INTRODUCTION This drainage report was prepared for the proposed site re-development at in Burlington, Massachusetts. The project site is approximately 1.05± acres consisting of approximately 70% impervious surfaces and 30% open space. The site contains an existing 9,900± sf building surrounded on all sides with paved parking. The site is accessed from B Street by three existing driveways. Abutting properties to the east, west, and south are fully developed and contain commercial buildings with associated parking. This drainage analysis was performed to determine and analyze the stormwater runoff characteristics resulting from the proposed site changes. There are no existing on-site stormwater systems to accommodate parking lot stormwater runoff. Stormwater from the paved areas of the site runs toward abutting properties to the south, east and west as well as into B Street. There is a small open wooded area on the east side of the building that collects a portion of the runoff from abutting parking areas. The proposed project will reconstruct the majority of parking areas and provide additional site parking and improved site circulation. An underground drainage system will be constructed to capture, treat and infiltrate stormwater runoff. The proposed system will improve treatment of the existing stormwater runoff where none currently exists. DRAINAGE SYSTEM DESIGN Drainage System Model The proposed drainage system is designed to mitigate and treat stormwater runoff occurring from 2, 10, 25 and 100-year 24-hour storm events. The project proposes to expand and redesign the layout of the existing driveway and parking. The proposed driveway and parking redesign will not increase the amount of impervious area on the property. The drainage system is designed according to the recommendations of the Department of Environmental Protection Stormwater Management Policy. The drainage system for this project was designed using the HydroCad Stormwater Modeling System. The HydroCad model consists of subcatchments and ponds. The subcatchments are the drainage areas to each respective structure; the structures are modeled as ponds. The site s drainage area is divided into subcatchments. In the pre-development analysis the central portion is modeled in HydroCad as subcatchment e1. Presently an isolated vegetated area surrounded by paved driveway and parking exists east of the building. Existing topography indicates a significant quantity of surface runoff generated on site as well as a portion of its easterly abutter flows toward a low point contained within the isolated wooded area modeled as HydroCad pond el1. Pre-development subcatchment model e2 represents stormwater runoff at the rear of the site which flows from the southeasterly corner to southwesterly corner towards the abutting property. Pre-development subcatchment model e3 represents stormwater surface runoff on site which flows uniformly from south to north towards B Street contributing to the existing municipal drainage system. SITE DESIGN ENGINEERING, LLC. 11 Cushman Street, Middleboro, MA 02346 P: 508-967-0673 F: 508-967-0674
The post-development site is divided into two subcatchments, S12 and S3. Subcatchment S12 represents a combination of pre-development subcatchment E1 and E2 which are now combined and flow into the proposed stormwater system. Post-development subcatchment S3 is the equivalent of pre-development E3 which flows towards B Street. The rate and volume of water directed to B Street is reduced in the poste-development condition due to decreases in impervious cover in this area. Stormwater Treatment & Storage System The proposed stormwater treatment and storage system utilizes stormwater management Best Management Practices (BMP s). The BMP s proposed consist of a sediment forebay, oil water separator and underground storage/infiltration system. The majority of the runoff generated from the parking area is captured and treated by the proposed BMP s. The proposed system will provide treatment and mitigation to stormwater flows where none currently exist. HydroCad was utilized to analyze and design the stormwater storage system. The HydroCad model simulates the system s function during a storm in order to evaluate its design. The system is modeled in series starting with the sediment forebay, oil/water separator and underground infiltration system. The sediment forebay and oil/water separator provide a minimum 44% TSS removal rate prior to water entering the underground system. The system is entirely selfcontained with no outlets discharging to abutting properties or public ways. Stormwater will first enter the sediment forebay where it will be stored and infiltrated at a slow infiltration rate of 2.41 inches per hour. This slow rate is utilized to allow for sediment buildup and clogging of soil pore space. In large storm events the water level will rise sufficiently to discharge water into the oil/water separator and the underground storage/infiltration system. The oil/water separator does not provide any meaningful storage component. The underground system stores water within the plastic chambers and surrounding stone void space. The stone void ratio is accounted to be 40 percent. A Rawls infiltration rate of 8.27 in/hour class A sand is utilized based on available soil boring information. The underground system is constructed with heavy duty H20 plastic chambers model Stormtech SC-310 as manufactured by ADS. The system will store and infiltrate stormwater as stipulated by the stormwater management policy. In HydroCad the underground system is modeled as pond US1. The system is designed utilizing a groundwater elevation of 43.75+/- (5.75 foot depth) based on soil borings completed by GZA. Copies of the soil borings are included in this report, refer to boring GZ-1, 2 and 8. This depth to groundwater provides a minimum separation of 2.0 feet from the bottom of the proposed infiltration system. RESULTS Post-development HydroCad Pond P1b is the analytical comparison to pre-development subcatchment e2. In the post-development condition all of the runoff generated from E1 and E2 is infiltrated in the proposed storage system on-site therefore there is no longer a postdevelopment discharge point on the south end of the site. Post-Development subcatchment S3 is the analytical comparison to pre-development subcatchment E3. S3 and E3 are direct runoff contributors to the existing municipal drainage network within B Street. S3 contains less SITE DESIGN ENGINEERING, LLC. 11 Cushman Street, Middleboro, MA 02346 P: 508-967-0673 F: 508-967-0674
impervious area than E3 and therefore reduces the rate and volume of water entering B Street. Post-development peak flow rates for applicable subcatchment comparison points do not exceed peak flow rate values of the comparative pre-development HydroCad subcatchment models. FLOW RATES & VOLUME SUMMARY Pre-Development Analysis Pt. e3 Post-Development Analysis Pt. S3 Storm Event Flow Rate (cfs) Volume (cf) Flow Rate (cfs) Volume (cf) 2 - Year 0.61 2,081 0.43 1,647 10 - Year 0.65 2,580 0.65 2,580 25 - Year 1.06 3,712 0.80 3,152 100 - Year 1.31 4,621 1.04 4,051 SITE DESIGN ENGINEERING, LLC. 11 Cushman Street, Middleboro, MA 02346 P: 508-967-0673 F: 508-967-0674
ANALYSIS DATA The following information was used in performing the calculations for the drainage system. NRCS Soils Information The NRCS Soil Survey lists the site as Urban Land (602) with Hinckley (253B) nearby. Site soil evaluation and monitoring have indicated that the prevalent material has the characteristics of a NRCS drainage class for this soil type is A. Please refer to the appendices for copies of the NRCS soil survey map and soil boring logs. 1. Existing & Proposed Ground Covers: The existing ground cover of the site is predominantly developed, consisting of landscaping and buildings. The Curve Numbers listed below, hydrologic soil type A, were used in all the calculations performed with HydroCad. RUNOFF CURVE NUMBERS Cover Description Cover Type Hydrologic condition Curve Number Dense Grass, Woods Fair 43 Landscaping, Lawns Fair 49 Rooftops, Pavements - 98 Walkways, Sidewalks - 98 2. Rainfall Data (24 Hour Storm Duration*) Storm Event Rainfall 2 - Year 3.1 inches 10 - Year 4.5 inches 25 - Year 5.3 inches 100 - Year 6.5 inches * From U.S. Department of Commerce Weather Bureau T.P. 40, May 1961, see attached. SITE DESIGN ENGINEERING, LLC. 11 Cushman Street, Middleboro, MA 02346 P: 508-967-0673 F: 508-967-0674
