POST CONSTRUCTION STORMWATER MANAGEMENT REPORT Adelphia Gateway Project Tilghman Lateral Phase 2B

Submitted to: September 2020 Pennsylvania Department of Environmental Protection (PADEP)

POST CONSTRUCTION STORMWATER MANAGEMENT REPORT

TABLE OF CONTENTS

I. PLAN PREPARER CREDENTIALS...... 2 II. PCSM PLANNING AND DESIGN ...... 2 III. SOIL CHARACTERISTICS ...... 3 IV. EXISTING TOPOGRAPHIC FEATURES OF THE PROJECT SITE AND THE IMMEDIATE SURROUNDING AREA...... 3 V. SURFACE WATER CLASSIFICATIONS ...... 4 VI. NARRATIVE DESCRIPTION OF THE LOCATION AND TYPE OF ON-SITE BMPS ...... 4 VII. VOLUME REDUCTION AND WATER QUALITY REQUIREMENTS ...... 5 VIII. RATE REQUIREMENTS ...... 7 IX. GEOLOGIC FORMATIONS OR SOIL CONDITIONS ...... 7 X. POTENTIAL THERMAL IMPACTS TO SURFACE WATERS ...... 8 XI. EXISTING/PROPOSED RIPARIAN FOREST BUFFERS ...... 8 XII. ANTIDEGRADATION REQUIREMENTS ...... 8 XIII. CONSTRUCTION SEQUENCE ...... 8 XIV. LONG-TERM MAINTENANCE SCHEDULE ...... 11 XV. OFF-SITE DRAINAGE ANALYSIS ...... 11

APPENDICES A. LOCATION MAP B. SOIL DATA 1. SOIL MAP 2. SOIL MAP UNIT DESCRIPTION 3. SOIL USE LIMITATIONS AND RESOLUTIONS C. CHAPTER 102 COMPLIANCE D. STORMWATER MANAGEMENT CALCULATIONS 1. BMP WORKSHEETS 2. BMP COMPUTATIONS - EXISTING CONDITIONS 3. BMP COMPUTATIONS – PROPOSED CONDITIONS E. DRAINAGE AREAS PLANS F. INFILTRATION TESTING REPORTS

I. PLAN PREPARER CREDENTIALS The PCSM plan was prepared by Shiny Mathew, P.E. She is a Professional Engineer and a graduate of Widener University with a Bachelor of Science in Civil Engineering. Mrs. Mathew has been designing project of similar size and scale for 14 years throughout Southeastern PA. She has delivered projects for several public and private clients. Her project experience includes American Street Improvement Project (Philadelphia), Bakers Centre Development (Philadelphia), SEPTA Jenkintown Stream Restoration (Montgomery Co), and Radnor High School Bus Loop Improvements (Delaware Co.).

II. PCSM PLANNING AND DESIGN

Johnson, Mirmiran & Thompson (JMT), on behalf of Adelphia Gateway, has prepared this Post Construction Stormwater Management (PCSM) Plan for the Adelphia Gateway Pipeline. The PCSM Plan has been designed in accordance with the criteria stated in the Pennsylvania Department of Environmental Protection (PADEP) Stormwater Best Management Practices Manual, dated December 2006; Pennsylvania Department of Environmental Protection (PADEP), Bureau of Waterways Engineering and Wetlands Erosion and Sediment Pollution Control Program Manual, dated March 2012, thus satisfying requirements for PADEP General Permit (ESCGP-3) for Earth Disturbance Associated with Oil and Gas Exploration, Production, Processing, or Treatment Operations or Transmission Facilities contained under Pa. Code Title 25 Chapter 102.

The Adelphia Gateway Pipeline is an 84-mile pipeline that runs from Martins Creek to Marcus Hook. Facility upgrades will occur to thirteen (13) sites along the pipeline: Quakertown Compressor Station, East Perkiomen Blowdown, Skippack Pike Valve Site, Perkiomen Creek Blowdown, Schuylkill River Blowdown, Cromby Blowdown, French Creek Blowdown, Mainline Valve 2, Paoli Pike Blowdown, Chester Creek Blowdown, Mainline Valve 1, Transco Meter Station, and Marcus Hook Compressor and Meter Station. The total limit of disturbance is 13.9 acres.

The Tilghman and Parkway lateral, known as Phase 2A consists of 1,925 LF of proposed pipeline between the Delaware State Line/Marcus Hook Compressor and Meter Station and Transco Meter Station. It is to be installed through traditional open cut installation and horizontal direction drill (HDD) installation methods. The limit of disturbance within Phase 2A is 0.15 acres.

The Tilghman lateral pipeline, known as Phase 2B, consists of approximately 4.4 miles of proposed 16-inch O.D. pipeline. The installation consists of open cut for approximately 0.6 miles and horizontal directional drill (HDD) for approximately 3.8 miles. The total limit of disturbance is 24.76 acres. However, only 1.3 acres is open cut trench. The remaining pipe installation is to be completed using HDD, minimizing surface disturbance. The remaining area included in the LOD is temporary workspace intended for parking, staging materials and equipment, and stockpiling. Mechanical piping and two buildings are proposed at the PECO Meter Station where the Tilghman Lateral ends.

The entire limit of disturbance for the Tilghman Lateral section will be restored to existing conditions and site restoration and PCSM devices (two dry wells) are proposed at the PECO Meter Station. This narrative describes the PCSM measures of Adelphia Gateway Pipeline Phase 2B and related site work.

This narrative applies to the PCSM activities for Phase 2B only. Phase 1 and 2A were submitted to DEP under a separate application.

III. SOIL CHARACTERISTICS Table III-1 below detail the types of soils, as contained within the Stormwater Management areas, for each of the thirteen sites, as defined by the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Web Soil Survey.

Table III-1: Soil Types within LOD Symbol Map Unit Name Brief Map Unit Description ByB2 Butlertown silt loam, 3 to 8 Soil Rating C, slow infiltration rate when thoroughly wet. percent slopes Mainly soils with layer that impedes downward movement of water or soils of fine texture. Slow rate of water transmission. Ma Made land, gravelly Soil Rating A, high infiltration rate when thoroughly wet. materials Mainly deep, well drained sands or gravelly sands. High rate of water transmission.

OtA Othello silt loams, 0 to 2 Soil Rating C/D, very slow infiltration rate when thoroughly percent slopes wet. Mainly clays, high water table soils, claypan or clay layer at or near surface, and shallow soils over nearly impervious material. Very slow rate of water transmission. We Wehadkee silt loam Soil Rating D, very slow infiltration rate when thoroughly wet. Mainly clays, high water table soils, claypan or clay later at or near surface, and shallow soils over nearly impervious material. Very slow rate of water transmission.

The Hydrologic Soil Group Rating Report from USDA NRCS Web Soil Survey, which includes a soil map, the physical properties of the soils, and the soil use limitations and resolutions is provided for each site in Appendix B.

IV. EXISTING TOPOGRAPHIC FEATURES OF THE PROJECT SITE AND THE IMMEDIATE SURROUNDING AREA

USGS quadrangle location maps are provided in Appendix A, which shows the location of the project site and the surrounding area.

The limit of disturbance is primarily roadway (SR 3006, SR 291, Flower Street and Delaware Ave), which was constructed well over 5 years ago. The remaining section of disturbance is land adjacent and through industrial sites.

Soil infiltration testing at PECO Meter Station was performed on July 24, 2020 using the Double Ring Infiltration Test method. Two (2) test infiltration tests were performed at the dry well bottom elevation. The infiltration testing resulted in infiltration rates of 1.00 and 1.25 in/hr, respectively. Both infiltration test pits demonstrated sandy silt at the testing depth with no limiting layers, such as impervious clay, bedrock, or groundwater. Based on the findings, infiltration was recommended at this site.

V. SURFACE WATER CLASSIFICATIONS Table V-1 below details the three (3) watersheds in which the project site is located within, as well as the receiving surface waters classification, as defined by the Pennsylvania Department of Environmental Protection (PADEP) Title 25, Chapter 93: Water Quality Standards. Note the following acronyms: WWF (Warm Water Fishes), and MF (Migratory Fishes).

Table V-1: Receiving Surface waters Classification Watershed Chapter 93 Classification Marcus Hook Creek WWF, MF, siltation-impaired Stoney Creek WWF, MF Delaware River WWF, MF

VI. NARRATIVE DESCRIPTION OF THE LOCATION AND TYPE OF ON-SITE BMPS The following Best Management Practices (BMP), in accordance with Pennsylvania Stormwater BMP Manual, dated December 2006, have been integrated into the design to reduce runoff volume, reduce peak rates and improve water quality. These structural BMPs will result in the prevention or minimization of increased stormwater runoff rate, volume and/or changes in stormwater runoff. Implementing these controls will preserve the integrity of stream channels and maintain and protect the physical, biological and chemical qualities of the receiving stream.

The limit of disturbance for the Tilghman Lateral will be restored to existing conditions. Following completion of the site work, the site shall be returned to existing grades maintain preconstruction drainage patterns. Any disturbed areas will be permanently seeded if previously vegetated and all gravel will be replaced and refreshed. All disturbed pavement will be replaced in kind and the impervious area will not be increased. By restoring the sites, the management of post construction stormwater will be conducted as follows:

• Preserve the integrity of stream channels and maintain and protect the physical, biological and chemical qualities of the receiving stream • Prevent an increase in the rate of stormwater runoff. • Minimize any increase in stormwater runoff volume.

• Minimize impervious areas. • Maximize the protection of existing drainage features and existing vegetation. • Minimize land clearing and grading.

Per Chapter 102.8(n), a restoration plan that identifies the site restoration activities to manage stormwater for oil and gas activities is adequate to demonstrate compliance with the stormwater management regulations outlined in Chapter 102.8 to minimize land clearing and grading, and to minimize soil compaction. Compliance to each subsection of Chapter 102.8(n) is summarized in Appendix C.

At the PECO Meter Station, two dry wells (BMP 6.4.6) are proposed to capture stormwater runoff from an 8’x10’ and 12’x15’ meter building. These BMPS serve the functions of volume reduction, runoff quality and peak rate. For the remaining limit of disturbance, the site will be restored to existing conditions, as noted on the PCSM design plans.

A sequence of construction was developed to minimize land clearing and grading, and to minimize soil compaction. See Section XIII.

VII. VOLUME REDUCTION AND WATER QUALITY REQUIREMENTS There is not an applicable Act 167 Stormwater Management Plan for the Delaware River, Marcus Hook and Stoney Creek watersheds.

The watersheds within the project limits follow the standard design criteria from Sections 102.8(g)(2) and (3), which states that post construction management requirements are met for all areas that are restored to pre-construction conditions or to a condition of meadow in good condition or better. For the Tilghman Lateral, all disturbed area will be restored to existing conditions through site restoration activities.

For the PECO Meter Station, approximately 2,038 SF of the limit of disturbance (2,345 SF) will be restored to existing conditions through site restoration activities. Approximately 321 SF cannot be restored to existing conditions due to facility upgrades which include an 8’x10’ building, a 12’x15’ building and five concrete pads. For the disturbed area that will not be restored to existing conditions, the project follows the criteria set forth by PADEP’s Stormwater Best Management Practices Manual, dated December 2006.

As per the requirements of CG-1 in the Pennsylvania Stormwater BMP Manual, “post-development total runoff volume for all storms equal or less than the two (2)-year 24-hour duration precipitation must not increase, while factoring in that twenty percent (20%) of the existing impervious area of a project site, when present, shall be considered meadow in the model for existing conditions.” Through stormwater BMPs, the BMPs will statically store the 2-year volume increase to ensure that the runoff volume does not increase after construction is complete. The 2-year, 24-hour rainfall duration was determined using PennDOT Publication 584, Chapter 7, Appendix 7A.

To meet the requirements of the PADEP ESCGP-3 permit, standard BMP worksheets 4 and 5 were completed to confirm that no negative impacts would occur for volume control. The spreadsheets indicated above are included in Appendix D. Per Chapter 102.8(g)(2), the Existing Conditions 2-yr, 24-hr runoff volume was calculated using 20% of gravel as meadow. Note that the Existing Conditions 2-yr, 24-hr runoff

5 volume from disturbed gravel areas that are to be restored to existing conditions were not calculated using 20% of gravel as meadow. The Existing Conditions 2-yr, 24-hr runoff volume for those disturbed gravel areas to be converted to new impervious were calculated using 20% of gravel as meadow.

