8,898 SF x 1IN/12IN/FT = 741 CF

• Proposed Infiltration System provided 1,925 CF > 741 CF requirements. Proprietary Mechanical Treatment Unit (Stormceptor) Sizing The sub-catchment runoff flows through the treatment unit consists of approximately 0.26 acres with 78.6% impervious coverage. (Excluded site roof drain, which by passed the treatment unit.) Contech Engineered Solutions, Stormceptor manufacturer claims that a STC 450i unit will provide 90% TSS removal, see Stormceptor sizing report. Greater than required 44%. Infiltration (Trench) System The proposed infiltration system consists of 890+/- linear feet of 15-inch diameter perforated HDPE pipe embedded within a 1,615 SF by 2.25-foot high stone bed. The storage volume is approximately 1,925 CF. TSS removal Infiltration Trenches with Stormceptor Pre-treatment = 80% (MassDEP) Pre-treatment Stormceptor 450i unit = 90% TSS removal > 44% (rapid soil) Summary of Flows at Design Points - (Standard 2) MassDEP Stormwater Management Standards and the City of Melrose Drainage and Stormwater Design Standards were used in the design of the stormwater management system. These standards included limiting post-development peak discharge rates to the pre-development peak discharge rates and recharging stormwater runoff to the groundwater. The following table includes a comparison for pre- and post-development runoff values obtained using total peak values from hydrographs in attached calculations.

TABLE 1

40 VINE STREET, RUNOFF PRE vs. POST DEVELOPMENT CONDITIONS

Discharge Point: Catch Basin on Vine Street

Peak Flow (cfs) Volume (af) Year

Storm Pre Post Pre Post 2 0.00 0.00 0.001 0.000 10 0.02 0.01 0.002 0.001 25 0.04 0.01 0.004 0.001 100 0.07 0.01 0.006 0.001


Melrose, MA 02176

TABLE 2

40 VINE STREET, RUNOFF PRE vs. POST DEVELOPMENT CONDITIONS

Discharge Point: SW Backyard Low Point

Peak Flow (cfs) Volume (af) Year

Storm Pre Post Pre Post 2 0.03 0.00 0.006 0.00 10 0.18 0.00 0.017 0.00 25 0.30 0.00 0.024 0.00 100 0.49 0.00 0.038 0.00

Project Information & LocationProject Name 40 Vine Street Project Number 1982

City Melrose State/ Province Massachusetts

Country United States of America Date 3/16/2020

Designer Information EOR Information (optional)

Name Kevin Carter Name

Company GCG Associates, Inc. Company

Phone # 978-657-9714 Phone #

Email [email protected] Email

Brief Stormceptor Sizing Report - 40 Vine Street

Site Name 40 Vine Street

Target TSS Removal (%) 44

TSS Removal (%) Provided 96

Recommended Stormceptor Model STC 2400

Stormceptor Sizing SummaryStormceptor Model % TSS Removal

Provided% Runoff Volume Captured Provided

STC 450i 90 96STC 900 94 99

STC 1200 94 99STC 1800 94 99STC 2400 96 100STC 3600 96 100STC 4800 97 100STC 6000 97 100STC 7200 98 100STC 11000 99 100STC 13000 99 100STC 16000 99 100

The recommended Stormceptor Model achieves the water quality objectives based on the selected inputs, historical rainfall records and selected particle size distribution.

Stormwater Treatment Recommendation The recommended Stormceptor Model(s) which achieve or exceed the user defined water quality objective for each site within the project are listed in the below Sizing Summary table.

Stormceptor Brief Sizing Report – Page 1 of 2

Notes• Stormceptor performance estimates are based on simulations using PCSWMM for Stormceptor, which uses the EPA Rainfall and Runoff modules.• Design estimates listed are only representative of specific project requirements based on total suspended solids (TSS) removal defined by the selected PSD, and based on stable site conditions only, after construction is completed.• For submerged applications or sites specific to spill control, please contact your local Stormceptor representative for further design assistance.