STORMWATER MANAGEMENT SYSTEM BEST MANAGEMENT PRACTICES (BMP) RECOMMENDED MAINTENANCE 10 B STREET BURLINGTON, MA SEDIMENT FOREBAYS Maintenance: Inspections shall be performed monthly. Accumulated sediment should be removed a minimum of one time per year or whenever the depth of accumulation exceeds 3 inches. Grass height should be maintained between 3 to 6 inches. All sediment, debris, floatables, contaminants shall be disposed of to a landfill or other permitted facility. OIL/WATER & SEDIMENT SEPARATOR Maintenance: Inspections shall be performed two times per year. Units shall be cleaned at least once a year or more frequently whenever the depth of sediment is greater than or equal to half the sump depth. The inlet grate shall not be welded to the frame so that the sump can be easily inspected and maintained. Maintenance of structure shall be performed by qualified personnel and in accordance with OSHA regulations. All sediment, debris, floatables, contaminants shall be disposed of to a landfill or other permitted facility. SUBSURFACE INFILTRATION/STORAGE CHAMBERS Maintenance: Inspections shall be performed on pretreatment BMP s per above outline to ensure proper function of chamber system. The infiltration system shall be inspected 24 hours after major rainfall events (4 inches or more) for retention of liquid following the first 6 months of full operation. After 6 months of operation the system should be inspected at least two time per year at upon the same schedule used for the oil/water separator. The inspection shall be by means of the inspection manhole and/or inspection ports. If liquid is found, the depth shall be recorded and a check of recent storm events and rainfall totals shall be obtained. A follow up inspection within twenty-four (24) hours shall be conducted and the depth of liquid shall be re-measured. If water is still present after the follow up inspection the owner shall notify the design engineer. SITE DESIGN ENGINEERING, LLC. 11 Cushman Street, Middleboro, MA 02346 P: 508-967-0673 F: 508-967-0674
e2 Ex Cond/ Pre Dev Subcatchment - flowing to NE rear of site el1 Exist. low point at westerly of site e1 Ex Cond/ Pre Dev Subcatchment - flowing to exist. low point e3 Ex Cond/ Pre Dev Subcatchment - flowing south to B-Street (municipal) P1b US1 P1a S12 Vegetated Depression - storage volume above OW/OCB Rim Underground Storage System - StormTech SC310 Vegetated Depression - storage volume below OW/OCB Rim Post Dev Subcatchment - flowing to proposed catch basin S3 Post Dev Subcatchment - flowing south to B-Street (municipal) Subcat Reach Pond Link Routing Diagram for 10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here}, Printed 12/3/2015 HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 2-year Rainfall=3.10" Printed 12/3/2015 Page 2 Summary for Subcatchment e1: Ex Cond/ Pre Dev Subcatchment - flowing to exist. low point Runoff = 0.35 cfs @ 12.15 hrs, Volume= 1,455 cf, Depth= 1.14" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 2-year Rainfall=3.10" Area (sf) CN Description * 0 98 Buildings - existing * 6,040 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 9,300 43 Woods/grass comb., Fair, HSG A 15,340 65 Weighted Average 9,300 43 60.63% Pervious Area 6,040 98 39.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.6 50 0.0120 0.09 Sheet Flow, SEGMENT AB Grass: Dense n= 0.240 P2= 3.50" 1.5 50 0.0120 0.55 Shallow Concentrated Flow, SEGMENT BC Woodland Kv= 5.0 fps 11.1 100 Total Summary for Subcatchment e2: Ex Cond/ Pre Dev Subcatchment - flowing to NE rear of site Runoff = 0.49 cfs @ 12.15 hrs, Volume= 2,025 cf, Depth= 1.91" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 2-year Rainfall=3.10"
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 2-year Rainfall=3.10" Printed 12/3/2015 Page 3 Area (sf) CN Description * 0 98 Buildings - existing * 8,450 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 4,300 43 Woods/grass comb., Fair, HSG A 12,750 79 Weighted Average 4,300 43 33.73% Pervious Area 8,450 98 66.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.4 40 0.0175 0.06 Sheet Flow, SEGMENT AB Woods: Light underbrush n= 0.400 P2= 3.50" 1.0 95 0.0060 1.57 Shallow Concentrated Flow, SEGMENT BC Paved Kv= 20.3 fps 11.4 135 Total Summary for Subcatchment e3: Ex Cond/ Pre Dev Subcatchment - flowing south to B-Street (municipal) Runoff = 0.61 cfs @ 12.07 hrs, Volume= 2,081 cf, Depth= 2.54" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 2-year Rainfall=3.10" Area (sf) CN Description * 0 98 Buildings - existing * 8,700 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 1,130 43 Woods/grass comb., Fair, HSG A 9,830 92 Weighted Average 1,130 43 11.50% Pervious Area 8,700 98 88.50% Impervious Area
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 2-year Rainfall=3.10" Printed 12/3/2015 Page 4 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, SEGMENT AB Summary for Subcatchment S12: Post Dev Subcatchment - flowing to proposed catch basin Runoff = 1.26 cfs @ 12.09 hrs, Volume= 4,554 cf, Depth= 2.08" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 2-year Rainfall=3.10" Area (sf) CN Description * 0 98 Buildings - existing * 18,920 98 Driveways, parking, walkways - proposed * 0 98 Other impervious - proposed * 4,300 49 Landscaping - proposed 0 49 50-75% Grass cover, Fair, HSG A 3,085 43 Woods/grass comb., Fair, HSG A 26,305 84 Weighted Average 7,385 46 28.07% Pervious Area 18,920 98 71.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.7 35 0.0400 0.09 Sheet Flow, SEGMENT AB Woods: Light underbrush n= 0.400 P2= 3.50" Summary for Subcatchment S3: Post Dev Subcatchment - flowing south to B-Street (municipal) Runoff = 0.43 cfs @ 12.11 hrs, Volume= 1,647 cf, Depth= 1.70" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 2-year Rainfall=3.10"
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 2-year Rainfall=3.10" Printed 12/3/2015 Page 5 Area (sf) CN Description * 0 98 Buildings - existing * 6,739 98 Driveways, parking, walkways - proposed * 0 98 Other impervious - proposed * 4,871 49 Landscaping - proposed 0 49 50-75% Grass cover, Fair, HSG A 0 43 Woods/grass comb., Fair, HSG A 11,610 77 Weighted Average 4,871 49 41.96% Pervious Area 6,739 98 58.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 35 0.0100 0.08 Sheet Flow, SEGMENT AB Grass: Dense n= 0.240 P2= 3.50" Summary for Pond el1: Exist. low point at westerly of site Inflow Area = 15,340 sf, 39.37% Impervious, Inflow Depth = 1.14" for 2-year event Inflow = 0.35 cfs @ 12.15 hrs, Volume= 1,455 cf Primary = 0.35 cfs @ 12.15 hrs, Volume= 1,455 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Summary for Pond P1a: Vegetated Depression - storage volume below OW/OCB Rim Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 2.08" for 2-year event Inflow = 1.26 cfs @ 12.09 hrs, Volume= 4,554 cf Outflow = 1.22 cfs @ 12.12 hrs, Volume= 4,553 cf, Atten= 3%, Lag= 1.5 min Discarded = 0.04 cfs @ 12.12 hrs, Volume= 2,210 cf Primary = 1.18 cfs @ 12.12 hrs, Volume= 2,343 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 2-year Rainfall=3.10" Printed 12/3/2015 Page 6 Peak Elev= 48.65' @ 12.12 hrs Surf.Area= 939 sf Storage= 728 cf Plug-Flow detention time= 126.5 min calculated for 4,549 cf (100% of inflow) Center-of-Mass det. time= 127.3 min ( 887.4-760.1 ) Volume Invert Avail.Storage Storage Description #1 47.00' 8,209 cf Custom Stage Data - Vegetated Depression (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 47.00 150 0 0 47.50 260 103 103 48.00 450 178 280 48.50 820 318 598 48.80 1,060 282 880 49.00 1,220 228 1,107 49.33 1,500 449 1,556 49.50 5,000 553 2,109 50.00 19,400 6,100 8,209 Device Routing Invert Outlet Devices #1 Discarded 47.00' 2.410 in/hr Exfiltration over Surface area from 47.00' - 48.90' Excluded Surface area = 150 sf #2 Primary 48.50' 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.04 cfs @ 12.12 hrs HW=48.65' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=1.17 cfs @ 12.12 hrs HW=48.65' TW=46.23' (Dynamic Tailwater) 2=Orifice/Grate (Weir Controls 1.17 cfs @ 1.26 fps)
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 2-year Rainfall=3.10" Printed 12/3/2015 Page 7 Summary for Pond P1b: Vegetated Depression - storage volume above OW/OCB Rim Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 0.00" for 2-year event Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 0%, Lag= 0.0 min Discarded = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Peak Elev= 48.80' @ 0.00 hrs Surf.Area= 1,060 sf Storage= 0 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no inflow) Volume Invert Avail.Storage Storage Description #1 48.80' 7,329 cf Custom Stage Data - Vegetated Depression (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 48.80 1,060 0 0 49.00 1,220 228 228 49.33 1,500 449 677 49.50 5,000 553 1,229 50.00 19,400 6,100 7,329 Device Routing Invert Outlet Devices #1 Discarded 48.80' 2.410 in/hr Exfiltration over Surface area from 48.80' - 48.90' Excluded Surface area = 1,060 sf Discarded OutFlow Max=0.00 cfs @ 0.00 hrs HW=48.80' (Free Discharge) 1=Exfiltration ( Controls 0.00 cfs)
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 2-year Rainfall=3.10" Printed 12/3/2015 Page 8 Summary for Pond US1: Underground Storage System - StormTech SC310 Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 1.07" for 2-year event Inflow = 1.18 cfs @ 12.12 hrs, Volume= 2,343 cf Outflow = 0.35 cfs @ 12.44 hrs, Volume= 2,350 cf, Atten= 70%, Lag= 19.2 min Discarded = 0.35 cfs @ 12.44 hrs, Volume= 2,350 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Peak Elev= 46.51' @ 12.44 hrs Surf.Area= 1,724 sf Storage= 699 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 14.8 min ( 757.6-742.8 ) Volume Invert Avail.Storage Storage Description #1A 45.75' 1,216 cf 38.17'W x 45.16'L x 2.33'H Field A 4,022 cf Overall - 983 cf Embedded = 3,039 cf x 40.0% Voids #2 48.08' 9 cf 2.00'D x 3.00'H Vertical Cone/Cylinder - OW/OCB Riser-Impervious #3A 46.25' 983 cf ADS_StormTech SC-310 x 66 Inside #1 Effective Size= 28.9"W x 16.0"H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0"W x 16.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 2.07 sf x 11 rows 2,208 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 45.75' 8.270 in/hr Exfiltration over Wetted area #2 Primary 48.50' 24.0" Horiz. Orifice/Grate - OW/OCB Rim C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.35 cfs @ 12.44 hrs HW=46.51' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.35 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=45.75' TW=48.80' (Dynamic Tailwater) 2=Orifice/Grate - OW/OCB Rim ( Controls 0.00 cfs)
