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HomeMy WebLinkAboutStormwater Management Report REV 06/25/2019 Mixed Use Expansion, North Andover, MA TABLE OF CONTENTS PAGE I. STORMWATER MANAGEMENT NARRATIVE 1.0 SITE LOCATION AND DESCRIPTION............................................................ 1 2.0 METHODOLOGY........................................................................................ 1 3.0 SOILS...................................................................................................... 1 4.0 POINTS OF ANALYSIS................................................................................. 2 5.0 EXISTING DRAINAGE WATERSHEDS............................................................ 2 6.0 PROPOSED DRAINAGE WATERSHEDS.......................................................... 2 7.0 PEAK FLOW RATE .................................................................................... 3 8.0 WATER QUALITY...................................................................................... 3 9.0 GROUNDWATER RECHARGE ....................................................................... 5 10.0 DRAINAGE CONVEYANCE SYSTEM.............................................................. 5 11.0 COMPLIANCE WITH THE MA DEP STORMWATER HANDBOOK........................ 6 12.0 SUMMARY.............................................................................................. 7 II. LIST OF FIGURES • FIGURE 1: USGS PLAN • FIGURE 2: SOIL MAP • FIGURE 3: PRE-DEVELOPMENT WATERSHEDS • FIGURE 4: POST-DEVELOPMENT WATERSHEDS • FIGURE 5: CATCH BASIN WATERSHEDS • MOUNDING ANALYSIS • BORING LOGS III. HYDROLOGICAL CALCULATIONS • PRE-DEVELOPMENT HYDROCAD CALCULATIONS • POST-DEVELOPMENT HYDROCAD CALCULATIONS IV. HYDRAULIC CALCULATIONS • PIPE DESIGN V. APPENDIX • MASSACHUSETTS DEP STORMWATER REPORT CHECKLIST • OPERATION AND MAINTENANCE PLAN (O&M) (WITH LONG-TERM POLLUTION PREVENTION PLAN) 0 p: 978-794-5400 f: 978.965.3935 www.cdgengineering.com Mixed Use Expansion, North Andover, MA 1.0 SITE LOCATION AND DESCRIPTION Civil Design Group, LLC (CDG) has been retained by Virginia, Inc. to prepare this Stormwater Management Report for the construction of a proposed mixed use expansion located at 695 & 701 Salem Street in North Andover, Massachusetts (refer to Figure 1). The project includes the construction of a new 8,700 square foot building expansion with an overall building size of 12,600 square feet with 70 off-street parking spaces and landscaping and stormwater improvements on a 1.41± acre site. The site is bounded to the northeast by Salem Street,to the northwest by residences, to the southwest by residences, and to the south by Abbott Street. According to FEMA flood insurance rate maps community panel number 25009CO237F, effective date July 3, 2012, the area of the site to be redeveloped lies within Zone X, which is defined as areas determined to be outside the 0.2% (500-year) annual chance floodplain. Based on available MassGIS information, the site does not lie within a resource/buffer area nor is the site located within an area mapped for rare and endangered species or certified vernal pools as mapped by the State of Massachusetts' Natural Heritage and Endangered Species Program (NHESP) or within an Area of Critical Environmental Concern (ACEC). This study presents a comparative analysis of the pre-development and post-development hydrologic characteristics of the site, and outlines the proposed measures to mitigate flow,provide groundwater recharge, and improve water quality from the site in accordance with the Town of North Andover and the Massachusetts Department of Environmental Protection(DEP's) requirements. The proposed best management practices (BMPs) as outlined in this report include one (1) infiltration basin, two (2) underground infiltration systems, and one (1)proprietary separator to treat stormwater to the maximum extent practicable prior to discharging off site. 2.0 METHODOLOGY Northeast Regional Climate Center(Cornell Rates) was utilized to source the precipitation values and Technical Release 55 (TR-55) methodology was utilized to determine weighted curve numbers (CNs) for each pre and post-development subcatchment area. Weighted CNs are based on ground cover type and hydrologic soil groups (HSGs). The times of concentration(Tc's) for each of the existing and proposed watersheds have been calculated. The areas that do not show a Tc travel path resulted in travel times of less than 6 minutes. CN and Tc values were then utilized to generate hydrographs using HydroCad 10.0, an industry standard software package that develops a hydrologic model based on the SCS method and computes peak discharges from rainfall runoff for urban and rural watersheds. 3.0 SOILS According to the Natural Resources Conservation Service Web Soil Survey (Figure 2), underlying soils within the vicinity of the site are classified as Sudbury fine sandy loam and include a hydrologic soil group (HSG) of B. However, based on the test pits that were dug in February 2019, sandy material was present at the depths at which groundwater will be infiltrating from the infiltration systems,therefore, this stormwater report utilizes a HSG rating of A for both the existing and proposed conditions for the purposes of generating peak flow rates. 1 p: 978-794-5400 f: 978.965.3935 www.cdgengineering.com Mixed Use Expansion,North Andover, MA 4.0 POINTS OF ANALYSIS Points of Analysis (POAs) are discharge points or lines that convey runoff from the study area via overland flow or through drain pipes. The pre-development and post-development areas of disturbance drain to one (1) POA listed and described below and shown on Figures 3 and 4. TABLE-1: POINTS OF ANALYSIS POINT OF ANALYSIS DESCRIPTION POA-1 The existing downstream drainage system that currently collects and conveys runoff from the site area, Salem Street, and Abbott Street,to the municipal stormwater system in Salem Street. 5.0 EXISTING DRAINAGE WATERSHEDS The existing watersheds are delineated based on topography, physical characteristics and drainage networks within the site limits and collect and direct stormwater towards the POAs. The total study area for the site is 1.41± acres and is divided into two (2)pre-development watersheds as described below: Subcatchment EX-1: The 0.64-acre watershed is comprised of roofs, pavement, and grass areas. Runoff is collected into the onsite drainage system and conveyed into the above ground basin and a portion drains into the depression via overland flow. The depression includes an overflow connection into the existing municipal drainage system in Salem Street(POA-1). Subcatchment EX-2: The 0.76-acre watershed is comprised of roofs,pavement, and grass areas. Runoff travels via overland flow in an easterly direction towards POA-1. 6.0 PROPOSED DRAINAGE WATERSHEDS Similar to the existing watersheds, the proposed watersheds are delineated based on topography, physical characteristics and drainage networks within the site limits and collect and direct stormwater towards POA-1. This area is divided into six (6) post-development watersheds described below: Subcatchment PR-1: The 0.04-acre watershed is comprised of landscaped area. Runoff travels via overland flow in an easterly direction towards POA-1. Subcatchment PR-2: The 0.17-acre watershed is comprised of landscaped area. Runoff travels via overland flow in a westerly and southerly direction towards Abbott Street and eventually into POA-1. Subcatchment PR-3: The 0.37-acre watershed is comprised of rooftop and pavement area. The runoff is collected into the onsite drainage/infiltration system, which has been designed to capture and infiltrate the 100- year storm without conveyance to POA-1 Subcatchment PR-4: The 0.62-acre watershed is comprised of pavement, landscaped areas, and pavement areas. The runoff is collected into the onsite drainage system and conveyed into the above ground basin and a portion drains into the depression via overland flow. The depression includes an overflow connection into the existing municipal drainage system in Salem Street (POA-1). 2 p: 978-794-5400 f: 978.965.3935 www.cdgengineering.com Mixed Use Expansion, North Andover, MA Subcatchment PR-5: The 0.19-acre watershed is comprised of landscape and pavement area. The runoff is collected into the onsite drainage/infiltration system, which has been designed to capture and infiltrate the 100- year storm without conveyance to POA-1. Subcatchment PR-6: The 0.01-acre watershed is comprised of landscaped area. Runoff travels via overland flow in a southerly direction towards POA-1. 7.0 PEAK FLOW RATE MITIGATION The stormwater management system is designed so that post-development peak discharge rates do not exceed pre-development peak discharge rates for the 0.5", 2-year, 10-year, 25-year, and 100-year, 24-hour NRCC storm events. Peak flow rates for the pre-development and post-development conditions are illustrated below: TABLE 2: PEAK FLOW RATE COMPARISON 0.5" STORM 2-YEAR STORM 10-YEAR STORM 25-YEAR STORM 100-YEAR POINT EVENT EVENT EVENT EVENT STORM EVENT OF (0.5"/24-HR) (3.15"/24-HR) (4.83"/24-HR) (6.16"/24-HR) (8.94"/24-HR) ANALYSIS PRE POST PRE POST PRE POST PRE POST PRE POST CFS CFS) (CFS) (CFS) I (CFS CFS CFS CFS CFS CFS POA-1 0.16 0.19 1.55 1.29 2.53 1.83 3.45 2.22 5.48 5.14 8.0 WATER QUALITY The redevelopment program includes measures to treat runoff from impervious areas prior to discharge. New stormwater controls have been incorporated into the design that result in a reduction in annual stormwater pollutant loads from the site. Through the use of structural and non-structural BMPs, the water quality volume from the watersheds contributing to the proposed drainage system will undergo treatment. Currently, the site area contains approximately 0.77 acres of impervious (rooftop/pavement) area or 55% of the project area. The redevelopment program proposes to increase the impervious area to approximately 1.12 acres of impervious or 80% of the site, resulting in a net increase of 0.35 acres of impervious area. As depicted in Figure-5, subcatchments 1, 2, 3, & 4 corresponding to TD-2, CB-1, CB-2, & TD-1 collect 0.56± acres of new non-rooftop impervious area and will be treated to 80% TSS removal (See below). The runoff from the remaining 0.27± acres of non-rooftop impervious area will be collected in the existing drainage system and directed to the existing on-site detention basin. The following BMPs were selected to treat the average annual TSS load from stormwater runoff under the post-development condition. Refer to the TSS Removal Calculation Worksheet below. • Deep Sump Hooded Catch Basins Stormwater runoff from proposed pavement areas will be directed via curbing and site grading to catch basins with deep sumps and hooded outlets. The catch basins will trap and remove sediment and larger particles from the stormwater and will improve the performance of subsequent BMPs. The sumps will be a minimum of 4' in depth and a regular inspection and cleaning schedule has been proposed to ensure optimal effectiveness. When properly designed and maintained, catch basin sumps are effective in reducing the sediment and pollutant load in runoff. 3 p: 978-794-5400 f: 978.965.3935 www.cdgengineering.com Mixed Use Expansion,North Andover, MA • Hydrodynamic Separator (HS-4 Unit) Hydrodynamic Separators are designed to remove heavy particles, floating debris and hydrocarbons from stormwater. Stormwater enters the system where floatables and oils are separated prior to the clarified stormwater runoff discharging to an outlet pipe. See below for additional information about the TSS rates utilized for these proprietary BMPs. • Subsurface Infiltration System SIS) Subsurface infiltration systems are designed to detain and infiltrate runoff from the site. System 1 (SIS- 1) is comprised of eighteen (18) concrete galleys, while System 2 (SIS-2) is comprised of twenty (20) concrete galleys. Runoff is designed to exfiltrate through the system bottom. TABLE 3: TSS REMOVAL CALCULATION WORKSHEET' TREATMENT TRAIN-1 (TT#1): SC-1,2,3,&4 TSS Removal Starting TSS Amount Remaining Load BMP Rate Load Removed (BxC) (C-D) A (B) (C) (D) (E Deep Sump CB's 0.25 1.0 0.25 0.75 HS-4 1 0.75* 0.75 0.56 0.19 Total TSS Removal= Summation of(D) = 81% * Technology Acceptance&Reciprocity Partnership(TARP)TSS Removal efficiency rate used. The TSS removal rates for the HS-4 unit are based on the performance results published by Alden Research Laboratory, which states that the HS-4 includes a TSS removal efficiency rate of 80% for flows up to 0.90 cfs. 3ased on the Massachusetts DEP's Standard Method to Convert Required Water Quality Volume to a Discharge Rate for Sizing Flow Based Manufactured Proprietary Stormwater Treatment Practices, effective October 15, 2013, the required rate to be treated is as follows: DMH-1 (HS-4): The required rate to be treated is: QI = (qu)(A)(WQV) = (774 csm/in)(0.19 ac)(0.0015625 mil/ac)(1 in) =0.23 efs where: Ql =peak flow associated with the first 1" of runoff qu=the unit peak discharge, in csm/in (774 csm/in for a 0.1 hour Tc) A=impervious surface drainage area, in square miles WQV =water quality volume in watershed inches C13-2 (HS-4): The required rate to be treated is: Qi = (qu)(A)(WQV) =(774 csm/in)(0.16 ac)(0.0015625 mil/ac)(l in) =0.19 cfs where: QI =peak flow associated with the first 1" of runoff qu=the unit peak discharge, in csm/in (774 csm/in for a 0.1 hour Tc) A= impervious surface drainage area, in square miles WQV =water quality volume in watershed inches TSS Removal Rate calculation includes non-rooftop impervious surfaces. 4 p: 978-794-5400 f: 978.965.3935 www.cdgengineering.com Mixed Use Expansion,North Andover, MA Therefore, the discharge rates reduced to be treated per the above calculation are within the treatable flows for the units. Since the Hydroworks units are designed to treat the required flow without overflow, bypass, surcharge, or scouring, and since they include a built-in bypass mechanism to accommodate high flow storm events, they are considered "offline" units under the DEP policy as proposed. 9.0 GROUNDWATER RECHARGE The DEP Stormwater Management Policy addresses the importance of recharging groundwater and reducing surface runoff. For a redevelopment project, the net increase in site impervious area must be infiltrated to approximate the annual recharge from pre-development conditions. On this site, there is a net increase in impervious area equal to 0.35± acres. The required recharge equals a depth of runoff corresponding to the soil type multiplied by the net increase in impervious area for each soil type in the post development condition. Using a target factor of 0.6 inches for HSG-A,the total required recharge volume is as follows: Rv = (F)x (newly created impervious area) where, Rv=Required recharge volume (cubic feet) F = Target depth factor corresponding to the HSG. Rv= 0.6 inch x 0.35 acres x (43,560 ft2/acre) x (1 ft/12 inch) =762 cubic feet `'he available storage within two (2) new subsurface infiltration systems below their respective overflow outlets total 3,700± cubic feet, thereby exceeding the required recharge volume. The soil borings indicate that groundwater is approximately 42"to 66"below the existing ground surface, as such the proposed design accommodates 2' separation to groundwater for each infiltration best management practice. Below are the drawdown calculations for the infiltration BMP's summarizing that each drawdown time will be less than 72 hours as follows: Drawdown calculation = Depth K Where k= 8.27 in/hour Subsurface System -1 Dawwdown calculation = 24 in = 2.9 hours < 72 hours = OK 8.27 in/hr Subsurface System -2 Daawdown calculation = 30 in = 3.6 hours < 72 hours = OK 8.27 in/hr 10.0 DRAINAGE CONVEYANCE SYSTEM The proposed stormwater conveyance system was designed to collect and convey runoff from developed areas to the associated stormwater management system BMP's described in this report. The drainage system consists of one (1) catch basin, two (2) trench drains, two (2) water quality units, two (2) subsurface infiltration systems 5 p: 978-794-5400 f: 978.965.3935 www.cdgengineering.com Mixed Use Expansion, North Andover, MA and associated piping. Using the rational method to determine peak runoff flows, the proposed conveyance system is designed for the 25-year storm event. 11.0 COMPLIANCE WITH THE MASSACHUSETTS DEP STORMWATER HANDBOOK This study presents a comparative analysis of the pre-development and post-development hydrologic characteristics of the site, and outlines the proposed measures to mitigate flow, provide groundwater recharge, and improve water quality from the site. The best management practices (BMPs) outlined in this report include measures to meet the municipal and the Massachusetts Department of Environmental Protection (DEP) requirements. Below is a summary of how the design complies with each applicable DEP standard. Standard 1: No new stormwater conveyances may discharge untreated directly to or cause erosion in wetlands or waters of the Commonwealth. The proposed stormwater conveyance system does not include any new untreated discharges. The overland and subsurface drainage connection points will remain consistent with the existing condition. Standard 2: Stormwater management systems shall be designed so that post-development peak discharge rates do not exceed pre-development peak discharge rates. As indicated above and within the supporting HydroCad calculations, the stormwater management system is designed so that post-development peak discharge rates do not exceed pre-development peak discharge rates. Standard 3: Loss of annual recharge to groundwater shall be eliminated or minimized through the use of nfiltration measures including environmentally sensitive site design, low impact development techniques, stormwater best management practices, and good operation and maintenance. At a minimum, the annual recharge from the post-development site shall approximate the annual recharge from pre-development conditions based on soil type. This standard is met when the stormwater management system is designed to infiltrate the required recharge volume as determine in accordance with the Massachusetts Stormwater Handbook. There is a net increase of impervious area and the corresponding required volume of runoff will be recharged to groundwater. Standard 4: Stormwater management systems shall be designed to remove 80% of the average annual post- construction load of Total Suspended Solids (TSS). To aid in removal of total suspended solids, a deep sump hooded catch basin and two water quality units are proposed. Onsite impervious areas will be treated beyond 80%. Standard 5: For land uses with higher potential pollutant loads, source control and pollution prevention shall be implemented in accordance with the Massachusetts Stormwater Handbook to eliminate or reduce the discharge of stormwater runoff from such land uses to the maximum extent practicable. Not applicable. 6 p: 978-794-5400 f: 978.965.3935 www.cdgengineering.com Mixed Use Expansion, North Andover, MA Standard 6: Stormwater discharges within the Zone H or Interim Wellhead Protection Area of a public water supply, and stormwater discharges near or to any other critical area, require the use of the specific .;ounce control andpollution prevention measures and the specific structural stormwater best management practices determined by the Department to be suitable for managing discharges to such areas, as provided in the Massachusetts Stormwater Handbook. Not applicable. Standard 7. A redevelopment project is required to meet the following Stormwater Management Standards only to the maximum extent practicable:Standard 2, Standard 3, and the pretreatment and structural best management practice requirements of Standards 4, S, and 6. Existing stormwater discharges shall comply with Standard I only to the maximum extent practicable. A redevelopment project shall also comply with all other requirements of the Stormwater Management Standards and improve existing conditions. Not applicable. Standard 8: A plan to control construction-related impacts including erosion, sedimentation and other pollutant sources during construction and land disturbance activities (construction period erosion, sedimentations, and pollution prevention plan) shall be developed and implemented. The `Demolition and Erosion Control Plan' outlines and depicts measures to control construction related impacts including erosion, sedimentation and other pollutant sources during construction and land disturbance activities. andard 9: A long-term operation and maintenance plan shall be developed and implemented to ensure that stormwater management systems function as designed. An Operation and Maintenance Plan (O&M) has been developed that outlines maintenance requirements to ensure longevity of BMP's. See Appendix A. Standard 10: All illicit discharges to the stormwater management system are prohibited. The proposed stormwater management system does not include any illicit discharges. 