Drainage Area

Total Area (acres) 0.26

Imperviousness % 78.6

Water Quality Objective

TSS Removal (%) 44.0

Runoff Volume Capture (%) 100.00

Oil Spill Capture Volume (Gal)

Peak Conveyed Flow Rate (CFS) 1.37

Water Quality Flow Rate (CFS) 0.01

Rainfall

Station Name BOSTON WSFO AP

State/Province Massachusetts

Station ID # 0770

Years of Records 58

Latitude 42°21'38"N

Longitude 71°0'38"W

Up Stream Storage

Storage (ac-ft) Discharge (cfs)

0.106 1.370

Particle Size Distribution (PSD)The selected PSD defines TSS removal

Fine Distribution

Particle Diameter(microns)

Distribution %

Specific Gravity

20.0 20.0 1.30

60.0 20.0 1.80

150.0 20.0 2.20

400.0 20.0 2.65

2000.0 20.0 2.65

Up Stream Flow Diversion

Max. Flow to Stormceptor (cfs)

Sizing Details

For Stormceptor Specifications and Drawings Please Visit: https://www.conteches.com/technical-guides/search?filter=1WBC0O5EYX

Stormceptor Brief Sizing Report – Page 2 of 2

STANDARD #10

STORMWATER AND DRAINAGE ILLICIT DISCHARGE STATEMENT

40 Vine Street

MELROSE, MASSACHUSETTS All illicit discharges to the stormwater management system are prohibited. I. STATEMENT This site as shown on the plan titled “Proposed Drainage and Utility Plan” for 40 Vine Street, Melrose, Massachusetts, prepared by GCG Associates, Inc. and dated April 28, 2020 does not contain any illicit discharges, this was confirmed using visual screening as required by standard 10 of the “Massachusetts Stormwater Handbook” Vol. 1, Ch. 1 page 25. The project proponent, owner, or lessee (in perpetuity) must comply with local, state, and federal regulations for the discharge of illicit discharges from the site. Illicit discharges are discharges that are not entirely comprised of storm water. Notwithstanding the foregoing, an illicit discharge does not include discharges from the following activities:

• Fire fighting • Water line flushing • Landscape irrigation • Uncontaminated ground water • Potable water sources • Foundation drains • Air conditioning condensation • Footing drains • Individual car washing • Water used for street washing and water used to clean residential buildings without

detergents The project proponent, owner, Daniel Galvin (in perpetuity) shall adhere to this report on file with the City of Melrose.


Melrose, MA 02176

APPENDIX A Existing Conditions – Pre-Development Analysis

X-1

NW Area of Property (Existing Conditions)

X-2

Rest of Property (Existing Conditions)

L-1

CB Vine Street

L-2

SE Backyard Low Point

Routing Diagram for 1982 - Pre DevelopmentPrepared by GCG Associates, Inc., Printed 4/23/2020

HydroCAD® 10.00-24 s/n 03555 © 2018 HydroCAD Software Solutions LLC

Subcat Reach Pond Link

1982 - Pre Development Printed 4/23/2020Prepared by GCG Associates, Inc.

Page 2HydroCAD® 10.00-24 s/n 03555 © 2018 HydroCAD Software Solutions LLC

Area Listing (all nodes)

Area(acres)

CN Description(subcatchment-numbers)

0.182 39 >75% Grass cover, Good, HSG A (X-1, X-2)0.019 98 Paved parking, HSG A (X-1, X-2)0.059 98 Roofs, HSG A (X-1, X-2)0.259 57 TOTAL AREA



Soil Listing (all nodes)

Area(acres)

SoilGroup

SubcatchmentNumbers

0.259 HSG A X-1, X-20.000 HSG B0.000 HSG C0.000 HSG D0.000 Other0.259 TOTAL AREA



Ground Covers (all nodes)

HSG-A(acres)

HSG-B(acres)

HSG-C(acres)

HSG-D(acres)

Other(acres)

Total(acres)

GroundCover

SubcatchmentNumbers

0.182 0.000 0.000 0.000 0.000 0.182 >75% Grass cover, Good X-1, X-20.019 0.000 0.000 0.000 0.000 0.019 Paved parking X-1, X-20.059 0.000 0.000 0.000 0.000 0.059 Roofs X-1, X-20.259 0.000 0.000 0.000 0.000 0.259 TOTAL AREA

Type III 24-hr 2-YR Rainfall=3.20"1982 - Pre Development Printed 4/23/2020Prepared by GCG Associates, Inc.


Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 pointsRunoff by SCS TR-20 method, UH=SCS, Weighted-CN

Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method

Runoff Area=1,668 sf 25.60% Impervious Runoff Depth>0.22"Subcatchment X-1: NW Area of Property Tc=6.0 min CN=54 Runoff=0.00 cfs 0.001 af

Runoff Area=9,634 sf 30.66% Impervious Runoff Depth>0.31"Subcatchment X-2: Rest of Property Tc=6.0 min CN=57 Runoff=0.03 cfs 0.006 af

Inflow=0.00 cfs 0.001 afLink L-1: CB Vine Street Primary=0.00 cfs 0.001 af

Inflow=0.03 cfs 0.006 afLink L-2: SE Backyard Low Point Primary=0.03 cfs 0.006 af