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 10-year Rainfall=4.50" Printed 12/3/2015 Page 9 Summary for Subcatchment e1: Ex Cond/ Pre Dev Subcatchment - flowing to exist. low point Runoff = 0.51 cfs @ 12.15 hrs, Volume= 2,322 cf, Depth= 1.82" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 10-year Rainfall=4.50" Area (sf) CN Description * 0 98 Buildings - existing * 6,040 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 9,300 43 Woods/grass comb., Fair, HSG A 15,340 65 Weighted Average 9,300 43 60.63% Pervious Area 6,040 98 39.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.6 50 0.0120 0.09 Sheet Flow, SEGMENT AB Grass: Dense n= 0.240 P2= 3.50" 1.5 50 0.0120 0.55 Shallow Concentrated Flow, SEGMENT BC Woodland Kv= 5.0 fps 11.1 100 Total Summary for Subcatchment e2: Ex Cond/ Pre Dev Subcatchment - flowing to NE rear of site Runoff = 0.71 cfs @ 12.15 hrs, Volume= 3,084 cf, Depth= 2.90" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 10-year Rainfall=4.50"
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 10-year Rainfall=4.50" Printed 12/3/2015 Page 10 Area (sf) CN Description * 0 98 Buildings - existing * 8,450 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 4,300 43 Woods/grass comb., Fair, HSG A 12,750 79 Weighted Average 4,300 43 33.73% Pervious Area 8,450 98 66.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.4 40 0.0175 0.06 Sheet Flow, SEGMENT AB Woods: Light underbrush n= 0.400 P2= 3.50" 1.0 95 0.0060 1.57 Shallow Concentrated Flow, SEGMENT BC Paved Kv= 20.3 fps 11.4 135 Total Summary for Subcatchment e3: Ex Cond/ Pre Dev Subcatchment - flowing south to B-Street (municipal) Runoff = 0.90 cfs @ 12.07 hrs, Volume= 3,113 cf, Depth= 3.80" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 10-year Rainfall=4.50" Area (sf) CN Description * 0 98 Buildings - existing * 8,700 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 1,130 43 Woods/grass comb., Fair, HSG A 9,830 92 Weighted Average 1,130 43 11.50% Pervious Area 8,700 98 88.50% Impervious Area
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 10-year Rainfall=4.50" Printed 12/3/2015 Page 11 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, SEGMENT AB Summary for Subcatchment S12: Post Dev Subcatchment - flowing to proposed catch basin Runoff = 1.85 cfs @ 12.09 hrs, Volume= 6,940 cf, Depth= 3.17" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 10-year Rainfall=4.50" Area (sf) CN Description * 0 98 Buildings - existing * 18,920 98 Driveways, parking, walkways - proposed * 0 98 Other impervious - proposed * 4,300 49 Landscaping - proposed 0 49 50-75% Grass cover, Fair, HSG A 3,085 43 Woods/grass comb., Fair, HSG A 26,305 84 Weighted Average 7,385 46 28.07% Pervious Area 18,920 98 71.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.7 35 0.0400 0.09 Sheet Flow, SEGMENT AB Woods: Light underbrush n= 0.400 P2= 3.50" Summary for Subcatchment S3: Post Dev Subcatchment - flowing south to B-Street (municipal) Runoff = 0.65 cfs @ 12.11 hrs, Volume= 2,580 cf, Depth= 2.67" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 10-year Rainfall=4.50"
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 10-year Rainfall=4.50" Printed 12/3/2015 Page 12 Area (sf) CN Description * 0 98 Buildings - existing * 6,739 98 Driveways, parking, walkways - proposed * 0 98 Other impervious - proposed * 4,871 49 Landscaping - proposed 0 49 50-75% Grass cover, Fair, HSG A 0 43 Woods/grass comb., Fair, HSG A 11,610 77 Weighted Average 4,871 49 41.96% Pervious Area 6,739 98 58.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 35 0.0100 0.08 Sheet Flow, SEGMENT AB Grass: Dense n= 0.240 P2= 3.50" Summary for Pond el1: Exist. low point at westerly of site Inflow Area = 15,340 sf, 39.37% Impervious, Inflow Depth = 1.82" for 10-year event Inflow = 0.51 cfs @ 12.15 hrs, Volume= 2,322 cf Primary = 0.51 cfs @ 12.15 hrs, Volume= 2,322 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Summary for Pond P1a: Vegetated Depression - storage volume below OW/OCB Rim Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 3.17" for 10-year event Inflow = 1.85 cfs @ 12.09 hrs, Volume= 6,940 cf Outflow = 1.80 cfs @ 12.12 hrs, Volume= 6,939 cf, Atten= 3%, Lag= 1.4 min Discarded = 0.05 cfs @ 12.12 hrs, Volume= 2,678 cf Primary = 1.76 cfs @ 12.12 hrs, Volume= 4,261 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 10-year Rainfall=4.50" Printed 12/3/2015 Page 13 Peak Elev= 48.69' @ 12.12 hrs Surf.Area= 975 sf Storage= 772 cf Plug-Flow detention time= 100.8 min calculated for 6,933 cf (100% of inflow) Center-of-Mass det. time= 101.6 min ( 858.6-756.9 ) Volume Invert Avail.Storage Storage Description #1 47.00' 8,209 cf Custom Stage Data - Vegetated Depression (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 47.00 150 0 0 47.50 260 103 103 48.00 450 178 280 48.50 820 318 598 48.80 1,060 282 880 49.00 1,220 228 1,107 49.33 1,500 449 1,556 49.50 5,000 553 2,109 50.00 19,400 6,100 8,209 Device Routing Invert Outlet Devices #1 Discarded 47.00' 2.410 in/hr Exfiltration over Surface area from 47.00' - 48.90' Excluded Surface area = 150 sf #2 Primary 48.50' 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.05 cfs @ 12.12 hrs HW=48.69' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=1.74 cfs @ 12.12 hrs HW=48.69' TW=46.52' (Dynamic Tailwater) 2=Orifice/Grate (Weir Controls 1.74 cfs @ 1.44 fps)
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 10-year Rainfall=4.50" Printed 12/3/2015 Page 14 Summary for Pond P1b: Vegetated Depression - storage volume above OW/OCB Rim Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 0.00" for 10-year event Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 0%, Lag= 0.0 min Discarded = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Peak Elev= 48.80' @ 0.00 hrs Surf.Area= 1,060 sf Storage= 0 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no inflow) Volume Invert Avail.Storage Storage Description #1 48.80' 7,329 cf Custom Stage Data - Vegetated Depression (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 48.80 1,060 0 0 49.00 1,220 228 228 49.33 1,500 449 677 49.50 5,000 553 1,229 50.00 19,400 6,100 7,329 Device Routing Invert Outlet Devices #1 Discarded 48.80' 2.410 in/hr Exfiltration over Surface area from 48.80' - 48.90' Excluded Surface area = 1,060 sf Discarded OutFlow Max=0.00 cfs @ 0.00 hrs HW=48.80' (Free Discharge) 1=Exfiltration ( Controls 0.00 cfs)
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 10-year Rainfall=4.50" Printed 12/3/2015 Page 15 Summary for Pond US1: Underground Storage System - StormTech SC310 Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 1.94" for 10-year event Inflow = 1.76 cfs @ 12.12 hrs, Volume= 4,261 cf Outflow = 0.37 cfs @ 12.54 hrs, Volume= 4,271 cf, Atten= 79%, Lag= 25.4 min Discarded = 0.37 cfs @ 12.54 hrs, Volume= 4,271 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Peak Elev= 47.15' @ 12.54 hrs Surf.Area= 1,724 sf Storage= 1,481 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 29.0 min ( 774.3-745.4 ) Volume Invert Avail.Storage Storage Description #1A 45.75' 1,216 cf 38.17'W x 45.16'L x 2.33'H Field A 4,022 cf Overall - 983 cf Embedded = 3,039 cf x 40.0% Voids #2 48.08' 9 cf 2.00'D x 3.00'H Vertical Cone/Cylinder - OW/OCB Riser-Impervious #3A 46.25' 983 cf ADS_StormTech SC-310 x 66 Inside #1 Effective Size= 28.9"W x 16.0"H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0"W x 16.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 2.07 sf x 11 rows 2,208 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 45.75' 8.270 in/hr Exfiltration over Wetted area #2 Primary 48.50' 24.0" Horiz. Orifice/Grate - OW/OCB Rim C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.37 cfs @ 12.54 hrs HW=47.15' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.37 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=45.75' TW=48.80' (Dynamic Tailwater) 2=Orifice/Grate - OW/OCB Rim ( Controls 0.00 cfs)
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 25-year Rainfall=5.30" Printed 12/3/2015 Page 16 Summary for Subcatchment e1: Ex Cond/ Pre Dev Subcatchment - flowing to exist. low point Runoff = 0.62 cfs @ 12.15 hrs, Volume= 2,890 cf, Depth= 2.26" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 25-year Rainfall=5.30" Area (sf) CN Description * 0 98 Buildings - existing * 6,040 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 9,300 43 Woods/grass comb., Fair, HSG A 15,340 65 Weighted Average 9,300 43 60.63% Pervious Area 6,040 98 39.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.6 50 0.0120 0.09 Sheet Flow, SEGMENT AB Grass: Dense n= 0.240 P2= 3.50" 1.5 50 0.0120 0.55 Shallow Concentrated Flow, SEGMENT BC Woodland Kv= 5.0 fps 11.1 100 Total Summary for Subcatchment e2: Ex Cond/ Pre Dev Subcatchment - flowing to NE rear of site Runoff = 0.85 cfs @ 12.15 hrs, Volume= 3,723 cf, Depth= 3.50" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 25-year Rainfall=5.30"