12.0 SUMMARY The stormwater management system for the proposed redevelopment includes measures for collecting, conveying, treating and controlling stormwater runoff from the site. Post-development peak runoff rates have been attenuated for the 0.5", 2-year, 10-year, 25-year and 100-year storm events and the collection system has been designed to convey runoff for the 25-year storm event. The stormwater management system incorporates both structural and non-structural BMP's to adequately treat runoff from the proposed redevelopment area and is designed in accordance with the DEP Stormwater Management Policy to the maximum extent practicable. Comprehensive computations and calculations with supporting figures and plans are attached. 7 p: 978-794-5400 f: 978.965.3935 www.cdgengineering.com t� � lo 1 00 t 1 r r , r r 1 r— r Ir I «:TIA t, �gfiY r i -ti \ r v L e Q GNU E G SITE � I y I i V 1 � r. ti , 1 �r e ch'uc" 500 0 250 500 1000 CLIENT CIVIL DESIGN FIGURE-1 VIRGINIA, INC. GROUP, LLc USGS PLAN GRAPHIC SCALE IN FEET 701 SALEM STREET 21 HIGH STREET SUITE 207 NORTH ANDOVER,MA 01845 SOURCE: USGS TOPO 2018 NORTH ANDOVER,MA 01845 www.cdgengincering.com 06 25 2019 QUADRANGLE: GROVELAND, MA p:978-794-5400 f:978-965-3971 Hydrologic Soil Group—Essex County, Massachusetts,Northern Part N (FIGURE 2-701 SALEM ST, NORTH ANDOVER,MA) o 3283M 328500 3287M 328900 329100 329300 329500 329700 329900 42°40'34'N 42'40'34'N z F i RF S S� 2G tg t. 3 m t, a z g g z 1 r � v moil Map ay not b valid at this cal �, 42'39 55'N - ° ... _ 42°39'S5'N 328100 328300 328500 328700 3289M 329100 329,300 329500 329700 329900 3 Map Scale:1:8,520 if printed on A landscape(11"x 8.5')sheet, a Meters N 0 100 200 400 600 Feet A0 400 800 1600 2400 Map projection:Web Mercator Comer coordinates:WGS84 Edge tics:UTM Zone 19N WGS84 USDA Natural Resources Web Soil Survey 3/22/2019 Conservation Service National Cooperative Soil Survey Page 1 of 5 Hydrologic Soil Group—Essex County, Massachusetts,Northern Part (FIGURE 2-701 SALEM ST, NORTH ANDOVER,MA) MAP LEGEND MAP INFORMATION Area of Interest(AOI) 13 C The soil surveys that comprise your AOI were mapped at Area of Interest(AOI) 1:15,800. 13 C/D Soils 13 D Warning:Soil Map may not be valid at this scale. Soil Rating Polygons Not rated or not available Enlargement of maps beyond the scale of mapping can cause 0 A misunderstanding of the detail of mapping and accuracy of soil 0 A/D Water Features line placement.The maps do not show the small areas of Streams and Canals contrasting soils that could have been shown at a more detailed B scale. Transportation 0 B/D Rails Please rely on the bar scale on each map sheet for map 0 C Interstate Highways measurements. 0 C/D US Routes Source of Map: Natural Resources Conservation Service Web Soil Survey URL: D Major Roads Coordinate System: Web Mercator(EPSG:3857) Not rated or not available Local Roads Maps from the Web Soil Survey are based on the Web Mercator Soil Rating Lines Background projection,which preserves direction and shape but distorts q distance and area.A projection that preserves area,such as the Aerial Photography Albers equal-area conic projection,should be used if more 0 A/D accurate calculations of distance or area are required. +, B This product is generated from the USDA-NRCS certified data as B/D of the version date(s)listed below. * C Soil Survey Area: Essex County,Massachusetts, Northern Part Survey Area Data: Version 14,Sep 7,2018 Soil map units are labeled(as space allows)for map scales D 1:50,000 or larger. Not rated or not available Date(s)aerial images were photographed: Aug 29,2014—Sep Soil Rating Points 19,2014 13 q The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background 13 A/D imagery displayed on these maps.As a result,some minor B shifting of map unit boundaries may be evident. B/D USDA Natural Resources Web Soil Survey 3/22/2019 Conservation Service National Cooperative Soil Survey Page 2 of 5 Hydrologic Soil Group-Essex County,Massachusetts,Northern Part FIGURE 2-701 SALEM ST, NORTH ANDOVER,MA Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 1 Water 0.2 0.1% 16A Scarboro mucky fine A/D 6.4 2.2/ sandy loam,0 to 3 percent slopes 31A - i Walpole sandy loam,0 B/D 6.9 - --- -2.3/o to 3 percent slopes 38A Pipestone loamy sand,0 A 5.6 1.9% to 3 percent slopes 52A Freetown muck,0 to 1 B/D 12.21 4.1% percent p slo es �72A Whitman loam,0 to 3 ID 4.3 1.5%!i percent slopes 73A Whitman fine sandy D 25.4 !i 8 6% loam,0 to 3 percent i slopes,extremely stony 253A - Hinckley loamy sand,0 A ---_-- _.- ___-___-- --- 22 -0.7% to 3 percent slopes 1 253B THinckley loamy sand,3 A 0.2 0.1% to 8 es 253C percent Hinckley loamy sap d 8 i A 5.1 L -- -- - ---_ - -- 1.7% to 15 percent slopes 254A Merrimac fine sandy A 8.5 2.9% loam,0 to 3 percent slopes 1 254B 1 Merrimac fine sandy A a, 5.4 1.8% loam,3 to 8 percent slopes 260A Sudbury fine sandy B 33.41 11.3%I loam,0 to 3 percent slopes I 1 260B Sudbury fine sandy B 2.9 i 1.0% loam,3 to 8 percent slopes 306D Paxton fine sandy loam, li C 10.1 3.4% 15 to 25 percent slopes,very stony 307E Paxton xt 3loam, C 15.2 5.2% 25 to5 percent slopes,extremely stony - --311 C Woodbridge fine sand C/D 2.01 0.7%. loam,8 to 15 percent slopes,very stony USDA Natural Resources Web Soil Survey 3/22/2019 Conservation Service National Cooperative Soil Survey Page 3 of 5 Hydrologic Soil Group—Essex County,Massachusetts, Northern Part FIGURE 2-701 SALEM ST,NORTH ANDOVER,MA Map unit symbol Map unit name ` Rating Acres in AOI percent of AOI 311 D Woodbridge fine sandy C/D 6.7 2.3%', loam, 15 to 25 percent - - - - - slopes,very stony -- -- - -- =-- 406C Charlton fine sandy B 19.6 6.7%' loam,8 to 15 percent slopes,very stony 411 B Sutton fine sandy loam, B/D 38.2 0 to 8 percent slopes, —very stony -- - -- - -- - -- - - — 420E Canton fine sandy loam, B 2.8 1.0% i 3 to 8 percent slopes 421 B Canton fine sandy loam, B �I i 19.1 ; 6.5% 0 to 8 percent slopes, very stony 421 C Canton fine sandy loam, B 36.5 12.4% 8 t p percent -y -- slopes, very stony 421 D Canton fine sandy loam, A 4.21 1.4% 15 to 25 percent slopes,very stony 711 C Charlton-Rock outcrop- A 1.5 0.5% Hollis complex,8 to 15 percent slopes 711 D Charlton-Rock outcrop /°A 2.9 1.0 Hollis complex, 15 to 25 percent slopes 715B Ridgebury and Leicester D 10.7 3.6% fine sandy loams,3 to j i 8 percent slopes, extremely stony - - —�� - - - 717E i Rock outcrop-Charlton- /o 1.7 0.6 Hollis complex, 15 to �I I 35 percent slopes 718A �Saco variant silt loam 0 I B/D - ---- 47 ° 1.6/0 to 3 percent slopes Totals for Area of Interest 294.8 100.0% USDA Natural Resources Web Soil Survey 3/22/2019 ;i- Conservation Service National Cooperative Soil Survey Page 4 of 5 Hydrologic Soil Group—Essex County,Massachusetts,Northern Part FIGURE 2-701 SALEM ST,NORTH ANDOVER,MA Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential)when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method. Dominant Condition Component Percent Cutoff. None Specified Tie-break Rule: Higher USDA Natural Resources Web Soil Survey 3/22/2019 Conservation Service National Cooperative Soil Survey Page 5 of 5 Groundwater Mounding Analysis Inputs 695&701 Salem Street,North Andover,MA 01845 SIS-1 Using the Hantush Derivation(1967)groundwater mounding calculator, the following are inputs used to calculate the groundwater mounding under an area: Footprint 1,252 square feet (100-year storm surface area from HydroCad) Volume 0.13E acre-feet (Volume infiltrated in 24-hours from HydroCad) R 5.2 ft/day (Volume/Footprint) Sy 0.22 unitless (Specific Yield) K 52 ft/day (Hydraulic Conductivity,assumed to be IOx R) x 12 (Half length of basin) y 24 (Half width of basin) t 24 hours (Storm duration) hi(0) 24 feet (Depth to bedrock from ESHGWT,no direct data within site,based on typical depth used) This spreadsheet will calculate the height of a groundwater mound beneath a stormwater infiltration basin. More information can be found in the U.S.Geological Survey Scientific Investigations Report 2010-5102"Simulation of groundwater mounding beneath hypothetical stormwater infiltration basins". The user must specify infiltration rate(R),specific yield(Sy),horizontal hydraulic conductivity(Kh), basin dimensions(x,y),duration of infiltration period(t),and the initial thickness of the saturated zone(hi(0),height of the water table if the bottom of the aquifer is the datum). For a square basin the half width equals the half length(x=y). For a rectangular basin,if the user wants the water-table changes perpendicular to the long side,specify x as the short dimension and y as the long dimension.Conversely,if the user wants the values perpendicular to the short side,specify y as the short dimension,x as the long dimension.All distances are from the center of the basin. Users can change the distances from the center of the basin at which water-table aquifer thickness are calculated. Cells highlighted in yellow are values that can be changed by the user. Cells highlighted in red are output values based on user-specified inputs. .,.., .,.. f""Peal otherwise necessary iterations to converge on the correct solution will not be done and values shown will be incorrect. Use consistent units for all input values(for example,feet and days) use consistent units(e.g.feet&days or inches&hours) Conversion Table Input Values inch/hour feet/day 5.2000`' R Recharge(infiltration)rate(feet/day) 0.67 1.33 0J20 Sy Specific yield,Sy(dimensionless,between 0 and 1) 52.UU K Horizontal hydraulic conductivity,Kh (feet/day)* 2,00 4.00 in the report accompanying this spreadsheet 12:600° x 1/2 length of basin(x direction,in feet) (USGS SIR 2010-5102),vertical soil permeability 24.000 y 1/2 width of basin(y direction,in feet) hours days (ft/d)is assumed to be one-tenth horizontal .006, t duration of infiltration period(days) 36 1.50 hydraulic conductivity(ft/d). 24.000! hi(0) initial thickness of saturated zone(feet) h(max) maximum thickness of saturated zone(beneath center of basin at end of infiltration period) Ah(max) maximum groundwater mounding(beneath center of basin at end of infiltration period) Ground- Distance from water center of basin Mounding,in in x direction,in feet feet 0- 20= e- akulate Now Groundwater Mounding,in fleet 1.800 1.600 �yyt0` 1.400 1.200 1.000 0.800 0.600 0.400 m 0.200 0.000 0 20 40 60 80 100 120 140 Disclaimer This spreadsheet solving the Hantush(1967)equation for ground-water mounding beneath an infiltration basin is made available to the general public as a convenience for those wishing to replicate values documented in the USGS Scientific Investigations Report 2010-5102"Groundwater mounding beneath hypothetical stormwater infiltration basins"or to calculate values based on user-specified site conditions.Any changes made to the spreadsheet(other than values identified as user-specified)after transmission from the USGS could have unintended, undesirable consequences.These consequences could include, but may not be limited to: erroneous output, numerical instabilities, and violations of underlying assumptions that are inherent in results presented in the accompanying USGS published report.The USGS assumes no responsibility for the consequences of any changes made to the spreadsheet.If changes are made to the spreadsheet,the user is responsible for documenting the changes and justifying the results and conclusions. Groundwater Mounding Analysis Inputs 695&701 Salem Street,North Andover,MA 01845 SIS-2 Using the Hantush Derivation(1967)groundwater mounding calculator, the following are inputs used to calculate the groundwater mounding under an area: Footprint 1,220 square feet (100-year storm surface area from HydroCad) Volume 0,22S acre-feet (Volume infiltrated in 24-hours from HydroCad) R 7.7 ft/day (Volume/Footprint) Sy 022 unitless (Specific Yield) K 77 ft/day (Hydraulic Conductivity,assumed to be 10x R) x 28 (Half length of basin) y 12 (Half width of basin) t 24 hours (Storm duration) hi(0) 24 feet (Depth to bedrock from ESHGVVT,no direct data within site available,based on typical depth in area) This spreadsheet will calculate the height of a groundwater mound beneath a stormwater infiltration basin. More information can be found in the U.S.Geological Survey Scientific Investigations Report 2010-5102"Simulation of groundwater mounding beneath hypothetical stormwater infiltration basins". The user must specify infiltration rate(R),specific yield(Sy),horizontal hydraulic conductivity(0), basin dimensions(x,y),duration of infiltration period(t),and the initial thickness of the saturated zone(hi(0),height of the water table if the bottom of the aquifer is the datum). For a square basin the half width equals the half length(x=y). For a rectangular basin,if the user wants the water-table changes perpendicular to the long side,specify x as the short dimension and y as the long dimension. Conversely,if the user wants the values perpendicular to the short side,specify y as the short dimension,x as the long dimension.All distances are from the center of the basin. Users can change the distances from the center of the basin at which water-table aquifer thickness are calculated. Cells highlighted in yellow are values that can be changed by the user. Cells highlighted in red are output values based on user-specified inputs. ... . .., .... ,. „ ._ r, . ..._ v z,,„_ , .. r r ,s ed otherwise necessary iterations to converge on the correct solution will not be done and values shown will be incorrect. Use consistent units for all input values(for example,feet and days) use consistent units(e.g.feet&days or inches&hours) Conversion Table Input Values inch/hour feet/day 7,7000 R Recharge(infiltration)rate(feet/day) 0.67 1.33 0,220 Sy Specific yield,Sy(dimensionless,between 0 and 1) 77.00 K Horizontal hydraulic conductivity,Kh (feet/day)* 2.00 4.00 12.000 x 1/2 length of basin(x direction,in feet) In the report accompanying this spreadsheet (USGS Slft 2010-5102),vertical soil permeability 28.000 y 1/2 width of basin(y direction,in feet) hours days (ft/d)is assumed to be one-tenth horizontal 1.000i t duration of infiltration period(days) 36 1.50 hydraulic conductivity(ft/d). 24.000 hi(0) initial thickness of saturated zone(feet) h(max) maximum thickness of saturated zone(beneath center of basin at end of infiltration period) Ah(max) maximum groundwater mounding(beneath center of basin at end of infiltration period) Ground- Distance from water center of basin Mounding,in in x direction,in feet feet o fie-Calculate No 20 Groundwater Mounding,in feet 2.500 � 0 2,000 1.500 1.000 0,500 0.000 0 20 40 60 80 100 120 140 Disclaimer This spreadsheet solving the Hantush (1967)equation for ground-water mounding beneath an infiltration basin is made available to the general public as a convenience for those wishing to replicate values documented in the USGS Scientific Investigations Report 2010-5102 "Groundwater mounding beneath hypothetical stormwater infiltration basins"or to calculate values based on user-specified site conditions.Any changes made to the spreadsheet(other than values identified as user-specified)after transmission from the USGS could have unintended, undesirable consequences.These consequences could include, but may not be limited to: erroneous output, numerical instabilities, and violations of underlying assumptions that are inherent in results presented in the accompanying USGS published report.The USGS assumes no responsibility for the consequences of any changes made to the spreadsheet.If changes are made to the spreadsheet,the user is responsible for documenting the changes and justifying the results and conclusions. Basin Q-- EX- 1 EX-2 ell POA-1 SubCat Reach on Lltlk Routing Diagram for Pre Development Prepared by Microsoft, Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Pre Development Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.615 39 >75% Grass cover, Good, HSG A (EX-1, EX7.2) 0.101 96 Gravel surface, HSG A (EX-2) 0.521 98 Paved parking, HSG A (EX-1, EX-2) 0.123 98 Roofs, HSG A (EX-1) 0.029 98 Unconnected roofs, HSG A (EX-1, EX-2) 0.019 98 Water Surface, HSG A (EX-1) 1.409 72 TOTAL AREA Pre Development Prepared by Microsoft Printed 6/25/2019 HydroCAD010.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 3 Soil Listing (all nodes) Area Soil Subcatchment (acres) Group Numbers 1.409 HSG A EX-1, EX-2 0.000 HSG B 0.000 HSG C 0.000 HSG D 0.000 Other 1.409 TOTAL AREA Pre Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 4 Time span=0.00-24.00 hrs, dt=0.10 hrs, 241 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentEX-1: Runoff Area=27,938 sf 68.77% Impervious Runoff Depth>0.22" Tc=6.0 min CN=42/98 Runoff=0.14 cfs 0.012 of SubcatchmentEX-2: Runoff Area=33,418 sf 28.93% Impervious Runoff Depth>0.09" Tc=6.0 min CN=52/98 Runoff=0.07 cfs 0.006 of Pond Basin: Peak Elev=147.19' Storage=5 cf Inflow=0.14 cfs 0.012 of Discarded=0.01 cfs 0.002 of Primary=0.12 cfs 0.010 of Outflow=0.13 cfs 0.012 of Link POA-1: Inflow=0.19 cfs 0.015 of Primary=0.19 cfs 0.015 of Total Runoff Area = 1.409 ac Runoff Volume = 0.018 of Average Runoff Depth = 0.15" 52.93% Pervious = 0.746 ac 47.07% Impervious = 0.663 ac Pre Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Paqe 5 Summary for Subcatchment EX-1: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.14 cfs @ 12.11 hrs, Volume= 0.012 af, Depth> 0.22" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 0.5" Storm Rainfall=0.50" Area (sf) CN Description 5,339 98 Roofs, HSG A 427 98 Unconnected roofs, HSG A 13,039 98 Paved parking, HSG A 8,298 39 >75% Grass cover, Good, HSG A 835 98 Water Surface, HSG A 27,938 80 Weighted Average 8,725 42 31.23% Pervious Area 19,213 98 68.77% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX-1: Hydrograph 0.15 - cfs 0.14 0.13 N RCC 24-h r Q '0 14 c I 0.12 0.5 Storm Rainfall=0.50" 0.11 Runoff Area-27 938.s# 01 -Runoff Volume=0.012 of 0.09 w Runoff-Depth>0.22" - - - - 0.08 0 0.07 Tc=6.0 min _ a 0.06 CN=42/98 0.05 0.04 ' 0.03 0.02 0.01 .<' 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment EX-2: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.07 cfs @ 12.11 hrs, Volume= 0.006 af, Depth> 0.09" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 0.5" Storm Rainfall=0.50" Area (so CN Description 857 98 Unconnected roofs, HSG A 9,668 98 Paved parking, HSG A 18,476 39 >75% Grass cover, Good, HSG A 4,417 96 Gravel surface, HSG A 33,418 65 Weighted Average 23,750 52 71.07% Pervious Area 9,668 98 28.93% Impervious Area Tc Length Slope Velocity Capacity Description --(min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX-2: Hydrograph 0.075 Runoff - 0.07 cfs - -0.07 0.065- -N RCC-24=h r-D -- ME 0.06 0.5'1' Storm_Rainfall-0.50" - _ - -- 0.055 - Runoff-Area-=33,418.sf ; 005 Runoff Volume=0.006 of = 0.045 0.04 Runoff Depth>0.09" - 0 0.035 TC-6.0 min 0.03 C N_=52L98 -- 0.025 0.02 0.015 0.01 0.005 ;,, 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCAD0 10.00-22 s/n 07576 02018 HydroCAD Software Solutions LLC Page 7 Summary for Pond Basin: Inflow Area = 0.641 ac, 68.77% Impervious, Inflow Depth > 0.22" for 0.5" Storm event Inflow = 0.14 cfs @ 12.11 hrs, Volume= 0.012 of Outflow = 0.13 cfs @ 12.13 hrs, Volume= 0.012 af, Atten= 4%, Lag= 0.8 min Discarded = 0.01 cfs @ 12.13 hrs, Volume= 0.002 of Primary = 0.12 cfs @ 12.13 hrs, Volume= 0.010 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 147.19' @ 12.13 hrs Surf.Area= 47 sf Storage= 5 cf Plug-Flow detention time= 0.5 min calculated for 0.012 of(100% of inflow) Center-of-Mass det. time= 0.4 min ( 832.4 - 832.0 ) Volume Invert Avail.Storage Storage Description #1 147.00' 1,702 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 0 0 0 148.00 250 125 125 149.00 421 336 461 150.00 613 517 978 151.00 835 724 1,702 Device Routing Invert Outlet Devices #1 Primary 145.93' 12.0" Round Culvert L= 22.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 145.93' / 145.39' S= 0.0245 '/' Cc= 0.900 n= 0.011, Flow Area= 0.79 sf #2 Device 1 147.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 150.23' 2.0" x 2.