Total Runoff Area = 0.259 ac Runoff Volume = 0.006 af Average Runoff Depth = 0.30"70.08% Pervious = 0.182 ac 29.92% Impervious = 0.078 ac



Summary for Subcatchment X-1: NW Area of Property (Existing Conditions)

Runoff = 0.07 cfs @ 12.10 hrs, Volume= 0.006 af, Depth> 1.78"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrsType III 24-hr 100-YR Rainfall=6.60"

Area (sf) CN Description181 98 Paved parking, HSG A

1,241 39 >75% Grass cover, Good, HSG A246 98 Roofs, HSG A

1,668 54 Weighted Average1,241 74.40% Pervious Area

427 25.60% Impervious Area

Tc Length Slope Velocity Capacity Description(min) (feet) (ft/ft) (ft/sec) (cfs)

6.0 Direct Entry, Less than 6 minutes

Summary for Subcatchment X-2: Rest of Property (Existing Conditions)



Area (sf) CN Description94 98 Roofs, HSG A

2,232 98 Roofs, HSG A628 98 Paved parking, HSG A

6,680 39 >75% Grass cover, Good, HSG A9,634 57 Weighted Average6,680 69.34% Pervious Area2,954 30.66% Impervious Area


6.0 Direct Entry, Less than 6 mins

Summary for Link L-1: CB Vine Street

Inflow Area = 0.038 ac, 25.60% Impervious, Inflow Depth > 1.78" for 100-YR eventInflow = 0.07 cfs @ 12.10 hrs, Volume= 0.006 afPrimary = 0.07 cfs @ 12.10 hrs, Volume= 0.006 af, Atten= 0%, Lag= 0.0 min

Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs



Summary for Link L-2: SE Backyard Low Point

Inflow Area = 0.221 ac, 30.66% Impervious, Inflow Depth > 2.05" for 100-YR eventInflow = 0.49 cfs @ 12.10 hrs, Volume= 0.038 afPrimary = 0.49 cfs @ 12.10 hrs, Volume= 0.038 af, Atten= 0%, Lag= 0.0 min



Melrose, MA 02176

APPENDIX B Proposed Conditions – Post-Development Analysis

P-1

Proposed Driveway and Lawn

P-2

Proposed Building Roof

P-3

Driveway Apron

S-1

Stormceptor & Infiltration Bed

L-1

CB Vine Street

L-2

SE Backyard Low Point

Routing Diagram for 1982 - Post DevelopmentPrepared by GCG Associates, Inc., Printed 4/23/2020

HydroCAD® 10.00-24 s/n 03555 © 2018 HydroCAD Software Solutions LLC

Subcat Reach Pond Link

1982 - Post Development Printed 4/23/2020Prepared by GCG Associates, Inc.


Area Listing (all nodes)

Area(acres)

CN Description(subcatchment-numbers)

0.055 39 >75% Grass cover, Good, HSG A (P-1)0.110 98 Paved parking, HSG A (P-1, P-3)0.095 98 Roofs, HSG A (P-2)0.259 85 TOTAL AREA



Soil Listing (all nodes)

Area(acres)

SoilGroup

SubcatchmentNumbers

0.259 HSG A P-1, P-2, P-30.000 HSG B0.000 HSG C0.000 HSG D0.000 Other0.259 TOTAL AREA



Ground Covers (all nodes)

HSG-A(acres)

HSG-B(acres)

HSG-C(acres)

HSG-D(acres)

Other(acres)

Total(acres)

GroundCover

SubcatchmentNumbers

0.055 0.000 0.000 0.000 0.000 0.055 >75% Grass cover, Good P-10.110 0.000 0.000 0.000 0.000 0.110 Paved parking P-1, P-30.095 0.000 0.000 0.000 0.000 0.095 Roofs P-20.259 0.000 0.000 0.000 0.000 0.259 TOTAL AREA

Type III 24-hr 2-YR Rainfall=3.20"1982 - Post Development Printed 4/23/2020Prepared by GCG Associates, Inc.