Stormwater management calculations were performed using the SCS TR-55 method for volume calculations. Stormwater BMPs were routed through HydroCAD, Version 10.0. Analysis for the project sites were performed for the 2-, 10-, 50-, and 100-year storm events for both the pre-developed condition and the post-developed conditions. All rainfall data was determined using PennDOT Publication 584, Chapter 7, Appendix 7A.

Two dry wells (BMP 6.4.6) will be installed at the PECO Meter Station to capture and infiltrate the stormwater runoff from the two buildings on-site. Each dry well has a storage capacity below a 3” overflow pipe of 71 CF, totaling 142 CF in storage volume of proposed BMPs. A pop-up emitter is proposed outlet the overflow pipe to the surface. Approximately 49 SF of new impervious could not be captured due to site/topographic constraints. However, the dry wells have been sized to appropriately treat and infiltrate the 2-year volume increase for the entire project site.

Below is a summary of pre- and post-construction runoff volumes to demonstrate that there will not be any increases at each respective project site.

Table VII-1: PECO Meter Station Runoff Volume Summary PECO Meter Station Existing Conditions 226.15 2-yr, 24-hr Runoff Volume (CF) Proposed Conditions 281.40 2-yr, 24-hr Runoff Volume (CF) 2-yr Volume Increase (CF) 55.25 Storage Volume of Proposed BMPs (CF) 142 DIFFERENCE (CF) 86.75

The stormwater management design achieves volume reduction criteria, and 98.00% of the disturbed area can be controlled by site restoration and dry well BMPs at the PECO Meter Station. However, Worksheet 10 could not be met. Calculations and Worksheet 10, 12 and 13 are included within Appendix D. Due to minimal changes between existing and post condition land covers and through the addition of a pollutant reducing BMP, the total pollutant load will not exceed pre-existing conditions, as shown in Table VII-2.

Table VII-2: PECO Meter Station Water Quality Summary Pollutant Load within LOD Pollutant Reduction Pollutant Load Pollutant Net Pre- Post- Achieved through after BMP Type Increase Change construction construction BMP installation TSS (lbs) 2.28 2.12 -0.16 0.09 2.03 -0.25 TP (lbs) 0.01 0.01 0.00 0.00 0.01 0.00 NO 3 0.02 0.02 0.00 0.00 0.01 -0.01 (lbs)

VIII. RATE REQUIREMENTS As stated in section VII of this PCSM Narrative, there is not an applicable Act 167 Stormwater Management Plan for the Delaware River, Marcus Hook and Stoney Creek watersheds. Therefore, this project follows the criteria set forth by PADEP, which states that the post development peak rates is to be less than or equal to pre-development peak rate.

The watersheds within the project limits follow the project limits follow the standard design criteria from Sections 102.8(g)(2) and 102.8(g)(3), which states that post construction management requirements are met for all areas that are restored to pre-construction conditions or to a condition of meadow in good condition or better.

Stormwater management calculations were performed using the SCS TR-55 method for runoff peak rate calculations. Stormwater BMPs were routed through HydroCAD, Version 10.0. Analysis for the project sites were performed for the 2-, 10-, 50-, and 100-year storm events for both the pre-developed condition and the post-developed conditions. All rainfall data was determined using PennDOT Publication 584, Chapter 7, Appendix 7A.

For the PECO Meter Station, a comparison between the analyzed conditions was made to assess the hydrological effects of the project and determine the best BMP to mitigate the volume and rate increases. The BMP facilities have been designed to manage the net change in peak rate for all storm events in a manner not to exceed pre-construction rates. Table VIII-1 below outlines the pre- and post-construction peak rates to show that there will not be any increases at any project site.

Table VIII-1: PECO Meter Station Peak Rate Summary

Existing Proposed Peak Rate Net Change Peak Dry Well #1 Dry Well #2 Storm Rate Inflow Outflow Inflow Outflow Bypass Total (cfs) (cfs) (cfs) (cfs) (cfs) (cfs) (cfs) (cfs) 2-yr 0.11 0.01 0.00 0.02 0.00 0.11 0.11 0.00 10-yr 0.23 0.01 0.00 0.03 0.00 0.21 0.21 -0.02 50-yr 0.39 0.02 0.00 0.04 0.00 0.35 0.36 -0.03 100-yr 0.47 0.02 0.00 0.05 0.00 0.43 0.44 -0.03

IX. GEOLOGIC FORMATIONS OR SOIL CONDITIONS There are no known geologic formations or soil conditions identified at the site that have the potential to cause pollution during construction. Should the potential for pollution arise, measures have been provided to avoid, minimize, or mitigate erosion and sedimentation using erosion and sediment control devices, as shown in the plan.

X. POTENTIAL THERMAL IMPACTS TO SURFACE WATERS Thermal impacts associated with the project will be minimized and/or mitigated through the incorporation of various site restoration activities. The disturbed areas will be restored and seeded as soon as practicable and /or directing runoff to vegetated areas to reduce the temperature of runoff prior to discharge into the streams. Thermal impacts within the roadway will not be impacted since an increase in impervious is not proposed. The runoff from the pavement within the limit of disturbance will drain to a storm sewer network, which will provide an opportunity for the storwmater to cool before discharging into the receiving surface water.

At the PECO Meter Station, the disturbed areas will be restored to existing conditions as soon as practicable or directing runoff prior to discharge into the streams into BMPs. Roof drains will be connected to the dry wells that will temporarily store and infiltrate stormwater runoff from the roofs of structures. This will provide an opportunity for the stormwater to cool before discharging into the receiving surface water.

XI. EXISTING/PROPOSED RIPARIAN FOREST BUFFERS The proposed earth disturbance activities of Phase 2B are not to be conducted within 150 ft of an HQ watershed; therefore, riparian buffers are not required.

XII. ANTIDEGRADATION REQUIREMENTS Compliance with antidegradation implementation is required, including evaluation of non-discharge alternatives and ABACT for where activities will be conducted in siltation impaired waters. Marcus Hook Creek is a siltation-impaired water.

All activities within the Marcus Hook Creek watershed will be restored to existing conditions. By limiting the disturbed areas, limiting extent and duration of disturbance and performing site restoration, these practices will eliminate the net change in rate, volume and water quality after construction. ABACT controls include, but are not limited to, compost filter socks and filter bag inlet protection.

XIII. CONSTRUCTION SEQUENCE TILGHMAN LATERAL

1. At least seven (7) days prior to starting any earth disturbance activities, including clearing and grubbing, the owner and/or operator shall invite all contractors, the landowner, appropriate municipal officers, the E&S plan preparer and a representative from the local conservation district to an on-site pre-construction meeting.

2. At least 3 days prior to starting any earth disturbance activities, or expanding into the area previously unmarked, the Pennsylvania One Call System Inc. shall be notified at 1-800-242-1776 for the location of existing underground utilities.

3. Stake or mark out the limit of disturbance. The area to be used for the installation of pipeline shall be clearly marked before any site work begins to avoid soil disturbance and compaction during construction

4. Install all E&S control devices such as: compost filter socks and inlet protection on existing inlets, as shown on the plans and details.

5. Perform clearing and grubbing as needed for the project. Limit clearing and grubbing to the areas of the project that are being constructed.

6. Construct proposed piping as shown on the pipeline plans prepared by others.

7. When constructing the proposed piping across Stoney Creek, install the stream crossing with temporary cofferdams and pump bypass as shown on the plans and details.

8. Contractor shall construct proposed piping that crosses the railroads as shown on the pipeline plans prepared by others. Ballast and tracks are to be restored to owners’ specifications and standards.

9. Contractor shall maintain traffic control as noted on the HOP Plans. Contractor shall perform all work within PennDOT right-of-way in accordance with PennDOT Publication 408.

10. Stabilize disturbed areas immediately. Contractor shall ensure that all grading is restored to existing conditions. Contractor shall match existing contours and maintain drainage features and topography per the site. For vegetated areas, decompact subgrade of disturbed areas to a depth of 12 inches.

11. Restore the disturbed areas to their existing ground cover per the site restoration schedule on SR- 4.

12. Maintain erosion and sediment control devices until site work is complete and a uniform 70% vegetative cover is established.

PECO METER STATION

4. Install all E&S control devices such as: compost filter socks, as shown on the plans and details.

5. Perform clearing and grubbing as needed for the project. Limit clearing and grubbing to the areas of the project that are being constructed.

6. Construct buildings, proposed mechanical piping and concrete pads as shown on the pipeline plans prepared by others.

7. Construct dry wells per the BMP Construction sequences below. DRY WELL – BMP 6.4.6

1. Protect infiltration area from compaction during construction. 2. If possible, install dry wells during later phases of site construction to prevent sedimentation and/or damage from construction activity. 3. Excavate dry well bottom to a uniform, level uncompacted subgrade free from rocks and debris. Do not compact subgrade. To the greatest extent possible, excavation should be performed with the lightest practical equipment. Excavation equipment should be placed outside the limits. 4. Place dry well as noted on the details and per the manufacturer installation specifications. Completely wrap with nonwoven geotextile. If sediment and/or debris have accumulated in dry well bottom, remove prior to geotextile placement. Geotextile rolls should overlap by a minimum of 24 inches within the trench. Fold back and secure excess geotextile during stone placement. 5. Install overflow pipe, and all other dry well structures as indicated on the plans and per manufacturer installation specifications. Connect roof leaders to dry well as indicated on the plans. 6. Place uniformly graded, clean-washed aggregate in 6-inch lifts, lightly compacted between lifts. 7. Place 12-inch lift of approved topsoil over dry well.

8. Stabilize disturbed areas immediately. Contractor shall ensure that all grading is restored to existing conditions. Contractor shall match existing contours and maintain drainage features and topography per the site. For vegetated areas, decompact subgrade of disturbed areas to a depth of 12 inches.

9. Restore the disturbed areas to their existing ground cover per the site restoration schedule on SR- 4.

10. Maintain erosion and sediment control devices until site work is complete and a uniform 70% vegetative cover is established.

11. Remove erosion and sediment control devices once site work is complete and a uniform 70% vegetative cover is established. Areas disturbed during removal of the BMPs must be stabilized immediately.

XIV. LONG-TERM MAINTENANCE SCHEDULE

SITE RESTORATION ACTIVITY FREQUENCY Perform visual inspections for sufficient vegetative growth and cover. On-going Maintain records of all inspections and maintenance activity. Vegetated areas should be inspected for erosion, scour, and invasive plants. Remove invasive plants with minimum Monthly during the growing season disruption to the planting soil bed and remaining vegetation. Bare areas and areas of insufficient cover, less than 70% vegetative growth, shall be re-seeded. As needed In the event of trench settling, the area shall be re-graded to maintain pre-construction drainage patterns, and re-seeded. DRY WELL – BMP 6.4.6 ACTIVITY FREQUENCY Inspect dry well for structural defects and proper operation. Quarterly Evaluate the drain down time of the dry well to ensure the maximum time of 72 hours is not exceeded. If drain down times are exceeding the maximum, drain the dry well via pumping and Quarterly clean out perforated piping. If slow drainage persists, the system may need replacing. Remove sediment and debris and any other waste material. Monthly

Clean out gutters and ensure proper connections. Monthly

Maintain records of all inspections and maintenance activity. On-going

XV. OFF-SITE DRAINAGE ANALYSIS In existing conditions, all drainage from the PECO Meter Station LOD is conveyed to an existing storm sewer network along Flower Street. The storm sewer network ultimately ends at the Delaware River through a series of storm sewer pipes that run from Flower Street to Seaport Drive and an access drive towards the Delaware River.

The drainage pattern from existing to proposed conditions is not altered. All post construction stormwater discharged from Dry Wells 1 and 2 drains to the Northwest corner of the project site before heading off-site (see Figure XV -1).