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 25-year Rainfall=5.30" Printed 12/3/2015 Page 17 Area (sf) CN Description * 0 98 Buildings - existing * 8,450 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 4,300 43 Woods/grass comb., Fair, HSG A 12,750 79 Weighted Average 4,300 43 33.73% Pervious Area 8,450 98 66.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.4 40 0.0175 0.06 Sheet Flow, SEGMENT AB Woods: Light underbrush n= 0.400 P2= 3.50" 1.0 95 0.0060 1.57 Shallow Concentrated Flow, SEGMENT BC Paved Kv= 20.3 fps 11.4 135 Total Summary for Subcatchment e3: Ex Cond/ Pre Dev Subcatchment - flowing south to B-Street (municipal) Runoff = 1.06 cfs @ 12.07 hrs, Volume= 3,712 cf, Depth= 4.53" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 25-year Rainfall=5.30" Area (sf) CN Description * 0 98 Buildings - existing * 8,700 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 1,130 43 Woods/grass comb., Fair, HSG A 9,830 92 Weighted Average 1,130 43 11.50% Pervious Area 8,700 98 88.50% Impervious Area
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 25-year Rainfall=5.30" Printed 12/3/2015 Page 18 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, SEGMENT AB Summary for Subcatchment S12: Post Dev Subcatchment - flowing to proposed catch basin Runoff = 2.22 cfs @ 12.09 hrs, Volume= 8,364 cf, Depth= 3.82" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 25-year Rainfall=5.30" Area (sf) CN Description * 0 98 Buildings - existing * 18,920 98 Driveways, parking, walkways - proposed * 0 98 Other impervious - proposed * 4,300 49 Landscaping - proposed 0 49 50-75% Grass cover, Fair, HSG A 3,085 43 Woods/grass comb., Fair, HSG A 26,305 84 Weighted Average 7,385 46 28.07% Pervious Area 18,920 98 71.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.7 35 0.0400 0.09 Sheet Flow, SEGMENT AB Woods: Light underbrush n= 0.400 P2= 3.50" Summary for Subcatchment S3: Post Dev Subcatchment - flowing south to B-Street (municipal) Runoff = 0.80 cfs @ 12.11 hrs, Volume= 3,152 cf, Depth= 3.26" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 25-year Rainfall=5.30"
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 25-year Rainfall=5.30" Printed 12/3/2015 Page 19 Area (sf) CN Description * 0 98 Buildings - existing * 6,739 98 Driveways, parking, walkways - proposed * 0 98 Other impervious - proposed * 4,871 49 Landscaping - proposed 0 49 50-75% Grass cover, Fair, HSG A 0 43 Woods/grass comb., Fair, HSG A 11,610 77 Weighted Average 4,871 49 41.96% Pervious Area 6,739 98 58.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 35 0.0100 0.08 Sheet Flow, SEGMENT AB Grass: Dense n= 0.240 P2= 3.50" Summary for Pond el1: Exist. low point at westerly of site Inflow Area = 15,340 sf, 39.37% Impervious, Inflow Depth = 2.26" for 25-year event Inflow = 0.62 cfs @ 12.15 hrs, Volume= 2,890 cf Primary = 0.62 cfs @ 12.15 hrs, Volume= 2,890 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Summary for Pond P1a: Vegetated Depression - storage volume below OW/OCB Rim Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 3.82" for 25-year event Inflow = 2.22 cfs @ 12.09 hrs, Volume= 8,364 cf Outflow = 2.17 cfs @ 12.12 hrs, Volume= 8,363 cf, Atten= 2%, Lag= 1.3 min Discarded = 0.05 cfs @ 12.12 hrs, Volume= 2,886 cf Primary = 2.12 cfs @ 12.12 hrs, Volume= 5,477 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 25-year Rainfall=5.30" Printed 12/3/2015 Page 20 Peak Elev= 48.72' @ 12.12 hrs Surf.Area= 996 sf Storage= 797 cf Plug-Flow detention time= 90.3 min calculated for 8,356 cf (100% of inflow) Center-of-Mass det. time= 91.1 min ( 847.0-755.9 ) Volume Invert Avail.Storage Storage Description #1 47.00' 8,209 cf Custom Stage Data - Vegetated Depression (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 47.00 150 0 0 47.50 260 103 103 48.00 450 178 280 48.50 820 318 598 48.80 1,060 282 880 49.00 1,220 228 1,107 49.33 1,500 449 1,556 49.50 5,000 553 2,109 50.00 19,400 6,100 8,209 Device Routing Invert Outlet Devices #1 Discarded 47.00' 2.410 in/hr Exfiltration over Surface area from 47.00' - 48.90' Excluded Surface area = 150 sf #2 Primary 48.50' 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.05 cfs @ 12.12 hrs HW=48.72' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=2.11 cfs @ 12.12 hrs HW=48.72' TW=46.70' (Dynamic Tailwater) 2=Orifice/Grate (Weir Controls 2.11 cfs @ 1.53 fps)
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 25-year Rainfall=5.30" Printed 12/3/2015 Page 21 Summary for Pond P1b: Vegetated Depression - storage volume above OW/OCB Rim Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 0.00" for 25-year event Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 0%, Lag= 0.0 min Discarded = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Peak Elev= 48.80' @ 0.00 hrs Surf.Area= 1,060 sf Storage= 0 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no inflow) Volume Invert Avail.Storage Storage Description #1 48.80' 7,329 cf Custom Stage Data - Vegetated Depression (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 48.80 1,060 0 0 49.00 1,220 228 228 49.33 1,500 449 677 49.50 5,000 553 1,229 50.00 19,400 6,100 7,329 Device Routing Invert Outlet Devices #1 Discarded 48.80' 2.410 in/hr Exfiltration over Surface area from 48.80' - 48.90' Excluded Surface area = 1,060 sf Discarded OutFlow Max=0.00 cfs @ 0.00 hrs HW=48.80' (Free Discharge) 1=Exfiltration ( Controls 0.00 cfs)
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 25-year Rainfall=5.30" Printed 12/3/2015 Page 22 Summary for Pond US1: Underground Storage System - StormTech SC310 Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 2.50" for 25-year event Inflow = 2.12 cfs @ 12.12 hrs, Volume= 5,477 cf Outflow = 0.39 cfs @ 12.57 hrs, Volume= 5,494 cf, Atten= 81%, Lag= 27.4 min Discarded = 0.39 cfs @ 12.57 hrs, Volume= 5,494 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Peak Elev= 47.78' @ 12.57 hrs Surf.Area= 1,724 sf Storage= 1,991 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 38.1 min ( 784.7-746.6 ) Volume Invert Avail.Storage Storage Description #1A 45.75' 1,216 cf 38.17'W x 45.16'L x 2.33'H Field A 4,022 cf Overall - 983 cf Embedded = 3,039 cf x 40.0% Voids #2 48.08' 9 cf 2.00'D x 3.00'H Vertical Cone/Cylinder - OW/OCB Riser-Impervious #3A 46.25' 983 cf ADS_StormTech SC-310 x 66 Inside #1 Effective Size= 28.9"W x 16.0"H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0"W x 16.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 2.07 sf x 11 rows 2,208 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 45.75' 8.270 in/hr Exfiltration over Wetted area #2 Primary 48.50' 24.0" Horiz. Orifice/Grate - OW/OCB Rim C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.39 cfs @ 12.57 hrs HW=47.78' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.39 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=45.75' TW=48.80' (Dynamic Tailwater) 2=Orifice/Grate - OW/OCB Rim ( Controls 0.00 cfs)
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 100-year Rainfall=6.50" Printed 12/3/2015 Page 23 Summary for Subcatchment e1: Ex Cond/ Pre Dev Subcatchment - flowing to exist. low point Runoff = 0.84 cfs @ 12.16 hrs, Volume= 3,823 cf, Depth= 2.99" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 100-year Rainfall=6.50" Area (sf) CN Description * 0 98 Buildings - existing * 6,040 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 9,300 43 Woods/grass comb., Fair, HSG A 15,340 65 Weighted Average 9,300 43 60.63% Pervious Area 6,040 98 39.37% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.6 50 0.0120 0.09 Sheet Flow, SEGMENT AB Grass: Dense n= 0.240 P2= 3.50" 1.5 50 0.0120 0.55 Shallow Concentrated Flow, SEGMENT BC Woodland Kv= 5.0 fps 11.1 100 Total Summary for Subcatchment e2: Ex Cond/ Pre Dev Subcatchment - flowing to NE rear of site Runoff = 1.08 cfs @ 12.16 hrs, Volume= 4,719 cf, Depth= 4.44" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 100-year Rainfall=6.50"
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 100-year Rainfall=6.50" Printed 12/3/2015 Page 24 Area (sf) CN Description * 0 98 Buildings - existing * 8,450 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 4,300 43 Woods/grass comb., Fair, HSG A 12,750 79 Weighted Average 4,300 43 33.73% Pervious Area 8,450 98 66.27% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.4 40 0.0175 0.06 Sheet Flow, SEGMENT AB Woods: Light underbrush n= 0.400 P2= 3.50" 1.0 95 0.0060 1.57 Shallow Concentrated Flow, SEGMENT BC Paved Kv= 20.3 fps 11.4 135 Total Summary for Subcatchment e3: Ex Cond/ Pre Dev Subcatchment - flowing south to B-Street (municipal) Runoff = 1.31 cfs @ 12.07 hrs, Volume= 4,621 cf, Depth= 5.64" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 100-year Rainfall=6.50" Area (sf) CN Description * 0 98 Buildings - existing * 8,700 98 Driveways, parkings, walkways - existing * 0 98 Other impervious - existing 0 49 50-75% Grass cover, Fair, HSG A 1,130 43 Woods/grass comb., Fair, HSG A 9,830 92 Weighted Average 1,130 43 11.50% Pervious Area 8,700 98 88.50% Impervious Area
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 100-year Rainfall=6.50" Printed 12/3/2015 Page 25 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, SEGMENT AB Summary for Subcatchment S12: Post Dev Subcatchment - flowing to proposed catch basin Runoff = 2.82 cfs @ 12.09 hrs, Volume= 10,563 cf, Depth= 4.82" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 100-year Rainfall=6.50" Area (sf) CN Description * 0 98 Buildings - existing * 18,920 98 Driveways, parking, walkways - proposed * 0 98 Other impervious - proposed * 4,300 49 Landscaping - proposed 0 49 50-75% Grass cover, Fair, HSG A 3,085 43 Woods/grass comb., Fair, HSG A 26,305 84 Weighted Average 7,385 46 28.07% Pervious Area 18,920 98 71.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.7 35 0.0400 0.09 Sheet Flow, SEGMENT AB Woods: Light underbrush n= 0.400 P2= 3.50" Summary for Subcatchment S3: Post Dev Subcatchment - flowing south to B-Street (municipal) Runoff = 1.04 cfs @ 12.11 hrs, Volume= 4,051 cf, Depth= 4.19" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Type III 24-hr 100-year Rainfall=6.50"