Runoff Area=7,114 sf 66.21% Impervious Runoff Depth>1.27"Subcatchment P-1: Proposed Driveway and Tc=6.0 min CN=78 Runoff=0.23 cfs 0.017 af

Runoff Area=4,124 sf 100.00% Impervious Runoff Depth>2.97"Subcatchment P-2: Proposed Building Tc=6.0 min CN=98 Runoff=0.29 cfs 0.023 af

Runoff Area=65 sf 100.00% Impervious Runoff Depth>2.97"Subcatchment P-3: Driveway Apron Tc=6.0 min CN=98 Runoff=0.00 cfs 0.000 af

Peak Elev=51.50' Storage=484 cf Inflow=0.52 cfs 0.041 afPond S-1: Stormceptor & Infiltration Bed Discarded=0.09 cfs 0.041 af Primary=0.00 cfs 0.000 af Outflow=0.09 cfs 0.041 af











Peak Elev=52.09' Storage=1,009 cf Inflow=0.86 cfs 0.067 afPond S-1: Stormceptor & Infiltration Bed Discarded=0.09 cfs 0.067 af Primary=0.00 cfs 0.000 af Outflow=0.09 cfs 0.067 af






Summary for Subcatchment P-1: Proposed Driveway and Lawn



Area (sf) CN Description4,710 98 Paved parking, HSG A2,404 39 >75% Grass cover, Good, HSG A7,114 78 Weighted Average2,404 33.79% Pervious Area4,710 66.21% Impervious Area



Summary for Subcatchment P-2: Proposed Building Roof



Area (sf) CN Description4,124 98 Roofs, HSG A4,124 100.00% Impervious Area



Summary for Subcatchment P-3: Driveway Apron



Area (sf) CN Description65 98 Paved parking, HSG A65 100.00% Impervious Area





Summary for Pond S-1: Stormceptor & Infiltration Bed

Inflow Area = 0.258 ac, 78.61% Impervious, Inflow Depth > 4.93" for 100-YR eventInflow = 1.37 cfs @ 12.09 hrs, Volume= 0.106 afOutflow = 0.09 cfs @ 11.25 hrs, Volume= 0.106 af, Atten= 93%, Lag= 0.0 minDiscarded = 0.09 cfs @ 11.25 hrs, Volume= 0.106 afPrimary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrsPeak Elev= 52.82' @ 13.73 hrs Surf.Area= 1,615 sf Storage= 1,935 cf

Plug-Flow detention time= 181.4 min calculated for 0.106 af (100% of inflow)Center-of-Mass det. time= 180.5 min ( 961.4 - 780.9 )

Volume Invert Avail.Storage Storage Description#1 50.75' 1,057 cf Custom Stage Data (Prismatic) Listed below (Recalc)

3,734 cf Overall - 1,092 cf Embedded = 2,642 cf x 40.0% Voids#2 51.75' 1,092 cf 15.0" Round Pipe Storage Inside #1

L= 890.0'2,149 cf Total Available Storage

Elevation Surf.Area Inc.Store Cum.Store(feet) (sq-ft) (cubic-feet) (cubic-feet)50.75 1,615 0 053.00 1,615 3,634 3,63453.10 12 81 3,71554.66 12 19 3,734

Device Routing Invert Outlet Devices#1 Discarded 50.75' 2.410 in/hr Exfiltration over Surface area #2 Primary 54.65' 2.0' long x 2.0' breadth Overflow

Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32

Discarded OutFlow Max=0.09 cfs @ 11.25 hrs HW=50.79' (Free Discharge)1=Exfiltration (Exfiltration Controls 0.09 cfs)

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=50.75' (Free Discharge)2=Overflow ( Controls 0.00 cfs)

Summary for Link L-1: CB Vine Street

Inflow Area = 0.001 ac,100.00% Impervious, Inflow Depth > 6.36" for 100-YR eventInflow = 0.01 cfs @ 12.09 hrs, Volume= 0.001 afPrimary = 0.01 cfs @ 12.09 hrs, Volume= 0.001 af, Atten= 0%, Lag= 0.0 min




Summary for Link L-2: SE Backyard Low Point

Inflow Area = 0.258 ac, 78.61% Impervious, Inflow Depth = 0.00" for 100-YR eventInflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 afPrimary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min



Melrose, MA 02176

APPENDIX C

Soils Data

Soil Map—Middlesex County, Massachusetts(40 Vine Street, Melrose, MA )

Natural ResourcesConservation Service

Web Soil SurveyNational Cooperative Soil Survey

1/30/2020Page 1 of 3

4702

540

4702

560

4702

580

4702

600

4702

620

4702

640

4702

660

4702

680

4702

700

4702

720

4702

540

4702

560

4702

580

4702

600

4702

620

4702

640

4702

660

4702

680

4702

700

4702

720

329870 329890 329910 329930 329950 329970 329990 330010

329870 329890 329910 329930 329950 329970 329990 330010

42° 27' 29'' N71

° 4

' 9'' W

42° 27' 29'' N

71° 4

' 2'' W

42° 27' 23'' N

71° 4

' 9'' W

42° 27' 23'' N

71° 4

' 2'' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 19N WGS840 45 90 180 270

Feet0 10 20 40 60

MetersMap Scale: 1:985 if printed on A portrait (8.5" x 11") sheet.