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Discarded 147.00' 8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.01 cfs @ 12.13 hrs HW=147.18' (Free Discharge) L4=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0.11 cfs @ 12.13 hrs HW=147.18' (Free Discharge) L1=Culvert (Passes 0.11 cfs of 2.59 cfs potential flow) 12=Orif ice/G rate (Orifice Controls 0.11 cfs @ 1.46 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Pre Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 8 Pond Basin: Hydrograph - 0.14 _CfS EI Inflow pp A �Outflow EM 0.15 Inf#low Area=®.64 0.13 cfs Discarded p Primary 0.14 Peak Elev=14 - 0.13 0.12 cfs 0.12 Storage=5 cf 0.1 0.09 0.08 0 0.07 0.06 u 0.05 0.04 - ------- - -- „ ' - -- ------ 0.03 0.02 S 0.01 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 9 Summary for Link POA-1: Inflow Area = 1.409 ac, 47.07% Impervious, Inflow Depth > 0.13" for 0.5" Storm event Inflow = 0.19 cfs @ 12.12 hrs, Volume= 0.015 of Primary = 0.19 cfs @ 12.12 hrs, Volume= 0.015 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Link POA-1: Hydrograph - - p Inflow 0.21 - 0 Primary 02 Inflow Area=1.4 0.19 ifs 0.19 0.18 "a=, 0.17 " - -- - - -- 0.16 -- -- - - - - --- - 0.15 0.14 0.13 w 0.12 0.11 0 3 0.1 0.08 0.07 0.06 t 0.05 ' 0.04 0.03 r 0.02 0.01 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 10 Time span=0.00-24.00 hrs, dt=0.10 hrs, 241 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentEX-1: Runoff Area=27,938 sf 68.77% Impervious Runoff Depth>2.01" Tc=6.0 min CN=42/98 Runoff=1.12 cfs 0.107 of SubcatchmentEX-2: Runoff Area=33,418 sf 28.93% Impervious Runoff Depth>0.96" Tc=6.0 min CN=52/98 Runoff=0.56 cfs 0.061 of Pond Basin: Peak Elev=147.68' Storage=57 cf Inflow=1.12 cfs 0.107 of Discarded=0.03 cfs 0.009 of Primary=1.00 cfs 0.098 of Outflow=1.03 cfs 0.107 of Link POA-1: Inflow=1.55 cfs 0.159 of Primary=1.55 cfs 0.159 of Total Runoff Area = 1.409 ac Runoff Volume = 0.169 of Average Runoff Depth = 1.44" 52.93% Pervious = 0.746 ac 47.07% Impervious = 0.663 ac Pre Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment EX-1: [49] Hint: Tc<2dt may require smaller dt Runoff = 1.12 cfs @ 12.11 hrs, Volume= 0.107 af, Depth> 2.01" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 2-Year Rainfall=3.15" Area (sf) CN Description 5,339 98 Roofs, HSG A 427 98 Unconnected roofs, HSG A 13,039 98 Paved parking, HSG A 8,298 39 >75% Grass cover, Good, HSG A 835 98 Water Surface, HSG A 27,938 80 Weighted Average 8,725 42 31.23% Pervious Area 19,213 98 68.77% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX-1: Hydrograph 1.12 cfs o Runoff NRCC 24-h r 1 2-Year Rainfall=3.15" Runoff Area=27,938 sf Runoff Volume=0.107 of Runoff Depth>2.01" Tc=6.0 m i n CN=42/98 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 12 Summary for Subcatchment EX-2: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.56 cfs @ 12.11 hrs, Volume= 0.061 af, Depth> 0.96" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 2-Year Rainfall=3.15" Area (so CN Description 857 98 Unconnected roofs, HSG A 9,668 98 Paved parking, HSG A 18,476 39 >75% Grass cover, Good, HSG A 4,417 96 Gravel surface, HSG A 33,418 65 Weighted Average 23,750 52 71.07% Pervious Area 9,668 98 28.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX-2: Hydrograph Runoff os 0.56 cfs 0.55 NRCC 24-h r D -- 0.5 2-Year Rainfall=3.15" 0.45 -Runoff Area=33,418_sf K: 04 Runoff Volu' e - me=0.061 of 0.35 Runoff De. t , � -Ru p h>Q.96 3 0 p .3 c= min 0.25 ----- -- - , CN=52/98 0.2 -- ---- 0.15 0.1 0.05 .. ._ ., .. 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 13 Summary for Pond Basin: Inflow Area = 0.641 ac, 68.77% Impervious, Inflow Depth > 2.01" for 2-Year event Inflow = 1.12 cfs @ 12.11 hrs, Volume= 0.107 of Outflow = 1.03 cfs @ 12.14 hrs, Volume= 0.107 af, Atten= 8%, Lag= 1.7 min Discarded = 0.03 cfs @ 12.13 hrs, Volume= 0.009 of Primary = 1.00 cfs @ 12.14 hrs, Volume= 0.098 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 147.68' @ 12.13 hrs Surf.Area= 169 sf Storage= 57 cf Plug-Flow detention time= 0.6 min calculated for 0.107 of(100% of inflow) Center-of-Mass det. time= 0.5 min ( 761.7 - 761.2 ) Volume Invert Avail.Storage Storage Description #1 147.00' 1,702 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 0 0 0 148.00 250 125 125 149.00 421 336 461 150.00 613 517 978 151.00 835 724 1,702 Device Routing Invert Outlet Devices #1 Primary 145.93' 12.0" Round Culvert L= 22.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 145.93' / 145.39' S=0.0245 7 Cc= 0.900 n= 0.011, Flow Area= 0.79 sf #2 Device 1 147.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 150.23' 2.0" x 2.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Discarded 147.00' 8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.03 cfs @ 12.13 hrs HW=147.65' (Free Discharge) L4=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.95 cfs @ 12.14 hrs HW=147.65' (Free Discharge) L1=Culvert (Passes 0.95 cfs of 3.30 cfs potential flow) 12=Orif ice/G rate (Orifice Controls 0.95 cfs @ 2.74 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Pre Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 14 Pond Basin: Hydrograph T.-i-2--c-fi-s-1 El Inflow Outflow Inflow Area=0.6441- ® i j 1.03 cfS O P Primarmary Peak Elev=l ,. _ 1.00 cfs 1 Storage=57 c v a LL .0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 15 Summary for Link POA-1: Inflow Area = 1.409 ac, 47.07% Impervious, Inflow Depth > 1.36" for 2-Year event Inflow = 1.55 cfs @ 12.12 hrs, Volume= 0.159 of Primary = 1.55 cfs @ 12.12 hrs, Volume= 0.159 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Link POA-1: Hydrograph p Inflow p Primary Inflow Area=1 .4 155 cfs N 1 o LL 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 16 Time span=0.00-24.00 hrs, dt=0.10 hrs, 241 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentEX-1: Runoff Area=27,938 sf 68.77% Impervious Runoff Depth>3.24" Tc=6.0 min CN=42/98 Runoff=1.72 cfs 0.173 of SubcatchmentEX-2: Runoff Area=33,418 sf 28.93% Impervious Runoff Depth>1.85" Tc=6.0 min CN=52/98 Runoff=1.12 cfs 0.118 of Pond Basin: Peak Elev=148.08' Storage=146 cf Inflow=1.72 cfs 0.173 of Discarded=0.05 cfs 0.013 of Primary=1.47 cfs 0.161 of Outflow=1.52 cfs 0.173 of Link POA-1: Inflow=2.53 cfs 0.279 of Primary=2.53 cfs 0.279 of Total Runoff Area = 1.409 ac Runoff Volume = 0.291 of Average Runoff Depth = 2.48" 52.93% Pervious = 0.746 ac 47.07% Impervious = 0.663 ac Pre Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 17 Summary for Subcatchment EX-1: [49] Hint: Tc<2dt may require smaller dt Runoff = 1.72 cfs @ 12.11 hrs, Volume= 0.173 af, Depth> 3.24" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 10-Year Rainfall=4.83" Area (sf) CN Description 5,339 98 Roofs, HSG A 427 98 Unconnected roofs, HSG A 13,039 98 Paved parking, HSG A 8,298 39 >75% Grass cover, Good, HSG A 835 98 Water Surface, HSG A 27,938 80 Weighted Average 8,725 42 31.23% Pervious Area 19,213 98 68.77% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX-1: Hydrograph Runoff 1.72 cfs NRCC 24-h r D 10-Year Rainfall=4.83,. Runoff Area=27,938 sf Runoff Volume=0.173 of Runoff Depth>3.24" Tc®6.0 min C N=42/98 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 18 Summary for Subcatchment EX-2: [49] Hint: Tc<2dt may require smaller dt Runoff = 1.12 cfs @ 12.12 hrs, Volume= 0.118 af, Depth> 1.85" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Ul as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 10-Year Rainfall=4.83" Area_(sf) CN Description 857 98 Unconnected roofs, HSG A 9,668 98 Paved parking, HSG A 18,476 39 >75% Grass cover, Good, HSG A 4,417 96 Gravel surface, HSG A 33,418 65 Weighted Average 23,750 52 71.07% Pervious Area 9,668 98 28.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX-2: Hydrograph 1.12`Cfs o Runoff NRCC 24-hr D 1 10-Year Rainfall v -4.83" , Runoff Area=33,418 sf Runoff Volume=9.118 of Runoff Depth>1 .85" T'c=6.0 m i n CN=52/98 Ot 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 19 Summary for Pond Basin: [85] Warning: Oscillations may require smaller dt or Finer Routing (severity=1) Inflow Area = 0.641 ac, 68.77% Impervious, Inflow Depth > 3.24" for 10-Year event Inflow = 1.72 cfs @ 12.11 hrs, Volume= 0.173 of Outflow = 1.52 cfs @ 12.16 hrs, Volume= 0.173 af, Atten= 12%, Lag= 3.1 min Discarded = 0.05 cfs @ 12.16 hrs, Volume= 0.013 of Primary = 1.47 cfs @ 12.16 hrs, Volume= 0.161 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 148.08' @ 12.16 hrs Surf.Area= 264 sf Storage= 146 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.6 min ( 758.8 - 758.1 ) Volume Invert Avail.Storage Storage Description #1 147.00' 1,702 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 0 0 0 148.00 250 125 125 149.00 421 336 461 150.00 613 517 978 151.00 835 724 1,702 Device Routing Invert Outlet Devices #1 Primary 145.93' 12.0" Round Culvert L= 22.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 145.93' / 145.39' S= 0.0245 '/' Cc= 0.900 n= 0.011, Flow Area= 0.79 sf #2 Device 1 147.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 150.23' 2.0" x 2.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Discarded 147.00' 8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.05 cfs @ 12.16 hrs HW=148.02' (Free Discharge) t-4=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=1.39 cfs @ 12.16 hrs HW=148.02' (Free Discharge) L1=Culvert (Passes 1.39 cfs of 3.76 cfs potential flow) t2=0 rif ice/G rate (Orifice Controls 1.39 cfs @ 3.99 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Pre Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 20 Pond Basin: Hydrograph 1.72 cfs o Inflow 0 Outflow Inflow Area=0.641 a El p Discarded - Primary Peak Elev 148.Q 1 52 cfs Storage=146 1.47 cfs w 3 1 � 0 LL 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 21 Summary for Link POA-1: Inflow Area = 1.409 ac, 47.07% Impervious, Inflow Depth > 2.37" for 10-Year event. Inflow = 2.53 cfs @ 12.13 hrs, Volume= 0.279 of Primary = 2.53 cfs @ 12.13 hrs, Volume= 0.279 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Link POA-1: Hydrograph E Inflow b Primary Inflow Area=1 .4 2:53 cfs 2 w 0 LL M v 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCAD010.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 22 Time span=0.00-24.00 hrs, dt=0.10 hrs, 241 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentEX-1: Runoff Area=27,938 sf 68.77% Impervious Runoff Depth>4.28" Tc=6.0 min CN=42/98 Runoff=2.25 cfs 0.229 of SubcatchmentEX-2: Runoff Area=33,418 sf 28.93% Impervious Runoff Depth>2.69" Tc=6.0 min CN=52/98 Runoff=1.73 cfs 0.172 of Pond Basin: Peak Elev=148.49' Storage=267 cf Inflow=2.25 cfs 0.229 of Discarded=0.06 cfs 0.015 of Primary=1.81 cfs 0.214 of Outflow=1.87 cfs 0.229 of Link POA-1: Inflow=3.45 cfs 0.385 of Primary=3.45 cfs 0.385 of Total: Runoff Area = 1.409 ac Runoff Volume = 0.400 of Average Runoff Depth = 3.41" 52.93% Pervious = 0.746 ac 47.07% Impervious = 0.663 ac Pre Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment EX-1: [49] Hint: Tc<2dt may require smaller dt Runoff = 2.25 cfs @ 12.11 hrs, Volume= 0.229 af, Depth> 4.28" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 25-Year Rainfall=6.16" Area (sf) CN Description 5,339 98 Roofs, HSG A 427 98 Unconnected roofs, HSG A 13,039 98 Paved parking, HSG A 8,298 39 >75% Grass cover, Good, HSG A 835 98 Water Surface, HSG A 27,938 80 Weighted Average 8,725 42 31.23% Pervious Area 19,213 98 68.77% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX-1: Hydrograph 2.25 cfs 0 Runoff NRCC 24-h r 2 25-Year.Rainfall=6.16" Runoff Area=27,938 sf Runoff Volume=0.229 of Runoff Depth>4.28," 3 Tc=6.0 m i n LL CN=42/98 o , 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCAD010.00-22 s/n 07576 02018 HydroCAD Software Solutions LLC Page 24 Summary for Subcatchment EX-2: [49] Hint: Tc<2dt may require smaller dt Runoff = 1.73 cfs @ 12.12 hrs, Volume= 0.172 af, Depth> 2.69" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Ul as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 25-Year Rainfall=6.16" Area(so CN Description 857 98 Unconnected roofs, HSG A 9,668 98 Paved parking, HSG A 18,476 39 >75% Grass cover, Good, HSG A 4,417 96 Gravel surface, HSG A 33,418 65 Weighted Average 23,750 52 71.07% Pervious Area 9,668 98 28.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX-2: Hydrograph 1.73"cfs o Runoff NRCC 24-h r D 25-Year Rainfa11=6.16" f Runoff Area=33,418 sf Runoff Volume=0.172 of -Runoff Depth>2-.69'' - - - - Tc=6.0 m i n LL CN=52/98 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 25 Summary for Pond Basin: Inflow Area = 0.641 ac, 68.77% Impervious, Inflow Depth > 4.28" for 25-Year event Inflow = 2.25 cfs @ 12.11 hrs, Volume= 0.229 of Outflow = 1.87 cfs @ 12.18 hrs, Volume= 0.229 af, Atten= 17%, Lag= 3.9 min Discarded = 0.06 cfs @ 12.18 hrs, Volume= 0.015 of Primary = 1.81 cfs @ 12.18 hrs, Volume= 0.214 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 148.49' @ 12.18 hrs Surf.Area= 333 sf Storage= 267 cf Plug-Flow detention time= 0.9 min calculated for 0.229 of(100% of inflow) Center-of-Mass det. time= 0.8 min ( 758.3 - 757.6 ) Volume Invert Avail.Storage Storage Description #1 147.00' 1,702 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 0 0 0 148.00 250 125 125 149.00 421 336 461 150.00 613 517 978 151.00 835 724 1,702 Device Routing Invert Outlet Devices #1 Primary 145.93' 12.0" Round Culvert L= 22.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 145.93' / 145.39' S= 0.0245 '/' Cc= 0.900 n= 0.011, Flow Area= 0.79 sf #2 Device 1 147.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 150.23' 2.0" x 2.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Discarded 147.00' 8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.06 cfs @ 12.18 hrs HW=148.43' (Free Discharge) L4=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=1.76 cfs @ 12.18 hrs HW=148.43' (Free Discharge) L1=Culvert (Passes 1.76 cfs of 4.22 cfs potential flow) 12=0 rif ice/G rate (Orifice Controls 1.76 cfs @ 5.03 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Pre Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 26 Pond Basin: Hydrograph 2.25 CfS El inflow 0 Outflow Inflow Area=0.641 a ®Discarded Peak Elev 148. Primary 4�'.87 cfs 2 Storage=267 �.s1 ifs v o LL 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 27 Summary for Link POA-1: Inflow Area = 1.409 ac, 47.07% Impervious, Inflow Depth > 3.28" for 25-Year event Inflow = 3.45 cfs @ 12.14 hrs, Volume= 0.385 of Primary = 3.45 cfs @ 12.14 hrs, Volume= 0.385 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Link POA-1: Hydrograph 0 Inflow p Primary Inflow re =1 .4 3.45 cfs 3 ' 2 3 o t7 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 28 Time span=0.00-24.00 hrs, dt=0.10 hrs, 241 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentEX-1: Runoff Area=27,938 sf 68.77% Impervious Runoff Depth>6.57" Tc=6.0 min CN=42/98 Runoff=3.51 cfs 0.351 of SubcatchmentEX-2: Runoff Area=33,418 sf 28.93% Impervious Runoff Depth>4.70" Tc=6.0 min CN=52/98 Runoff=3.19 cfs 0.301 of Pond Basin: Peak Elev=149.49' Storage=689 cf Inflow=3.51 cfs 0.351 of Discarded=0.10 cfs 0.020 of Primary=2.47 cfs 0.331 of Outflow=2.57 cfs 0.351 of Link POA-1: Inflow=5.48 cfs 0.632 of Primary=5.48 cfs 0.632 of Total Runoff Area = 1.409 ac Runoff Volume = 0.652 of Average Runoff Depth = 5.56" 52.93% Pervious = 0.746 ac 47.07% Impervious = 0.663 ac Pre Development NRCC 24-hr D 100-Y'ear Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 29 Summary for Subcatchment EX-1: [49] Hint: Tc<2dt may require smaller dt Runoff = 3.51 cfs @ 12.11 hrs, Volume= 0.351 af, Depth> 6.57" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0, NRCC 24-hr D 100-Year Rainfall=8.94" Area (sf) CN Description 5,339 98 Roofs, HSG A 427 98 Unconnected roofs, HSG A 13,039 98 Paved parking, HSG A 8,298 39 >75% Grass cover, Good, HSG A 835 98 Water Surface, HSG A 27,938 80 Weighted Average 8,725 42 31.23% Pervious Area 19,213 98 68.77% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX-1: Hydrograph 3.51 cfs o Runoff NRCC 24- r D 3 100-Year Rainfall=8.94" Runoff Area=27,938 sf Runoff Volume=0.351 of 2 Runoff Depth>6.57" LL Tc=6.0 m i n CN=42/98 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 30 Summary for Subcatchment EX-2: [49] Hint: Tc<2dt may require smaller dt Runoff = 3.19 cfs @ 12.12 hrs, Volume= 0.301 af, Depth> 4.70" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 100-Year Rainfall=8.94" Area (so CN Description 857 98 Unconnected roofs, HSG A 9,668 98 Paved parking, HSG A 18,476 39 >75% Grass cover, Good, HSG A 4,417 96 Gravel surface, HSG A 33,418 65 Weighted Average 23,750 52 71.07% Pervious Area 9,668 98 28.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment EX-2: Hydrograph I 3.19 CfS' NRCC 24-hr -D - ----_ -- - - -- -- - - - 3 100-Year Rainfall=8.94" Runoff Area=33,418 sf Runoff_Volume=0.301 of 2-Runoff Depth>4.70" Tc=6.0 m i n CN=52/98 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 31 Summary for Pond Basin: Inflow Area = 0.641 ac, 68.77% Impervious, Inflow Depth > 6.57" for 100-Year event Inflow = 3.51 cfs @ 12.11 hrs, Volume= 0.351 of Outflow = 2.57 cfs @ 12.21 hrs, Volume= 0.351 af, Atten= 27%, Lag= 5.6 min Discarded = 0.10 cfs @ 12.20 hrs, Volume= 0.020 of Primary = 2.47 cfs @ 12.21 hrs, Volume= 0.331 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 149.49' @ 12.20 hrs Surf.Area= 515 sf Storage= 689 cf Plug-Flow detention time= 1.3 min calculated for 0.350 of(100% of inflow) Center-of-Mass det. time= 1.2 min ( 758.6 - 757.4 ) Volume Invert Avail.Storage Storage Description #1 147.00' 1,702 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 0 0 0 148.00 250 125 125 149.00 421 336 461 150.00 613 517 978 151.00 835 724 1,702 Device Routing Invert Outlet Devices #1 Primary 145.93' 12.0" Round Culvert L= 22.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 145.93' / 145.39' S= 0.0245 '/' Cc= 0.900 n= 0.011, Flow Area= 0.79 sf #2 Device 1 147.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 150.23' 2.0" x 2.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Discarded 147.00' 8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.10 cfs @ 12.20 hrs HW=149.47' (Free Discharge) L-4=Exfiltration (Exfiltration Controls 0.10 cfs) Primary OutFlow Max=2.46 cfs @ 12.21 hrs HW=149.47' (Free Discharge) L1=Culvert (Passes 2.46 cfs of 5.20 cfs potential flow) T--2=Orifice/Grate (Orifice Controls 2.46 cfs @ 7.03 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Pre Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 32 Pond Basin: Hydrograph 3.51 CfS El Inflow L Outflow Inflow Area=0.641 a ®Discarded p Primary Peak Elev=149.49' Tim 3 Storage=689 Cf N2 57 cfs 2.41 Cfs w 3 2 o LL 1 .1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Pre Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 33 Summary for Link POA-1: Inflow Area = 1.409 ac, 47.07% Impervious, Inflow Depth > 5.39" for 100-Year event Inflow = 5.48 cfs @ 12.13 hrs, Volume= 0.632 of Primary = 5.48 cfs @ 12.13 hrs, Volume= 0.632 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Link POA-1: Hydrograph p Inflow 6 SAS nfqD Primary Inflow Area=1 . 5.48 cfs 5 4 w LL 3 2 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 5Is#1 PR-5 PR-1 PR-4 �— a� PR-3 POA-1 sis#2 PR-6 PR-2 SubCaf Reach on Llnk Routing Diagram for Post Development Prepared by Microsoft, Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Post Development Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.272 39 >75% Grass cover, Good, HSG A (PR-1, PR-2, PR-3, PR-4, PR-5, PR-6) 0.827 98 Paved parking, HSG A (PR-3, PR-4, PR-5) 0.291 98 Roofs, HSG A (PR-3, PR-4) 0.019 98 Water Surface, HSG A (PR-4) 1.409 87 TOTAL AREA Post Development Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 3 Soil Listing (all nodes) Area Soil Subcatchment (acres) Group Numbers 1.409 HSG A PR-1, PR-2, PR-3, PR-4, PR-5, PR-6 0.000 HSG B 0.000 HSG C 0.000 HSG D 0.000 Other 1.409 TOTAL AREA Post Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 4 Time span=0.00-24.00 hrs, dt=0.10 hrs, 241 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentPR-1: Runoff Area=1,926 sf 0.00% Impervious Runoff Depth=0.00" Tc=6.0 min CN=39/0 Runoff=0.00 cfs 0.000 of SubcatchmentPR-2: Runoff Area=7,645 sf 0.00% Impervious Runoff Depth=0.00" Tc=6.0 min CN=39/0 Runoff=0.00 cfs 0.000 of SubcatchmentPR-3: Runoff Area=15,910 sf 99.35% Impervious Runoff Depth>0.32" Tc=6.0 min CN=39/98 Runoff=0.11 cfs 0.010 of SubcatchmentPR-4: Runoff Area=27,120 sf 93.95% Impervious Runoff Depth>0.30" Tc=6.0 min CN=39/98 Runoff=0.18 cfs 0.015 of SubcatchmentPR-5: Runoff Area=8,482 sf 97.28% Impervious Runoff Depth>0.31" Tc=6.0 min CN=39/98 Runoff=0.06 cfs 0.005 of SubcatchmentPR-6: Runoff Area=307 sf 0.00% Impervious Runoff Depth=0.00" Tc=6.0 min CN=39/0 Runoff=0.00 cfs 0.000 of Pond Basin: Peak Elev=147.22' Storage=6 cf Inflow=0.18 cfs 0.015 of Discarded=0.01 cfs 0.003 of Primary=0.16 cfs 0.013 of Outflow=0.17 cfs 0.015 of Pond SIS#1: Peak Elev=153.68' Storage=7 cf Inflow=0.06 cfs 0.005 of Discarded=0.05 cfs 0.005 of Primary=0.00 cfs 0.000 of Outflow=0.05 cfs 0.005 of Pond SIS#2: Peak Elev=153.27' Storage=19 cf Inflow=0.11 cfs 0.010 of Discarded=0.10 cfs 0.010 of Primary=0.00 cfs 0.000 of Outflow=0.10 cfs 0.010 of Link POA-1: Inflow=0.16 cfs 0.013 of Primary=0.16 cfs 0.013 of Total Runoff Area = 1.409 ac Runoff Volume = 0.030 of Average Runoff Depth = 0.26" 19.31% Pervious = 0.272 ac 80.69% Impervious = 1.137 ac Post Development NRCC 24-hr D 0.5" Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment PR-1: [49] Hint: Tc<2dt may require smaller dt [45) Hint: Runoff=Zero Runoff = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Depth= 0.00" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 0.5" Storm Rainfall=0.50" Area_(sf) CN Description 1,926 39 >75% Grass cover, Good, HSG A 1,926 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) &0 Direct Entry, Subcatchment PR-1: Hydrograph 1 �Runoff NRCC 24-hr D 0.5" Storm Rainfall=0.50" Runoff Area=1 ,926 sf Runoff Volume=0.000 of Runoff Depth 0.00 " Tc=6.0 min U. CN=39/0 0.00 cfs 0 0 1 2 3 4 . 5 6 7 8, 9 10 11 12 13 14 15 16 17 18 19 - 20 21 22 23 . 