Figure XV-1: PECO Meter Station

Beyond the property fence line, the stormwater discharge travels via sheet flow along Delaware Avenue (South of the railroad tracks). A channel is not present along Delaware Avenue (see Figure XV -2). Sheet flow from Delaware Avenue discharges into an inlet within Flower Street, just south of Delaware Avenue. (see Figure XV-3). Figure XV-2: Flow Path along Delaware Avenue

Figure XV-3: Flow Path from Delaware Ave to Flower Street Inlet

Once discharged into the storm sewer system, flow travels South on Flower Street, then West on Seaport Drive, then South on an access road to DELCORA’s combined sewer overflow (CSO) outfall to the Delaware River (see Figure XV–4). The stormwater discharge from the two dry wells runs through approximately 2,100 LF of storm sewer to the CSO outfall.

Figure XV-4: DELCORA Combined Sewer Outfall Location Map

PECO Meter Station q

CSO Outfall

https://www.delcora.org/wp-content/uploads/2015/10/Outfall-Map-for-DELCORA-website.jpg

The flow path from the dry well discharge pipe drains from the property through public right-of-way until reaching the CSO outfall location.

As noted within Sections VII and VIII of this report, the proposed volume and peak rate of stormwater discharging to the flow path will avoid, minimize, or mitigate accelerated erosion or sedimentation for storm events up to and including the 10-year/24-hour storm. The 10-year/24-hour storm outflow from each dry well is 0.00 cfs.

While the stormwater discharge will enter a combined sewer system with combined sewer overflows (CSOs), there will not be an increase in runoff volume or peak rate.

POST CONSTRUCTION STORMWATER1 MANAGEMENT REPORT

Appendix A Location Map

POST CONSTRUCTION STORMWATER2 MANAGEMENT REPORT

Appendix B Soil Data

United States A product of the National Custom Soil Resource Department of Cooperative Soil Survey, Agriculture a joint effort of the United Report for States Department of Agriculture and other Federal agencies, State Delaware Natural agencies including the Resources Agricultural Experiment Conservation Stations, and local County, Service participants Pennsylvania

May 28, 2020 Preface

Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require

2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.

3 Contents

Preface...... 2 How Soil Surveys Are Made...... 5 Soil Map...... 8 Soil Map...... 9 Legend...... 10 Map Unit Legend...... 11 Map Unit Descriptions...... 11 Delaware County, Pennsylvania...... 13 ByB2—Butlertown silt loam, 3 to 8 percent slopes, moderately eroded...... 13 Ma—Made land, gravelly materials...... 14 OtA—Othello silt loams, 0 to 2 percent slopes, northern coastal plain...... 16 We—Wehadkee silt loam...... 18 References...... 20

4 How Soil Surveys Are Made

Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil

5 Custom Soil Resource Report scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and

6 Custom Soil Resource Report identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately.

7 Soil Map

The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit.

8 Custom Soil Resource Report Soil Map 75° 26' 28'' W 75° 22' 15'' W

462600 463200 463800 464400 465000 465600 466200 466800 467400 468000 39° 50' 41'' N 39° 50' 41'' N 4410500 4410500 4409900 4409900 4409300 4409300 4408700 4408700 4408100 4408100 4407500 4407500 4406900 4406900

39° 48' 35'' N 39° 48' 35'' N 462600 463200 463800 464400 465000 465600 466200 466800 467400 468000

Map Scale: 1:27,500 if printed on A landscape (11" x 8.5") sheet. Meters

75° 26' 28'' W N 0 400 800 1600 2400 75° 22' 15'' W Feet 0 1000 2000 4000 6000 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 9 Custom Soil Resource Report

MAP LEGEND MAP INFORMATION

Area of Interest (AOI) Spoil Area The soil surveys that comprise your AOI were mapped at Area of Interest (AOI) 1:20,000. Stony Spot Soils Very Stony Spot Please rely on the bar scale on each map sheet for map Soil Map Unit Polygons measurements. Wet Spot Soil Map Unit Lines Other Source of Map: Natural Resources Conservation Service Soil Map Unit Points Web Soil Survey URL: Special Line Features Special Point Features Coordinate System: Web Mercator (EPSG:3857) Blowout Water Features Streams and Canals Maps from the Web Soil Survey are based on the Web Mercator Borrow Pit projection, which preserves direction and shape but distorts Transportation distance and area. A projection that preserves area, such as the Clay Spot Rails Albers equal-area conic projection, should be used if more Closed Depression accurate calculations of distance or area are required. Interstate Highways Gravel Pit US Routes This product is generated from the USDA-NRCS certified data as Gravelly Spot of the version date(s) listed below. Major Roads Landfill Local Roads Soil Survey Area: Delaware County, Pennsylvania Lava Flow Survey Area Data: Version 17, Sep 17, 2019 Background Marsh or swamp Aerial Photography Soil map units are labeled (as space allows) for map scales Mine or Quarry 1:50,000 or larger.

Miscellaneous Water Date(s) aerial images were photographed: May 26, 2019—Jul Perennial Water 10, 2019

Rock Outcrop The orthophoto or other base map on which the soil lines were Saline Spot compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor Sandy Spot shifting of map unit boundaries may be evident. Severely Eroded Spot

Sinkhole

Slide or Slip

Sodic Spot

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Map Unit Legend

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

ByB2 Butlertown silt loam, 3 to 8 8.6 4.5% percent slopes, moderately eroded Ma Made land, gravelly materials 175.1 91.9% OtA Othello silt loams, 0 to 2 2.5 1.3% percent slopes, northern coastal plain We Wehadkee silt loam 4.2 2.2% Totals for Area of Interest 190.4 100.0%

Map Unit Descriptions

The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape.

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The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example.

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Delaware County, Pennsylvania

ByB2—Butlertown silt loam, 3 to 8 percent slopes, moderately eroded

Map Unit Setting National map unit symbol: 121dl Elevation: 0 to 800 feet Mean annual precipitation: 35 to 55 inches Mean annual air temperature: 48 to 61 degrees F Frost-free period: 160 to 240 days Farmland classification: All areas are prime farmland

Map Unit Composition Butlertown and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit.

Description of Butlertown Setting Landform: Coastal plains Landform position (two-dimensional): Toeslope, footslope Landform position (three-dimensional): Base slope Down-slope shape: Linear, concave Across-slope shape: Linear, concave Parent material: Thick deposits silty over sandy fluvial coastal plain sediments Typical profile H1 - 0 to 8 inches: silt loam H2 - 8 to 34 inches: silt loam H3 - 34 to 50 inches: silt loam H4 - 50 to 60 inches: silt loam Properties and qualities Slope: 3 to 8 percent Depth to restrictive feature: 25 to 40 inches to fragipan Natural drainage class: Well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.20 in/hr) Depth to water table: About 24 to 48 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Moderate (about 6.5 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Hydric soil rating: No

Minor Components Beltsville Percent of map unit: 6 percent Landform: Flats

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Landform position (two-dimensional): Summit, shoulder, backslope Landform position (three-dimensional): Interfluve, side slope Down-slope shape: Linear, concave Across-slope shape: Concave, linear Hydric soil rating: No Othello Percent of map unit: 5 percent Landform: Terraces Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Hydric soil rating: Yes Woodstown Percent of map unit: 4 percent Landform: Terraces Landform position (two-dimensional): Footslope Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Hydric soil rating: No

Ma—Made land, gravelly materials

Map Unit Setting National map unit symbol: 121fv Elevation: 200 to 1,500 feet Mean annual precipitation: 36 to 55 inches Mean annual air temperature: 45 to 57 degrees F Frost-free period: 160 to 214 days Farmland classification: Not prime farmland

Map Unit Composition Udorthents, shale and sandstone, and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit.

Description of Udorthents, Shale And Sandstone Setting Landform: Ridges Landform position (two-dimensional): Summit, shoulder, backslope Landform position (three-dimensional): Nose slope, interfluve, side slope Down-slope shape: Convex, linear Across-slope shape: Convex, linear Parent material: Graded areas of sandstone and shale Typical profile Ap - 0 to 6 inches: silt loam

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C - 6 to 60 inches: silt loam Properties and qualities Slope: 0 to 8 percent Depth to restrictive feature: 20 to 99 inches to lithic bedrock Natural drainage class: Well drained Runoff class: Very high Capacity of the most limiting layer to transmit water (Ksat): Moderately low to high (0.06 to 6.00 in/hr) Depth to water table: About 60 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Very low (about 2.9 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 7s Hydrologic Soil Group: A Hydric soil rating: No

Minor Components Penn Percent of map unit: 5 percent Landform: Hillslopes Landform position (two-dimensional): Shoulder, backslope Landform position (three-dimensional): Side slope, nose slope Down-slope shape: Linear, convex Across-slope shape: Convex, linear Hydric soil rating: No Abbottstown Percent of map unit: 2 percent Landform: Hillslopes Landform position (two-dimensional): Footslope, toeslope Landform position (three-dimensional): Base slope, head slope Down-slope shape: Concave, linear Across-slope shape: Concave, linear Hydric soil rating: No Readington Percent of map unit: 2 percent Landform: Hillslopes Landform position (two-dimensional): Footslope, backslope Landform position (three-dimensional): Base slope, head slope, side slope Down-slope shape: Concave, linear Across-slope shape: Concave, linear Hydric soil rating: No Reaville Percent of map unit: 2 percent Landform: Hillslopes Landform position (two-dimensional): Footslope, summit Landform position (three-dimensional): Interfluve, base slope Down-slope shape: Concave, linear Across-slope shape: Concave, linear Hydric soil rating: No

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Bowmansville Percent of map unit: 2 percent Landform: Flood plains Landform position (two-dimensional): Footslope, toeslope Landform position (three-dimensional): Head slope Down-slope shape: Concave, linear Across-slope shape: Linear, concave Hydric soil rating: No Berks Percent of map unit: 1 percent Landform: Valleys, ridges Landform position (two-dimensional): Backslope Landform position (three-dimensional): Side slope Down-slope shape: Convex, linear Across-slope shape: Convex, linear Hydric soil rating: No Croton Percent of map unit: 1 percent Landform: Depressions Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Base slope Down-slope shape: Concave, linear Across-slope shape: Linear, concave Hydric soil rating: Yes

OtA—Othello silt loams, 0 to 2 percent slopes, northern coastal plain

Map Unit Setting National map unit symbol: 2thwm Elevation: 0 to 300 feet Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 46 to 64 degrees F Frost-free period: 190 to 250 days Farmland classification: Not prime farmland

Map Unit Composition Othello, drained, and similar soils: 50 percent Othello, undrained, and similar soils: 30 percent Minor components: 20 percent Estimates are based on observations, descriptions, and transects of the mapunit.

Description of Othello, Drained Setting Landform: Flats, depressions, swales Landform position (two-dimensional): Footslope Landform position (three-dimensional): Talf, dip Down-slope shape: Linear, concave

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Across-slope shape: Linear, concave Parent material: Silty eolian deposits over fluviomarine deposits Typical profile Ap - 0 to 9 inches: silt loam Btg - 9 to 29 inches: silt loam 2BCg - 29 to 34 inches: sandy loam 2Cg - 34 to 80 inches: loamy sand Properties and qualities Slope: 0 to 2 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.57 in/hr) Depth to water table: About 10 to 20 inches Frequency of flooding: None Frequency of ponding: Rare Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Moderate (about 8.8 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3w Hydrologic Soil Group: C/D Hydric soil rating: Yes

Description of Othello, Undrained Setting Landform: Depressions, swales, flats, drainageways Landform position (two-dimensional): Footslope Landform position (three-dimensional): Dip, talf Down-slope shape: Concave, linear Across-slope shape: Concave, linear Parent material: Silty eolian deposits over fluviomarine deposits Typical profile Oe - 0 to 2 inches: peat A - 2 to 4 inches: silt loam Eg - 4 to 10 inches: silt loam Btg - 10 to 29 inches: silt loam 2BCg - 29 to 35 inches: sandy loam 2Cg - 35 to 80 inches: loamy sand Properties and qualities Slope: 0 to 2 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.57 in/hr) Depth to water table: About 0 to 10 inches Frequency of flooding: None Frequency of ponding: Occasional Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm)

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Available water storage in profile: High (about 9.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 5w Hydrologic Soil Group: C/D Hydric soil rating: Yes

Minor Components Fallsington, undrained Percent of map unit: 8 percent Landform: Swales, flats, drainageways, depressions Landform position (two-dimensional): Footslope Landform position (three-dimensional): Dip, talf Down-slope shape: Concave, linear Across-slope shape: Linear, concave Hydric soil rating: Yes Kentuck, undrained Percent of map unit: 7 percent Landform: Flats, depressions, swales Landform position (two-dimensional): Toeslope Landform position (three-dimensional): Talf, dip Down-slope shape: Linear, concave Across-slope shape: Linear, concave Hydric soil rating: Yes Mattapex Percent of map unit: 5 percent Landform: Flats, depressions, broad interstream divides, swales Landform position (two-dimensional): Summit, footslope Landform position (three-dimensional): Talf, dip Down-slope shape: Linear, concave Across-slope shape: Linear, concave Hydric soil rating: No

We—Wehadkee silt loam

Map Unit Setting National map unit symbol: 121h2 Elevation: 200 to 800 feet Mean annual precipitation: 36 to 50 inches Mean annual air temperature: 48 to 57 degrees F Frost-free period: 140 to 200 days Farmland classification: Not prime farmland

Map Unit Composition Wehadkee and similar soils: 90 percent Minor components: 10 percent

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Estimates are based on observations, descriptions, and transects of the mapunit.