Soil Map may not be valid at this scale.

MA

P LE

GEN

DM

AP

INFO

RM

ATIO

N

Are

a of

Inte

rest

(AO

I)Ar

ea o

f Int

eres

t (AO

I)

Soils

Soil

Map

Uni

t Pol

ygon

s

Soil

Map

Uni

t Lin

es

Soil

Map

Uni

t Poi

nts

Spec

ial P

oint

Fea

ture

sBl

owou

t

Borro

w P

it

Cla

y Sp

ot

Clo

sed

Dep

ress

ion

Gra

vel P

it

Gra

velly

Spo

t

Land

fill

Lava

Flo

w

Mar

sh o

r sw

amp

Min

e or

Qua

rry

Mis

cella

neou

s W

ater

Pere

nnia

l Wat

er

Roc

k O

utcr

op

Salin

e Sp

ot

Sand

y Sp

ot

Seve

rely

Ero

ded

Spot

Sink

hole

Slid

e or

Slip

Sodi

c Sp

ot

Spoi

l Are

a

Ston

y Sp

ot

Very

Sto

ny S

pot

Wet

Spo

t

Oth

er

Spec

ial L

ine

Feat

ures

Wat

er F

eatu

res

Stre

ams

and

Can

als

Tran

spor

tatio

nR

ails

Inte

rsta

te H

ighw

ays

US

Rou

tes

Maj

or R

oads

Loca

l Roa

ds

Bac

kgro

und Ae

rial P

hoto

grap

hy

The

soil

surv

eys

that

com

pris

e yo

ur A

OI w

ere

map

ped

at

1:25

,000

.

War

ning

: Soi

l Map

may

not

be

valid

at t

his

scal

e.

Enla

rgem

ent o

f map

s be

yond

the

scal

e of

map

ping

can

cau

se

mis

unde

rsta

ndin

g of

the

deta

il of

map

ping

and

acc

urac

y of

soi

l lin

e pl

acem

ent.

The

map

s do

not

sho

w th

e sm

all a

reas

of

cont

rast

ing

soils

that

cou

ld h

ave

been

sho

wn

at a

mor

e de

taile

d sc

ale.

Plea

se re

ly o

n th

e ba

r sca

le o

n ea

ch m

ap s

heet

for m

ap

mea

sure

men

ts.

Sour

ce o

f Map

: N

atur

al R

esou

rces

Con

serv

atio

n Se

rvic

eW

eb S

oil S

urve

y U

RL:

C

oord

inat

e Sy

stem

: W

eb M

erca

tor (

EPSG

:385

7)

Map

s fro

m th

e W

eb S

oil S

urve

y ar

e ba

sed

on th

e W

eb M

erca

tor

proj

ectio

n, w

hich

pre

serv

es d

irect

ion

and

shap

e bu

t dis

torts

di

stan

ce a

nd a

rea.

A p

roje

ctio

n th

at p

rese

rves

are

a, s

uch

as th

e Al

bers

equ

al-a

rea

coni

c pr

ojec

tion,

sho

uld

be u

sed

if m

ore

accu

rate

cal

cula

tions

of d

ista

nce

or a

rea

are

requ

ired.

This

pro

duct

is g

ener

ated

from

the

USD

A-N

RC

S ce

rtifie

d da

ta a

s of

the

vers

ion

date

(s) l

iste

d be

low.

Soil

Surv

ey A

rea:

M

iddl

esex

Cou

nty,

Mas

sach

uset

tsSu

rvey

Are

a D

ata:

Ve

rsio

n 19

, Sep

12,

201

9

Soil

map

uni

ts a

re la

bele

d (a

s sp

ace

allo

ws)

for m

ap s

cale

s 1:

50,0

00 o

r lar

ger.

Dat

e(s)

aer

ial i

mag

es w

ere

phot

ogra

phed

: Se

p 11

, 201

9—O

ct 5

, 20

19

The

orth

opho

to o

r oth

er b

ase

map

on

whi

ch th

e so

il lin

es w

ere

com

pile

d an

d di

gitiz

ed p

roba

bly

diffe

rs fr

om th

e ba

ckgr

ound

im

ager

y di

spla

yed

on th

ese

map

s. A

s a

resu

lt, s

ome

min

or

shift

ing

of m

ap u

nit b

ound

arie

s m

ay b

e ev

iden

t.