24 Time (hours) Post Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment PR-2: [49] Hint: Tc<2dt may require smaller dt [45] Hint: Runoff=Zero Runoff = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Depth= 0.00" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= & NRCC 24-hr D 0.5" Storm Rainfall=0.50" Area (sf) CN Description 7,645 39 >75% Grass cover, Good, HSG A 7,645 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-2: Hydrograph 1 , �Runoff NRCC 24-h r D 0.5" Storm Rainfall 0.50, Runoff Area=7,645 sf Runoff Volume=0.000 of Runoff Depth 0.00'" Tc=6.0 min CN=39/0 0.00 cfs 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Paqe 7 Summary for Subcatchment PR-3: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.11 cfs @ 12.11 hrs, Volume= 0.010 af, Depth> 0.32" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Ul as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 0.5" Storm Rainfall=0.50" Area (sf) CN Description 8,703 98 Roofs, HSG A 7,103 98 Paved parking, HSG A 104 39 >75% Grass cover, Good, HSG A 15,910 98 Weighted Average 104 39 0.65% Pervious Area 15,806 98 99.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-3: Hydrograph --------------- --------------------------------- 0.12s 0.12 0.115 0.11 CS 0.11 NRCC 24-h r D 0.105 0.1 0.5 Storm Rainfall 0.50 0.095 - - - - - - 0.09 Runoff Area=15,910 sf 0.085 ' 0.08 -Runoff Volume=0'.010 of - - 0.075 w 0.07 -Runoff-Depth>0.32" - -- - 0.065 0 0.06 Tc=6.0 min a 0.055 ��; 0.05 CN=39198 0.045 - -- - 0.04 - 0.035 0.03 ' 0.025 0.02 0.015 0.01 - 0.005 , 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 0.5" Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment PR-4: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.18 cfs @ 12.11 hrs, Volume= 0.015 af, Depth> 0.30" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 0.5" Storm Rainfall=0.50" Area (sf) CN Description 3,960 98 Roofs, HSG A 20,684 98 Paved parking, HSG A 835 98 Water Surface, HSG A 1,641 39 >75% Grass cover, Good, HSG A 27,120 94 Weighted Average 1,641 39 6.05% Pervious Area 25,479 98 93.95% Impervious Area Tc Length Slope Velocity Capacity Description -(min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-4: Hydrograph 0.2 - - - - - - -- - -- --- FOR no 0.19 0.18 cfs 0.18 NRCC 24-h r D 0.17 0.5- Storm Rainfall- - - - - - - -- - -- y ' -0.50r, 0.15 0.14 Runoff noff-Area-=27,120 s - - T - --- 0.13 - Runoff-Volume=0.015 of w 0.12 w' 0.11 ' -Runoff.Depth>0.3'0" -- - --- 3 009 Tc=6.O min -- -- -- -- - 0.08 C N=39/98 - -- 0.07 " Y G . 0.06 - ---- --- 0.05 0.04 --—----- -- ---- 0.03 0.02 0.01 ,_ .. . 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 0.5" Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment PR-5: [49] Hint: Tc<2dt may require smaller dt Runoff 1 0.06 cfs @ 12.11 hrs, Volume= 0.005 af, Depth> 0.31" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 0.5" Storm Rainfall=0.50" Area (so CN Description 8,251 98 Paved parking, HSG A 231 39 >75% Grass cover, Good, HSG A 8,482 96 Weighted Average 231 39 2.72% Pervious Area 8,251 98 97.28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-5: Hydrograph 0.065 0.06 cfs 0.06 o Runoff N RAC 24-h r D 0.055 0.5 Storm Rainfall=0.50'' 0.05 0.045 -Runoff-Area 8-482-sf 0.04 Runoff Volume=0.005 of - - - 0.035 Runoff-Depth>0.31" 3 0 0.03 Tc=6.0 min 0.025 CN=39198 0.02 0.015 0.01 0.005 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment PR-6: [49] Hint: Tc<2dt may require smaller dt [45] Hint: Runoff=Zero Runoff = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Depth= 0.00" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 0.5" Storm Rainfall=0.50" Area (sf) CN Description 307 39 >75% Grass cover, Good, HSG A 307 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-6: Hydrograph 1 �Runoff NRCC 24-h r D 0.5" Storm Rainfall=0.50'," Runoff Area=307 sf Runoff Volume=0.000 of Runoff Depth=0.00" Tc=6.0 min LL CN=39/0 0.00 cfs 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 11 Summary for Pond Basin: Inflow Area = 0.817 ac, 94.74% Impervious, Inflow Depth > 0.23" for 0.5" Storm event Inflow = 0.18 cfs @ 12.11 hrs, Volume= 0.015 of Outflow = 0.17 cfs @ 12.13 hrs, Volume= 0.015 af, Atten= 4%, Lag= 0.9 min Discarded = 0.01 cfs @ 12.13 hrs, Volume= 0.003 of Primary = 0.16 cfs @ 12.13 hrs, Volume= 0.013 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 147.22' @ 12.13 hrs Surf.Area= 55 sf Storage= 6 cf Plug-Flow detention time= 0.5 min calculated for 0.015 of(100% of inflow) Center-of-Mass det. time= 0.4 min ( 832.4 - 832.0 ) Volume Invert Avail.Storage Storage Description #1 147.00' 1,702 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 0 0 0 148.00 250 125 125 149.00 421 336 461 150.00 613 517 978 151.00 835 724 1,702 Device Routing Invert Outlet Devices #1 Primary 145.93' 12.0" Round Culvert L= 22.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 145.93' / 145.39' S= 0.0245 '/' Cc= 0.900 n= 0.011, Flow Area= 0.79 sf #2 Device 1 147.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 150.23' 2.0" x 2.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Discarded 147.00' 8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.01 cfs @ 12.13 hrs HW=147.21' (Free Discharge) L4=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0.15 cfs @ 12.13 hrs HW=147.21' (Free Discharge) L1=Culvert (Passes 0.15 cfs of 2.64 cfs potential flow) T--2=Orifice/Grate (Orifice Controls 0.15 cfs @ 1.58 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Post Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 12 Pond Basin: Hydrograph 0.18 Cfis Inflow Outflow Inflow Area=O 81 0.17 cfs Discarded 0.2 -- - - - -- ❑Primary 0.19 -Peak Elev=1 - - -- --- 0.1 a 0.16 cfs -- 0.17 Storage=6 cf- --- -- --- 0.16 0.15 0.14 0.13 0.12 u 0.11 LL - o 0.09 - - ---- - - i 0.08 0.07 0.06 0.05 0.04 - r 0.03 S 0.02 0.01 „ 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 13 Summary for Pond SIS#1: Inflow Area = 0.195 ac, 97.28% Impervious, Inflow Depth > 0.31" for 0.5" Storm event Inflow = 0.06 cfs @ 12.11 hrs, Volume= 0.005 of Outflow = 0.05 cfs @ 12.16 hrs, Volume= 0.005 af, Atten= 10%, Lag= 3.0 min Discarded = 0.05 cfs @ 12.16 hrs, Volume= 0.005 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 153.68' @ 12.16 hrs Surf.Area= 882 sf Storage= 7 cf Plug-Flow detention time= 2.2 min calculated for 0.005 of(100% of inflow) Center-of-Mass det. time= 1.8 min ( 833.8 - 832.0 ) Volume Invert Avail.Storage Storage Description #1 153.67' 882 cf 7.00'W x 7.00'L x 1.50'H Prismatoid x 12 #2 153.67' 588 cf 7.00'W x 7.00'L x 2.00'H Prismatoid x 6 #3 155.67' 6 cf Custom Stage Data (Prismatic)Listed below (Recalc) -Impervious 1,476 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 155.67 2 0 0 156.20 2 1 1 156.21 1,000 5 6 Device Routing Invert Outlet Devices #1 Discarded 153.67' 8.270 in/hr Exfiltration over Horizontal area #2 Primary 156.20' 12.0" x 300.0" Horiz. TD-2 C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.17 cfs @ 12.16 hrs HW=153.68' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.17 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=153.67' (Free Discharge) t2=TD-2 ( Controls 0.00 cfs) Post Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 14 Pond SIS#1: Hydrograph - +- -- - 0.06 cfS -- - El Inflow Inflow Area - o Outflow 195 ac --- ®Discarded -O: 0.065 — �� 0 Primary i 0.06 ' - �" Peak Elev=153� 0.05 cfs 0.055 Storage=T cf - 0.05 0.045 - 0.04 0.035 - LL 0.025 - -- 0.02 - - 0.01 0.00 cfs 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by'Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 15 Summary for Pond SIS##2: Inflow Area = 0.365 ac, 99.35% Impervious, Inflow Depth > 0.32" for 0.5" Storm event Inflow = 0.11 cfs @ 12.11 hrs, Volume= 0.010 of Outflow = 0.10 cfs @ 12.18 hrs, Volume= 0.01Oaf, Atten= 13%, Lag= 3.8 min Discarded = 0.10 cfs @ 12.18 hrs, Volume= 0.010 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 153.27' @ 12.18 hrs Surf.Area= 980 sf Storage= 19 cf Plug-Flow detention time= 3.3 min calculated for 0.010 of(100% of inflow) Center-of-Mass det. time= 2.6 min ( 834.6 - 832.0 ) Volume Invert Avail.Storage Storage Description #1 153.25' 784 cf 7.00'W x 7.001 x 2.00'H Prismatoid x 8 #2 153.25' 1,470 cf 7.00'W x 7.00'L x 2.50'H Prismatoid x 12 #3 155.75' 152 cf Custom Stage Data (Prismatic)Listed below (Recalc) -Impervious 2,406 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 155.75 2 0 0 156.50 2 2 2 157.00 600 151 152 Device Routing Invert Outlet Devices #1 Discarded 153.25' 8.270 in/hr Exfiltration over Horizontal area #2 Primary 156.50' 24.0" x 24.0" Horiz. CB-1 C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.19 cfs @ 12.18 hrs HW=153.27' (Free Discharge) L11=Exfiltration (Exfiltration Controls 0.19 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=153.25' (Free Discharge) L2=CB-1 ( Controls 0.00 cfs) Post Development NRCC 24-hr D 0.5"Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 16 Pond SIS#2: Hydrograph - - - -- 0.11 cfs III Inflow r Outflow ®Discarded Inflow Area=0.365 ac 0.12 Y Primary -Peak Elev=153. ---- ------ 0.11 0.10 cfs Storage=19 Cf - - - -- 0.09 0.08 ------- -------- --- - - - ----- -- - u' 0.07 ' --'- 3 0.06 o U. 0.05 - 0.04 � - - -- -- -- - 0.03 ' 0.02 0.00 cfs 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 0.5" Storm Rainfall=0.50" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 17 Summary for Link POA-1: Inflow Area = 1.409 ac, 80.69% Impervious, Inflow Depth > 0.11" for 0.5" Storm event Inflow = 0.16 cfs @ 12.13 hrs, Volume= 0.013 of Primary = 0.16 cfs @ 12.13 hrs, Volume= 0.013 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Link POA-1: Hydrograph ---•- El 0.17 0 Primary Inflow Arfq e - 16 cfs - - - a=1-.4 . 7 - --- - - - 0.16 0.15 0.14 0.13 0.12 - 3 0.09 �° 0.08 0.07 0.06 0.05 0.04 M , - . 0.03 0.02 0.01 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 18 Time span=0.00-24.00 hrs, dt=0.10 hrs, 241 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentPR-1: Runoff Area=1,926 sf 0.00% Impervious Runoff Depth>0.00" Tc=6.0 min CN=39/0 Runoff=0.00 cfs 0.000 of SubcatchmentPR-2: Runoff Area=7,645 sf 0.00% Impervious Runoff Depth>0.00" Tc=6.0 min CN=39/0 Runoff=0.00 cfs 0.000 of SubcatchmentPR-3: Runoff Area=15,910 sf 99.35% Impervious Runoff Depth>2.90" Tc=6.0 min CN=39/98 Runoff=0.92 cfs 0.088 of SubcatchmentPR-4: Runoff Area=27,120 sf 93.95% Impervious Runoff Depth>2.74" Tc=6.0 min CN=39/98 Runoff=1.48 cfs 0.142 of SubcatchmentPR-5: Runoff Area=8,482 sf 97.28% Impervious Runoff Depth>2.84" Tc=6.0 min CN=39/98 Runoff=0.48 cfs 0.046 of SubcatchmentPR-6: Runoff Area=307 sf 0.00% Impervious Runoff Depth>0.00" Tc=6.0 min CN=39/0 Runoff=0.00 cfs 0.000 of Pond Basin: Peak Elev=147.91' Storage=103 cf Inflow=1.48 cfs 0.142 of Discarded=0.04 cfs 0.011 of Primary=1.29 cfs 0.131 of Outflow=1.34 cfs 0.142 of Pond SIS#1: Peak Elev=153.94' Storage=240 cf Inflow=0.48 cfs 0.046 of Discarded=0.17 cfs 0.046 of Primary=0.00 cfs 0.000 of Outflow=0.17 cfs 0.046 of Pond SIS#2: Peak Elev=153.98' Storage=716 cf Inflow=0.92 cfs 0.088 of Discarded=0.19 cfs 0.088 of Primary=0.00 cfs 0.000 of Outflow=0.19 cfs 0.088 of Link POA-1: Inflow=1.29 cfs 0.131 of Primary=1.29 cfs 0.131 of Total Runoff Area = 1.409 ac Runoff Volume = 0.276 of Average Runoff Depth = 2.35" 19.31% Pervious = 0.272 ac 80.69% Impervious = 1.137 ac Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment PR-1: [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff = 0.00 cfs @ 24.00 hrs, Volume= 0.000 af, Depth> 0.00" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 2-Year Rainfall=3.15" Area (sf) CN Description 1,926 39 >75% Grass cover, Good, HSG A 1,926 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-1: Hydrograph - - - ° a Runoff ° . . - 0.00 cfs ° -NRCC 24=hr-D: - ° -2-Year Rainfall=115 - 0 0 - - - -- o „ -Runoff Area=1 ,9 6 sf 0 ° -Runoff Volute=0.000-af- -- -- Om Runoff Depth>0.00" LL ° Te-6 0 min -. - ° C =39/� - - 0 o --- - - 0 0 - - - 0 o 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCAD010.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment PR-2: [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff = 0.00 cfs @ 24.00 hrs, Volume= 0.000 af, Depth> 0.00" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 2-Year Rainfall=3.15" Area (so CN Description 7,645 39 >75% Grass cover, Good, HSG A 7,645 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-2: Hydrograph 0 �Runoff - 0.00 cfs -- -- o NRCC 24=hr D- _ ° 2-Year Rainfall=315 ° - -- - ----- -- Runoff Area=7 645 sf ---, -- - - _ ----- -- - ° Runoff Volume=0.000 of - 0 - 3 0 RuHoff Depth -0.00" --- --- - LL ° ° Tc=6:0 min- ° C N=39/0 - - - -- -- - -- - - ° --- - ----- --- ----- - ° 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 21 Summary for Subcatchment PR-3: [49) Hint: Tc<2dt may require smaller dt Runoff = 0.92 cfs @ 12.11 hrs, Volume= 0.088 af, Depth> 2.90" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0, NRCC 24-hr D 2-Year Rainfall=3.15" Area (sf) CN Description 8,703 98 Roofs, HSG A 7,103 98 Paved parking, HSG A 104 39 >75% Grass cover, Good, HSG A 15,910 98 Weighted Average 104 39 0.65% Pervious Area 15,806 98 99.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-3: Hydrograph 1 0.92 cfs o Runoff NRCC 24-h r D 2-Year Rainfall=3.15" Runoff Area=15,910 sf Runoff Volume=0.088 of Runoff Depth>2.90'` Tc=6.0 rn i n CN=39/98 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment PR-4: [49] Hint: Tc<2dt may require smaller dt Runoff = 1.48 cfs @ 12.11 hrs, Volume= 0.142 af, Depth> 2.74" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 2-Year Rainfall=3.15" Area (sf) CN Description 3,960 98 Roofs, HSG A 20,684 98 Paved parking, HSG A 835 98 Water Surface, HSG A 1,641 39 >75% Grass cover, Good, HSG A 27,120 94 Weighted Average 1,641 39 6.05% Pervious Area 25,479 98 93.95% Impervious Area Tc Length Slope Velocity Capacity Description - (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-4: Hydrograph 1.48'cfs` o Runoff NRCC 24-h r D 2-Year Rainfall=3.15" Runoff Area=27,120 sf Runoff Volume=0.1-42 of „f Runoff Depth>2.74" Tc=6.0 rn i n C N=39/98 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment PR-5: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.48 cfs @ 12.11 hrs, Volume= 0.046 af, Depth> 2.84" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 2-Year Rainfall=3.15" Area (sf) CN Description 8,251 98 Paved parking, HSG A 231 39 >75% Grass cover, Good, HSG A 8,482 96 Weighted Average 231 39 2.72% Pervious Area 8,251 98 97.28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-5: Hydrograph -- -- - ❑Runoff 0.5 0.48 cfs - --- NR'CQ 24-hr fl 0.45 -2-Year-Rainfall=315" - - - - -- - -0-4- Runoff Aarea=8,482 sf 0.35 Runoff Vo>ume=0.046 -- of 03 Runoff Depth>2.84" 0 0.25 Tc=6.0 min -- 0.2 CN=3,9/98 0.15 0.1 0.05 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 24 Summary for Subcatchment PR-6: [49] Hint: Tc<2dt may require smaller dt [73] Warning: Peak may fall outside time span Runoff = 0.00 cfs @ 24.00 hrs, Volume= 0.000 af, Depth> 0.00" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 2-Year Rainfall=3.15" Area (sf) CN Description 307 39 >75% Grass cover, Good, HSG A 307 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description minim (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-6: Hydrograph 1 ' �Runoff NRCC 24-h r D 2-Year Rainfall'=3.15" Runoff Area=307 sf Runoff Volume=0.000 of Runoff Depth>0.00" LL Tc=6.0 m i n CN=39/0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 25 Summary for Pond Basin: Inflow Area = 0.817 ac, 94.74% Impervious, Inflow Depth > 2.09" for 2-Year event Inflow = 1.48 cfs @ 12.11 hrs, Volume= 0.142 of Outflow = 1.34 cfs @ 12.15 hrs, Volume= 0.142 af, Atten= 10%, Lag= 2.6 min Discarded = 0.04 cfs @ 12.15 hrs, Volume= 0.011 of Primary = 1.29 cfs @ 12.15 hrs, Volume= 0.131 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 147.91' @ 12.15 hrs Surf.Area= 227 sf Storage= 103 cf Plug-Flow detention time= 0.7 min calculated for 0.142 of(100% of inflow) Center-of-Mass det. time= 0.6 min ( 760.9 - 760.4 ) Volume Invert Avail.Storage Storage Description #1 147.00' 1,702 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 0 0 0 148.00 250 125 125 149.00 421 336 461 150.00 613 517 978 151.00 835 724 1,702 Device Routing Invert Outlet Devices #1 Primary 145.93' 12.0" Round Culvert L= 22.0' CPP, projecting, no headwall, Ke= 0.900 inlet/Outlet Invert= 145.93' / 145.39' S= 0.0245 '/' Cc= 0.900 n= 0.011, Flow Area= 0.79 sf #2 Device 1 147.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 150.23' 2.0" x 2.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Discarded 147.00' 8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.04 cfs @ 12.15 hrs HW=147.86' (Free Discharge) L4=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=1.22 cfs @ 12.15 hrs HW=147.86' (Free Discharge) L1=Culvert (Passes 1.22 cfs of 3.57 cfs potential flow) 1--2=Orifice/G rate (Orifice Controls 1.22 cfs @ 3.49 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Post Development NRCC 24-hr D 2-Year Rainfall=345" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 26 Pond Basin: Hydrograph 1.48 CfS o Inflow 0 Outflow Inflow Area=0.817 a ®Discarded O Primary Peals Elev'147.g"1 34 cfs _Storage=103 12 9 cfs 1 ' w v LL 0 0 1 2 3 4 5 6 7 8 .9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 27 Summary for Pond SIS#1: Inflow Area = 0.195 ac, 97.28% Impervious, Inflow Depth > 2.84" for 2-Year event Inflow = 0.48 cfs @ 12.11 hrs, Volume= 0.046 of Outflow = 0.17 cfs @ 12.00 hrs, Volume= 0.046 af, Atten= 65%, Lag= 0.0 min Discarded = 0.17 cfs @ 12.00 hrs, Volume= 0.046 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 153.94' @ 12.33 hrs Surf.Area= 882 sf Storage= 240 cf Plug-Flow detention time= 6.1 min calculated for 0.046 of(100% of inflow) Center-of-Mass det. time= 5.8 min ( 766.1 - 760.4 ) Volume Invert Avail.Storage Storage Description #1 153.67' 882 cf 7.00'W x 7.00'L x 1.50'H Prismatoid x 12 #2 153.67' 588 cf 7.00'W x 7.00'L x 2.00'H Prismatoid x 6 #3 155.67' 6 cf Custom Stage Data (Prismatic)Listed below (Recalc) -Impervious 1,476 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 155.67 2 0 0 156.20 2 1 1 156.21 1,000 5 6 Device Routing Invert Outlet Devices #1 Discarded 153.67' 8.270 in/hr Exfiltration over Horizontal area #2 Primary 156.20' 12.0" x 300.0" Horiz. TD-2 C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.17 cfs @ 12.00 hrs HW=153.72' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.17 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=153.67' (Free Discharge) t-2=TD-2 ( Controls 0.00 cfs) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 02018 HydroCAD Software Solutions LLC Page 28 Pond SIS#1: Hydrograph - --- -- -- 0.48 efS o outflow of -- -- - Discarded low Area=0195 ac o Primary 0.5 Peak Elev=153.94' 0.45 Sto rage=240 cf - --- - -- 0.4 0.35 F 0.3 - ------ --- -- -- --- --- ----- ----- ---- v 0 0.25 ---- - - --- LL 0.17 cfs 0.2 - - - - 0.15 --�'�- --- - --- -- - - _ . v 0.1 e - 0.00 cfs 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 - Time (hours) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 29 Summary for Pond SIS#2: Inflow Area = 0.365 ac, 99.35% Impervious, Inflow Depth > 2.90" for 2-Year event Inflow = 0.92 cfs @ 12.11 hrs, Volume= 0.088 of Outflow = 0.19 cfs @ 11.80 hrs, Volume= 0.088 af, Atten= 80%, Lag= 0.0 min Discarded = 0.19 cfs @ 11.80 hrs, Volume= 0.088 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 153.98' @ 12.49 hrs Surf.Area= 980 sf Storage= 716 cf Plug-Flow detention time= 19.0 min calculated for 0.088 of(100% of inflow) Center-of-Mass det. time= 18.3 min ( 778.7 - 760.4 ) Volume Invert Avail.Storage Storage Description #1 153.25' 784 cf 7.00'W x 7.00'L x 2.00'H Prismatoid x 8 #2 153.25' 1,470 cf 7.00'W x 7.00'L x 2.50'H Prismatoid x 12 #3 155.75' 152 cf Custom Stage Data (Prismatic)Listed below (Recalc) -Impervious 2,406 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 155.75 2 0 0 156.50 2 2 2 157.00 600 151 152 Device Routing Invert Outlet Devices #1 Discarded 153.25' 8.270 in/hr Exfiltration over Horizontal area #2 Primary 156.50' 24.0" x 24.0" Horiz. CB-1 C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.19 cfs @ 11.80 hrs HW=153.29' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.19 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=153.25' (Free Discharge) L2=CB-1 ( Controls 0.00 cfs) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 30 Pond SIS#2: Hydrograph 2 CfS' o inflow 0.9 0 Outflow Inflow Area=0.365 a 0 Discarded 1 O Primary Peak Elev=153.98' Storage=7,16 cf w V o LL 7 0.00 cfs , , 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 2-Year Rainfall=3.15" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 31 Summary for Link POA-1: Inflow Area = 1.409 ac, 80.69% Impervious, Inflow Depth > 1.12" for 2-Year event Inflow = 1.29 cfs @ 12.15 hrs, Volume= 0.131 of Primary = 1.29 cfs @ 12.15 hrs, Volume= 0.131 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Link POA-1: Hydrograph 0 Inflow O Primary Inflow re = 4.0 .29 cfs N 3 o LLPOP�t 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 32 Time span=0.00-24.00 hrs, dt=0.10 hrs, 241 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentPR-1: Runoff Area=1,926 sf 0.00% Impervious Runoff Depth>0.17" Tc=6.0 min CN=39/0 Runoff=0.00 cfs 0.001 of SubcatchmentPR-2: Runoff Area=7,645 sf 0.00% Impervious Runoff Depth>0.17" Tc=6.0 min CN=39/0 Runoff=0.00 cfs 0.002 of SubcatchmentPR-3: Runoff Area=15,910 sf 99.35% Impervious Runoff Depth>4.56" Tc=6.0 min CN=39/98 Runoff=1.42 cfs 0.139 of SubcatchmentPR-4: RunoffArea=27,120 sf 93.95% Impervious Runoff Depth>4.32" Tc=6.0 min CN=39/98 Runoff=2.29 cfs 0.224 of SubcatchmentPR-5: RunoffArea=8,482 sf 97.28% Impervious Runoff Depth>4.47" Tc=6.0 min CN=39/98 Runoff=0.74 cfs 0.073 of SubcatchmentPR-6: Runoff Area=307 sf 0.00% Impervious Runoff Depth>0.17" Tc=6.0 min CN=39/0 Runoff=0.00 cfs 0.000 of Pond Basin: Peak Elev=148.51' Storage=275 cf Inflow=2.29 cfs 0.224 of Discarded=0.06 cfs 0.015 of Primary=1.83 cfs 0.210 of Outflow=1.89 cfs 0.224 of Pond SIS#1: Peak Elev=154.27' Storage=527 cf Inflow=0.74 cfs 0.073 of Discarded=0.17 cfs 0.072 of Primary=0.00 cfs 0.000 of Outflow=0.17 cfs 0.072 of Pond SIS#2: Peak Elev=154.74' Storage=1,460 cf Inflow=1.42 cfs 0.139 of Discarded=0.19 cfs 0.139 of Primary=0.00 cfs 0.000 of Outflow=0.19 cfs 0.139 of Link POA-1: Inflow=1.83 cfs 0.213 of Primary=1.83 cfs 0.213 of Total Runoff Area = 1.409 ac Runoff Volume = 0.439 of Average Runoff Depth = 3.74" 19.31% Pervious = 0.272 ac 80.69% Impervious = 1.137 ac Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 33 Summary for Subcatchment PR-1: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.00 cfs @ 14.27 hrs, Volume= 0.001 af, Depth> 0.17" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 10-Year Rainfall=4.83" Area (sf) CN Description 1,926 39 >75% Grass cover, Good, HSG A 1,926 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-1: Hydrograph 0.001 p Runoff 0.001 0.00 cfs 0.001-11NRCC 24-hrD 0.001 10 Yeas Rainfal1=4.83°' -- 0.001 0.001 Runoff Area=1 ,926 sf 0001 Runoff Volume=0.001 of 0.000 o.000 Runoff Depth>0.17' o 0.000 ' Tc=6.0 ra i n 0.000 0.000- CN=39/0 0.000 0.000 0.000 0 0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 34 Summary for Subcatchment PR-2: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.00 cfs @ 14.27 hrs, Volume= 0.002 af, Depth> 0.17" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 10-Year Rainfall=4.83" Area (so CN Description 7,645 39 >75% Grass cover, Good, HSG A 7,645 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-2: Hydrograph 0.003 0.003 0.00 cfS I j O Runoff 0.003 NRCC_24-h_r D 0.003 1 0- `.; ar Rainfall=4.83" 0.003 0.002 Ru-noff_Area=7,645_sf -_ 0.002 - - - noff Vo 0.002 of- - - ----Runoff lu;rne- - - 0.002 0.002 Runoff Depth>0.17 - 0 0.001 Tc=6.0 m i n - ,- 0.00 . 