Description of Wehadkee Setting Landform: Flood plains Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Concave Parent material: Loamy alluvium derived from igneous and metamorphic rock Typical profile H1 - 0 to 9 inches: silt loam H2 - 9 to 28 inches: silt loam H3 - 28 to 60 inches: silty clay loam H4 - 60 to 64 inches: stratified clay Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Very high Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 2.00 in/hr) Depth to water table: About 0 to 6 inches Frequency of flooding: Frequent Frequency of ponding: None Available water storage in profile: Moderate (about 8.9 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4w Hydrologic Soil Group: B/D Hydric soil rating: No

Minor Components Chewacla Percent of map unit: 7 percent Landform: Flood plains Landform position (two-dimensional): Toeslope, footslope Down-slope shape: Linear Across-slope shape: Linear Hydric soil rating: No Glenville Percent of map unit: 3 percent Hydric soil rating: No

19 References

American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084

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United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf

POST CONSTRUCTION STORMWATER3 MANAGEMENT REPORT

Appendix C Chapter 102 Compliance

ADELPHIA GATEWAY PROJECT , LLC 102.8 Compliance Matrix Code Description Documentation Plans Narrative 102.8.b General PCSM Planning and Design Preserve the integrity of stream channels and maintain and protect the physical, biological and PCSM Narrative, 1 PCSM-5 to PCSM-8, SR-9 to SR-41 chemical qualities of the receiving stream. Section II, VI PCSM-5 to PCSM-8, SR-9 to SR-41, 2 Prevent an increase in the rate of stormwater runoff. note SR-4 & SR- 6 provides details PCSM Narrative, regarding the site restoration Section II, VI 3 Minimize any increase in stormwater runoff volume. operations. 4 Minimize impervious areas. PCSM-5 to PCSM-8, SR-9 to SR-41

5 Maximize the protection of existing drainage features and existing vegetation. PCSM-5 to PCSM-8, SR-9 to SR-41 PCSM Narrative, Section II, VI 6 Minimize land clearing and grading. PCSM-5 to PCSM-8, SR-9 to SR-41

7 Minimize soil compaction. PCSM-5 to PCSM-8, SR-9 to SR-41

PCSM-5 to PCSM-8, SR-9 to SR-41, Utilize other structural or nonstructural BMPs that prevent or minimize changes in stormwater note SR-4 & SR-6 provides details PCSM Narrative, 8 runoff. regarding the site restoration Section II, VI operations.

102.8.c Consistency with E&S Plan

Adelphia Gateway Project, Tilghman and Parkway Laterals, Phase 2B- The PCSM Plan shall be planned, designed and implemented to be consistent with the E&S Plan Post Construction Management and under § 102.4(b) (relating to erosion and sediment control requirements). Erosion and Sediment Control Plan, 52 sheets total.

9/25/2020 1 of 5 ADELPHIA GATEWAY PROJECT , LLC 102.8 Compliance Matrix Code Description Documentation Plans Narrative 102.8.e PCSM Plan preparer requirements PCSM narrative, PCSM Plan preparer requirements Section I 102.8.f PCSM Plan Content PCSM-5 to PCSM-8, SR-9 to SR-41, 1 The existing topographic features of the project site and the immediate surrounding area. see above for noted subsections

PCSM-1, PCSM-5 to PCSM-8, SR-5, PCSM Narrative 2 The types, depth, slope, locations and limitations of the soils and geologic formations. SR-9 to SR-41 Section III The characteristics of the project site, including the past, present and proposed land uses and the PCSM Narrative, 3 proposed alteration to the project site. Section IV An identification of the net change in volume and rate of stormwater from preconstruction 4 Section VII & VIII hydrology to post construction hydrology for the entire project site and each drainage area An identification of the location of surface waters of this Commonwealth, which may receive PCSM Narrative, 5 runoff within or from the project site and their classification under Chapter 93 (relating to water PCSM-5 to PCSM-8, SR-9 to SR-41 Section V quality standards). A written description of the location and type of PCSM BMPs including construction details for PCSM Narrative, 6 permanent stormwater BMPs including permanent stabilization specifications and locations. Section VI

A sequence of PCSM BMP implementation or installation in relation to earth disturbance activities PCSM Narrative, 7 PCSM-3, SR-3 of the project site and a schedule of inspections for critical stages of PCSM BMP installation. Section XIII PCSM Narrative, 8 Supporting calculations. App. D PCSM-5 to PCSM-8, SR-9 to SR-41, 9 Plan drawings. see above for noted subsections A long-term operation and maintenance schedule, which provides for inspection of PCSM BMPs, including the repair, replacement, or other routine maintenance of the PCSM BMPs to ensure 10 proper function and operation. The program must provide for completion of a written report PCSM-1, SR-2 documenting each inspection and all BMP repair and maintenance activities and how access to the PCSM BMPs will be provided.

9/25/2020 2 of 5 ADELPHIA GATEWAY PROJECT , LLC 102.8 Compliance Matrix Code Description Documentation Plans Narrative Procedures which ensure that the proper measures for recycling or disposal of materials 11 associated with or from the PCSM BMPs are in accordance with Department laws, regulations and PCSM-1, SR-3 requirements. An identification of naturally occurring geologic formations or soil conditions that may have the potential to cause pollution after earth disturbance activities are completed and PCSM BMPs are PCSM Narrative, 12 PCSM-3, SR-5 operational and development of a management plan to avoid or minimize potential pollution and Section IX its impacts. An identification of potential thermal impacts from post construction stormwater to surface PCSM Narrative, 13 waters of this Commonwealth including BMPs to avoid, minimize or mitigate potential pollution Section X from thermal impacts. A riparian forest buffer management plan when required under § 102.14 (relating to riparian PCSM Narrative, 14 buffer requirements). Section IX 15 Additional information requested by the Department. 102.8.h PCSM implementation for special protection waters Evaluate and include nondischarge alternatives in the PCSM Plan unless a person demonstrates 1 that nondischarge alternatives do not exist for the project. If the person makes the demonstration in paragraph (1) that nondischarge alternatives do not 2 exist for the project, the PCSM Plan must include ABACT, except as provided in § 93.4c(b)(1)(iii). PCSM Narrative, SR-13 to SR-20 Section X For purposes of this chapter, nondischarge alternatives and ABACT and their design standards are listed in the Pennsylvania Stormwater Best Management Practices Manual Commonwealth of 3 Pennsylvania, Department of Environmental Protection, No. 363-0300-002 (December 2006), as amended and updated. 102.8.i Complaint or site inspection Upon complaint or site inspection, the Department or conservation district may require that the PCSM-1, SR-2 PCSM Plan be submitted for review and approval to ensure compliance with this chapter. 102.8.l Final Certification 1 The permittee shall retain a copy of the record drawings as a part of the approved PCSM Plan. PCSM-1, SR-2 The permittee shall provide a copy of the record drawings as a part of the approved PCSM Plan to 2 the person identified in this section as being responsible for the long-term operation and PCSM-1, SR-2 maintenance of the PCSM BMPs. 102.8.m PCSM long-term operation and maintenance requirements The permittee or co-permittee shall be responsible for long-term operation and maintenance of PCSM Narrative, 1 PCSM BMPs unless a different person is identified in the notice of termination and has agreed to PCSM-1, SR-2 Section XII long-term operation and maintenance of PCSM BMPs.

9/25/2020 3 of 5 ADELPHIA GATEWAY PROJECT , LLC 102.8 Compliance Matrix Code Description Documentation Plans Narrative For any property containing a PCSM BMP, the permittee or co-permittee shall record an instrument with the recorder of deeds which will assure disclosure of the PCSM BMP and the related obligations in the ordinary course of a title search of the subject property. The recorded instrument must identify the PCSM BMP, provide for necessary access related to long-term PCSM Narrative, 2 PCSM-1, SR-2 operation and maintenance for PCSM BMPs and provide notice that the responsibility for long- Section XII term operation and maintenance of the PCSM BMP is a covenant that runs with the land that is binding upon and enforceable by subsequent grantees, and provide proof of filing with the notice of termination under § 102.7(b)(5) (relating to permit termination).

For Commonwealth owned property, a covenant that runs with the land is not required until the PCSM Narrative, 3 transfer of the land containing a PCSM BMP occurs. Upon transfer of the Commonwealth-owned PCSM-1, SR-2 Section XII property containing a PCSM BMP, the deed must comply with this subsection. The person responsible for performing long-term operation and maintenance may enter into an agreement with another person including a conservation district, nonprofit organization, PCSM Narrative, 4 municipality, authority, private corporation or other person, to transfer the responsibility for N/A Section XII PCSM BMPs or to perform long-term operation and maintenance and provide notice thereof to the Department. A permittee or co-permittee that fails to transfer long-term operation and maintenance of the PCSM BMP or otherwise fails to comply with this requirement shall remain jointly and severally 5 PCSM-1, SR-2 responsible with the landowner for long-term operation and maintenance of the PCSM BMPs located on the property.

9/25/2020 4 of 5 ADELPHIA GATEWAY PROJECT , LLC 102.8 Compliance Matrix Code Description Documentation Plans Narrative

102.8.n. Regulated activities that require site restoration or reclamation, and small earth disturbance activities.

The portion of a site reclamation or restoration plan that identifies PCSM BMPs to manage stormwater from oil and gas activities or mining activities permitted in accordance with Chapters 78 and 86—90; timber harvesting activities; pipelines; other similar utility infrastructure; PCSM-5 to PCSM-8, SR-9 to SR-41, Department permitted activities involving less than 1 acre of earth disturbance; or abandoned see above for noted subsections mine land reclamation activities, that require compliance with this chapter, may be used to satisfy the requirements of this section if the PCSM, reclamation or restoration plan meets the requirements of subsections (b), (c), (e), (f), (h), (i) and (l) and, when applicable, subsection (m).