Soil

Map

—M

iddl

esex

Cou

nty,

Mas

sach

uset

ts(4

0 Vi

ne S

treet

, Mel

rose

, MA

)

Nat

ural

Res

ourc

esC

onse

rvat

ion

Serv

ice

Web

Soi

l Sur

vey

Nat

iona

l Coo

pera

tive

Soil

Surv

ey1/

30/2

020

Page

2 o

f 3

Map Unit Legend

Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI

603 Urban land, wet substratum 3.4 100.0%

Totals for Area of Interest 3.4 100.0%

Soil Map—Middlesex County, Massachusetts 40 Vine Street, Melrose, MA



1/30/2020Page 3 of 3

Hyd

rolo

gic

Soil

Gro

up—

Mid

dles

ex C

ount

y, M

assa

chus

etts

(44

Vine

Stre

et M

elro

se G

ener

al A

rea

)

Nat

ural

Res

ourc

esC

onse

rvat

ion

Serv

ice

Web

Soi

l Sur

vey

Nat

iona

l Coo

pera

tive

Soil

Surv

ey1/

30/2

020

Page

1 o

f 4

4701900470220047025004702800470310047034004703700

4701900470220047025004702800470310047034004703700

3282

0032

8500

3288

0032

9100

3294

0032

9700

3300

0033

0300

3306

0033

0900

3312

00

3282

0032

8500

3288

0032

9100

3294

0032

9700

3300

0033

0300

3306

0033

0900

3312

00

42° 2

8' 3

'' N71° 5' 26'' W

42° 2

8' 3

'' N

71° 3' 6'' W

42° 2

6' 5

6'' N

71° 5' 26'' W

42° 2

6' 5

6'' N

71° 3' 6'' W

N

Map

pro

ject

ion:

Web

Mer

cato

r C

orne

r coo

rdin

ates

: WGS

84

Edge

tics

: UTM

Zon

e 19

N W

GS84

050

010

0020

0030

00Feet

020

040

080

012

00Met

ers

Map

Sca

le: 1

:14,

600

if prin

ted

on A

land

scap

e (1

1" x

8.5

") sh

eet.

MA

P LE

GEN

DM

AP

INFO

RM

ATIO

N

Are

a of

Inte

rest

(AO

I)Ar

ea o

f Int

eres

t (AO

I)

Soils So

il R

atin

g Po

lygo

nsA A/

D

B B/D

C C/D

D Not

rate

d or

not

ava

ilabl

e

Soil

Rat

ing

Line

sA A/

D

B B/D

C C/D

D Not

rate

d or

not

ava

ilabl

e

Soil

Rat

ing

Poin

tsA A/

D

B B/D

C C/D

D Not

rate

d or

not

ava

ilabl

e

Wat

er F

eatu

res

Stre

ams

and

Can

als

Tran

spor

tatio

nR

ails

Inte

rsta

te H

ighw

ays

US

Rou

tes

Maj

or R

oads

Loca

l Roa

ds

Bac

kgro

und Ae

rial P

hoto

grap

hy

The

soil

surv

eys

that

com

pris

e yo

ur A

OI w

ere

map

ped

at

1:25

,000

.

Plea

se re

ly o

n th

e ba

r sca

le o

n ea

ch m

ap s

heet

for m

ap

mea

sure

men

ts.

Sour

ce o

f Map

: N

atur

al R

esou

rces

Con

serv

atio

n Se

rvic

eW

eb S

oil S

urve

y U

RL:

C

oord

inat

e Sy

stem

: W

eb M

erca

tor (

EPSG

:385

7)

Map

s fro

m th

e W

eb S

oil S

urve

y ar

e ba

sed

on th

e W

eb M

erca

tor

proj

ectio

n, w

hich

pre

serv

es d

irect

ion

and

shap

e bu

t dis

torts

di

stan

ce a

nd a

rea.

A p

roje

ctio

n th

at p

rese

rves

are

a, s

uch

as th

e Al

bers

equ

al-a

rea

coni

c pr

ojec

tion,

sho

uld

be u

sed

if m

ore

accu

rate

cal

cula

tions

of d

ista

nce

or a

rea

are

requ

ired.

This

pro

duct

is g

ener

ated

from

the

USD

A-N

RC

S ce

rtifie

d da

ta a

s of

the

vers

ion

date

(s) l

iste

d be

low.

Soil

Surv

ey A

rea:

M

iddl

esex

Cou

nty,

Mas

sach

uset

tsSu

rvey

Are

a D

ata:

Ve

rsio

n 19

, Sep

12,

201

9

Soil

map

uni

ts a

re la

bele

d (a

s sp

ace

allo

ws)

for m

ap s

cale

s 1:

50,0

00 o

r lar

ger.