0.001 CN`=3910 -- 0.001 0.001 0.001 0.000 0.000 ., 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 35 Summary for Subcatchment PR-3: [49] Hint: Tc<2dt may require smaller dt Runoff = 1.42 cfs @ 12.11 hrs, Volume= 0.139 af, Depth> 4.56" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 10-Year Rainfall=4.83" Area(sf) CN Description 8,703 98 Roofs, HSG A 7,103 98 Paved parking, HSG A 104 39 >75% Grass cover, Good, HSG A 15,910 98 Weighted Average 104 39 0.65% Pervious Area 15,806 98 99.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-3: Hydrograph 1.42 cfS o Ruoff NRCC 24-h r DeA 10-Year Rainfall=4.83" Runoff Area=15,910 sf Runoff Volume=0.139 of . Runoff Depth>4.56" 3 0 Tc=6.0 m i n CN=39/98 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 36 Summary for Subcatchment PR-4: [49] Hint: Tc<2dt may require smaller dt Runoff = 2.29 cfs @ 12.11 hrs, Volume= 0.224 af, Depth> 4.32" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/[mperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 10-Year Rainfall=4.83" Area (sf) CN Description ---------- 3,960 98 Roofs, HSG A 20,684 98 Paved parking, HSG A 835 98 Water Surface, HSG A 1,641 39 >75% Grass cover, Good, HSG A 27,120 94 Weighted Average 1,641 39 6.05% Pervious Area 25,479 98 93.95% Impervious Area Tc Length Slope Velocity Capacity Description min (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-4: Hydrograph 2.29 cfs' o Runoff NRCC 24-hr D - -- -- -- 2 10-Year Rainfall=4.83" Runoff Area=27,120 sf Runoff Volume=0.224 of Runoff Depth>4.32" o LL -Tc=6.0_min - --- 1 CN=39/98 t........... ............ 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 37 Summary for Subcatchment PR-5: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.74 cfs @ 12.11 hrs, Volume= 0.073 af, Depth> 4.47" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0, NRCC 24-hr D 10-Year Rainfall=4.83" Area (sf CN Description 8,251 98 Paved parking, HSG A 231 39 >75% Grass cover, Good, HSG A 8,482 96 Weighted Average 231 39 2.72% Pervious Area 8,251 98 97.28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-5: Hydrograph 0.8 0.74 cfs 0.7s - 0.7 N RCS 24-h r D - -- -- -- 0.65 10-Year Rainfall=4.83" Runoff Area=8482 sf 0.5s 0.5 Runoff Volume=0.073 of y 0.45 -Runoff Depth>4.47" 0 0.4 u_ 0.35 Tc=6.0 min - - 0.3 CN=39/98 0.25 0.2 0.15 0.1 0.05 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 38 Summary for Subcatchment PR-6: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.00 cfs @ 14.27 hrs, Volume= 0.000 af, Depth> 0.17" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 10-Year Rainfall=4.83" Area (sf) CN Description 307 39 >75% Grass cover, Good, HSG A 307 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-6: Hydrograph -- - - --- +- - pRUnoff o.000 0.00 cfs 0.000 NRCC 24-h r D °°°° 10-Year Rainfall=4.83" 0.000-1 Runoff Area=307 sf-0-1 Runoff Volum u e=0.000 of Runoff Depth>0.17 _ -- - -- - M 0 Tc=6.0 m i n ° CN=39/0 0 0 0 0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 39 Summary for Pond Basin: Inflow Area = 0.817 ac, 94.74% Impervious, Inflow Depth > 3.29" for 10-Year event Inflow = 2.29 cfs @ 12.11 hrs, Volume= 0.224 of Outflow = 1.89 cfs @ 12.17 hrs, Volume= 0.224 af, Atten= 17%, Lag= 3.9 min Discarded = 0.06 cfs @ 12.18 hrs, Volume= 0.015 of Primary = 1.83 cfs @ 12.17 hrs, Volume= 0.210 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 148.51' @ 12.18 hrs Surf.Area= 337 sf Storage= 275 cf Plug-Flow detention time= 0.9 min calculated for 0.223 of(100% of inflow) Center-of-Mass det. time= 0.8 min ( 752.3 - 751.5 ) Volume Invert Avail.Storage Storage Description #1 147.00' 1,702 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 0 0 0 148.00 250 125 125 149.00 421 336 461 150.00 613 517 978 151.00 835 724 1,702 Device Routing Invert Outlet Devices #1 Primary 145.93' 12.0" Round Culvert L= 22.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 145.93' / 145.39' S= 0.0245 7' Cc= 0.900 n= 0.011, Flow Area= 0.79 sf #2 Device 1 147.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 150.23' 2.0" x 2.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Discarded 147.00' 8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.06 cfs @ 12.18 hrs HW=148.45' (Free Discharge) t-4=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=1.77 cfs @ 12.17 hrs HW=148.45' (Free Discharge) t-1=Culvert (Passes 1.77 cfs of 4.24 cfs potential flow) 12=0 rifice/G rate (Orifice Controls 1.77 cfs @ 5.08 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCAD010.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 40 Pond Basin: Hydrograph 2.29 CfS o inflow Outflow Inflow Area=0.817 a 0 Discarded O Primary Peak Elev=148.5" 1.89 cfs 2 , Storage=275 1.83 cfs , , 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 41 Summary for Pond SIS#1: Inflow Area = 0.195 ac, 97.28% Impervious, Inflow Depth > 4.47" for 10-Year event Inflow = 0.74 cfs @ 12.11 hrs, Volume= 0.073 of Outflow = 0.17 cfs @ 11.90 hrs, Volume= 0.072 af, Atten= 77%, Lag= 0.0 min Discarded = 0.17 cfs @ 11.90 hrs, Volume= 0.072 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 154.27' @ 12.44 hrs Surf.Area= 882 sf Storage= 527 cf Plug-Flow detention time= 14.0 min calculated for 0.072 of(100% of inflow) Center-of-Mass det. time= 13.7 min ( 764.7 - 751.1 ) Volume Invert Avail.Storage Storage Description #1 153.67' 882 cf 7.00'W x 7.00'L x 1.50'H Prismatoid x 12 #2 153.67' 588 cf 7.00'W x 7.00'L x 2.00'H Prismatoid x 6 #3 155,67' 6 cf Custom Stage Data (Prismatic)Listed below (Recalc) -Impervious 1,476 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 155.67 2 0 0 156.20 2 1 1 156.21 1,000 5 6 Device Routing Invert Outlet Devices #1 Discarded 153.67' 8.270 in/hr Exfiltration over Horizontal area #2 Primary 156.20' 12.0" x 300.0" Horiz. TD-2. C= 0.600 Limited to weir-flow at low heads Discarded OutFlow Max=0.17 cfs @ 11.90 hrs HW=153.72' (Free Discharge) t1=Exfiltration (Exfiltration Controls 0.17 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=153.67' (Free Discharge) t2=TD-2 ( Controls 0.00 cfs) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 42 Pond SIS#1: Hydrograph --- 0.74 cfs LDiscarded - -- --- -- w - - -- - -- - Inflow Area=0.195 ac ry 0.8 ' 0.75 Peak Elev=154.27' = 0.7 --- -Storage=527 cf 0.65 -- -- --- 0.6 0.55 w 0.5 ------------- --;- - -' ---- - v0.45 -- r- ' 3 0.4 - - o LL 0.35 -- 0.3 - -- - - - ----- 0.25 0.17 cfs - 0.2 L 0.15 0.1 0.00 cfs K 0+444 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 43 Summary for Pond SIS#2: Inflow Area = 0.365 ac, 99.35% Impervious, Inflow Depth > 4.56" for 10-Year event Inflow = 1.42 cfs @ 12.11 hrs, Volume= 0.139 of Outflow = 0.19 cfs @ 11.50 hrs, Volume= 0.139 af, Atten= 87%, Lag= 0.0 min Discarded = 0.19 cfs @ 11.50 hrs, Volume= 0.139 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 154.74' @ 12.79 hrs Surf.Area= 980 sf Storage= 1,460 cf Plug-Flow detention time= 43.9 min calculated for 0.138 of(100% of inflow) Center-of-Mass det. time= 43.2 min ( 793.9 - 750.8 ) Volume Invert Avail.Storage Storage Description #1 153.25' 784 cf 7.00'W x 7.001 x 2.00'H Prismatoid x 8 #2 153.25' 1,470 cf 7.00'W x 7.00'L x 2.50'H Prismatoid x 12 #3 155.75' 152 cf Custom Stage Data (Prismatic)Listed below (Recalc) -Impervious 2,406 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 155.75 2 0 0 156.50 2 2 2 157.00 600 151 152 Device Routing Invert Outlet Devices #1 Discarded 153.25' 8.270 in/hr Exfiltration over Horizontal area #2 Primary 156.50' 24.0" x 24.0" Horiz. CB-1 C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.19 cfs @ 11.50 hrs HW=153.29' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.19 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=153.25' (Free Discharge) L2=CB-1 ( Controls 0.00 cfs) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 44 Pond SIS#2: Hydrograph 1 El Inflow .42 Cf5 Outflow Inflow Area=0.365 a C Discarded ©Primary Peak Elev=154.74' Storage=1 ,460 cf ---- 1 LL f w 0.19 cfs 0.00 cfs 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 10-Year Rainfall=4.83" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 5 Summary for Link POA-1: Inflow Area = 1.409 ac, 80.69% Impervious, Inflow Depth > 1.81" for 10-Year event Inflow = 1.83 cfs @ 12.17 hrs, Volume= 0.213 of Primary = 1.83 cfs @ 12.17 hrs, Volume= 0.213 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Link POA-1: Hydrograph ®Inflow 2 �Primary Inflowre = .40 1.83 cfs 0 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 ' 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 46 Time span=0.00-24.00 hrs, dt=0.10 hrs, 241 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentPR-1: Runoff Area=1,926 sf 0.00% Impervious Runoff Depth>0.49" Tc=6.0 min CN=39/0 Runoff=0.01 cfs 0.002 of SubcatchmentPR-2: Runoff Area=7,645 sf 0.00% Impervious Runoff Depth>0.49" Tc=6.0 min CN=39/0 Runoff=0.03 cfs 0.007 of SubcatchmentPR-3: Runoff Area=15,910 sf 99.35% Impervious Runoff Depth>5.88" Tc=6.0 min CN=39/98 Runoff=1.81 cfs 0.179 of SubcatchmentPR-4: Runoff Area=27,120 sf 93.95% Impervious Runoff Depth>5.59" Tc=6.0 min CN=39/98 Runoff=2.92 cfs 0.290 of SubcatchmentPR-5: Runoff Area=8,482 sf 97.28% Impervious Runoff Depth>5.77" Tc=6.0 min CN=39/98 Runoff=0.95 cfs 0.094 of SubcatchmentPR-6: RunoffArea=307 sf 0.00% Impervious Runoff Depth>0.49" Tc=6.0 min CN=39/0 Runoff=0.00 cfs 0.000 of Pond Basin: Peak EIev=149.02' Storage=469 cf Inflow=2.92 cfs 0.290 of Discarded=0.08 cfs 0.017 of Primary=2.18 cfs 0.273 of Outflow=2.27 cfs 0.290 of Pond SIS#1: Peak EIev=154.58' Storage=800 cf Inflow=0.95 cfs 0.094 of Discarded=0.17 cfs 0.094 of Primary=0.00 cfs 0.000 of Outflow=0.17 cfs 0.094 of Pond SIS#2: Peak EIev=155.61' Storage=2,170 cf Inflow=1.81 cfs 0.179 of Discarded=0.19 cfs 0.179 of Primary=0.00 cfs 0.000 of Outflow=0.19 cfs 0.179 of Link POA-1: Inflow=2.22 cfs 0.282 of Primary=2.22 cfs 0.282 of Total Runoff Area = 1.409 ac Runoff Volume = 0.572 of Average Runoff Depth = 4.87" 19.31% Pervious = 0.272 ac 80.69% Impervious = 1.137 ac Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 47 Summary for Subcatchment PR-1: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.01 cfs @ 12.24 hrs, Volume= 0.002 af, Depth> 0.49" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 25-Year Rainfall=6.16" Area (sf) CN Description 1,926 39 >75% Grass cover, Good, HSG A 1,926 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-1: Hydrograph 0.007 0.01 cfs Runoff 0.007 NRCC 24-hr_D 0.006 25-Year Rainfall=6.16" 0.005 ff 0.005 Runoff sf 0.004 Runoff Volume=0.002 of 0.004 Runoff Depth>0.49" 0 0.003 Tc=6:0 min 0.003 0.002 C `=39/0 0.002 0.001 0.001 0.000 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 48 Summary for Subcatchment PR-2: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.03 cfs @ 12.24 hrs, Volume= 0.007 af, Depth> 0.49" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0, NRCC 24-hr D 25-Year Rainfall=6.16" Area (sf) CN Description 7,645 39 >75% Grass cover, Good, HSG A 7,645 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-2: Hydrograph 0.028 0 03 O Runoff -- - -- - -- cfs 0.026 N R,C-C_24-h-r D - 0.024 ' 25 ear-Rainfa11T6.-16" - - --- 0.022 --- -- 0.02 Runoff Area=71645-sf --- - -- - 0.018 Runoff Volume=0.007 of 0.016 Runoff Depth>0-.49" - 0 0.014 Tc=6 0 m i n 0.012 0.01 CN-39/0 - - 0.008 , 0.006 0.004 , 0.002 ' 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 7 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 49 Summary for Subcatchment PR-3: [49) Hint: Tc<2dt may require smaller dt Runoff = 1.81 cfs @ 12.11 hrs, Volume= 0.179 af, Depth> 5.88" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/[mperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 25-Year Rainfall=6.16" Area (so CN Description 8,703 98 Roofs, HSG A 7,103 98 Paved parking, HSG A 104 39 >75% Grass cover, Good, HSG A 15,910 98 Weighted Average 104 39 0.65% Pervious Area 15,806 98 99.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-3: Hydrograph 2 Runoff 1.81 cfs NRCC 24-hr D 25-Year Rainfall=6.16" Runoff Area=15,910 sf Runoff Volume=0.179 of Runoff Depth>5.88" 3 1 Tc=6.0 m i n CN=39/98 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 ydroCADO 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 50 Summary for Subcatchment PR-4: [49] Hint: Tc<2dt may require smaller dt Runoff = 2.92 cfs @ 12.11 hrs, Volume= 0.290 af, Depth> 5.59" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= O. NRCC 24-hr D 25-Year Rainfall=6.16" Area (so CN Description 3,960 98 Roofs, HSG A 20,684 98 Paved parking, HSG A 835 98 Water Surface, HSG A 1,641 39 >75% Grass cover, Good, HSG A 27,120 94 Weighted Average 1,641 39 6.05% Pervious Area 25,479 98 93.95% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-4: Hydrograph -- - 0 Runoff 2.92 cfs --- - --- 3 - - NRCC 24-h r D 25-Year'Rainfall 6.16" Runoff Area=27,120 sf Runoff um of 2 Runoff Depth>5.59'` LL Tc=6.0 m i n -CN=39/98 - 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 -©2018 HydroCAD Software Solutions LLC Page 51 Summary for Subcatchment PR-5: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.95 cfs @ 12.11 hrs, Volume= 0.094 af, Depth> 5.77" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 25-Year Rainfall=6.16" Area (sf) CN Description 8,251 98 Paved parking, HSG A 231 39 >75% Grass cover, Good, HSG A 8,482 96 Weighted Average 231 39 2.72% Pervious Area 8,251 98 97.28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-5: Hydrograph 1 0.95 cfs NRCC 24-hr D 25-Year Rainfall=6.16" Runoff Area=8482 sf Runoff Volume=0.094 of Runoff Depth>5.77" Tc=6.0 m i n CN=39/98 0 0 1 2 3 4 5 6 11 7 11 8 11 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 52 Summary for Subcatchment PR-6: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.00 cfs @ 12.24 hrs, Volume= 0.000 af, Depth> 0.49" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 25-Year Rainfall=6.16" Area (sf) CN Description 307 39 >75% Grass cover, Good, HSG A 307 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-6: Hydrograph 0.001 Runoff 0.001 0.00 cfs 0.001 0.001- N R_,C C 24-h r D- 0001 ainfall=6.16 ' - 0.001 25-Yea r R 0.001 1 0.0017 Runoff Area=307 sf---- - - - 0"001 Runoff-Volume=0.000 of -- -- - 0.001 --------------------- 0.001 Runoff Depth>0.49 �- 0.001 TC-6.0_tl1 °- 0.001 - n-- - 0.000 CN=3910 - -- o.000- O.000 0.000 `�" 0.000 - o.000 - -- ---- - - - 0 0 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 53 Summary for Pond Basin: Inflow Area = 0.817 ac, 94.74% Impervious, Inflow Depth > 4.26" for 25-Year event Inflow = 2.92 cfs @ 12.11 hrs, Volume= 0.290 of Outflow = 2.27 cfs @ 12.19 hrs, Volume= 0.290 af, Atten= 23%, Lag= 4.8 min Discarded = 0.08 cfs @ 12.19 hrs, Volume= 0.017 of Primary = 2.18 cfs @ 12.19 hrs, Volume= 0.273 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 149.02' @ 12.19 hrs Surf.Area= 425 sf Storage= 469 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 1.0 min ( 748.6 - 747.6 ) Volume Invert Avail.Storage Storage Description #1 147.00' 1,702 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 0 0 0 148.00 250 125 125 149.00 421 336 461 150.00 613 517 978 151.00 835 724 1,702 Device Routing Invert Outlet Devices #1 Primary 145.93' 12.0" Round Culvert L= 22.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 145.93' / 145.39' S= 0.0245 '/' Cc= 0.900 n= 0.011, Flow Area= 0.79 sf #2 Device 1 147.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 150.23' 2.0" x 2.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Discarded 147.00' 8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.08 cfs @ 12.19 hrs HW=148.99' (Free Discharge) t-4=Exfiltration (Exfiltration Controls 0.08 cfs) Primary OutFlow Max=2.16 cfs @ 12.19 hrs HW=148.98' (Free Discharge) L1=Culvert (Passes 2.16 cfs of 4.77 cfs potential flow) �2=Orifice/G rate (Orifice Controls 2.16 cfs @ 6.19 fps) 3=Orifice/Grate ( Controls 0.00 cfs) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 54 Pond Basin: Hydrograph - - - El Inflow 2.92 CfS 0 Outflow Inflow Area=0.817 a 0 Discarded �Y Primary 3 Peak Elev 149.02' O r1 2.27 cfs -St ge=469 Cf - 2.18 cfs 2 LL 1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 55 Summary for Pond SIS#1: Inflow Area = 0.195 ac, 97.28% Impervious, Inflow Depth > 5.77" for 25-Year event Inflow = 0.95 cfs @ 12.11 hrs, Volume= 0.094 of Outflow = 0.17 cfs @ 11.70 hrs, Volume= 0.094 af, Atten= 82%, Lag= 0.0 min Discarded = 0.17 cfs @ 11.70 hrs, Volume= 0.094 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 154.58' @ 12.56 hrs Surf.Area= 882 sf Storage= 800 cf Plug-Flow detention time= 23.1 min calculated for 0.093 of (100% of inflow) Center-of-Mass det. time= 22.7 min ( 769.5 - 746.9 ) Volume Invert Avail.Storage Storage Description #1 153.67' 882 cf 7.00'W x 7.00'L x 1.50'H Prismatoid x 12 #2 153.67' 588 cf 7.00'W x 7.00'L x 2.00'H Prismatoid x 6 #3 155.67' 6 cf Custom Stage Data (Prismatic)Listed below (Recalc) -Impervious 1,476 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 155.67 2 0 0 156.20 2 1 1 156.21 1,000 5 6 Device Routing Invert Outlet Devices #1 Discarded 153.67' 8.270 in/hr Exfiltration over Horizontal area #2 Primary 156.20' 12.0" x 300.0" Horiz. TD-2 C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.17 cfs @ 11.70 hrs HW=153.70' (Free Discharge) 't--1=Exfiltration (Exfiltration Controls 0.17 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=153.67' (Free Discharge) L2=TD-2 ( Controls 0.00 cfs) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 56 Pond SIS#1: Hydrograph 0 El inflow .95CfS El Outflow Inflow Area=0.195 a discarded p Primary Peak Elev=154.58' Storage=800 cf f , 0 LL 0.1,7 cfs r 0.00 cfs 0 0 1 2 3 4 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 57 Summary for Pond SIS#2: Inflow Area = 0.365 ac, 99.35% Impervious, Inflow Depth > 5.88" for 25-Year event Inflow = 1.81 cfs @ 12.11 hrs, Volume= 0.179 of Outflow = 0.19 cfs @ 11.20 hrs, Volume= 0.179 af, Atten= 90%, Lag= 0.0 min Discarded = 0.19 cfs @ 11.20 hrs, Volume= 0.179 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 155.61' @ 13.08 hrs Surf.Area= 980 sf Storage= 2,170 cf Plug-Flow detention time= 71.2 min calculated for 0.179 of(100% of inflow) Center-of-Mass det. time= 70.7 min ( 817.1 - 746.4 ) Volume Invert Avail.Storage Storage Description #1 153.25' 784 cf 7.00'W x 7.00'L x 2.00'H Prismatoid x 8 #2 153.25' 1,470 cf 7.00'W x 7.00'L x 2.50'H Prismatoid x 12 #3 155.75' 152 cf Custom Stage Data (Prismatic)Listed below (Recalc) -Impervious 2,406 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 155.75 2 0 0 156.50 2 2 2 157.00 600 151 152 Device Routing Invert Outlet Devices #1 Discarded 153.25' 8.270 in/hr Exfiltration over Horizontal area #2 Primary 156.50' 24.0" x 24.0" Horiz. CB-1 C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.19 cfs @ 11.20 hrs HW=153.29' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.19 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=153.25' (Free Discharge) L2=CBA ( Controls 0.00 cfs) Post Development NRCC 24-hr D 25-Year Rainfall=6.16" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 58 Pond SIS#2: Hydrograph 1.81 Cfs 13 Inflow Outflow Inflow Area=0.365 a 2 p Prmarded ry Peak Elev=155.61' Storage=2,170 cf 3 1 o i r 0.19 cfs 0.00 cfs 011, 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 25-Year