9/25/2020 5 of 5

POST CONSTRUCTION STORMWATER4 MANAGEMENT REPORT

Appendix D Stormwater Management Calculations

POST CONSTRUCTION STORMWATER8 MANAGEMENT REPORT

Appendix D.1 BMP Worksheets

Job No._18-00672-005 __

PROJECT: Adelphia Gateway Pipeline By: ATH Checked: SMM Drainage Area: PECO Meter Station Date: 7/14/20 Date: 9/24/20 2-Year Rainfall: 3.25 in

Total Site Area: 0.0538 acres Protected Site Area: acres Managed Area: acres

Existing Conditions: Q Runoff 2 Soil Area Area la Runoff1 Volume Cover Type/Condition Type (sf) (ac) CN S (0.2*S) (in) (ft3)

Gravel (80%) A 245 0.006 76 3.16 0.63 1.19 24.27 Gravel (20%) 1 A 61 0.001 30 23.33 4.67 0.00 0.0000 Gravel (Site Restoration Area) A 2,038 0.047 76 3.16 0.63 1.19 202.1000

TOTAL: 2,344 226.37 1 Per Chapter 102, 20% of the existing impervious and gravel aeas to be disturbed must be considered meadow in good condition. CN=30 (Meadow, A)

Developed Conditions:

Q Runoff 2 Soil Area Area la Runoff1 Volume Cover Type/Condition Type (sf) (ac) CN S (0.2*S) (in) (ft3)

12x15 Building Building 180 0.004 98 0.20 0.04 3.02 45.30

8x10 Building and Stairs Building 80 0.002 98 0.20 0.04 3.02 20.13

Stairs at 8x10 Builiding Impervious 20 0.000 98 0.20 0.04 3.02 5.03

Concrete Pad-1'-4"x3'-0" (2) Impervious 8 0.000 98 0.20 0.04 3.02 2.01

Concrete Pad-1'-4"x3'-4" (2) Impervious 9 0.000 98 0.20 0.04 3.02 2.24

Concrete Pad-3'x3 Impervious 9 0.000 98 0.20 0.04 3.02 2.27 Gravel (Site Restoration Area) A 2,038 0.047 76 3.16 0.63 1.19 202.10 TOTAL: 2,344 279.08

2-Year Volume Increase (ft3): 52.71

2-Year Volume Increase = Developed Conditions Runoff Volume - Existing Conditions Runoff Volume

1. Runoff (in) = Q = (P-0.2S)2 / (P+0.8S) where P = 2-Year Rainfall (in) S = (1000/CN)-10 2. Runoff Volume (CF) = Q x Area x 1/12 Q = Runoff (in) Area = Land use area (sq. ft) Note: Runoff Volume must be calculated for EACH land use type/condition and HSGI. The use of a weighted CN value for volume calculations is not acceptable.

Worksheet 4 & 5.xlsx Job No._18-00672-005 __

Worksheet 5. Structural BMP Volume Credits

PROJECT: Adelphia Gateway Pipeline By: ATH Checked: SMM Drainage Area: PECO Meter Station Date: 7/14/20 Date: 9/24/20 2-Year Rainfall: 3.25 in

SUB-BASIN: PECO Meter Station

Required Control Volume (ft3) – from Worksheet 4 : 52.71 Non-structural Volume Credit (ft3) – from Worksheet 3 : - 0 (maximum is 25% of required volume)

Structural Volume Reqmt (ft3): = 52.71 0 (Required Control Volume minus Non-structural Credit)

Proposed BMP Area (ft2) Storage Volume (ft3)

6.4.1 Porous Pavement 6.4.2 Infiltration Basin 6.4.3 Infiltration Bed 6.4.4 Infiltration Trench 6.4.5 Rain Garden/Bioretention 6.4.6 Dry Well / Seepage Pit - #1 28 71 6.4.7 Dry Well / Seepage Pit - #2 28 71 6.4.7 Constructed Filter 6.4.8 Vegetated Swale 6.4.9 Vegetated Filter Strip 6.4.10 Berm 6.5.2 Capture and Re-use - Dry Well #1 6.5.2 Capture and Re-use - Dry Well #2 6.6.1 Constructed Wetlands 6.6.2 Wet Pond / Retention Basin 6.7.1 Riparian Buffer/Riparian Forest Buffer Restoration 6.7.2 Landscape Restoration / Reforestation 6.7.3 Soil Amendment 6.8.1 Level Spreader 6.8.2 Special Storage Areas

Total Structure Volume (ft3): 142 Structural Volume Requirement (ft3): 52.71

DIFFERENCE: 89.29

Worksheet 4 & 5.xlsx 90% DISTURBED AREA COMPLIANCE Adelphia PECO Meter Station Disturbed / Non-Restoration Area 2345 SF

Total Drainage Area Treated (including onsite areas only ) 2038 SF Site Restoration Adelphia PECO Meter Station 80 SF Dry Well #1 180 SF Dry Well #2

90% of the disturbed area 2110.50 SF

% of Disturbed Area Treated in BMPs 98.00 % Project: Adelphia - Quakertown Job No.______Subject: Worksheet 10 Sheet No._____2 _____ of ___5_____ Computed By:_____ Date: ______Checked By__ Date __

Worksheet 10 – Water Quality Compliance for Nitrate

Does the site design incorporate the following BMPs to address nitrate pollution? A summary “yes” rating is achieved if at least 2 Primary BMPs for nitrate are provided across the site or 4 secondary BMPs for nitrate are provided across the site (or the equivalent) “provided across the site” is taken to mean the specifications for that BMP set forward in Sections 5 and 6 are satisfied.

Adelphia PECO Meter Station Yes No Primary BMPs for Nitrate: NS BMP 5.4.2 – Protect/Conserve/Enhance Riparian Buffers NS BMP 5.5.4 – Cluster Uses at Each Site NS BMP 5.6.1 – Minimize Total Disturbed Area NS BMP 5.6.3 – Re-Vegetate/Re-Forest Disturbed Areas (Native Species) NS BMP 5.9.1 – Street Sweeping/Vacuuming Structural BMP 6.7.1 – Riparian Buffer Restoration Structural BMP 6.7.2 – Landscape Restoration

Secondary BMPs for Nitrate: NS BMP 5.4.1 – Protect Sensitive/Special Value Features NS BMP 5.4.3 – Protect/Utilize Natural Drainage Features NS BMP 5.6.2 – Minimize Soil Compaction Structural BMP 6.4.5 – Rain Garden/Bioretention Structural BMP 6.4.8 – Vegetated Swale Structural BMP 6.4.9 – Vegetated Filter Strip Structural BMP 6.6.1 – Constructed Wetland Structural BMP 6.7.1 – Riparian Buffer Restoration Structural BMP 6.7.2 – Landscape Restoration Structural BMP 6.7.3 – Soils Amendment/Restoration

Q:\2018\1800672_005_Tilghman_Lateral\Working Data\Calculations\PECO\WQ Worksheets.xlsx Project: Adelphia Job No.______Subject: Worksheet 12-PECO Sheet No.___3___ of ___5___ Computed By: ATH Date:9/24/20 Checked By: SMM Date 09/24/20

Worksheet 12 – Water Quality Analysis of Pollutant Loading from All Disturbed Areas

EXISTING Total Site Area (AC) 0.05 Total Disturbed Area (AC) 2-Year, 24 Hour Rainfall (in) 3.25 Total Disturbed Areas: Pollutant Pollutant Load* TSS TP Nitrate- Runoff Cover TSS** Land Cover Classification EMC EMC Nitrite EMC Volume TP** (LBS) NO3 (LBS) (Acres) (LBS) (mg/l) (mg/l) (mg/l as N) (AF) Forest 39 0.15 0.17 Meadow 47 0.19 0.3 Fertilized Planting Area 55 1.34 0.73 Native Planting Area 55 0.4 0.33 Lawn, Low-Input 180 0.4 0.44 Lawn, High-Input 180 2.22 1.46

Pervious Surfaces Golf Course Fairway/Green 305 1.07 1.84 Grassed Athletic Field 200 1.07 1.01 Rooftop 21 0.13 0.32 High Traffic Street/Highway 261 0.4 0.83 Medium Traffic Street 113 0.33 0.58 Low Traffic/Residential Street 86 0.36 0.47 Res. Driveway, Play Courts, etc. 60 0.46 0.47 High Traffic Parking Lot 120 0.39 0.6

Impervious Surfaces Low Traffic Parking Lot 58 0.15 0.39 0.05 0.0145738 2.2822521 0.0059024 0.0153462 TOTAL LOAD 2.28 0.01 0.02

*Pollutant Load = [EMC, mg/l] X [Volume, AF] X [2.7, Unit Conversion]

**TSS and TP calculations only required for projects not meeting CG1/CG2 or not controlling less than 90% of the disturbed area

Q:\2018\1800672_005_Tilghman_Lateral\Working Data\Calculations\PECO\WQ Worksheets.xlsx Project: Adelphia Job No.______Subject: Worksheet 12-PECO Sheet No.___4___ of ___5___ Computed By: ATH Date:9/24/20 Checked By: SMM Date 09/24/20

Worksheet 12 – Water Quality Analysis of Pollutant Loading from All Disturbed Areas

PROPOSED Total Site Area (AC) 0.05 Total Disturbed Area (AC) 0.05 Disturbed Area Controlled by BMPs (AC) 2-Year, 24 Hour Rainfall (in) 3.25 Total Disturbed Areas: Pollutant Pollutant Load* TSS TP Nitrate- Runoff Cover TSS** Land Cover Classification EMC EMC Nitrite EMC Volume TP** (LBS) NO3 (LBS) (Acres) (LBS) (mg/l) (mg/l) (mg/l as N) (AF) Forest 39 0.15 0.17 Meadow 47 0.19 0.3 Fertilized Planting Area 55 1.34 0.73 Native Planting Area 55 0.4 0.33 Lawn, Low-Input 180 0.4 0.44 Lawn, High-Input 180 2.22 1.46

Pervious Surfaces Golf Course Fairway/Green 305 1.07 1.84 Grassed Athletic Field 200 1.07 1.01 Rooftop 21 0.13 0.32 0.006 0.0016165 0.0916581 0.0005674 0.0013967 High Traffic Street/Highway 261 0.4 0.83 Medium Traffic Street 113 0.33 0.58 Low Traffic/Residential Street 86 0.36 0.47 Res. Driveway, Play Courts, etc. 60 0.46 0.47 High Traffic Parking Lot 120 0.39 0.6

Impervious Surfaces Low Traffic Parking Lot 58 0.15 0.39 0.048 0.0129572 2.0291012 0.0052477 0.013644 TOTAL LOAD 2.12 0.01 0.02

*Pollutant Load = [EMC, mg/l] X [Volume, AF] X [2.7, Unit Conversion]

**TSS and TP calculations only required for projects not meeting CG1/CG2 or not controlling less than 90% of the disturbed area

Q:\2018\1800672_005_Tilghman_Lateral\Working Data\Calculations\PECO\WQ Worksheets.xlsx Project: Adelphia Job No.______Subject: Worksheet 13-PECO Sheet No.___5___ of ___5___ Computed By: ATH Date: 09/24/20 Checked By: SMM Date 09/24/20

Worksheet 13 - Pollutant Reduction Through BMP Applications* *Fill this worksheet out for each BMP type with different pollutant removal efficiencies. Sum pollutant reduction achieved for all BMP types on final sheet.

BMP TYPE: Total Area to dry wells

Disturbed Area Controlled by BMPs (AC) 0.01 2-Year, 24 Hour Rainfall (in) 3.25 Total Disturbed Areas: Pollutant Pollutant Load** TSS TP Nitrate- Runoff Cover TSS*** Land Cover Classification EMC EMC Nitrite EMC Volume TP*** (LBS) NO3 (LBS) (Acres) (LBS) (mg/l) (mg/l) (mg/l as N) (AF) Forest 39 0.15 0.17 Meadow 47 0.19 0.3 Fertilized Planting Area 55 1.34 0.73 Native Planting Area 55 0.4 0.33 Lawn, Low-Input 180 0.4 0.44 Lawn, High-Input 180 2.22 1.46

Pervious Surfaces Golf Course Fairway/Green 305 1.07 1.84 Grassed Athletic Field 200 1.07 1.01 Rooftop 21 0.13 0.32 0.01 0.0016165 0.0916581 0.0005674 0.0013967 High Traffic Street/Highway 261 0.4 0.83 Medium Traffic Street 113 0.33 0.58 Low Traffic/Residential Street 86 0.36 0.47 Res. Driveway, Play Courts, etc. 60 0.46 0.47 High Traffic Parking Lot 120 0.39 0.6

Impervious Surfaces Low Traffic Parking Lot 58 0.15 0.39 TOTAL LOAD TO THIS BMP TYPE 0.09 0.00 0.00 POLLUTANT REMOVAL EFFICIENCES FROM APPENDIX A. STORMWATER MANUAL 100% 100% 100% POLLUTANT REDUCTION ACHIEVED BY THIS BMP TYPE (LBS) 0.09 0.00 0.00

**Pollutant Load = [EMC, mg/l] X [Volume, AF] X [2.7, Unit Conversion]

***TSS and TP calculations only required for projects not meeting CG1/CG2 or not controlling less than 90% of the disturbed area

Q:\2018\1800672_005_Tilghman_Lateral\Working Data\Calculations\PECO\WQ Worksheets.xlsx