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 100-year Rainfall=6.50" Printed 12/3/2015 Page 26 Area (sf) CN Description * 0 98 Buildings - existing * 6,739 98 Driveways, parking, walkways - proposed * 0 98 Other impervious - proposed * 4,871 49 Landscaping - proposed 0 49 50-75% Grass cover, Fair, HSG A 0 43 Woods/grass comb., Fair, HSG A 11,610 77 Weighted Average 4,871 49 41.96% Pervious Area 6,739 98 58.04% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.8 35 0.0100 0.08 Sheet Flow, SEGMENT AB Grass: Dense n= 0.240 P2= 3.50" Summary for Pond el1: Exist. low point at westerly of site Inflow Area = 15,340 sf, 39.37% Impervious, Inflow Depth = 2.99" for 100-year event Inflow = 0.84 cfs @ 12.16 hrs, Volume= 3,823 cf Primary = 0.84 cfs @ 12.16 hrs, Volume= 3,823 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Summary for Pond P1a: Vegetated Depression - storage volume below OW/OCB Rim Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 4.82" for 100-year event Inflow = 2.82 cfs @ 12.09 hrs, Volume= 10,563 cf Outflow = 2.76 cfs @ 12.12 hrs, Volume= 10,561 cf, Atten= 2%, Lag= 1.3 min Discarded = 0.05 cfs @ 12.44 hrs, Volume= 3,115 cf Primary = 2.71 cfs @ 12.12 hrs, Volume= 7,447 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 100-year Rainfall=6.50" Printed 12/3/2015 Page 27 Peak Elev= 48.82' @ 12.44 hrs Surf.Area= 1,077 sf Storage= 902 cf Plug-Flow detention time= 77.3 min calculated for 10,553 cf (100% of inflow) Center-of-Mass det. time= 78.1 min ( 833.0-754.9 ) Volume Invert Avail.Storage Storage Description #1 47.00' 8,209 cf Custom Stage Data - Vegetated Depression (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 47.00 150 0 0 47.50 260 103 103 48.00 450 178 280 48.50 820 318 598 48.80 1,060 282 880 49.00 1,220 228 1,107 49.33 1,500 449 1,556 49.50 5,000 553 2,109 50.00 19,400 6,100 8,209 Device Routing Invert Outlet Devices #1 Discarded 47.00' 2.410 in/hr Exfiltration over Surface area from 47.00' - 48.90' Excluded Surface area = 150 sf #2 Primary 48.50' 24.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.05 cfs @ 12.44 hrs HW=48.81' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=2.69 cfs @ 12.12 hrs HW=48.76' TW=47.03' (Dynamic Tailwater) 2=Orifice/Grate (Weir Controls 2.69 cfs @ 1.66 fps)
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 100-year Rainfall=6.50" Printed 12/3/2015 Page 28 Summary for Pond P1b: Vegetated Depression - storage volume above OW/OCB Rim Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 0.30" for 100-year event Inflow = 1.68 cfs @ 12.52 hrs, Volume= 661 cf Outflow = 0.00 cfs @ 12.32 hrs, Volume= 572 cf, Atten= 100%, Lag= 0.0 min Discarded = 0.00 cfs @ 12.32 hrs, Volume= 572 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Peak Elev= 49.32' @ 12.56 hrs Surf.Area= 1,488 sf Storage= 656 cf Plug-Flow detention time= 1,061.3 min calculated for 572 cf (87% of inflow) Center-of-Mass det. time= 1,060.1 min ( 1,804.2-744.1 ) Volume Invert Avail.Storage Storage Description #1 48.80' 7,329 cf Custom Stage Data - Vegetated Depression (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 48.80 1,060 0 0 49.00 1,220 228 228 49.33 1,500 449 677 49.50 5,000 553 1,229 50.00 19,400 6,100 7,329 Device Routing Invert Outlet Devices #1 Discarded 48.80' 2.410 in/hr Exfiltration over Surface area from 48.80' - 48.90' Excluded Surface area = 1,060 sf Discarded OutFlow Max=0.00 cfs @ 12.32 hrs HW=48.98' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.00 cfs)
10 B STREET HYDROCAD MODEL 12-3-15 Prepared by {enter your company name here} HydroCAD 10.00-11 s/n 05085 2014 HydroCAD Software Solutions LLC Type III 24-hr 100-year Rainfall=6.50" Printed 12/3/2015 Page 29 Summary for Pond US1: Underground Storage System - StormTech SC310 Inflow Area = 26,305 sf, 71.93% Impervious, Inflow Depth = 3.40" for 100-year event Inflow = 2.71 cfs @ 12.12 hrs, Volume= 7,447 cf Outflow = 2.08 cfs @ 12.52 hrs, Volume= 7,459 cf, Atten= 23%, Lag= 24.2 min Discarded = 0.40 cfs @ 12.28 hrs, Volume= 6,798 cf Primary = 1.68 cfs @ 12.52 hrs, Volume= 661 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.04 hrs Peak Elev= 49.31' @ 12.50 hrs Surf.Area= 1,724 sf Storage= 2,202 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 37.3 min ( 788.0-750.7 ) Volume Invert Avail.Storage Storage Description #1A 45.75' 1,216 cf 38.17'W x 45.16'L x 2.33'H Field A 4,022 cf Overall - 983 cf Embedded = 3,039 cf x 40.0% Voids #2 48.08' 9 cf 2.00'D x 3.00'H Vertical Cone/Cylinder - OW/OCB Riser-Impervious #3A 46.25' 983 cf ADS_StormTech SC-310 x 66 Inside #1 Effective Size= 28.9"W x 16.0"H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0"W x 16.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 2.07 sf x 11 rows 2,208 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 45.75' 8.270 in/hr Exfiltration over Wetted area #2 Primary 48.50' 24.0" Horiz. Orifice/Grate - OW/OCB Rim C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.40 cfs @ 12.28 hrs HW=48.82' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.40 cfs) Primary OutFlow Max=0.00 cfs @ 12.52 hrs HW=49.16' TW=49.23' (Dynamic Tailwater) 2=Orifice/Grate - OW/OCB Rim ( Controls 0.00 cfs)
Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report A. Introduction Important: When filling out forms on the computer, use only the tab key to move your cursor - do not use the return key. A Stormwater Report must be submitted with the Notice of Intent permit application to document compliance with the Stormwater Management Standards. The following checklist is NOT a substitute for the Stormwater Report (which should provide more substantive and detailed information) but is offered here as a tool to help the applicant organize their Stormwater Management documentation for their Report and for the reviewer to assess this information in a consistent format. As noted in the Checklist, the Stormwater Report must contain the engineering computations and supporting information set forth in 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. 1 This Checklist is to be used as the cover for the completed Stormwater Report. Applicant/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 8 2 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. 1 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 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: 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 LID Site Design Credit 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 Report 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 predevelopment 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. Standard 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 1 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. 1 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 for Stormwater Report 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 storing 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. 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 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 for Stormwater Report Checklist (continued) Standard 4: Water Quality (continued) The BMP is sized (and calculations provided) based on: The ½ 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 04/01/08 Stormwater Report Checklist Page 6 of 8
Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report 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 and/or Foot Path Redevelopment Project 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; Vegetation Planning; Site Development Plan; Construction Sequencing Plan; Sequencing of Erosion and Sedimentation Controls; Operation and Maintenance of Erosion and Sedimentation Controls; Inspection Schedule; Maintenance Schedule; Inspection and Maintenance Log Form. 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 Checklist for Stormwater Report 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
10 B STREET STORMWATER MANAGEMENT TSS REMOVAL CALCULATION WORKSHEET FOR REMOVAL RATE PRIOR TO ENTERING INFILTRATION SYSTEM SDE Job No.: 15071 Date: 12/3/15 Prepared by: RPBT Checked by: DCM A B C D E TSS Removal Starting TSS Amount Remaining BMP Rate Load* Removed (BxC) Load (C-D) Sediment Forebay 25.0% 1.000 0.250 0.750 Oil/water separator 25.0% 0.750 0.188 0.563 0.563 0.000 0.563 0.563 0.000 0.563 Total TSS Removal = 44% * Equals remaining load from previous BMP (E) which enters the BMP
10 B STREET STORMWATER MANAGEMENT WATER QUALITY TREATMENT VOLUME CALCULATION WORKSHEET SDE Job No.: 15071 Date: 12/3/15 Prepared by: RPBT Checked by: DCM Area X in. of runoff 1 Impervious Area sf cf Total Impervious Area Excluding Roof 25,659 2,138 Total Volume = 2,138 Drainage Storage Structure Treatment Storage Capacity ( cf ) Primary Secondary Subtotal Sediment Forebay 1,108 1,108 Oil Water Separator 2,000 2,000 0 0 Total WQv Provided, (cf) = 3,108 3,108 Note: 1. Surface storage primary available water quality volume storage is based on volume below structures' lowest outlet excluding infiltration.