Rainfall=6.16° Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 59 Summary for Link POA-1: Inflow Area = 1.409 ac, 80.69% Impervious, Inflow Depth > 2.40" for 25-Year event Inflow = 2.22 cfs @ 12.19 hrs, Volume= 0.282 of Primary = 2.22 cfs @ 12.19 hrs, Volume= 0.282 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Link POA-1: Hydrograph p Inflow Primary Inflow Area=1,40 2.22 cfs 2 h� LL 1. r, 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 60 Time span=0.00-24.00 hrs, dt=0.10 hrs, 241 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentPR-1: Runoff Area=1,926 sf 0.00% Impervious Runoff Depth>1.57" Tc=6.0 min CN=39/0 Runoff=0.05 cfs 0.006 of SubcatchmentPR-2: Runoff Area=7,645 sf 0.00% Impervious Runoff Depth>1.57" Tc=6.0 min CN=39/0 Runoff=0.21 cfs 0.023 of SubcatchmentPR-3: Runoff Area=15,910 sf 99.35% Impervious Runoff Depth>8.65" Tc=6.0 min CN=39/98 Runoff=2.64 cfs 0.263 of SubcatchmentPR-4: Runoff Area=27,120 sf 93.95% Impervious Runoff Depth>8.26" Tc=6.0 min CN=39/98 Runoff=4.29 cfs 0.429 of SubcatchmentPR-5: Runoff Area=8,482 sf 97.28% Impervious Runoff Depth>8.50" . Tc=6.0 min CN=39/98 Runoff=1.38 cfs 0.138 of SubcatchmentPR-6: Runoff Area=307 sf 0.00% Impervious Runoff Depth>1.57" Tc=6.0 min CN=39/0 Runoff=0.01 cfs 0.001 of Pond Basin: Peak EIev=150.09' Storage=1,034 cf Inflow=4.29 cfs 0.429 of Discarded=0.12 cfs 0.023 of Primary=2.79 cfs 0.406 of Outflow=2.91 cfs 0.429 of Pond SIS#1: Peak EIev=156.27' Storage=1,476 cf Inflow=1.38 cfs 0.138 of Discarded=0.17 cfs 0.138 of Primary=0.02 cfs 0.000 of Outflow=0.19 cfs 0.138 of Pond SIS#2: Peak EIev=156.69' Storage=2,277 cf Inflow=2.64 cfs 0.263 of Discarded=0.19 cfs 0.225 of Primary=2.11 cfs 0.038 of Outflow=2.30 cfs 0.263 of Link POA-1: Inflow=5.14 cfs 0.473 of Primary=5.14 cfs 0.473 of Total Runoff Area = 1.409 ac Runoff Volume = 0.860 of Average Runoff Depth = 7.32" 19.31% Pervious = 0.272 ac 80.69% Impervious = 1.137 ac Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 C 2018 HydroCAD Software Solutions LLC Page 61 Summary for Subcatchment PR-1: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.05 cfs @ 12.14 hrs, Volume= 0.006 af, Depth> 1.57" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 100-Year Rainfall=8.94" Area (sf) CN Description 1,926 39 >75% Grass cover, Good, HSG A 1,926 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-1: Hydrograph 0.055 ,- 0 Runoff 0.05 cfs NRCC 24-hr D " 1Do-Year Rainfall= 0.0458.94" 0.04 Runoff Area=1 ,926 sf 0.035 Runoff Volume=0.006 of v 0.03 Runoff Depth'1; 57,E % -- - LL 002s. " Tc=6.0 min CN-39/0 -- - .: - -- 0.015 0.01 0.005 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 62 Summary for Subcatchment PR-2: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.21 cfs @ 12.14 hrs, Volume= 0.023 af, Depth> 1.57" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 100-Year Rainfall=8.94" Area (so CN Description 7,645 39 >75% Grass cover, Good, HSG A 7,645 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-2: Hydrograph -- - -- ----- ----- ----- -- -- -- -- 0.23 - -- 0.22 0.21 efS - 0 Runoff 0.21 0.2 NRCC 24-hr,D 0.19 ; 0.18 100-Year Rainfall=8.94" t 0.17 - unoff Area'=7 645 sf- - --0.16 -R ' - - 0.15 Runoff-Voaume-0.0 - - - - _ -- 0.14 23 �f - 0.12 - off-De�pt ..-- Ru -n h>1 .57 _ -- -- - .. 0 0.11 - 0.1 Tc=6.0 m i n 0.09 0.08 _ CN=39/0 0.07 - - - 0.06 -- - - - -- 0.05 - - - - 0.04 - -- -- - 0.03 0.02 0.01 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 63 Summary for Subcatchment PR-3: [49] Hint: Tc<2dt may require smaller dt Runoff = 2.64 cfs @ 12.11 hrs, Volume= 0.263 af, Depth> 8.65" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 100-Year Rainfall=8.94" Area (sf) CN Description 8,703 98 Roofs, HSG A 7,103 98 Paved parking, HSG A 104 39 >75% Grass cover, Good, HSG A 15,910 98 Weighted Average 104 39 0.65% Pervious Area 15,806 98 99.35% Impervious Area Tc Length Slope Velocity Capacity Description Lin (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-3: Hydrograph 2.64 cfs ❑Runoff NRCC 24-hr D 100-Year Rainfall=8.94" 2 Runoff Area=15,910 sf Runoff Volume=0.263 of Runoff Depth>8.65" Tc=6.0 m i n 1 CN=39/ 8 -- -- - -- - 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 64 Summary for Subcatchment PR-4: [49] Hint: Tc<2dt may require smaller dt Runoff = 4.29 cfs @ 12.11 hrs, Volume= 0.429 af, Depth> 8.26" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 100-Year Rainfall=8.94" Area (sf) CN Description 3,960 98 Roofs, HSG A 20,684 98 Paved parking, HSG A 835 98 Water Surface, HSG A 1,641 39 >75% Grass cover, Good, HSG A 27,120 94 Weighted Average 1,641 39 6.05% Pervious Area 25,479 98 93.95% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-4: Hydrograph 4.29 cfs 0 Runoff N RCC 24-h r D 4 100-Year Rainfall=8.94" Runoff Area=27,120 sf 3-Runoff Volume=0.429 of -- Runoff Depth>8.26" 3 - o Tc=6.0 min - - LL 2 CN=39/98 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 65 Summary for Subcatchment PR-5: [49] Hint: Tc<2dt may require smaller dt Runoff = 1.38 cfs @ 12.11 hrs, Volume= 0.138 af, Depth> 8.50" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. UI as Pervious, Time Span= 0.00-24.00 hrs, dt= 0 NRCC 24-hr D 100-Year Rainfall=8.94" Area (sf) CN Description 8,251 98 Paved parking, HSG A 231 39 >75% Grass cover, Good, HSG A 8,482 96 Weighted Average 231 39 2.72% Pervious Area 8,251 98 97.28% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-5: Hydrograph 1.38 cfs o Runoff NRCC 24-hr D 100-Year Rainfall=8.94" Runoff Area=8,482 sf:_ Runoff Volume=0.138 of Runoff Depth>8.50" U. Tc=6.0 m i n CN=39/98 L ... .......... 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 66 Summary for Subcatchment PR-6: [49] Hint: Tc<2dt may require smaller dt Runoff = 0.01 cfs @ 12.14 hrs, Volume= 0.001 af, Depth> 1.57" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Ul as Pervious, Time Span= 0.00-24.00 hrs, dt= 0. NRCC 24-hr D 100-Year Rainfall=8.94" Area (sf) CN Description 307 39 >75% Grass cover, Good HSG A 307 39 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR-6: Hydrograph 0.009 0.009 0.01 cfs `-- 0.008 NRCC_24-hr D -- - --- ---- - --1-- 0007 100-Year Rainfall=8.94" - 0.007 0.006 Runoff Area=307 sf 0006 Runoff Volume=0.001 of 0.005 - -- -- --- - -- - - - 0.005 ---Runoff Depth>1-.57` 0.004 --, ° L- 0.004 Tc=6:0 min - 0.003 CN=39/0 0.003 0.002 0.002 , 0.001 0.001 0.000 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/26/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 67 Summary for Pond Basin: Inflow Area = 0.817 ac, 94.74% Impervious, Inflow Depth > 6.30" for 100-Year event Inflow = 4.29 cfs @ 12.11 hrs, Volume= 0.429 of Outflow = 2.91 cfs @ 12.22 hrs, Volume= 0.429 af, Atten= 32%, Lag= 6.4 min Discarded = 0.12 cfs @ 12.22 hrs, Volume= 0.023 of Primary = 2.79 cfs @ 12.22 hrs, Volume= 0.406 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 150.09' @ 12.22 hrs Surf.Area= 633 sf Storage= 1,034 cf Plug-Flow detention time= 1.6 min calculated for 0.427 of(100% of inflow) Center-of-Mass det. time= 1.5 min ( 744.5 - 743.0 ) Volume Invert Avail.Storage Storage Description #1 147.00' 1,702 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation SurF.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 147.00 0 0 0 148.00 250 125 125 149.00 421 336 461 150.00 613 517 978 151.00 835 724 1,702 Device Routing Invert Outlet Devices #1 Primary 145.93' 12.0" Round Culvert L= 22.0' CPP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 145.93' / 145.39' S= 0.0245 '/' Cc= 0.900 n= 0.011, Flow Area= 0.79 sf #2 Device 1 147.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Device 1 150.23' 2.0" x 2.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #4 Discarded 147.00' 8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.12 cfs @ 12.22 hrs HW=150.03' (Free Discharge) L4=Exfiltration (Exfiltration Controls 0.12 cfs) Primary OutFlow Max=2.76 cfs @ 12.22 hrs HW=150.03' (Free Discharge) t1=Culvert (Passes 2.76 cfs of 5.66 cfs potential flow) T--3=Orifice/Grate 2=Orifice/Grate (Orifice Controls 2.76 cfs @ 7.91 fps) ( Controls 0.00 cfs) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 68 Pond Basin: Hydrograph 4.29 cfs o Inflow /� El Outflow I of I OW`Mrea ® �1 - - E3 Discarded C1 p Primary Peak Elev=150.09' 4 ---- - - StOrage=1 ,034 c - ----- 2.91 cfs 3 2.79 cfs 3 o a 2 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCAD® 10.00-22 s/ri 07576 ©2018 HydroCAD Software Solutions LLC Page 69 Summary for Pond SIS#1: [93] Warning: Storage range exceeded by 0.06' Inflow Area = 0.195 ac, 97.28% Impervious, Inflow Depth > 8.50" for 100-Year event Inflow = 1.38 cfs @ 12.11 hrs, Volume= 0.138 of Outflow = 0.19 cfs @ 12.74 hrs, Volume= 0.138 af, Atten= 86%, Lag= 37.7 min Discarded = 0.17 cfs @ 11.40 hrs, Volume= 0.138 of Primary = 0.02 cfs @ 12.74 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 156.27' @ 12.75 hrs Surf.Area= 882 sf Storage= 1,476 cf Plug-Flow detention time= 49.0 min calculated for 0.137 of(100% of inflow) Center-of-Mass det. time= 48.5 min ( 790.2 - 741.7 ) Volume Invert Avail.Storage Storage Description #1 153.67' 882 cf 7.00'W x 7.00'L x 1.50'H Prismatoid x 12 #2 153.67' 588 cf 7.00'W x 7.001 x 2.00'H Prismatoid x 6 #3 155.67' 6 cf Custom Stage Data (Prismatic)Listed below (Recalc) -Impervious 1,476 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 155.67 2 0 0 156.20 2 1 1 156.21 1,000 5 6 Device Routing Invert Outlet Devices #1 Discarded 153.67' 8.270 in/hr Exfiltration over Horizontal area #2 Primary 156.20' 12.0" x 300.0" Horiz. TD-2 C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.17 cfs @ 11.40 hrs HW=153.70' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.17 cfs) Primary OutFlow Max=0.01 cfs @ 12.74 hrs HW=156.20' (Free Discharge) L2=TD-2 (Weir Controls 0.01 cfs @ 0.11 fps) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 70 Pond SIS#1: Hydrograph 1.38 cfs it Inflow ElOutflow Inflow, Area=0.195 a ®Discarded p Primary Peak Elev=156.27' Storage=1 ,476 cf v 3 a U. 0.19 cfs , T 017 cfs of 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 71 Summary for Pond SIS#2: [85] Warning: Oscillations may require smaller dt or Finer Routing (severity=4) Inflow Area = 0.365 ac, 99.35% Impervious, Inflow Depth > 8.65" for 100-Year event Inflow = 2.64 cfs @ 12.11 hrs, Volume= 0.263 of Outflow = 2.30 cfs @ 12.21 hrs, Volume= 0.263 af, Atten= 13%, Lag= 5.8 min Discarded = 0.19 cfs @ 10.70 hrs, Volume= 0.225 of Primary = 2.11 cfs @ 12.21 hrs, Volume= 0.038 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Peak Elev= 156.69' @ 12.20 hrs Surf.Area= 980 sf Storage= 2,277 cf Plug-Flow detention time= 67.7 min calculated for 0.263 of(100% of inflow) Center-of-Mass det. time= 67.2 min ( 808.1 - 741.0 ) Volume Invert Avail.Storage Storage Description #1 153.25' 784 cf 7.00'W x 7.001 x 2.00'H Prismatoid x 8 #2 153.25' 1,470 cf 7.00'W x 7.00'L x 2.50'H Prismatoid x 12 #3 155.75' 152 cf Custom Stage Data (Prismatic)Listed below (Recalc) -Impervious 2,406 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 155.75 2 0 0 156.50 2 2 2 157.00 600 151 152 Device Routing Invert Outlet Devices _ #1 Discarded 153.25' 8.270 in/hr Exfiltration over Horizontal area #2 Primary 156.50' 24.0" x 24.0" Horiz. CB-1 C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.19 cfs @ 10.70 hrs HW=153.29' (Free Discharge) t1=Exfiltration (Exfiltration Controls 0.19 cfs) Primary OutFlow Max=1.98 cfs @ 12.21 hrs HW=156.68' (Free Discharge) Z2=CB-1 (Weir Controls 1.98 cfs @ 1.38 fps) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 72 Pond SIS#2: Hydrograph 2.64 CfS o inflow El Outflow Inflow Area=0.365 a M Discarded p Primary Peak Elev=156.6 2.30 cfs 13 - - - - Storage=2,27 2.1 1 cfs 2 3 0 LL 1 0.19 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Development NRCC 24-hr D 100-Year Rainfall=8.94" Prepared by Microsoft Printed 6/25/2019 HydroCADO 10.00-22 s/n 07576 ©2018 HydroCAD Software Solutions LLC Page 73 Summary for Link POA-1: Inflow Area = 1.409 ac, 80.69% Impervious, Inflow Depth > 4.03" for 100-Year event Inflow = 5.14 cfs @ 12.21 hrs, Volume= 0.473 of Primary = 5.14 cfs @ 12.21 hrs, Volume= 0.473 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.10 hrs Link POA-1: Hydrograph p Inflow p Primary Inflow Area=1 . 5.14 cfs 5 rr� 4 J 3 o `r 2 < 1 y' 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Commonwealth of Massachusetts City/Town of Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (minimum of two holes required at every proposed primary and reserve disposal area) Deep Observation Hole Number: T_1 02-07-2019 9:00am Cloudy 35 deg 701 Salem North Andover Hole# Date Time Weather St. Lonclitude: Open lawn Grass None 2%+/- 1. Land Use (e.g.,woodland,agricultural field,vacant lot,etc.) Vegetation Surface Stones(e.g.,cobbles,stones, boulders,etc.) Slope(%) Description of Location: 2, Soil Parent Material: Landform Position on Landscape(SU,SH, BS,FS,TS) 3. Distances from: Open Water Body feet Drainage Way feet Wetlands feet Property Line feet Drinking Water Well feet Other feet 4. Unsuitable Materials Present: ❑ Yes ❑ No If Yes: ❑ Disturbed Soil ❑ Fill Material ❑ Weathered/Fractured Rock ❑ Bedrock 5. Groundwater Observed:❑ Yes ® No` If yes: Depth Weeping from Pit Depth Standing Water in Hole Soil Log Redoximorphic Features °Coarse Fragments Soil Soil Horizon Soil Texture Soil Matrix: Color- /°by Volume Depth(in) /Layer (USDA Moist(Munsell) Cobbles& Soil Structure Consistence Other Depth Color Percent Gravel Stones (Moist) 0-12 A X X X X X X X X X Loam/Topsoil 12-24 B LS 10YR3/6 X X X 50 25 BLOCKY FRIABLE 24-42 C1 SAND 10YR6/4 X X X 50 25 SINGLE LOOSE GRAIN 42-78 C2 SAND 10YR4/6 52 5YR4/6 50 50 25 SINGLE LOOSE GRAIN Additional Notes: CDG Test Pit Logs 2019-02-07.doc-rev.3/15118 Form 11 —Soil Suitability Assessment for On-Site Sewage Disposal Commonwealth of Massachusetts a City/Town of Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (minimum of two holes required at every proposed primary and reserve disposal area) Deep Observation Hole Number: T=2 02-07-2019 9:00am Cloudy 35 deg 701 Salem North Andover Hole# Date Time Weather St. Longitude: Open lawn Grass None 2%+/- 1. Land Use (e.g.,woodland, agricultural field,vacant lot,etc.) Vegetation Surface Stones(e.g.,cobbles,stones, boulders,etc.) Slope(%) Description of Location: 2. Soil Parent Material: Landform Position on Landscape(SU,SH, BS, FS,TS) 3. Distances from: Open Water Body feet Drainage Way feet Wetlands feet Property Line feet Drinking Water Well feet Other feet 4. Unsuitable Materials Present: ❑ Yes ❑ No If Yes: ❑ Disturbed Soil ❑ Fill Material ❑ Weathered/Fractured Rock ❑ Bedrock 5. Groundwater Observed:❑ Yes ® No If yes: Depth Weeping from Pit Depth Standing Water in Hole Soil Log Redoximorphic Features Coarse Fragments Soil Soil Horizon Soil Texture Soil Matrix: Color- %by Volume Depth(in) /Layer (USDA Moist(Munsell) Cobbles& Soil Structure Consistence Other Depth Color Percent Gravel Stones (Moist) 0-12 A X X X X X X X X X Loam/Topsoil 12-42 B LS 10YR3/6 X X X 50 25 BLOCKY FRIABLE 42-78 C SAND 10YR4/6 60 5YR4/6 50+ 50 25 SINGLE LOOSE ROOTS TO 54 GRAIN Additional Notes: ADJACENT BASEMENT FLOOR IS 66" BELOW GRADE. BASEMENT IS DRY BUT SUMP PUMP PIT BELOW FLOOR HAS STANDING WATER. CDG Test Pit Logs 2019-02-07.doc-rev.3/15/18 Form 11 —Soil Suitability Assessment for On-Site Sewage Disposal Commonwealth of Massachusetts City/Town of Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (minimum of two holes required at every proposed primary and reserve disposal area) Deep Observation Hole Number: T=3 02-07-2019 9:00am Cloudy 35 deg 701 Salem North Andover Hole# Date Time Weather St. Lonqitude: RAP driveway None None 2%+/- 1. Land Use (e.g.,woodland, agricultural field,vacant lot,etc.) Vegetation Surface Stones(e.g.,cobbles,stones, boulders,etc.) Slope(%) Description of Location: 2. Soil Parent Material: Landform Position on Landscape(SU,SH,BS,FS,TS) 3. Distances from: Open Water Body feet Drainage Way feet Wetlands feet Property Line feet Drinking Water Well feet Other feet 4. Unsuitable Materials Present: ❑ Yes ❑ No If Yes: ❑ Disturbed Soil ❑ Fill Material ❑ Weathered/Fractured Rock ❑ Bedrock 5. Groundwater Observed:® Yes ❑ No If yes: Depth Weeping from Pit 78 Depth Standing Water in Hole Soil Log Redoximorphic Features Coarse Fragments Soil Depth(in) Soil Horizon Soil Texture Soil Matrix:Color- %by Volume Soil Structure Consistence Other /Layer (USDA Moist(Munsell) Cobbles& Depth Color Percent Gravel Stones (Moist) 0-6 HTM X X X X X X X X X RAP surface 6-16 Ab X X X X X X X X X Buried loam/Topsoil 16-42 B LS 10YR3/6 X X X 50 25 BLOCKY FRIABLE 42-60 C1 SAND 10YR6/4 42 5YR4/6 75 50 25 GRAIN SINGLE LOOSE LIKELY INFLUENCED BY OLD LEACH FIELD 60-84 C2 SAND 10YR4/6 X X X 50 25 SINGLE LOOSE GRAIN Additional Notes: ADJACENT BASEMENT FLOOR IS 66" BELOW GRADE. BASEMENT IS DRY BUT SUMP PUMP PIT BELOW FLOOR HAS STANDING WATER. CDG Test Pit Logs 2019-02-07.doc-rev.3/15/18 Form 11 —Soil Suitability Assessment for On-Site Sewage Disposal Commonwealth of Massachusetts City/Town of Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (minimum of two holes required at every proposed primary and reserve disposal area) Deep Observation Hole Number: T=4 02-07-2019 9:00am Cloudy 35 deg 701 Salem North Andover Hole# Date Time Weather St. Lonqitude: Treeline Brush None 2%+/- 1. Land Use g ) Vegetation (e.g., ) p ( ) (e.g.,woodland, agricultural field,vacant lot,etc. Surface Stonescobbles,stones,boulders,etc. Sloe Description of Location: 2. Soil Parent Material: Landform Position on Landscape(SU,SH, BS,FS,TS) 3. Distances from: Open Water Body feet Drainage Way feet Wetlands feet Property Line feet Drinking Water Well feet Other feet 4. Unsuitable Materials Present: ❑ Yes ❑ No If Yes: ❑ Disturbed Soil ❑ Fill Material ❑ Weathered/Fractured Rock ❑ Bedrock 5. Groundwater Observed:® Yes ❑ No If yes: Depth Weeping from Pit 74 Depth Standing Water in Hole Soil Log Redoximorphic Features °Coarse Fragments Soil Soil Horizon Soil Texture Soil Matrix:Color- /o by Volume Depth(in) Soil Structure Consistence Other /Layer (USDA Moist(Munsell) Depth Color Percent Gravel Cobbles& (Moist) Stones 0-12 A X X X X X X X X X Loam/Topsoil 12-30 B LS 10YR3/6 X X X 50 25 BLOCKY FRIABLE 30-78 C SAND 10YR4/6 60 5YR4/6 50 50 25 SINGLE LOOSE GRAIN Additional Notes: CDG Test Pit Logs 2019-02-07.doc-rev.3/15/18 Form 11 —Soil Suitability Assessment for On-Site Sewage Disposal Commonwealth of Massachusetts u City/Town of p Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal C. On-Site Review (minimum of two holes required at every proposed primary and reserve disposal area) Deep Observation Hole Number: T=5 02-07-2019 9:00am Cloudy 35 deg 701 Salem North Andover Hole# Date Time Weather St. Lonqitude: Open lawn Grass None 2%+/- 1. Land Use g.,woodland, agricultural field,vacant lot,etc. Vegetation Surface Stones e. ) Slope e, g ) g ( g.,cobbles,stones, boulders,etc. ( ) Description of Location: 2. Soil Parent Material: Landform Position on Landscape(SU,SH,BS,FS,TS) 3. Distances from: Open Water Body feet Drainage Way feet Wetlands feet Property Line feet Drinking Water Well feet Other feet 4. Unsuitable Materials Present: ❑ Yes ❑ No If Yes: ❑ Disturbed Soil ❑ Fill Material ❑ Weathered/Fractured Rock ❑ Bedrock 5. Groundwater Observed:® Yes ❑ No If yes: Depth Weeping from Pit 84 Depth Standing Water in Hole Soil Log Redoximorphic Features Coarse Fragments° Soil /° Soil Horizon Soil Texture Soil Matrix:Color- by Volume Depth(in) /Layer (USDA Moist(Munsell) Cobbles& Soil Structure Consistence Other Depth Color Percent Gravel Stones (Moist) 0-6 A X X X X X X X X X Loam/Topsoil 6-36 B LS 10YR3/6 X X X 50 25 BLOCKY FRIABLE 36-54 C1 SAND 10YR6/4 X X X 50 25 SINGLE LOOSE GRAIN 54-90 C2 COARSE 10YR4/6 66 5YR4/6 50 50 25 SINGLE LOOSE SAND GRAIN Additional Notes: CDG Test Pit Logs 2019-02-07.doc•rev.3/15/18 Form 11 —Soil Suitability Assessment for On-Site Sewage Disposal Hydra _ ow Storm Sewers Extension for A 'odesk® AutoCAD® Civil 3D® Plan CB1 2 DMH1 Outfall 040 3 TD2. Project File: System-1.stm Number of lines:3 Date:6/18/2019 Storm Sewers v11.00 Storr, Sewer Inventory Report Page Line Alignment Flow Data Physical Data Line ID No. Dnstr Line Defl Junc Known Drng Runoff Inlet Invert Line Invert Line Line N J-Loss Inlet/ Line Length angle Type Q Area Coeff Time El Dn Slope El Up Size Shape Value Coeff Rim El No. (ft) (deg) (cfs) (ac) (C) (min) (ft) M (ft) (in) (n) (K) (ft) 1 End 3.000 0.000 MH 0.00 0.00 0.00 6.0 153.67 1.00 153.70 12 Cir 0.011 1.00 158.30 DMH1-SIS1 2 1 47.000 -90.000 Grate 0.00 0.14 0.90 6.0 153.80 0.85 154.20 8 Cir 0.011 1.00 156.75 CB1-DMH1 3 1 48.000 90.000 DrGrt 0.00 0.05 0.90 6.0 153.80 1.87 154.70 6 Cir 0.011 1.00 156.20 TD2-DMH1 Project File: System-1.stm Number of lines:3 Date: 6/18/2019 Storm Sewers v11 Storm awer Summary Report Pagel Line Line ID Flow Line Line Line Invert Invert Line HGL HGL Minor HGL Dns Junction No. rate Size shape length EL Dn EL Up Slope Down Up loss Junct Line Type (cfs) (in) (ft) (ft) (ft) N (ft) (ft) (ft) (ft) No. 1 DMH1-SIS1 0.99 12 Cir 3.000 153.67 153.70 1.000 155.67* 155.67* 0.02 155.70 End Manhole 2 CB1-DMH1 0.75 8 Cir 47.000 153.80 154.20 0.851 155.70* 155.83* 0.07 155.90 1 Grate 3 TD2-DMH1 0.27 6 Cir 48.000 153.80 154.70 1.875 155.70* 155.77* 0.03 155.80 1 DropGrate Project File: System-1.stm Number of lines:3 Run Date:6/18/2019 NOTES: Return period=25 Yrs. ;*Surcharged(HGL above crown). Storm Sewers v11.00 nyar iow dorm oewers c:xiension ror P-'LOUe5KkW IAUIO%#/ALJv l#IVII 3uv Proj. F'-: System-1.stm Beer(14 Ise 1 -EW-M si 161-00 101JDD 1511.OiQ 153.1D0 155M 1ssm 152- 0 152A0 1+49-00 1+49M 1+46M 1+46-00 0 5 10 15 21D 25 30 5'lar"HGL=1�,B'�ixai�ai low upskemoL F CKh(M) Cfnrm Aaniarc 1" yur 'OW atorm oeWers CXien5ion iro m- --KoQe5Kv HUZOI.