POST CONSTRUCTION STORMWATER9 MANAGEMENT REPORT

Appendix D.2 BMP Computations

Project: Adelphia Job No._ 18-00672-005 ______Subject: PECO Meter Station Sheet No.___1___ of ___4___ Computed By: ATH Date: 07/14/20 Checked By: ATH Date: 07/14/20

Check one: Present Developed PECO METER STATION STATION: EXISTING CONDITIONS WITHIN LOD 1. Runoff curve number

Cover description CN Area Product Soil name of CN x and area hydrologic group sq. ft. (cover type, treatment, and hydrologic condition; percent mi2 impervious; unconnected/connected impervious area ratio % Table 2-2a Table A Gravel 76 245 18605

A Gravel (Site Restoration Area) 76 2039 154964

A Meadow 30 61 1836

Totals 2345 175405

CN(weighted) = total product = 175404.80 = 74.80 ; Use CN 75 total area 2345.00

2. Runoff Storm #1 Storm #2 Storm #3 Storm #4

Frequency ...... yr 2-YR 10-YR 50-YR 100-YR

Rainfall, P (24-hour) ...... in 3.16 4.57 6.53 7.63

Runoff, Q ...... in 1.06 2.09 3.72 4.69 2 1000 0.2 10 (SCS Method)

Runoff CN Calcs.xlsx Project: Adelphia Job No._ 18-00672-005 ______Subject: PECO Meter Station Sheet No.___2___ of ___4___ Computed By: ATH Date: 07/14/20 Checked By: ATH Date: 07/14/20

Check one: Present Developed PECO METER STATION: DA TO DRY WELL #1 1. Runoff curve number

Cover description CN Area Soil name Product of and CN x area hydrologic group sq. ft. (cover type, treatment, and hydrologic condition; percent mi2 impervious; unconnected/connected impervious area ratio % Table 2-2a Table

Impervious 98 180 17640

Totals 180 17640

CN(weighted) = total product = 17640.00 = 98.00 ; Use CN 98 total area 180.00

2. Runoff Storm #1 Storm #2 Storm #3 Storm #4

Frequency ...... yr 2-YR 10-YR 50-YR 100-YR

Rainfall, P (24-hour) ...... in 3.16 4.57 6.53 7.63

Runoff, Q ...... in 2.93 4.33 6.29 7.39 2 1000 0.2 10 (SCS Method)

Runoff CN Calcs.xlsx Project: Adelphia Job No._ 18-00672-005 ______Subject: PECO Meter Station Sheet No.___3___ of ___4___ Computed By: ATH Date: 07/14/20 Checked By: ATH Date: 07/14/20

Check one: Present Developed PECO METER STATION: DA TO DRY WELL #2 1. Runoff curve number

Impervious 98 80 7840

Totals 80 7840

CN(weighted) = total product = 7840.00 = 98.00 ; Use CN 98 total area 80.00

2. Runoff Storm #1 Storm #2 Storm #3 Storm #4

Frequency ...... yr 2-YR 10-YR 50-YR 100-YR

Rainfall, P (24-hour) ...... in 3.16 4.57 6.53 7.63

Runoff, Q ...... in 2.93 4.33 6.29 7.39 2 1000 0.2 10 (SCS Method)

Runoff CN Calcs.xlsx Project: Adelphia Job No._ 18-00672-005 ______Subject: PECO Meter Station Sheet No.___4___ of ___4___ Computed By: ATH Date: 07/14/20 Checked By: ATH Date: 07/14/20

Check one: Present Developed PECO METER STATION: BYPASS 1. Runoff curve number

Impervious 98 46 4508

Gravel (Site Restoration Area) 76 2039 154964

Totals 2085 159472

CN(weighted) = total product = 159472.00 = 76.49 ; Use CN 76 total area 2085.00

2. Runoff Storm #1 Storm #2 Storm #3 Storm #4

Frequency ...... yr 2-YR 10-YR 50-YR 100-YR

Rainfall, P (24-hour) ...... in 3.16 4.57 6.53 7.63

Runoff, Q ...... in 1.15 2.23 3.89 4.88 2 1000 0.2 10 (SCS Method)

Runoff CN Calcs.xlsx Worksheet 3: Time of concentration (T c) or travel time (T t)

Project Adelphia By ATH Date 7/14/2020 Location Peco Meter Station Checked SMM Date 7/14/2020 Circle one: Present Developed

Circle one: Tc Tt

NOTES: Space for as many as two segments per flow type can be used for each worksheet. Sheet flow calculated using Rational Method Nomograph. Include a map, schematic, or description of flow segments.

Sheet Flow (Applicable to T c only) Segment ID L1 1. Surface description (table 3-1) Gravel 2. Manning's roughness coeff., n (table 3-1) 0.01 3. Flow length, L (total L < 150 ft) ft 50.00 4. Two-yr 24-hr rainfall, P2 in 3.25 5. Land slope, s ft/ft 0.020 0.8 6. T t = 0.007 (nL) Compute T t hr 0.011 + = 0.011 0.5 0.4 P2 s

Shallow Concentrated Flow Segment ID 7. Surface description (paved or unpaved) 8. Flow length, L ft 9. Watercourse slope, s ft/ft 10. Average velocity, V (figure 3-1) ft/s

11. T t = L Compute T t hr + = 0.000 3600V

Channel Flow Segment ID 12. Cross sectional flow area, a ft 2

13. Wetted perimeter, p w ft 14. Hydraulic radius, r = a ft

pw 15. Channel slope, s ft/ft 16. Manning's roughness coeff., n 17. V = 1.49r 2/3 s1/2 Compute V ft/s n 18. Flow length, L ft

19. T t = L Compute T t hr + = 0.000 3600V

20. Watershed or subarea T c or T t (add T t in steps 6, 11, and 19) Total min. 0.64 MIN (min) 5.00 Worksheet 3: Time of concentration (T c) or travel time (T t)

Project Adelphia By ATH Date 7/14/2020 Location Peco Meter Station to Dry Well 1 Checked SMM Date 7/14/2020 Circle one: Present Developed

Circle one: Tc Tt

Sheet Flow (Applicable to T c only) Segment ID 1. Surface description (table 3-1) 2. Manning's roughness coeff., n (table 3-1) 3. Flow length, L (total L < 150 ft) ft 4. Two-yr 24-hr rainfall, P2 in 5. Land slope, s ft/ft 0.8 6. T t = 0.007 (nL) Compute T t hr + = 0.000 0.5 0.4 P2 s

Shallow Concentrated Flow Segment ID 7. Surface description (paved or unpaved) 8. Flow length, L ft 9. Watercourse slope, s ft/ft 10. Average velocity, V (figure 3-1) ft/s

11. T t = L Compute T t hr + = 0.000 3600V

Channel Flow Segment ID 12. Cross sectional flow area, a ft 2

13. Wetted perimeter, p w ft 14. Hydraulic radius, r = a ft

pw 15. Channel slope, s ft/ft 16. Manning's roughness coeff., n 17. V = 1.49r 2/3 s1/2 Compute V ft/s n 18. Flow length, L ft

19. T t = L Compute T t hr + = 3600V

20. Watershed or subarea T c or T t (add T t in steps 6, 11, and 19) Total min. 0.00 MIN (min) 5.00 Worksheet 3: Time of concentration (T c) or travel time (T t)

Project Adelphia By ATH Date 7/14/2020 Location Peco Meter Station to Dry Well 2 Checked SMM Date 7/14/2020 Circle one: Present Developed

Circle one: Tc Tt

Shallow Concentrated Flow Segment ID 7. Surface description (paved or unpaved) 8. Flow length, L ft 9. Watercourse slope, s ft/ft 10. Average velocity, V (figure 3-1) ft/s

11. T t = L Compute T t hr + = 0.000 3600V

Channel Flow Segment ID 12. Cross sectional flow area, a ft 2

13. Wetted perimeter, p w ft 14. Hydraulic radius, r = a ft

pw 15. Channel slope, s ft/ft 16. Manning's roughness coeff., n 17. V = 1.49r 2/3 s1/2 Compute V ft/s n 18. Flow length, L ft

19. T t = L Compute T t hr + = 3600V

20. Watershed or subarea T c or T t (add T t in steps 6, 11, and 19) Total min. 0.00 MIN (min) 5.00 Worksheet 3: Time of concentration (T c) or travel time (T t)

Project Adelphia By RRY Date 2/5/2019 Location Marcus Hook Compressor Station - Bypass Checked ATH Date 3/19/2019 Circle one: Present Developed

Circle one: Tc Tt

Shallow Concentrated Flow Segment ID 7. Surface description (paved or unpaved) 8. Flow length, L ft 9. Watercourse slope, s ft/ft 10. Average velocity, V (figure 3-1) ft/s

11. T t = L Compute T t hr + = 0.000 3600V

Channel Flow Segment ID 12. Cross sectional flow area, a ft 2

13. Wetted perimeter, p w ft 14. Hydraulic radius, r = a ft

pw 15. Channel slope, s ft/ft 16. Manning's roughness coeff., n 17. V = 1.49r 2/3 s1/2 Compute V ft/s n 18. Flow length, L ft

19. T t = L Compute T t hr + = 0.000 3600V

20. Watershed or subarea T c or T t (add T t in steps 6, 11, and 19) Total min. 0.64 MIN (min) 5.00 PR EX Bypass EX

4S 2P 3L

Building - 12x15 Dry Well 1 PR

1S 5P

Building - 10x8 Dry Well 2

Subcat Reach Pond Link Routing Diagram for PECO Prepared by JMT, Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC PECO Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 2

Area Listing (all nodes)

Area CN Description (sq-ft) (subcatchment-numbers) 260 98 Building (1S, 4S) 64 30 Gravel (20%) (EX) 257 76 Gravel (80%) (EX) 4,063 76 Gravel (Site Restoration) (EX, PR) 61 98 Impervious (PR) 4,705 77 TOTAL AREA PECO Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 3

Soil Listing (all nodes)

Area Soil Subcatchment (sq-ft) Group Numbers 0 HSG A 0 HSG B 0 HSG C 0 HSG D 4,705 Other 1S, 4S, EX, PR 4,705 TOTAL AREA PECO Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 4

Ground Covers (all nodes)

HSG-A HSG-B HSG-C HSG-D Other Total Ground Sub (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) Cover Num 0 0 0 0 260 260 Building 0 0 0 0 64 64 Gravel (20%) 0 0 0 0 257 257 Gravel (80%) 0 0 0 0 4,063 4,063 Gravel (Site Restoration) 0 0 0 0 61 61 Impervious 0 0 0 0 4,705 4,705 TOTAL AREA PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 5

Time span=0.00-300.00 hrs, dt=0.01 hrs, 30001 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method

Subcatchment 1S: Building - 10x8 Runoff Area=80 sf 100.00% Impervious Runoff Depth=3.02" Tc=5.0 min CN=0/98 Runoff=0.01 cfs 20 cf

Subcatchment 4S: Building - 12x15 Runoff Area=180 sf 100.00% Impervious Runoff Depth=3.02" Tc=5.0 min CN=0/98 Runoff=0.02 cfs 45 cf

Subcatchment EX: EX Runoff Area=2,345 sf 0.00% Impervious Runoff Depth=1.13" Tc=5.0 min CN=75/0 Runoff=0.11 cfs 220 cf

Subcatchment PR: Bypass Runoff Area=2,100 sf 2.90% Impervious Runoff Depth=1.24" Tc=5.0 min CN=76/98 Runoff=0.11 cfs 217 cf

Pond 2P: Dry Well 1 Peak Elev=10.49' Storage=28 cf Inflow=0.02 cfs 45 cf Discarded=0.00 cfs 45 cf Primary=0.00 cfs 0 cf Outflow=0.00 cfs 45 cf

Pond 5P: Dry Well 2 Peak Elev=10.34' Storage=10 cf Inflow=0.01 cfs 20 cf Discarded=0.00 cfs 20 cf Primary=0.00 cfs 0 cf Outflow=0.00 cfs 20 cf