Dat

e(s)

aer

ial i

mag

es w

ere

phot

ogra

phed

: Se

p 11

, 201

9—O

ct 5

, 20

19

The

orth

opho

to o

r oth

er b

ase

map

on

whi

ch th

e so

il lin

es w

ere

com

pile

d an

d di

gitiz

ed p

roba

bly

diffe

rs fr

om th

e ba

ckgr

ound

im

ager

y di

spla

yed

on th

ese

map

s. A

s a

resu

lt, s

ome

min

or

shift

ing

of m

ap u

nit b

ound

arie

s m

ay b

e ev

iden

t.

Hyd

rolo

gic

Soil

Gro

up—

Mid

dles

ex C

ount

y, M

assa

chus

etts

(44

Vine

Stre

et M

elro

se G

ener

al A

rea

)

Nat

ural

Res

ourc

esC

onse

rvat

ion

Serv

ice

Web

Soi

l Sur

vey

Nat

iona

l Coo

pera

tive

Soil

Surv

ey1/

30/2

020

Page

2 o

f 4

Hydrologic Soil Group

Map unit symbol Map unit name Rating Acres in AOI Percent of AOI

1 Water 23.7 2.6%

30B Raynham silt loam, 0 to 5 percent slopes

C/D 12.2 1.3%

51A Swansea muck, 0 to 1 percent slopes

B/D 0.7 0.1%

71B Ridgebury fine sandy loam, 3 to 8 percent slopes, extremely stony

D 1.5 0.2%

73B Whitman fine sandy loam, 0 to 3 percent slopes, extremely stony

D 1.6 0.2%

103C Charlton-Hollis-Rock outcrop complex, 8 to 15 percent slopes

B 16.6 1.8%

103D Charlton-Hollis-Rock outcrop complex, 15 to 25 percent slopes

A 0.5 0.0%

104C Hollis-Rock outcrop-Charlton complex, 0 to 15 percent slopes

D 33.1 3.6%

104D Hollis-Rock outcrop-Charlton complex, 15 to 25 percent slopes

A 15.9 1.7%

105E Rock outcrop-Hollis complex, 3 to 35 percent slopes

66.0 7.2%

602 Urban land 17.1 1.9%

603 Urban land, wet substratum

272.3 29.8%

621B Scio-Urban land complex, 0 to 8 percent slopes

22.9 2.5%

622C Paxton-Urban land complex, 3 to 15 percent slopes

C 41.4 4.5%

623C Woodbridge-Urban land complex, 3 to 15 percent slopes

C/D 9.3 1.0%

626B Merrimac-Urban land complex, 0 to 8 percent slopes

A 34.4 3.8%

629C Canton-Charlton-Urban land complex, 3 to 15 percent slopes

A 2.1 0.2%

Hydrologic Soil Group—Middlesex County, Massachusetts 44 Vine Street Melrose General Area



1/30/2020Page 3 of 4

Map unit symbol Map unit name Rating Acres in AOI Percent of AOI

631C Charlton-Urban land-Hollis complex, 3 to 15 percent slopes, rocky

A 314.1 34.3%

655 Udorthents, wet substratum

30.1 3.3%

Totals for Area of Interest 915.4 100.0%

Description

Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms.

The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows:

Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission.

Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission.

Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission.

Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission.

If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes.

Rating Options

Aggregation Method: Dominant Condition

Component Percent Cutoff: None Specified

Tie-break Rule: Higher

Hydrologic Soil Group—Middlesex County, Massachusetts 44 Vine Street Melrose General Area