10 B STREET STORMWATER MANAGEMENT STORMWATER RECHARGE CALCULATION WORKSHEET SDE Job No.: 15071 Date: 12/3/15 Prepared by: RPBT Checked by: DCM Hydrologic Group A B C D Total ReV Target Runoff Depth Factor (Inches of Runoff) 0.60 0.35 0.25 0.10 Total Impervious Area, (sf) 25,659 0 0 X inches of runoff, (cf) 1,283 0 0 0 1,283 Total Recharge Volume Required, (cf) = 1,283 Soil Texture Class Loamy Sand Infiltration Rate (inches / hour) 8.27 Structure Available Structure Recharged Volume, (cf) 6,798 Storage, (cf) Underground Storage Chambers System 6,798 Total Recharge Volume Provided, (cf) = 0 Note: 1. Infiltration rates are derived from the 1982 Rawls rates based on soil texture. 2. Recharged volume are calculated utilizing Simple Dynamic Method : Automated 3. Calculations are based on 2-Yr, 24-Hr storm event.
APPROXIMATE PROPERTY BOUNDARY APPROXIMATE REVISED POOL LOCATION GZGZ- GZ- T GZ-7 GZ- GZ-4 T GZ-9 N GZ-10 GZ-6 GZ-3 W GZ-5 E S GZ-2 APPROXIMATE LOCATION OF CUT IN CONCRETE FLOOR 0 25 50 100 SCALE IN FEET GZ-8 GZ-1 PHASE I AND II ESA 10 B STREET, BURLINGTON, MA SITE PLAN WITH EXPLORATION LOCATIONS PREPARED FOR: PREPARED BY: GZA GeoEnvironmental, Inc. Engineers and Scientists www.gza.com REMF CORP. 60 WELLS AVENUE, SUITE 100 NEWTON, MA PROJ MGR: MLS REVIEWED BY: CDC CHECKED BY: DESIGNED BY: MLS DRAWN BY: AJK SCALE: DATE: 6/26/2015 PROJECT NO. 18.0172305.00 FSV AS SHOWN REVISION NO. FIG 2 SHEET NO.
Drilling Co.: Geologic Earth Exploration, Inc. Type of Rig: Track Foreman: Taylor Grenier Rig Model: Geoprobe 6620 DT Logged By: Matt Steele Drilling Method: DPT Auger/Casing Type: Macrocore I.D./O.D.: Hammer Weight (lb.): Hammer Fall (in.): Other: Casing Sample Depth Blows/ Pen. (ft) Core Depth Rec. No. Rate (ft.) (in) (in) S-1 0-4 48 36 1 GZA GeoEnvironmental, Inc. Engineers and Scientists Blows (per 6 in.) S-1: S-1: Dry, brown, fine to medium SAND, little Gravel, trace Silt, trace Asphalt. Boring Location: See Plan Ground Surface Elev. (ft.): Final Boring Depth (ft.): 12 Date Start - Finish: 5/11/2015-5/11/2015 Sampler Type: I.D./O.D (in.): Macrocore 2"/3" Date Sampler Hmr Wt: 05/11/2015 Sampler Hmr Fall: Other: SPT Value TEST BORING LOG REMF Corp. Burlington, MA Sample Description Modified Burmister Remark 1 Field Test Data ND BORING NO.: GZ-1 SHEET: 1 of 1 PROJECT NO: 18.0172305.00 REVIEWED BY: Frank Vetere Depth (ft) 0.2' Groundwater Depth (ft.) Time Water Depth 0935 5.75 Stratum Description ASPHALT Elev. (ft) ' H. Datum: V. Datum: Stab. Time +/-1.0 hr. Equipment Installed 2 3 Cuttings 0-12' 4 5 6 S-2 4-8 48 48 S-2: S-2: Wet, grey, fine to medium SAND, trace Gravel, trace Silt. 2 3 ND 1" PVC Screen 0-10' 7 SAND 8 9 S-3 8-12 48 48 S-3: S-3: Wet, brown, fine to medium SAND, trace Silt. ND 10 11 18.0172305.00.GPJ; STANDARD BORING W/E W/SMPL 2PG; 6/5/2015 12 13 14 15 REMARKS Bottom of boring at 12 feet. 1. Field testing results represent total organic vapor levels, referenced to a benzene standard, measured in the headspace of sealed soil sample jars using a MiniRae 3000 organic vapor meter equipped with a photoionization detector (PID) and 10.6eV lamp. Results in parts per million by volume (ppmv). ND indicates nothing detected (<0.1 ppmv). 2. Soil sample for analysis from 3-4' bgs. 3. Saturated soils +/- 5' bgs. 4. Well removed, boring backfilled with cuttings to surface and patched to match surroundings. See log key for explanation of sample descriptions and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. 4 12' ' Boring No.: GZ-1
Drilling Co.: Geologic Earth Exploration, Inc. Type of Rig: Track Foreman: Taylor Grenier Rig Model: Geoprobe 6620 DT Logged By: Matt Steele Drilling Method: Auger/Casing Type: Macrocore I.D./O.D.: Hammer Weight (lb.): Hammer Fall (in.): Other: Casing Sample Depth Blows/ Pen. (ft) Core Depth Rec. No. Rate (ft.) (in) (in) S-1 0-4 48 32 1 2 GZA GeoEnvironmental, Inc. Engineers and Scientists Blows (per 6 in.) S-1: S-1: Dry, brown, fine to medium SAND, trace Gravel, trace Silt. Boring Location: See Plan Ground Surface Elev. (ft.): Final Boring Depth (ft.): 12 Date Start - Finish: 5/11/2015-5/11/2015 Sampler Type: I.D./O.D (in.): Macrocore 2"/3" Date Sampler Hmr Wt: 05/11/2015 Sampler Hmr Fall: Other: SPT Value TEST BORING LOG REMF Corp. Burlington, MA Sample Description Modified Burmister Remark 1 2 Field Test Data ND BORING NO.: GZ-2 SHEET: 1 of 1 PROJECT NO: 18.0172305.00 REVIEWED BY: Frank Vetere Depth (ft) 0.2' Groundwater Depth (ft.) Time Water Depth 1035 5.75 Stratum Description ASPHALT Elev. (ft) ' H. Datum: V. Datum: Stab. Time +/-2.0 hr. Equipment Installed 3 Cuttings 0-10' 4 5 6 S-2 4-8 48 48 S-2: S-2: Wet, light brown, fine to medium SAND, trace Silt. 3 4 ND 1" PVC Screen 0-10' 7 SAND 8 9 S-3 8-12 48 48 S-3: S-3: Wet, grey to brown, fine to medium SAND, trace Silt. ND 10 11 18.0172305.00.GPJ; STANDARD BORING W/E W/SMPL 2PG; 6/5/2015 12 13 14 15 REMARKS Bottom of boring at 12 feet. 1. Field testing results represent total organic vapor levels, referenced to a benzene standard, measured in the headspace of sealed soil sample jars using a MiniRae 3000 organic vapor meter equipped with a photoionization detector (PID) and 10.6eV lamp. Results in parts per million by volume (ppmv). ND indicates nothing detected (<0.1 ppmv). 2. Asphalt pavement at surface. 3. Soil sample for analysis from 3-4' bgs. 4. Saturated soils +/- 5' bgs. 5. Well removed, boring backfilled with cuttings to surface and patched to match surroundings. See log key for explanation of sample descriptions and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. 5 12' ' Boring No.: GZ-2
Drilling Co.: Geologic Earth Exploration, Inc. Type of Rig: Track Foreman: Taylor Grenier Rig Model: Geoprobe 6620 DT Logged By: Matt Steele Drilling Method: Auger/Casing Type: Macrocore I.D./O.D.: Hammer Weight (lb.): Hammer Fall (in.): Other: Casing Sample Depth Blows/ Pen. (ft) Core Depth Rec. No. Rate (ft.) (in) (in) S-1 0-4 48 36 1 2 GZA GeoEnvironmental, Inc. Engineers and Scientists Blows (per 6 in.) S-1: S-1: Dry, light brown, fine SAND, trace Gravel, trace Silt Boring Location: See Plan Ground Surface Elev. (ft.): Final Boring Depth (ft.): 12 Date Start - Finish: 5/11/2015-5/11/2015 Sampler Type: I.D./O.D (in.): Macrocore 2"/3" Date Sampler Hmr Wt: 05/11/2015 Sampler Hmr Fall: Other: SPT Value TEST BORING LOG REMF Corp. Burlington, MA Sample Description Modified Burmister Remark 1 2 Field Test Data ND BORING NO.: GZ-3 SHEET: 1 of 1 PROJECT NO: 18.0172305.00 REVIEWED BY: Frank Vetere Depth (ft) 0.2' Groundwater Depth (ft.) Time Water Depth 1148 6.36 Stratum Description ASPHALT Elev. (ft) ' H. Datum: V. Datum: Stab. Time +/-1.5 hr. Equipment Installed 3 Cuttings 0-12' 4 5 6 S-2 4-8 48 48 S-2: S-2: Wet, brown, fine to medium SAND, trace Silt. 3 ND 1" PVC Screen 0-10' 7 SAND 8 9 S-3 8-12 48 48 S-3: S-3: Wet, brown, fine to medium SAND, trace Silt. 10 11 18.0172305.00.GPJ; STANDARD BORING W/E W/SMPL 2PG; 6/5/2015 12 13 14 15 REMARKS Bottom of boring at 12 feet. 1. Field testing results represent total organic vapor levels, referenced to a benzene standard, measured in the headspace of sealed soil sample jars using a MiniRae 3000 organic vapor meter equipped with a photoionization detector (PID) and 10.6eV lamp. Results in parts per million by volume (ppmv). ND indicates nothing detected (<0.1 ppmv). 2. Asphalt at surface. 3. Saturated soils +/- 5' bgs. 4. Well removed, boring backfilled with cuttings to surface and patched to match surroundings. See log key for explanation of sample descriptions and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. 4 12' ' Boring No.: GZ-3