►HLJV %.+IVII 3LJV Proj. 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Storm Sewers v11.00 1'1yur ,OW axon I oewer5 axle sion TOf R"ZOUe5KV HUIOtrHVIKJ LAVII 31JV file: New.stm 8e r(4 lie 1 -CB2- S2 16i_00 16�1.0a 15ilJ00 15r00 _ 155JO0 15L00 149-00 149M 0 5 10 15 20 25 30 35 40 45 50 55 60 65 '�i�rgi HGL=153�64�iic�i dq�#r a�s�aed�up�sciiic�lif�r yFslrt� Readh� C4nrm Cnniarc Hydr ._ Jow Storm Sewers Extension for P `,odesk® AutoCAD® Civil 3D® Plar 6 5 1 4 Outfall 2 3 Project File: System-3.stm Number of lines:6 Date:3/29/2019 Storm Sewers v11.00 Stor _ ;ewer Inventory Report Page Line Alignment Flow Data Physical Data Line ID No. Dnstr Line Defl Junc Known Drng Runoff Inlet Invert Line Invert Line Line N J-Loss Inlet/ Line Length angle Type Q Area Coeff Time El Dn Slope El Up Size Shape Value Coeff Rim El No. (ft) (deg) (cfs) (ac) (C) (min) (ft) M (ft) (in) (n) (K) (ft) 1 End 20.000 0.000 MH 0.00 0.00 0.90 6.0 148.45 3.10 149.07 12 Cir 0.013 1.00 153.07 EXDMH-EXFES 2 1 22.000 110.000 Grate 0.00 0.13 0.90 6.0 149.07 0.73 149.23 12 Cir 0.013 1.00 152.13 EXCB1-EXDMH 3 1 55.000 35.000 Grate 0.00 0.14 0.09 6.0 148.97 0.91 149.47 12 Cir 0.013 1.00 153.57 EXCB2-EXDHM 4 1 78.000 -3.000 None 0.00 0.09 0.09 &0 150.07 3.76 153.00 6 Cir 0.011 1.00 156.20 EXDR-EXDMH 5 1 53.000 -50.000 MH 0.00 0.21 0.09 6.0 149.22 -0.87 148.76 12 Cir 0.012 0.15 154.16 DMH2-EXDMH 6 5 106.000 5.000 DrGrt 0.00 0.21 0.09 6.0 151.00 0.99 152.05 12 Cir 0.011 1.00 153.50 TD1-DMH2 Project File: System-3.stm Number of lines:6 Date: 3/29/2019 Storm Sewers v11 Storm ewer Summary Report Pagel Line Line ID Flow Line Line Line Invert Invert Line HGL HGL Minor HGL Dns Junction No. rate Size shape length EL Dn EL Up Slope Down Up loss Junct Line Type (cfs) (in) (ft) (ft) (ft) N (ft) (ft) (ft) (ft) No. 1 EXDMH-EXFES 0.64 12 Cir 20.000 148.45 149.07 3.100 149.50 149.47 0.07 149.54 End Manhole 2 EXCB1-EXDMH 0.69 12 Cir 22.000 149.07 149.23 0.727 149.54 149.58 n/a 149.58j 1 Grate 3 EXCB2-EXDHM 0.07 12 Cir 55.000 148.97 149.47 0.909 149.54 149.58 n/a 149.58 j 1 Grate 4 EXDR-EXDMH 0.05 6 Cir 78.000 150.07 153.00 3.756 150.14 153.11 n/a 153.11 1 None 5 DMH2-EXDMH 0.15 12 Cir 53.000 149.22 148.76 -0.868 149.54 149.56 0.00 149.56 1 Manhole 6 TD1-DMH2 O.11 12 Cir 106.000 151.00 152.05 0.991 151.11 152.19 n/a 152.19 5 DropGrate Project File: System-3.stm Number of lines:6 Date:3/29/2019 NOTES: Return period=25 Yrs. ;j-Line contains hyd.jump. 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Reach� Rtnrm q—tarc rlyUr- -IOW OlOrM J@WUr5 CXlen5lOn TOr P°IZOUe5KkK) HUZOI+HLJV lilVll 3LJV Proi "q: System-3.stm Bev'M Lbw 4-EXER EMM 159.100 � 159�0 F 156,A0 _ 156�Q0 ........................... 150.00 150�00 f 147-00 147-00 144-00 144A0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 dWM assumed dwmnkeaiL aieallm gtskow P%eedr M Ctnrm Rainiore 1' yur` ®OW storm JeWer5 CXten51OI7 TOf P -xoue5KV HUtOt.#HUV UIV11 .)UV Proj. System-3.stm ElEv(M) 159 oD 159.Oo _ E&M 156-00 156-00 153_IID .—,,z,-: 153.100 1-%GG L�._ - 1 -M 4{ _ 147J00 1+47_00 1+44M _ 144-M 0 5 10 15 20 75 30 35 +40 45 50 55 60 65 ic�llfo�r � ROK:h M C4nrm Raniarc LiMassachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program ll, uhlecklist for Stormwater R"'Aleport A. Introduction Important:When A Stormwater Report must be submitted with the Notice of Intent permit application to document filling out forms compliance with the Stormwater Management Standards. The following checklist is NOT a substitute for on the computer, use only the tab the Stormwater Report(which should provide more substantive and detailed information) but is offered key to move your here as a tool to help the applicant organize their Stormwater Management documentation for their cursor-do not Report and for the reviewer to assess this information in a consistent format. As noted in the Checklist, use the return the Stormwater Report must contain the engineering computations and supporting information set forth in key. Volume 3 of the Massachusetts Stormwater Handbook. The Stormwater Report must be prepared and certified by a Registered Professional Engineer(RPE) licensed in the Commonwealth. The Stormwater Report must include: • The Stormwater Checklist completed and stamped by a Registered Professional Engineer(see page 2)that certifies that the Stormwater Report contains all required submittals.' This Checklist is to be used as the cover for the completed Stormwater Report. • 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 82 • Operation and Maintenance Plan required by Standard 9 In addition to all plans and supporting information, the Stormwater Report must include a brief narrative describing stormwater management practices, including environmentally sensitive site design and LID techniques, along with a diagram depicting runoff through the proposed BMP treatment train. Plans are required to show existing and proposed conditions, identify all wetland resource areas, NRCS soil types, critical areas, Land Uses with Higher Potential Pollutant Loads (LUHPPL), and any areas on the site where infiltration rate is greater than 2.4 inches per hour. The Plans shall identify the drainage areas for both existing and proposed conditions at a scale that enables verification of supporting calculations. As noted in the Checklist, the Stormwater Management Report shall document compliance with each of the Stormwater Management Standards as provided in the Massachusetts Stormwater Handbook. The soils evaluation and calculations shall be done using the methodologies set forth in Volume 3 of the Massachusetts Stormwater Handbook. To ensure that the Stormwater Report is complete, applicants are required to fill in the Stormwater Report Checklist by checking the box to indicate that the specified information has been included in the Stormwater Report. If any of the information specified in the checklist has not been submitted, the applicant must provide an explanation. The completed Stormwater Report Checklist and Certification must be submitted with the Stormwater Report. ----------------------------------------------------------------------------------------------------------------__..-...-------------------------------- 'The Stormwater Report may also include the Illicit Discharge Compliance Statement required by Standard 10. If not included in the Stormwater Report,the Illicit Discharge Compliance Statement must be submitted prior to the discharge of stormwater runoff to the post-construction best management practices. 2 For some complex projects, it may not be possible to include the Construction Period Erosion and Sedimentation Control Plan in the Stormwater Report. In that event,the issuing authority has the discretion to issue an Order of Conditions that approves the project and includes a condition requiring the proponent to submit the Construction Period Erosion and Sedimentation Control Plan before commencing any land disturbance activity on the site. SW Checklist^04/01/08 Stormwater Report Checklist•Page 1 of 8 Massachusetts Department of Environmental Protection F ' Bureau of Resource Protection -Wetlands Program I, B. Stormwater Checklist and Certification The following checklist is intended to serve as a guide for applicants as to the elements that ordinarily need to be addressed in a complete Stormwater Report. The checklist is also intended to provide conservation commissions and other reviewing authorities with a summary of the components necessary for a comprehensive Stormwater Report that addresses the ten Stormwater Standards. Note. Because stormwater requirements vary from project to project, it is possible that a complete Stormwater Report may not include information on some of the subjects specified in the Checklist. If it is determined that a specific item does not apply to the project under review, please note that the item is not applicable (N.A.) and provide the reasons for that determination. A complete checklist must include the Certification set forth below signed by the Registered Professional Engineer who prepared the Stormwater Report. Registered Professional Engineer's Certification I have reviewed the Stormwater Report, including the soil evaluation, computations, Long-term Pollution Prevention Plan, the Construction Period Erosion and Sedimentation Control Plan (if included), the Long- term Post-Construction Operation and Maintenance Plan, the Illicit Discharge Compliance Statement(if included) and the plans showing the stormwater management system, and have determined that they have been prepared in accordance with the requirements of the Stormwater Management Standards as further elaborated by the Massachusetts Stormwater Handbook. I have also determined that the information presented in the Stormwater Checklist is accurate and that the information presented in the Stormwater Report accurately reflects conditions at the site as of the date of this permit application. Registered Professional Engineer Block and Signature (D 06/25/2019 Signature and Date ` Checklist Project Type: Is the application for new development, redevelopment, or a mix of new and redevelopment? ❑ New development ❑ Redevelopment ® Mix of New Development and Redevelopment SW Checklist•04/01/08 Stormwater Report Checklist•Page 2 of 8 Massachusetts Department of Environmental Protection -" Bureau of Resource Protection -Wetlands Program Checklist for Stormwater Re ®rt p 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. SW Checklist•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 pre- development rates for the 2-year and 10-year 24-hour storms. If evaluation shows that off-site flooding increases during the 100-year 24-hour storm, calculations are also provided to show that post-development peak discharge rates do not exceed pre-development rates for the 100-year 24- hour storm. Standard 3: Recharge Z Soil Analysis provided. ® Required Recharge Volume calculation provided. ❑ Required Recharge volume reduced through use of the LID site Design Credits. ® Sizing the infiltration, BMPs is based on the following method: Check the method used. ® Static ❑ Simple Dynamic ❑ Dynamic Field' ® Runoff from all impervious areas at the site discharging to the infiltration BMP. ❑ Runoff from all impervious areas at the site is not discharging to the infiltration BMP and calculations are provided showing that the drainage area contributing runoff to the infiltration BMPs is sufficient to generate the required recharge volume. ® Recharge BMPs have been sized to infiltrate the Required Recharge Volume. ❑ Recharge BMPs have been sized to infiltrate the Required Recharge Volume only to the maximum extent practicable for the following reason: ❑ Site is comprised solely of C and D soils and/or bedrock at the land surface ❑ M.G.L. c. 21 E 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. 21 E site or a solid waste landfill and a mounding analysis is included. _..._---------------_---.------------------ __..............-------------------------------------- 80%TSS removal is required prior to discharge to infiltration BMP if Dynamic Field method is used. SW Checklist•04/01/08 Stormwater Report Checklist•Page 4 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program 'hecklist for ^tormwater Report Lill, 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. SW Checklist•04/01/08 Stormwater Report Checklist^Page 5 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater P%ep Checklist (continued) Standard 4: Water Quality (continued) ® The BMP is sized (and calculations provided) based on: ® The %" 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. SW Checklist•04/01/08 Stormwater Report Checklist•Page 6 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater "Rheport 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. SW Checklist•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 BM 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. SW Checklist•04/01/08 Stormwater Report Checklist•Page 8 of 8 OPERATION AND MAINTENANCEPLAN FOR PROPOSED MIXED USE EXPANSION 695 & 701 SALEN STREET NORTH ANDOVER, MA 01845 PREPARED FOR: VIRGINIA, INC. 701 SALEM STREET NORTH ANDOVER, MA 01845 PREPARED BY: CIVIL DESIGN GROUP, LLC 21 HIGH STREET, SUITE 207 NORTH ANDOVER, MA Ol 845 DATE: MARCH 27, 2019 TABLE OF CONTENTS 1:0 INTRODUCTION...............................................................................................................3 2.0 LONG TERM POLLUTION PREVENTION PLAN (LTPPP)..................................................3 3.0 STORMWATER MANAGEMENT SYSTEM...........................................................................4 4.0 SNOW MANAGEMENT AND DEICING CONTROL............................................................6 5.0 ESTIMATED OPERATION AND MAINTENANCE BUDGET.....................................................6 6.0 ILLICIT DISCHARGE STATEMENT.....................................................................................6 7.0 PUBLIC SAFETY FEATURES..............................................................................................6 APPENDIX A—OPERATION AND MAINTENANCE REPORT FORM FIGURE I —BMP LOCATION PLAN 2 p: 978-794-5400 f: 978.965.3971 www.cdgengineering.com OPERATION AND MAINTENANCE PLAN 1.0 INTRODUCTION In accordance with the standards set forth by the Massachusetts Department of Environmental Protection (MADEP) Stormwater Management Policy, Civil Design Group, LLC has prepared the following Operations and Maintenance (O&M) Plan for a mixed use development located at 695 & 701 Salem St. North Andover, MA 01845. PROPERTY INFORMATION PROPERTY ADDRESS LANDOWNER&STORMWATER MANAGEMENT SYSTEM OWNER Owner: Virginia,Inc. 695&701 SALEM STREET Contact: Mr.Jim Xenakis NORTH ANDOVER,MA 01845 Phone: 978-210-9177 Email:jmxenakis@yahoo.com The landowner shall be responsible for the long-term operation and maintenance of the site and the stormwater management system, and shall be responsible for record keeping of inspections, maintenance and repairs. If the site owner changes,the new site owner shall assume all responsibilities outlined in this O&M plan. The site owner shall hire a qualified professional to conduct scheduled inspections and maintain records in accordance with the inspection schedule outline enclosed within this document. Site Engineer: Civil Design Group, LLC Address: 21 High Street, Suite 207,North Andover, MA 01845 Office Phone: 978-794-5400 Contact: Philip Henry, P.E. 2.0 LONG TERM POLLUTION PREVENTION PLAN (LTPPP) In accordance with Standard#4 from the MADEP Stormwater Management Policy, the following LTPPP has been prepared as part of this O&M Plan. The purpose of the LTPPP is to identify potential pollutant sources in stormwater discharges and implement prevention measures prior to affecting downstream resource areas. Housekeeping: The site shall be kept in a clean and working order. Substances and materials to be used on site that are consistent with the nature of business shall be protected from the elements by storing indoors or in containers with appropriate lids. Proper disposal and care shall be followed when disposing of empty containers. Solid Waste: Solid waste materials shall be stored in the dumpsters provided on site. The dumpster enclosure shall be kept closed when not in use and the trash shall not be left outside of the enclosure. The owner shall contract with a waste management company to properly dispose of waste material. The dumpsters shall be emptied on a regular basis. Pet Waste Management: Pet waste is not anticipated based on the proposed use of the site. 3 p: 978-794-5400 f: 978.965.3971 www.cdgengineering.com Petroleum Products: Petroleum products shall be stored in sealed containers and clearly labeled. Petroleum storage tanks shall be located a minimum of 100 linear feet from wetland resource areas, drainage ways, inlets and surface waters unless stored within a building. Petroleum storage tanks shall be equipped with a secondary means of containment designed to provide a containment volume that is equal to 110% of the volume of the largest tank unless otherwise required. Drip pans or other form of containment shall be provided for all dispensers. Any asphalt substances used onsite will be applied according to the manufacturer's recommendations. Fertilizers Herbicides and Pesticides: Fertilizers, herbicides and pesticides shall be used in the minimum amounts recommended by the manufacturer and applied to limit contact with stormwater. These products shall be stored in containers indoors. Paints and Cleaning Solvents: Paints and containers shall be properly stored in their original containers. Disposal of these products and their containers shall be in accordance with the manufacturer's recommendations. Spill Prevention and Response: In the event of a spill of a hazardous substance the following response action items shall be followed in order to prevent or minimize discharge to the stormwater management system. 1. Spills shall be immediately addressed. 2. Spills of hazardous substances shall be remediated using the manufacturers' protocol for cleanup. 3. Vehicular and fuel spills shall be remediated in accordance to local and state regulations. 4. The following equipment and materials shall be present on site and shall be clearly identifiable: a. Absorbent materials, brooms, dust pans, mops, rags, gloves, goggles, trash containers, etc. 5. Spills that are toxic or hazardous in nature shall be reported to the MA DEP and professional emergency contractor. 6. The owner shall designate individuals who will receive spill prevention and response training. These individuals will each become responsible for a particular phase of prevention and response. The names of these personnel shall be posted in the material storage area and in the management office. 3.0 STORMWATER MANAGEMENT SYSTEM The components of the stormwater management system shall be inspected, monitored and maintained in accordance with the following to ensure that the on-site stormwater management/BMP facilities for the project function as intended. Routine inspection and proper maintenance of these individual components is essential to providing the long-term enhancement of both the quality and quantity of the runoff from the site. The proposed stormwater management Best Management Practices (BMP's) have been designed to collect and convey runoff from developed areas in accordance with the Massachusetts DEP's Stormwater Management Policy. The onsite drainage system is designed for the 25-year storm event. The drainage system consists of one (1) infiltration basin,two (2) subsurface infiltration systems, one (1) catch basins, two (2)proprietary separators,two (2)trench drains, and associated piping. 4 p: 978-794-5400 f: 978.965.3971 www.cdgengineering.com Street Sweeping Sweeping shall be performed routinely (a minimum twice per year spring and fall) within the parking lot and driveway areas to reduce the amount of sediment and trash entering the catch basins Infiltration Basins Infiltration Basins are designed to infiltrate runoff from the site. The system is comprised of slopes graded at 3H:1 V with interior turf side slopes and bottom. • Inspection Frequency: Quarterly • Cleaning; Threshold(s): 4" sediment or bi-annually • Equipment: By hand &mower Deep Sump Hooded Catch Basins Stormwater runoff from proposed pavement areas is directed via curbing and site grading to catch basins with deep sumps and hooded outlets and trench drains. These structures are designed to trap and remove sediment and larger particles from the stormwater and improve the performance of subsequent BMP's. The catch basin sumps are a minimum of 4' in depth and a routine inspection and cleaning schedule shall be followed to ensure optimal effectiveness. Inspection Frequency: Quarterly Inspection Tools: Manhole hook; survey rod; sludge judge Items to Inspect: Measure sediment in sump using survey rod; visually check for floating debris or trash; visually check for oil and if more than a sheen is present, use sludge judge to measure thickness of layer; visually ensure that hood is in place; visually ensure that grate is in good condition; visually ensure that outlet pipe is unobstructed Maintenance Threshold(s): Annually or>24" sediment in sump (whichever comes first); discernible layer of oil/hydrocarbons on surface; floating trash Maintenance Equipment: Vactor or camshell for sediment removal; vactor and/or oil sorbent pads for oil/hydrocarbon removal; net for floating debris or trash removal Trench Drains Stormwater runoff from proposed pavement areas will be directed via curbing and site grading to trench drains. The trench drains will trap and remove sediment and larger particles from the stormwater and will improve the performance of subsequent BMP's. Regular inspection and cleaning schedule has been proposed to ensure optimal effectiveness. When properly designed and maintained,these trenches are effective in reducing the sediment and pollutant load in runoff. • Inspection Frequency: Quarterly • Cleanings Threshold(s): 18" sediment in sump; discernable layer of oil on surface; floating trash • Equipment: Clamshell or vactor, absorbing pillows or similar device Hydrodynamic Separators Hydrodynamic Separators are designed to remove heavy particles, floating debris and hydrocarbons from stormwater. Stormwater enters the system where floatables and oils are separated prior to the clarified stormwater runoff discharging to an outlet pipe. See the attached Hydroworks product description sheets for additional information, including maintenance recommendations. 