1/30/2020Page 4 of 4


Melrose, MA 02176

APPENDIX D

Operation & Maintenance

STORMWATER AND DRAINAGE OPERATION AND MAINTENANCE PLAN

Name of Project: 40 Vine Street Site Development

Location: 40 Vine Street, Melrose, Massachusetts Name of Owner/Operator: Daniel Galvin, Melrose, MA Owner/Operator Signature: _______________________, Date ____________ I. INTRODUCTION The maintenance program below provides for a general plan with specific requirements for stormwater management controls for 40 Vine Street, Watertown, MA. The program is based on the recommended standards presented in the DEP Stormwater Management Policy Handbook Volume 2, Chapter 2 and Guidelines for Stormwater Management and Controlling Urban Runoff: A Practical Manual for Planning and Designing Urban BMPs, by Thomas R. Schueler, July 1987. II. RESPONSIBILITY AND IMPLEMENTATION The property owner is the owner of all components of the drainage system as listed in Section III below, until property ownership is transferred, at which the drainage system becomes the property of the successive owner. The implementation, execution, and financing of this maintenance program and emergency repairs shall be the responsibility of the property owner until property ownership is transferred, at which time maintenance and repairs shall be the responsibility of the successive owner. III. GENERAL REQUIREMENTS Construction activities shall conform to the approved site plans and any other regulations or requirements of the City of Melrose. Silt sack, Mulch filter tubes, silt fence or similar erosion control, construction entrance shall be installed at the limit of work prior to construction. All sediment controls shall be in place before construction shall begin and shall be properly maintained throughout the course of construction. During construction, silt laden runoff shall not be permitted to enter the nearby drainage facilities or abutting properties. All BMPs and sediment controls shall be inspected, by the Applicant, on a weekly basis and within 24 hours of a rain event that generates more than ½” of rain in a 24 hour period. Once each BMP is installed it shall be operated and maintained in accordance with the Post Construction Operation & Maintenance Plan. Should any dewatering activities be required, the Applicant shall make certain that the all pumped water is free of sediment prior to discharging to the nearby wetlands. The methods for removing any sediment shall be approved by the Town prior to any dewatering activities commence. IV. BMP MAINTENANCE Maintenance of Facilities: The Owner agrees to comply with a minimum maintenance schedule as follows: A. Street Sweeping: Street sweeping roadways and parking areas twice a year minimum. (early Spring

and late Fall)

B. Catch Basin Grate (See Stormceptor for Structure Maintenance): Catch basin grate should be inspected every 4 times per year and after every major storm. During each inspection, the drains should be inspected for damage and any evidence of blockages. All accumulated trash, sediment, debris, etc., should be removed as necessary.

C. Infiltration System: Preventative maintenance, twice a year; Inspect after every major storm during

first 3 months of operation and twice a year thereafter to ensure that the facilities are operating as intended and if necessary take corrective action. Note how long water remains standing in the basin after a storm; standing water within the basin 48 to 72 hours after a storm indicates that the infiltration capacity may not functional correctly. All accumulated sediment, debris, should be removed during this time. Inspections conducted at intervals during and after storms will help determine if the facility is meeting the expected infiltration rates.

D. Stormceptor: Per the manufacturer’s recommendations, the Stormceptor should be inspected every

6 months in the first year to determine the oil and sediment accumulation rate. In subsequent years, inspections are based on first-year observations. Maintenance is to be performed when the sediment depth reached 8 inches with a standard vacuum truck. Inspection shall be performed immediately after an oil, fuel or chemical spill. A licensed waste management company should remove oil and sediment and dispose responsibly. All sediment removed should be properly handled and disposed of in accordance with local, state, and federal guidelines and regulations.

E. Grassed Area: Maintain vegetation; mow or cut back if impedes water movement or grass health.

Inspect eroded areas repair and reseed as needed. V. GENERAL Dispose of the collected grit, sediment and debris in accordance with current Town/City State and Federal guidelines and regulations. Operation and Maintenance Budget

• Inspection: $300 per year

• Mowing: $200 per year

• Cleaning catch basin grate: $100 per year

• Stormceptor cleaning: $300 per year

• Street Sweeping: $200 per year

• Total annual budget = $1,100

Sample Stormwater System Inspection Log/Checklist

INSPECTOR’S NAME &

DATE: NAME & ADDRESS

OF FACILITY:

GENERAL OBSERVATIONS:

Checked? (Y/N)

Maintenance Needed?

(Y/N)

Maintenance Completed/ Observations & Remarks

Catch Basins

CB-1 (Stormceptor Grate Cover)

Stormceptor Treatment Unit

STC 450i

Infiltration System (Pipe Embedded in Stone Bed)

Infiltration System

Grassed Area

Grassed Area

Street Sweeping

Roadways and Parking Areas

Attach pictures, summary, sketches, and notes as appropriate.


Melrose, MA 02176

APPENDIX E

Drainage Watershed Plans

1982-Drainage Analysis.dwg Saved: 4/23/2020 1:49 PM Plotted: Apr 23, 2020 2:31:pm

Tab:

Pre

-Dev

elop

men

t P

lot S

tyle

: GC

G-2

018.

ctb

Plo

tted

By:

Kev

in C

arte

r

·

·

·

·

·

1982-Drainage Analysis.dwg Saved: 4/23/2020 1:49 PM Plotted: Apr 23, 2020 2:34:pm

Tab:

Pos

t-Dev

elop

men

t P

lot S

tyle

: GC

G-2

018.

ctb

Plo

tted

By:

Kev

in C

arte

r

·

·

·

·

·

drainage calculations and stormwater management plan

Documents