GZA GeoEnvironmental, Inc. Engineers and Scientists TEST BORING LOG REMF Corp. Burlington, MA BORING NO.: GZ-4 SHEET: 1 of 1 PROJECT NO: 18.0172305.00 REVIEWED BY: Frank Vetere Drilling Co.: Geologic Earth Exploration, Inc. Type of Rig: Track Boring Location: See Plan H. Datum: Foreman: Taylor Grenier Ground Surface Elev. (ft.): Rig Model: Geoprobe 6620 DT Final Boring Depth (ft.): 6 Logged By: Drilling Method: V. Datum: Matt Steele Date Start - Finish: 5/11/2015-5/11/2015 Auger/Casing Type: Macrocore Sampler Type: Macrocore Groundwater Depth (ft.) I.D/O.D.(in): I.D./O.D. (in.): 2"/3" Date Time Water Depth Casing Stab. Time Hammer Weight (lb.): Hammer Fall (in.): Other: Sampler Hmr Wt (lb): Sampler Hmr Fall (in): Other: 05/11/2015 Not Recorded Casing Sample Field Depth Sample Description and Identification Stratum Blows/ Depth Pen. Rec. Blows SPT Test Description (ft) Core No. (Modified Burmister Procedure) Rate (ft.) (in) (in) (per 6 in.) Value Data 1 2 S-1 2-6 60 60 S-1: Dry, brown, fine SAND, trace Silt. Remark 1 2 3 4 Depth (ft.) 0.5' CONCRETE Elev. (ft.) ' 3 SAND 4 5 6 Bottom of boring at 6 feet. 5 6' ' 7 8 9 10 11 12 13 14 18.0172305.00.GPJ; STRATUM ONLY; 6/5/2015 15 REMARKS 1. Field testing results represent total organic vapor levels, referenced to a benzene standard, measured in the headspace of sealed soil sample jars using a MiniRae 3000 organic vapor meter equipped with a photoionization detector (PID) and 10.6eV lamp. Results in parts per million by volume (ppmv). ND indicates nothing detected (<0.1 ppmv). 2. +/-6" concrete at surface. 3. Soil sample for analysis from 3-4' bgs. 4. Saturated soils +/- 5' bgs. 5. Boring backfilled with cuttings to surface and patched to match surroundings. See Log Key for explanation of sample description and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. Boring No.: GZ-4
GZA GeoEnvironmental, Inc. Engineers and Scientists TEST BORING LOG REMF Corp. Burlington, MA BORING NO.: GZ-5 SHEET: 1 of 1 PROJECT NO: 18.0172305.00 REVIEWED BY: Frank Vetere Drilling Co.: Geologic Earth Exploration, Inc. Type of Rig: Track Boring Location: See Plan H. Datum: Foreman: Taylor Grenier Ground Surface Elev. (ft.): Rig Model: Geoprobe 6620 DT Final Boring Depth (ft.): 6 Logged By: Drilling Method: V. Datum: Matt Steele Date Start - Finish: 5/11/2015-5/11/2015 Auger/Casing Type: Macrocore Sampler Type: Macrocore Groundwater Depth (ft.) I.D/O.D.(in): I.D./O.D. (in.): 2"/3" Date Time Water Depth Casing Stab. Time Hammer Weight (lb.): Hammer Fall (in.): Other: Sampler Hmr Wt (lb): Sampler Hmr Fall (in): Other: 05/11/2015 Not Recorded Casing Sample Field Depth Sample Description and Identification Stratum Blows/ Depth Pen. Rec. Blows SPT Test Description (ft) Core No. (Modified Burmister Procedure) Rate (ft.) (in) (in) (per 6 in.) Value Data 1 Remark 1 2 Depth (ft.) 0.5' CONCRETE Elev. (ft.) ' 2 3 3 4 S-1 3-6 60 60 S-1A: 10" Dry, dark brown, fine SAND, trace Silt. S-1B: 50" Dry, brown, fine SAND, trace Silt. SAND 5 6 Bottom of boring at 6 feet. 4 6' ' 7 8 9 10 11 12 13 14 18.0172305.00.GPJ; STRATUM ONLY; 6/5/2015 15 REMARKS 1. Field testing results represent total organic vapor levels, referenced to a benzene standard, measured in the headspace of sealed soil sample jars using a MiniRae 3000 organic vapor meter equipped with a photoionization detector (PID) and 10.6eV lamp. Results in parts per million by volume (ppmv). ND indicates nothing detected (<0.1 ppmv). 2. +/- 6" concrete at surface. 3. Saturated soils +/- 5' bgs. 4. Boring backfilled with cuttings to surface and patched to match surroundings. See Log Key for explanation of sample description and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. Boring No.: GZ-5
GZA GeoEnvironmental, Inc. Engineers and Scientists TEST BORING LOG REMF Corp. Burlington, MA BORING NO.: GZ-6 SHEET: 1 of 1 PROJECT NO: 18.0172305.00 REVIEWED BY: Frank Vetere Drilling Co.: Geologic Earth Exploration, Inc. Type of Rig: Track Boring Location: See Plan H. Datum: Foreman: Taylor Grenier Ground Surface Elev. (ft.): Rig Model: Geoprobe 6620 DT Final Boring Depth (ft.): 6 Logged By: Drilling Method: V. Datum: Matt Steele Date Start - Finish: 5/11/2015-5/11/2015 Auger/Casing Type: Macrocore Sampler Type: Macrocore Groundwater Depth (ft.) I.D/O.D.(in): I.D./O.D. (in.): 2"/3" Date Time Water Depth Casing Stab. Time Hammer Weight (lb.): Hammer Fall (in.): Other: Sampler Hmr Wt (lb): Sampler Hmr Fall (in): Other: 05/11/2015 Not Recorded Casing Sample Field Depth Sample Description and Identification Stratum Blows/ Depth Pen. Rec. Blows SPT Test Description (ft) Core No. (Modified Burmister Procedure) Rate (ft.) (in) (in) (per 6 in.) Value Data 1 2 S-1 1-6 60 60 S-1: Dry, brown, fine SAND, trace Silt. Remark 1 2 3 4 Depth (ft.) 0.5' CONCRETE Elev. (ft.) ' 3 SAND 4 5 6 Bottom of boring at 6 feet. 5 6' ' 7 8 9 10 11 12 13 14 18.0172305.00.GPJ; STRATUM ONLY; 6/5/2015 15 REMARKS 1. Field testing results represent total organic vapor levels, referenced to a benzene standard, measured in the headspace of sealed soil sample jars using a MiniRae 2000 organic vapor meter equipped with a photoionization detector (PID) and 10.6eV lamp. Results in parts per million by volume (ppmv). ND indicates nothing detected (<0.1 ppmv). 2. +/- 6" concrete at surface. 3. Soil sample for analysis from +/- 2-3' bgs. 4. Saturated soils +/- 5' bgs. 5. Boring backfilled with cuttings to surface and patched to match surroundings. See Log Key for explanation of sample description and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. Boring No.: GZ-6
GZA GeoEnvironmental, Inc. Engineers and Scientists TEST BORING LOG REMF Corp. Burlington, MA BORING NO.: GZ-7 SHEET: 1 of 1 PROJECT NO: 18.0172305.00 REVIEWED BY: Frank Vetere Drilling Co.: Geologic Earth Exploration, Inc. Type of Rig: Track Boring Location: See Plan H. Datum: Foreman: Taylor Grenier Ground Surface Elev. (ft.): Rig Model: Geoprobe 6620 DT Final Boring Depth (ft.): 12 Logged By: Drilling Method: V. Datum: Matt Steele Date Start - Finish: 5/11/2015-5/11/2015 Auger/Casing Type: Macrocore Sampler Type: Macrocore Groundwater Depth (ft.) I.D/O.D.(in): I.D./O.D. (in.): 2"/3" Date Time Water Depth Casing Stab. Time Hammer Weight (lb.): Sampler Hmr Wt (lb): 05/11/2015 Not Recorded Hammer Fall (in.): Sampler Hmr Fall (in): Other: Other: Casing Sample Field Depth Sample Description and Identification Stratum Blows/ Depth Pen. Rec. Blows SPT Test Description (ft) Core No. (Modified Burmister Procedure) Rate (ft.) (in) (in) (per 6 in.) Value Data S-1 0-4 48 36 1 2 S-1A: 14" Dry, brown, fine to coase SAND, little Gravel, little Silt, trace roots. (topsoil) S-1B: 22" Dry, grey, fine to medium SAND, trace Gravel, trace Silt. Remark 1 2 Depth (ft.) 1.2' TOPSOIL Elev. (ft.) ' 3 4 S-2 4-8 48 48 S-2: Wet, grey, fine SAND, trace Silt. 3 5 6 7 SAND 8 9 S-3 8-12 48 48 S-3A: 36" Wet, grey, fine SAND, trace Silt. S-3B: 12" Wet, gray, fine to coarse SAND, trace Silt. 10 11 12 Bottom of boring at 12 feet. 4 12' ' 13 14 18.0172305.00.GPJ; STRATUM ONLY; 6/5/2015 15 REMARKS 1. Field testing results represent total organic vapor levels, referenced to a benzene standard, measured in the headspace of sealed soil sample jars using a MiniRae 2000 organic vapor meter equipped with a photoionization detector (PID) and 10.6eV lamp. Results in parts per million by volume (ppmv). ND indicates nothing detected (<0.1 ppmv). 2. Soil sample for analysis from +/- 2-3' bgs. 3. Saturated soils +/- 5' bgs. 4. Boring backfilled with cuttings to surface and patched to match surroundings. See Log Key for explanation of sample description and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. Boring No.: GZ-7