Link 3L: PR Inflow=0.11 cfs 217 cf Primary=0.11 cfs 217 cf

Total Runoff Area = 4,705 sf Runoff Volume = 503 cf Average Runoff Depth = 1.28" 93.18% Pervious = 4,384 sf 6.82% Impervious = 321 sf PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 6

Summary for Subcatchment 1S: Building - 10x8

Runoff = 0.01 cfs @ 11.96 hrs, Volume= 20 cf, Depth= 3.02"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 2-YR Rainfall=3.25"

Area (sf) CN Description * 80 98 Building 80 98 100.00% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment 1S: Building - 10x8 Hydrograph

0.009 Runoff 0.009 0.01 cfs 0.008 Type II 24-hr 0.008 0.007 2-YR Rainfall=3.25" 0.007 0.006 Runoff Area=80 sf 0.006 0.005 Runoff Volume=20 cf 0.005 0.004 Runoff Depth=3.02" Flow (cfs) 0.004 0.003 Tc=5.0 min 0.003 0.002 CN=0/98 0.002 0.001 0.001 0.000 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 7

Hydrograph for Subcatchment 1S: Building - 10x8

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 0.59 0.00 0.40 0.00 20.00 3.09 0.00 2.86 0.00 30.00 3.25 0.00 3.02 0.00 40.00 3.25 0.00 3.02 0.00 50.00 3.25 0.00 3.02 0.00 60.00 3.25 0.00 3.02 0.00 70.00 3.25 0.00 3.02 0.00 80.00 3.25 0.00 3.02 0.00 90.00 3.25 0.00 3.02 0.00 100.00 3.25 0.00 3.02 0.00 110.00 3.25 0.00 3.02 0.00 120.00 3.25 0.00 3.02 0.00 130.00 3.25 0.00 3.02 0.00 140.00 3.25 0.00 3.02 0.00 150.00 3.25 0.00 3.02 0.00 160.00 3.25 0.00 3.02 0.00 170.00 3.25 0.00 3.02 0.00 180.00 3.25 0.00 3.02 0.00 190.00 3.25 0.00 3.02 0.00 200.00 3.25 0.00 3.02 0.00 210.00 3.25 0.00 3.02 0.00 220.00 3.25 0.00 3.02 0.00 230.00 3.25 0.00 3.02 0.00 240.00 3.25 0.00 3.02 0.00 250.00 3.25 0.00 3.02 0.00 260.00 3.25 0.00 3.02 0.00 270.00 3.25 0.00 3.02 0.00 280.00 3.25 0.00 3.02 0.00 290.00 3.25 0.00 3.02 0.00 300.00 3.25 0.00 3.02 0.00 PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 8

Summary for Subcatchment 4S: Building - 12x15

Runoff = 0.02 cfs @ 11.96 hrs, Volume= 45 cf, Depth= 3.02"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 2-YR Rainfall=3.25"

Area (sf) CN Description * 180 98 Building 180 98 100.00% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment 4S: Building - 12x15 Hydrograph

Runoff 0.021 0.02 cfs 0.02 0.019 Type II 24-hr 0.018 0.017 2-YR Rainfall=3.25" 0.016 0.015 Runoff Area=180 sf 0.014 0.013 0.012 Runoff Volume=45 cf 0.011 0.01 Runoff Depth=3.02" Flow (cfs) 0.009 0.008 Tc=5.0 min 0.007 0.006 CN=0/98 0.005 0.004 0.003 0.002 0.001 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 9

Hydrograph for Subcatchment 4S: Building - 12x15

Summary for Subcatchment EX: EX

Runoff = 0.11 cfs @ 11.97 hrs, Volume= 220 cf, Depth= 1.13"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 2-YR Rainfall=3.25"

Area (sf) CN Description * 257 76 Gravel (80%) * 64 30 Gravel (20%) * 2,024 76 Gravel (Site Restoration) 2,345 75 Weighted Average 2,345 75 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment EX: EX Hydrograph

0.125 Runoff 0.12 0.11 cfs 0.115 0.11 Type II 24-hr 0.105 0.1 0.095 2-YR Rainfall=3.25" 0.09 0.085 Runoff Area=2,345 sf 0.08 0.075 Runoff Volume=220 cf 0.07 0.065 0.06 Runoff Depth=1.13"

Flow (cfs) 0.055 0.05 Tc=5.0 min 0.045 0.04 0.035 CN=75/0 0.03 0.025 0.02 0.015 0.01 0.005 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 11

Hydrograph for Subcatchment EX: EX

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 0.59 0.00 0.00 0.00 20.00 3.09 1.02 0.00 0.00 30.00 3.25 1.13 0.00 0.00 40.00 3.25 1.13 0.00 0.00 50.00 3.25 1.13 0.00 0.00 60.00 3.25 1.13 0.00 0.00 70.00 3.25 1.13 0.00 0.00 80.00 3.25 1.13 0.00 0.00 90.00 3.25 1.13 0.00 0.00 100.00 3.25 1.13 0.00 0.00 110.00 3.25 1.13 0.00 0.00 120.00 3.25 1.13 0.00 0.00 130.00 3.25 1.13 0.00 0.00 140.00 3.25 1.13 0.00 0.00 150.00 3.25 1.13 0.00 0.00 160.00 3.25 1.13 0.00 0.00 170.00 3.25 1.13 0.00 0.00 180.00 3.25 1.13 0.00 0.00 190.00 3.25 1.13 0.00 0.00 200.00 3.25 1.13 0.00 0.00 210.00 3.25 1.13 0.00 0.00 220.00 3.25 1.13 0.00 0.00 230.00 3.25 1.13 0.00 0.00 240.00 3.25 1.13 0.00 0.00 250.00 3.25 1.13 0.00 0.00 260.00 3.25 1.13 0.00 0.00 270.00 3.25 1.13 0.00 0.00 280.00 3.25 1.13 0.00 0.00 290.00 3.25 1.13 0.00 0.00 300.00 3.25 1.13 0.00 0.00 PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 12

Summary for Subcatchment PR: Bypass

Runoff = 0.11 cfs @ 11.97 hrs, Volume= 217 cf, Depth= 1.24"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 2-YR Rainfall=3.25"

Area (sf) CN Description * 61 98 Impervious * 2,039 76 Gravel (Site Restoration) 2,100 77 Weighted Average 2,039 76 97.10% Pervious Area 61 98 2.90% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment PR: Bypass Hydrograph

0.12 Runoff 0.115 0.11 cfs 0.11 0.105 Type II 24-hr 0.1 0.095 2-YR Rainfall=3.25" 0.09 0.085 0.08 Runoff Area=2,100 sf 0.075 0.07 Runoff Volume=217 cf 0.065 0.06 Runoff Depth=1.24" 0.055 Flow (cfs) 0.05 Tc=5.0 min 0.045 0.04 0.035 CN=76/98 0.03 0.025 0.02 0.015 0.01 0.005 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 13

Hydrograph for Subcatchment PR: Bypass

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 0.59 0.00 0.40 0.00 20.00 3.09 1.08 2.86 0.00 30.00 3.25 1.19 3.02 0.00 40.00 3.25 1.19 3.02 0.00 50.00 3.25 1.19 3.02 0.00 60.00 3.25 1.19 3.02 0.00 70.00 3.25 1.19 3.02 0.00 80.00 3.25 1.19 3.02 0.00 90.00 3.25 1.19 3.02 0.00 100.00 3.25 1.19 3.02 0.00 110.00 3.25 1.19 3.02 0.00 120.00 3.25 1.19 3.02 0.00 130.00 3.25 1.19 3.02 0.00 140.00 3.25 1.19 3.02 0.00 150.00 3.25 1.19 3.02 0.00 160.00 3.25 1.19 3.02 0.00 170.00 3.25 1.19 3.02 0.00 180.00 3.25 1.19 3.02 0.00 190.00 3.25 1.19 3.02 0.00 200.00 3.25 1.19 3.02 0.00 210.00 3.25 1.19 3.02 0.00 220.00 3.25 1.19 3.02 0.00 230.00 3.25 1.19 3.02 0.00 240.00 3.25 1.19 3.02 0.00 250.00 3.25 1.19 3.02 0.00 260.00 3.25 1.19 3.02 0.00 270.00 3.25 1.19 3.02 0.00 280.00 3.25 1.19 3.02 0.00 290.00 3.25 1.19 3.02 0.00 300.00 3.25 1.19 3.02 0.00 PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 14

Summary for Pond 2P: Dry Well 1

Inflow Area = 180 sf,100.00% Impervious, Inflow Depth = 3.02" for 2-YR event Inflow = 0.02 cfs @ 11.96 hrs, Volume= 45 cf Outflow = 0.00 cfs @ 9.21 hrs, Volume= 45 cf, Atten= 98%, Lag= 0.0 min Discarded = 0.00 cfs @ 9.21 hrs, Volume= 45 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf

Routing by Stor-Ind method, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Peak Elev= 10.49' @ 15.93 hrs Surf.Area= 28 sf Storage= 28 cf

Plug-Flow detention time= 765.2 min calculated for 45 cf (100% of inflow) Center-of-Mass det. time= 765.2 min ( 1,516.4 - 751.2 )

Volume Invert Avail.Storage Storage Description #1 9.50' 84 cf Custom Stage Data (Prismatic) Listed below (Recalc)

Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 9.50 28 0 0 12.50 28 84 84

Device Routing Invert Outlet Devices #1 Primary 12.05' 3.0" Vert. Orifice/Grate C= 0.600 #2 Discarded 9.50' 0.500 in/hr Exfiltration over Surface area

Discarded OutFlow Max=0.00 cfs @ 9.21 hrs HW=9.53' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.00 cfs)

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=9.50' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 15

Pond 2P: Dry Well 1 Hydrograph

Inflow 0.02 cfs Outflow Discarded Inflow Area=180 sf Primary 0.021 0.02 0.019 Peak Elev=10.49' 0.018 0.017 Storage=28 cf 0.016 0.015 0.014 0.013 0.012 0.011 0.01

Flow (cfs) 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.00 cfs 0.002 0.00 cfs 0.0010.00 cfs 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 16

Hydrograph for Pond 2P: Dry Well 1

Time Inflow Storage Elevation Outflow Discarded Primary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 9.50 0.00 0.00 0.00 10.00 0.00 1 9.54 0.00 0.00 0.00 20.00 0.00 26 10.45 0.00 0.00 0.00 30.00 0.00 17 10.11 0.00 0.00 0.00 40.00 0.00 6 9.70 0.00 0.00 0.00 50.00 0.00 0 9.50 0.00 0.00 0.00 60.00 0.00 0 9.50 0.00 0.00 0.00 70.00 0.00 0 9.50 0.00 0.00 0.00 80.00 0.00 0 9.50 0.00 0.00 0.00 90.00 0.00 0 9.50 0.00 0.00 0.00 100.00 0.00 0 9.50 0.00 0.00 0.00 110.00 0.00 0 9.50 0.00 0.00 0.00 120.00 0.00 0 9.50 0.00 0.00 0.00 130.00 0.00 0 9.50 0.00 0.00 0.00 140.00 0.00 0 9.50 0.00 0.00 0.00 150.00 0.00 0 9.50 0.00 0.00 0.00 160.00 0.00 0 9.50 0.00 0.00 0.00 170.00 0.00 0 9.50 0.00 0.00 0.00 180.00 0.00 0 9.50 0.00 0.00 0.00 190.00 0.00 0 9.50 0.00 0.00 0.00 200.00 0.00 0 9.50 0.00 0.00 0.00 210.00 0.00 0 9.50 0.00 0.00 0.00 220.00 0.00 0 9.50 0.00 0.00 0.00 230.00 0.00 0 9.50 0.00 0.00 0.00 240.00 0.00 0 9.50 0.00 0.00 0.00 250.00 0.00 0 9.50 0.00 0.00 0.00 260.00 0.00 0 9.50 0.00 0.00 0.00 270.00 0.00 0 9.50 0.00 0.00 0.00 280.00 0.00 0 9.50 0.00 0.00 0.00 290.00 0.00 0 9.50 0.00 0.00 0.00 300.00 0.00 0 9.50 0.00 0.00 0.00 PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 17