5 p:978-794-5400 f: 978.965.3971 www.cdgengineering.com • Inspection Frequency: Quarterly • Cleaning Threshold(s): Per manufacturer's recommendations • Equipment: Vactor Subsurface Infiltration System (SIS) The SIS is designed to infiltrate runoff from the site. The system is comprised of concrete galleys and is equipped with an inspection port to facilitate inspection for standing water and sediment. • Inspection Frequency: Annually and after storms equal to or greater than 1-year, 24-hour Type- III storm events. • Cleaning Threshold(s): 4" sediment or standing water for>48 hours following a rain event • Equipment: Water jet and vactor 4.0 SNOW MANAGEMENT AND DEICING CONTROL The Owner shall contract with a company to properly clear and remove snow. The contractor shall be responsible for maintaining all roads, driveways, parking lots, sidewalks and pedestrian access onsite as well as along the right-of-way frontage. Snow shall be piled in the designated areas snow storage areas to the extent practicable. Snow shall be removed from the site if the capacity of the designated areas is reached, and disposed of in accordance with applicable regulations and requirements. Deicing chemicals shall be kept indoors in a safe location and shall be clearly labeled. Deicing solutions such as calcium chloride, rock salt and/or sand may be used unless otherwise restricted by the municipality. Deicing methods shall be used in conjunction with snow removal to maintain safe pedestrian and vehicular access. 5.0 ESTIMATED OPERATION AND MAINTENANCE BUDGET The estimated average annual operating and maintenance budget for the proposed system is shown below: • Catch Basins and Trench Drains: $200 each= $800 • Proprietary Separator: $1,000= $1,000 • Subsurface infiltration system: $1,500 each= $3,000 • Routine maintenance= $2,000 o Removal of trash o Annual street sweeping o Pipe network/outfall inspections 6.0 ILLICIT DISCHARGE STATEMENT The proposed stormwater management system consists of a hydrodynamic separator, infiltration basins, bioretention areas, and associated piping & drain manholes, which are intended to collect and convey stormwater discharges from the site. The stormwater management system is not intended to convey any illicit discharges and or pollutants and as such, control measures that are identified within this report shall be strictly adhered to in order to minimize the risk of contamination. Any unknown existing illicit discharges that are discovered as part of the redevelopment of the subject site shall be eliminated in accordance with local, state and federal regulations. 7.0 PUBLIC SAFETY FEATURES Public safety features, such as lighting, hydrants and sidewalks are depicted in the attached Figure 1 BMP Location Plan. 6 p: 978-794-5400 f: 978.965.3971 www.cdgengincering.com APPENDIX-A OPERATION AND MAINTENANCE REPORT FORM STORMWATER DIVISION "�'�'dover,t,M01847 North Andover,1\LA U7845 Tel 978.794.5400 or CIVIL DESIGN GROUP LLC www.cdgenpneenng.com QUARTERLY STORMWATER INSPECTION REPORT Site: Proposed Mixed Use Expansion Date: Address: 695 & 701 Salem Street, North Andover, MA Time: Inspector: Weather: CATCH BASIN & TRENCH DRAINS Unit Sediment Oil Hood/Pipes Grate Last # (inches) (inches) Cleaned Attention Recommended CB-1 CB-2 (HS-4) EXCB-1 EXCB-2 DMH-1 (HS-4) DMH-2 TD-1 TD-2 INFILTRATION BASIN Unit Sediment Trash Last # (inches) Cover Cleaned Attention Recommended INFILTRATION BASIN SIS-1 SIS-2 Date of previous street sweeping: flydroworks Hydroworks° HydroStorm Operations & Maintenance Manual Version 1 .0 Please call Hydroworks at 888-290-7900 or email us at support@hydroworks.com if you have any questions regarding the Inspection Checklist. Please fax a copy of the completed checklist to Hydroworks at 888-783-7271 for our records. Introduction The HydroStorm is a state of the art hydrodynamic separator. Hydrodynamic separators remove solids, debris and lighter than water (oil, trash, floating debris) pollutants from stormwater. Hydrodynamic separators and other water quality measures are mandated by regulatory agencies (Town/City, State, Federal Government) to protect storm water quality from pollution generated by urban development (traffic, people) as part of new development permitting requirements. As storm water treatment structures fill up with pollutants they become less and less effective in removing new pollution. Therefore, it is important that storm water treatment structures be maintained on a regular basis to ensure that they are operating at optimum performance. The HydroStorm is no different in this regard and this manual has been assembled to provide the owner/operator with the necessary information to inspect and coordinate maintenance of their HydroStorm. Hydroworks° HydroStorm Operation The Hydroworks HydroStorm (HS) separator is a unique hydrodynamic by-pass separator. It incorporates a protected submerged pretreatment zone to collect larger solids, a treatment tank to remove finer solids, and a dual set of weirs to create a high flow bypass. High flows are conveyed directly to the outlet and do not enter the treatment area, however, the submerged pretreatment area still allows removal of coarse solids during high flows. Under normal or low flows, water enters an inlet area with a horizontal grate. The area underneath the grate is submerged with openings to the main treatment area of the separator. Coarse solids fall through the grate and are either trapped in the pretreatment area or conveyed into the main treatment area depending on the flow rate. Fines are transported into the main treatment area. Openings and weirs in the pretreatment area allow entry of water and solids into the main treatment area and cause water to rotate in the main treatment area creating a vortex motion. Water in the main treatment area is forced to rise along the walls of the separator to discharge from the treatment area to the downstream pipe. The vortex motion forces solids and floatables to the middle of the inner chamber. Floatables are trapped since the inlet to the treatment area is submerged. The design maximizes the retention of settled solids since solids are forced to the center of the inner chamber by the vortex motion of water while water must flow up the walls of the separator to discharge into the downstream pipe. A set of high flow weirs near the outlet pipe create a high flow bypass over both the pretreatment area and main treatment chamber. The rate of flow into the treatment area is regulated by the number and size of openings into the treatment chamber and the height of by-pass weirs. High flows flow over the weirs directly to the outlet pipe preventing the scour and resuspension of any fines collected in the treatment chamber. Oydroworks A central access tube is located in the structure to provide access.for cleaning. The arrangement of the inlet area and bypass weirs near the outlet pipe facilitate the use of multiple inlet pipes. Outlet AL ALAL d Ly d \ \ 4 a h a' a \ d; High Flow Low Flow Inlet Figure 1. Hydroworks HydroStorm Operation — Plan View Figure 2 is a profile view of the HydroStorm separator showing the flow patterns for low and high flows. Kydroworks i� I Inlet _ Outletµ r / m High Flow Low Flow - a Figure 2. Hydroworks HydroStorm Operation — Profile View The HS 4i is an inlet version of the HS 4 separator. There is a catch-basin grate on top of the HS 4i. A funnel sits sits underneath the grate on the frame and directs the water to the inlet side of the separator to ensure all lows flows are properly treated. The whole funnel is removed for inspection and cleaning. 14ydroWol-ks Outlet 7 AL a41 f f! A 4 tl High Flow Low Flow Figure 3. Hydroworks HS 4i Funnel Inspection Procedure Floatables A visual inspection can be conducted for floatables by removing the covers and looking down into the center access tube of the separator. Separators with an inlet grate (HS 4i or custom separator) will have a plastic funnel located under the grate that must be removed from the frame prior to inspection or maintenance. If you are missing a funnel please contact Hydroworks at the numbers provided at the end of this document. Hydroworks TSS/Sediment Inspection for TSS build-up can be conducted using a Sludge Judge®, Core Pro®, AccuSludge®or equivalent sampling device that allows the measurement of the depth of TSS/sediment in the unit. These devices typically have a ball valve at the bottom of the tube that allows water and TSS to flow into the tube when lowering the tube into the unit. Once the unit touches the bottom of the device, it is quickly pulled upward such that the water and TSS in the tube forces the ball valve closed allowing the user to see a full core of water/TSS in the unit. The unit should be inspected for TSS through each of the access covers. Several readings (2 or 3) should be made at each access cover to ensure that an accurate TSS depth measurement is recorded. Frequency Construction Period The HydroStorm separator should be inspected every four weeks and after every large storm (over 0.5" (12.5 mm) of rain) during the construction period. Post-Construction Period The Hydroworks HydroStorm separator should be inspected during the first year of operation for normal stabilized sites (grassed or paved areas). If the unit is subject to oil spills or runoff from unstabilized (storage piles, exposed soils) areas the HydroStorm separator should be inspected more frequently (4 times per year). The initial annual inspection will indicate the required future frequency of inspection and maintenance if the unit was maintained after the construction period. Reporting Reports should be prepared as part of each inspection and include the following information: 1. Date of inspection 2. GPS coordinates of Hydroworks unit 3. Time since last rainfall 4. Date of last inspection 5. Installation deficiencies (missing parts, incorrect installation of parts) 6. Structural deficiencies (concrete cracks, broken parts) 7. Operational deficiencies (leaks, blockages) 8. Presence of oil sheen or depth of oil layer 9. Estimate of depth/volume of floatables (trash, leaves) captured 10. Sediment depth measured 11. Recommendations for any repairs and/or maintenance for the unit 12. Estimation of time before maintenance is required if not required at time of inspection klYdroworks A sample inspection checklist is provided at the end of this manual. Maintenance Procedure The Hydroworks HydroStorm unit is typically maintained using a vacuum truck. There are numerous companies that can maintain the HydroStorm separator. Maintenance with a vacuum truck involves removing all of the water and sediment together. The water is then separated from the sediment on the truck or at the disposal facility. A central access opening (24" or greater) is provided to the gain access to the lower treatment tank of the unit. This is the primary location to maintain by vacuum truck. The pretreatment area can also be vacuumed and/or flushed into the lower treatment tank of the separator for cleaning via the central access once the water level is lowered below the pretreatment floor. In instances where a vacuum truck is not available other maintenance methods (i.e. clamshell bucket) can be used, but they will be less effective. If a clamshell bucket is used the water must be decanted prior to cleaning since the sediment is under water and typically fine in nature. Disposal of the water will depend on local requirements. Disposal options for the decanted water may include: 1. Discharge into a nearby sanitary sewer manhole 2. Discharge into a nearby LID practice (grassed swale, bioretention) 3. Discharge through a filter bag into a downstream storm drain connection The local municipality should be consulted for the allowable disposal options for both water and sediments prior to any maintenance operation. Once the water is decanted the sediment can be removed with the clamshell bucket. Disposal of the contents of the separator depend on local requirements. Maintenance of a Hydroworks HydroStorm unit will typically take 1 to 2 hours based on a vacuum truck and longer for other cleaning methods (i.e. clamshell bucket). Hydroworks Outlet w all Access to w Lower Treatment ° Chamber [k L}' 3 .. k c 4 Submerged Pretreatment Inlet Area Figure 3. Maintenance Access Frequency Construction Period A HydroStorm separator can fill with construction sediment quickly during the construction period. The HydroStorm must be maintained during the construction period when the depth of TSS/sediment reaches 24" (600 mm). It must also be maintained during the construction period if there is an appreciable depth of oil in the unit (more than a sheen) or if floatables other than oil cover over 50% of the area of the separator The HydroStorm separator should be maintained at the end of the construction period, prior to operation for the post-construction period. Hydroworks Post-Construction Period The HydroStorm was independently tested by Alden Research Laboratory in 2017. A HydroStorm HS 4 was tested for scour with a 50% sediment depth of 0.5 ft. Therefore, maintenance for sediment accumulation is required if the depth of sediment is 1 ft or greater in separators with standard water (sump) depths (Table 1). There will be designs with increased sediment storage based on specifications or site-specific criteria. A measurement of the total water depth in the separator through the central access tube should be taken and compared to water depth given in Table 1. The standard water depth from Table 1 should be subtracted from the measured water depth and the resulting extra depth should be added to the 1 ft to determine the site-specific sediment maintenance depth for that separator. For example, if the measured water depth in the HS-7 is 7 feet, then the sediment maintenance depth for that HS-7 is 2 ft (= 1 + 7 —6) and the separator does not need to be cleaned for sediment accumulation until the measure sediment depth is 2 ft. The HydroStorm separator must also be maintained if there is an appreciable depth of oil in the unit (more than a sheen) or if floatables other than oil cover over 50% of the water surface of the separator. Table 1 Standard Dimensions for Hydroworks HydroStorm Models Model Diameter(ft) Total Water Sediment Maintenance Depth for Table 1 Depth(ft) Total Water Depth(ft) HS-3 3 3 1 HS-4 4 4 1 HS-5 5 4 1 HS-6 6 4 1 HS-7 7 6 1 HS-8 8 7 1 HS-9 9 7.5 1 US-10 10 8 1 HS-1 l 11 9 1 HS-12 12 9.5 1 Kydroworks HYDROSTORM INSPECTION SHEET Date Date-of Last Inspection Site City State Owner GPS Coordinates Date of last rainfall Site Characteristics Yes No Soil erosion evident ❑ ❑ Exposed material storage on site ❑ ❑ Large exposure to leaf litter (lots of trees) ❑ ❑ High traffic (vehicle) area ❑ ❑ HydroStorm Yes No Obstructions in the inlet or outlet ❑ * ❑ Missing internal components ❑ ** ❑ Improperly installed inlet or outlet pipes ❑ *** ❑ Internal component damage (cracked, broken, loose pieces) ❑ ** ❑ Floating debris in the separator (oil, leaves, trash) ❑ ❑ Large debris visible in the separator ❑ * ❑ Concrete cracks/deficiencies ❑ *** ❑ Exposed rebar ❑ ** ❑ Water seepage (water level not at outlet pipe invert) ❑ *** ❑ Water level depth below outlet pipe invert " Routine Measurements Floating debris depth < 0.5" (13mm) ❑ >0.5" 13mm) ❑ Floating debris coverage < 50% of surface area ❑ > 50% surface area ❑ Sludge depth < 12" (300mm) ❑ > 12" (300mm) ❑ * Maintenance required ** Repairs required *** Further investigation is required Kydroworks Other Comments: KydroW01-k5 Kydr0wohks Hydroworks' HydroStorm One Year Limited Warranty Hydroworks, LLC warrants, to the purchaser and subsequent owner(s) during the warranty period subject to the terms and conditions hereof, the Hydroworks HydroStorm to be free from defects in material and workmanship under normal use and service, when properly installed, used, inspected and maintained in accordance with Hydroworks written instructions, for the period of the warranty. The standard warranty period is 1 year. The warranty period begins once the separator has been manufactured and is available for delivery. Any components determined to be defective, either by failure or by inspection, in material and workmanship will be repaired, replaced or remanufactured at Hydroworks' option provided, however, that by doing so Hydroworks, LLC will not be obligated to replace an entire insert or concrete section, or the complete unit. This warranty does not cover shipping charges, damages, labor, any costs incurred to obtain access to the unit, any costs to repair/replace any surface treatment/cover after repair/replacement, or other charges that may occur due to product failure, repair or replacement. This warranty does not apply to any material that has been disassembled or modified without prior approval of Hydroworks, LLC, that has been subjected to misuse, misapplication, neglect, alteration, accident or act of God, or that has not been installed, inspected, operated or maintained in accordance with Hydroworks, LLC instructions and is in lieu of all other warranties expressed or implied. Hydroworks, LLC does not authorize any representative or other person to expand or otherwise modify this limited warranty. The owner shall provide Hydroworks, LLC with written notice of any alleged defect in material or workmanship including a detailed description of the alleged defect upon discovery of the defect. Hydroworks, LLC should be contacted at 136 Central Ave., Clark, NJ 07066 or any other address as supplied by Hydroworks, LLC. (888-290-7900). This limited warranty is exclusive. There are no other warranties, express or implied, or merchantability or fitness for a particular purpose and none shall be created whether under the uniform commercial code, custom or usage in the industry or the course of dealings between the parties. Hydroworks, LLC will replace any goods that are defective under this warranty as the sole and exclusive remedy for breach of this warranty. Subject to the foregoing, all conditions, warranties, terms, undertakings or liabilities (including liability as to negligence), expressed or implied, and howsoever arising, as to the condition, suitability, fitness, safety, or title to the Hydroworks HydroStorm are hereby negated and excluded and Hydroworks, LLC gives and makes no such representation, warranty or undertaking except as expressly set forth herein. Under no circumstances shall Hydroworks, LLC be liable to the Purchaser or to any third party for product liability claims; claims arising from the design, shipment, or installation of the HydroStorm, or the cost of other goods or services related to the purchase and installation of the HydroStorm. For this Limited Warranty to apply, the HydroStorm must be installed in accordance with all site conditions required by state and local codes; all other applicable laws; and Hydroworks'written installation instructions. Hydroworks, LLC expressly disclaims liability for special, consequential or incidental damages (even if it has been advised of the possibility of the same) or breach of expressed or implied warranty. Hydroworks, LLC shall not be liable for penalties or liquidated damages, including loss of production and profits; labor and materials; overhead costs; or other loss or expense incurred by the purchaser or any third party. Specifically excluded from limited warranty coverage are damages to the HydroStorm arising from ordinary wear and tear; alteration, accident, misuse, abuse or neglect; improper maintenance, failure of the product due to improper installation of the concrete sections or improper sizing; or any other event not caused by Hydroworks, LLC. This limited warranty represents Hydroworks' sole liability to the purchaser for claims related to the HydroStorm, whether the claim is based upon contract, tort, or other legal basis. i J IS ABBOP SIBLEI \ \ B .if.4P65 LCIT IM p �'00 �� ✓OSPLN NICIXNSEN � / BanEwAr� RESIDENTAL 3 i \I �— OISTRIcr(H7) / I SNOW 7 T D— '.../ STGRA ��, y-SUBS0RrkE B_2 ti_ I N FI STRATI O - ,^ RESIDE_ AL 2 �, Sri;A A F\ O �Is7Rrcr(R7) SYSTEM-- PROPOSED-❑❑t�(I—�I,,�I�I �JP � o �: � '��—= �o�o__ _ '_q�^ _�•�bAOINc. `gym L A " �UILOING EXPANSIO)a A e,700t S.F. , EXISTING BUILDING TO REMAIN Lor.n " F6=158.20 III i s+\�.�•��� ,/ i � I„ 3,900f S.F. 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