GZA GeoEnvironmental, Inc. Engineers and Scientists TEST BORING LOG REMF Corp. Burlington, MA BORING NO.: GZ-8 SHEET: 1 of 1 PROJECT NO: 18.0172305.00 REVIEWED BY: Frank Vetere Drilling Co.: Foreman: Logged By: Geologic Earth Exploration, Inc. Matt Steele Auger/Casing Type: Macrocore I.D./O.D.: Hmr Weight (lb.): Hmr Fall (in.): Other: Casing Sample Depth Blows/ Pen. Rec. (ft) Core Depth No. Rate (ft.) (in) (in) S-1 0-4 48 36 1 Damian Jacobs Type of Rig: Rig Model: Drilling Method: Sampler Type: Macrocore I.D./O.D (in.): 2"/3" Sampler Hmr Wt: Sampler Hmr Fall: Other: Blows (per 6 in.) SPT Value Track Geoprobe 6620 DT Sample Description Modified Burmister S-1: Dry, brown, fine to medium SAND, little Gravel, trace Silt. Boring Location: See Plan Ground Surface Elev. (ft.): Final Boring Depth (ft.): 12 Date Start - Finish: 8/5/2015-8/5/2015 1 Date 0.2' Groundwater Depth (ft.) Time Water Depth Casing TOPSOIL ' H. Datum: V. Datum: 08/05/2015 0930 5.6 out completion 08/05/2015 1000 5.6 out 30 min. Remark Field Test Data Depth (ft) Stratum Description Elev. (ft) Equipment Installed Stab. Time 2 3 2 ND Cuttings 0-12' 4 5 S-2 4-8 48 48 S-2: Wet, brown, fine to medium SAND, trace Silt. 3 ND 1" PVC Screen 0-10' 6 SAND 7 8 9 S-3 8-12 48 48 S-3: Wet, brown, fine to medium SAND, trace Silt. ND 10 ND 11 18.0172305.00.GPJ; STANDARD BORING W/E W/O SMP 2PG2; 8/14/2015 12 13 14 15 REMARKS Bottom of boring at 12 feet. 1. Field testing results represent total organic vapor levels, referenced to a benzene standard, measured in the headspace of sealed soil sample jars using a MiniRae 3000 organic vapor meter equipped with a photoionization detector (PID) and 10.6eV lamp. Results in parts per million by volume (ppmv). ND indicates nothing detected (<0.1 ppmv). 2. Soil sample for analysis from 2-5 feet bgs. 3. Saturated soils observed approximately 5 feet bgs. 4. Well material removed, boring backfilled with cuttings. See log key for explanation of sample descriptions and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. 4 12' ' Boring No.: GZ-8
GZA GeoEnvironmental, Inc. Engineers and Scientists TEST BORING LOG REMF Corp. Burlington, MA BORING NO.: GZ-9 SHEET: 1 of 1 PROJECT NO: 18.0172305.00 REVIEWED BY: Frank Vetere Drilling Co.: Foreman: Logged By: Geologic Earth Exploration, Inc. Damian Jacobs Matt Steele Auger/Casing Type: Macrocore I.D./O.D.: Hmr Weight (lb.): Hmr Fall (in.): Other: Casing Sample Depth Blows/ Pen. (ft) Core Depth No. Rate (ft.) (in) 1 Rec. (in) Type of Rig: Rig Model: Drilling Method: Sampler Type: Macrocore I.D./O.D (in.): 2"/3" Sampler Hmr Wt: Sampler Hmr Fall: Other: Blows (per 6 in.) SPT Value Track Geoprobe 6620 DT Sample Description Modified Burmister Boring Location: See Plan Ground Surface Elev. (ft.): Final Boring Depth (ft.): 5 Date Start - Finish: 8/5/2015-8/5/2015 08/05/2015 Remark 1 2 Date Field Test Data Depth (ft) 0.5' Groundwater Depth (ft.) Time Water Depth Casing Not Stratum Description CONCRETE Encountered Elev. (ft) ' H. Datum: V. Datum: Equipment Installed Stab. Time No Equipment Installed 2 S-1 2-5 42 30 S-1: Dry, brown, fine SAND, trace Silt. ND 3 3 SAND 4 ND 5 Bottom of boring at 5 feet. 4 5 5' ' 6 7 8 9 10 11 18.0172305.00.GPJ; STANDARD BORING W/E W/O SMP 2PG2; 8/14/2015 12 13 14 15 REMARKS 1. Field testing results represent total organic vapor levels, referenced to a benzene standard, measured in the headspace of sealed soil sample jars using a MiniRae 3000 organic vapor meter equipped with a photoionization detector (PID) and 10.6eV lamp. Results in parts per million by volume (ppmv). ND indicates nothing detected (<0.1 ppmv). 2. Approximate 6-inch concrete at surface. 3. Hand hammer refusal approximate 4-feet bgs; boring advanced with hand auger. 4. Hand auger refusal at 5-feet bgs. 5. Boring backfilled with cuttings. See log key for explanation of sample descriptions and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. Boring No.: GZ-9
GZA GeoEnvironmental, Inc. Engineers and Scientists TEST BORING LOG REMF Corp. Burlington, MA BORING NO.: GZ-10 SHEET: 1 of 1 PROJECT NO: 18.0172305.00 REVIEWED BY: Frank Vetere Drilling Co.: Foreman: Logged By: Geologic Earth Exploration, Inc. Damian Jacobs Matt Steele Auger/Casing Type: Macrocore I.D./O.D.: Hmr Weight (lb.): Hmr Fall (in.): Other: Casing Sample Depth Blows/ Pen. (ft) Core Depth No. Rate (ft.) (in) 1 Rec. (in) Type of Rig: Rig Model: Drilling Method: Sampler Type: Macrocore I.D./O.D (in.): 2"/3" Sampler Hmr Wt: Sampler Hmr Fall: Other: Blows (per 6 in.) SPT Value Track Geoprobe 6620 DT Sample Description Modified Burmister Boring Location: See Plan Ground Surface Elev. (ft.): Final Boring Depth (ft.): 6 Date Start - Finish: 8/5/2015-8/5/2015 08/05/2015 Remark 1 Date Field Test Data Depth (ft) 0.5' Groundwater Depth (ft.) Time Water Depth Casing Not Stratum Description CONCRETE Encountered Elev. (ft) ' H. Datum: V. Datum: Equipment Installed Stab. Time No Equipment Installed 2 S-1 2-6 42 28 S-1: Dry, brown, fine SAND, trace Silt. 2 ND 3 3 SAND 4 ND 5 4 5 6 Bottom of boring at 6 feet. 6' ' 7 8 9 10 11 18.0172305.00.GPJ; STANDARD BORING W/E W/O SMP 2PG2; 8/14/2015 12 13 14 15 REMARKS 1. Field testing results represent total organic vapor levels, referenced to a benzene standard, measured in the headspace of sealed soil sample jars using a MiniRae 3000 organic vapor meter equipped with a photoionization detector (PID) and 10.6eV lamp. Results in parts per million by volume (ppmv). ND indicates nothing detected (<0.1 ppmv). 2. Approximate 6-inch concrete at surface. 3. Hand hammer refusal approximate 4-feet bgs; boring advanced with hand auger. 4. Hand auger completed at approximately 6-feet bgs. 5. Boring backfilled with cuttings. See log key for explanation of sample descriptions and identification procedures. Stratification lines represent approximate boundaries between soil and bedrock types. Actual transitions may be gradual. Water level readings have been made at the times and under the conditions stated. Fluctuations of groundwater may occur due to other factors than those present at the times the measurements were made. Boring No.: GZ-10
PROPOSED NYLOPLAST CLEANOUT DMH PROPOSED SYSTEM INSPECTION PORT (TYP)