Summary for Pond 5P: Dry Well 2

Inflow Area = 80 sf,100.00% Impervious, Inflow Depth = 3.02" for 2-YR event Inflow = 0.01 cfs @ 11.96 hrs, Volume= 20 cf Outflow = 0.00 cfs @ 11.35 hrs, Volume= 20 cf, Atten= 96%, Lag= 0.0 min Discarded = 0.00 cfs @ 11.35 hrs, Volume= 20 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf

Routing by Stor-Ind method, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Peak Elev= 10.34' @ 13.08 hrs Surf.Area= 28 sf Storage= 10 cf

Plug-Flow detention time= 218.5 min calculated for 20 cf (100% of inflow) Center-of-Mass det. time= 218.5 min ( 969.7 - 751.2 )

Volume Invert Avail.Storage Storage Description #1 10.00' 84 cf Custom Stage Data (Prismatic) Listed below (Recalc)

Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 10.00 28 0 0 13.00 28 84 84

Device Routing Invert Outlet Devices #1 Primary 12.55' 3.0" Vert. Orifice/Grate C= 0.600 #2 Discarded 10.00' 0.565 in/hr Exfiltration over Surface area

Discarded OutFlow Max=0.00 cfs @ 11.35 hrs HW=10.03' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.00 cfs)

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=10.00' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 18

Pond 5P: Dry Well 2 Hydrograph

Inflow 0.01 cfs Outflow Discarded Primary 0.009 Inflow Area=80 sf 0.009 0.008 Peak Elev=10.34' 0.008 0.007 Storage=10 cf 0.007 0.006 0.006 0.005 0.005 0.004

Flow (cfs) 0.004 0.003 0.003 0.002 0.002 0.00 cfs 0.001 0.00 cfs 0.001

0.0000.00 cfs 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 19

Hydrograph for Pond 5P: Dry Well 2

Time Inflow Storage Elevation Outflow Discarded Primary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 10.00 0.00 0.00 0.00 10.00 0.00 0 10.01 0.00 0.00 0.00 20.00 0.00 4 10.15 0.00 0.00 0.00 30.00 0.00 0 10.00 0.00 0.00 0.00 40.00 0.00 0 10.00 0.00 0.00 0.00 50.00 0.00 0 10.00 0.00 0.00 0.00 60.00 0.00 0 10.00 0.00 0.00 0.00 70.00 0.00 0 10.00 0.00 0.00 0.00 80.00 0.00 0 10.00 0.00 0.00 0.00 90.00 0.00 0 10.00 0.00 0.00 0.00 100.00 0.00 0 10.00 0.00 0.00 0.00 110.00 0.00 0 10.00 0.00 0.00 0.00 120.00 0.00 0 10.00 0.00 0.00 0.00 130.00 0.00 0 10.00 0.00 0.00 0.00 140.00 0.00 0 10.00 0.00 0.00 0.00 150.00 0.00 0 10.00 0.00 0.00 0.00 160.00 0.00 0 10.00 0.00 0.00 0.00 170.00 0.00 0 10.00 0.00 0.00 0.00 180.00 0.00 0 10.00 0.00 0.00 0.00 190.00 0.00 0 10.00 0.00 0.00 0.00 200.00 0.00 0 10.00 0.00 0.00 0.00 210.00 0.00 0 10.00 0.00 0.00 0.00 220.00 0.00 0 10.00 0.00 0.00 0.00 230.00 0.00 0 10.00 0.00 0.00 0.00 240.00 0.00 0 10.00 0.00 0.00 0.00 250.00 0.00 0 10.00 0.00 0.00 0.00 260.00 0.00 0 10.00 0.00 0.00 0.00 270.00 0.00 0 10.00 0.00 0.00 0.00 280.00 0.00 0 10.00 0.00 0.00 0.00 290.00 0.00 0 10.00 0.00 0.00 0.00 300.00 0.00 0 10.00 0.00 0.00 0.00 PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 20

Summary for Link 3L: PR

Inflow Area = 2,360 sf, 13.60% Impervious, Inflow Depth = 1.10" for 2-YR event Inflow = 0.11 cfs @ 11.97 hrs, Volume= 217 cf Primary = 0.11 cfs @ 11.97 hrs, Volume= 217 cf, Atten= 0%, Lag= 0.0 min

Primary outflow = Inflow, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs

Link 3L: PR Hydrograph

Inflow 0.12 0.11 cfs Primary 0.115 0.11 cfs 0.11 Inflow Area=2,360 sf 0.105 0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 Flow (cfs) 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 2-YR Rainfall=3.25" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 21

Hydrograph for Link 3L: PR

Time Inflow Elevation Primary Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) (hours) (cfs) (feet) (cfs) 0.00 0.00 0.00 0.00 260.00 0.00 0.00 0.00 5.00 0.00 0.00 0.00 265.00 0.00 0.00 0.00 10.00 0.00 0.00 0.00 270.00 0.00 0.00 0.00 15.00 0.00 0.00 0.00 275.00 0.00 0.00 0.00 20.00 0.00 0.00 0.00 280.00 0.00 0.00 0.00 25.00 0.00 0.00 0.00 285.00 0.00 0.00 0.00 30.00 0.00 0.00 0.00 290.00 0.00 0.00 0.00 35.00 0.00 0.00 0.00 295.00 0.00 0.00 0.00 40.00 0.00 0.00 0.00 300.00 0.00 0.00 0.00 45.00 0.00 0.00 0.00 50.00 0.00 0.00 0.00 55.00 0.00 0.00 0.00 60.00 0.00 0.00 0.00 65.00 0.00 0.00 0.00 70.00 0.00 0.00 0.00 75.00 0.00 0.00 0.00 80.00 0.00 0.00 0.00 85.00 0.00 0.00 0.00 90.00 0.00 0.00 0.00 95.00 0.00 0.00 0.00 100.00 0.00 0.00 0.00 105.00 0.00 0.00 0.00 110.00 0.00 0.00 0.00 115.00 0.00 0.00 0.00 120.00 0.00 0.00 0.00 125.00 0.00 0.00 0.00 130.00 0.00 0.00 0.00 135.00 0.00 0.00 0.00 140.00 0.00 0.00 0.00 145.00 0.00 0.00 0.00 150.00 0.00 0.00 0.00 155.00 0.00 0.00 0.00 160.00 0.00 0.00 0.00 165.00 0.00 0.00 0.00 170.00 0.00 0.00 0.00 175.00 0.00 0.00 0.00 180.00 0.00 0.00 0.00 185.00 0.00 0.00 0.00 190.00 0.00 0.00 0.00 195.00 0.00 0.00 0.00 200.00 0.00 0.00 0.00 205.00 0.00 0.00 0.00 210.00 0.00 0.00 0.00 215.00 0.00 0.00 0.00 220.00 0.00 0.00 0.00 225.00 0.00 0.00 0.00 230.00 0.00 0.00 0.00 235.00 0.00 0.00 0.00 240.00 0.00 0.00 0.00 245.00 0.00 0.00 0.00 250.00 0.00 0.00 0.00 255.00 0.00 0.00 0.00 PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 22

Time span=0.00-300.00 hrs, dt=0.01 hrs, 30001 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method

Subcatchment 1S: Building - 10x8 Runoff Area=80 sf 100.00% Impervious Runoff Depth=4.62" Tc=5.0 min CN=0/98 Runoff=0.01 cfs 31 cf

Subcatchment 4S: Building - 12x15 Runoff Area=180 sf 100.00% Impervious Runoff Depth=4.62" Tc=5.0 min CN=0/98 Runoff=0.03 cfs 69 cf

Subcatchment EX: EX Runoff Area=2,345 sf 0.00% Impervious Runoff Depth=2.34" Tc=5.0 min CN=75/0 Runoff=0.23 cfs 457 cf

Subcatchment PR: Bypass Runoff Area=2,100 sf 2.90% Impervious Runoff Depth=2.48" Tc=5.0 min CN=76/98 Runoff=0.22 cfs 435 cf

Pond 2P: Dry Well 1 Peak Elev=11.18' Storage=47 cf Inflow=0.03 cfs 69 cf Discarded=0.00 cfs 69 cf Primary=0.00 cfs 0 cf Outflow=0.00 cfs 69 cf

Pond 5P: Dry Well 2 Peak Elev=10.57' Storage=16 cf Inflow=0.01 cfs 31 cf Discarded=0.00 cfs 31 cf Primary=0.00 cfs 0 cf Outflow=0.00 cfs 31 cf

Link 3L: PR Inflow=0.22 cfs 435 cf Primary=0.22 cfs 435 cf

Total Runoff Area = 4,705 sf Runoff Volume = 992 cf Average Runoff Depth = 2.53" 93.18% Pervious = 4,384 sf 6.82% Impervious = 321 sf PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 23

Summary for Subcatchment 1S: Building - 10x8

Runoff = 0.01 cfs @ 11.96 hrs, Volume= 31 cf, Depth= 4.62"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 10-YR Rainfall=4.86"

Area (sf) CN Description * 80 98 Building 80 98 100.00% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment 1S: Building - 10x8 Hydrograph

Runoff 0.014 0.01 cfs 0.013 Type II 24-hr 0.012

0.011 10-YR Rainfall=4.86" 0.01 Runoff Area=80 sf 0.009

0.008 Runoff Volume=31 cf 0.007 Runoff Depth=4.62" Flow (cfs) 0.006 Tc=5.0 min 0.005 0.004 CN=0/98 0.003

0.002

0.001

0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 24

Hydrograph for Subcatchment 1S: Building - 10x8

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 0.88 0.00 0.67 0.00 20.00 4.63 0.00 4.39 0.00 30.00 4.86 0.00 4.62 0.00 40.00 4.86 0.00 4.62 0.00 50.00 4.86 0.00 4.62 0.00 60.00 4.86 0.00 4.62 0.00 70.00 4.86 0.00 4.62 0.00 80.00 4.86 0.00 4.62 0.00 90.00 4.86 0.00 4.62 0.00 100.00 4.86 0.00 4.62 0.00 110.00 4.86 0.00 4.62 0.00 120.00 4.86 0.00 4.62 0.00 130.00 4.86 0.00 4.62 0.00 140.00 4.86 0.00 4.62 0.00 150.00 4.86 0.00 4.62 0.00 160.00 4.86 0.00 4.62 0.00 170.00 4.86 0.00 4.62 0.00 180.00 4.86 0.00 4.62 0.00 190.00 4.86 0.00 4.62 0.00 200.00 4.86 0.00 4.62 0.00 210.00 4.86 0.00 4.62 0.00 220.00 4.86 0.00 4.62 0.00 230.00 4.86 0.00 4.62 0.00 240.00 4.86 0.00 4.62 0.00 250.00 4.86 0.00 4.62 0.00 260.00 4.86 0.00 4.62 0.00 270.00 4.86 0.00 4.62 0.00 280.00 4.86 0.00 4.62 0.00 290.00 4.86 0.00 4.62 0.00 300.00 4.86 0.00 4.62 0.00 PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 25

Summary for Subcatchment 4S: Building - 12x15

Runoff = 0.03 cfs @ 11.96 hrs, Volume= 69 cf, Depth= 4.62"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 10-YR Rainfall=4.86"

Area (sf) CN Description * 180 98 Building 180 98 100.00% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment 4S: Building - 12x15 Hydrograph

0.032 Runoff 0.03 cfs 0.03 0.028 Type II 24-hr 0.026 10-YR Rainfall=4.86" 0.024 0.022 Runoff Area=180 sf 0.02 0.018 Runoff Volume=69 cf 0.016 Runoff Depth=4.62"

Flow (cfs) 0.014 0.012 Tc=5.0 min 0.01 CN=0/98 0.008 0.006 0.004 0.002 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 26

Hydrograph for Subcatchment 4S: Building - 12x15

Summary for Subcatchment EX: EX

Runoff = 0.23 cfs @ 11.96 hrs, Volume= 457 cf, Depth= 2.34"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 10-YR Rainfall=4.86"

Area (sf) CN Description * 257 76 Gravel (80%) * 64 30 Gravel (20%) * 2,024 76 Gravel (Site Restoration) 2,345 75 Weighted Average 2,345 75 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment EX: EX Hydrograph

0.26 Runoff 0.25 0.24 0.23 cfs 0.23 0.22 Type II 24-hr 0.21 0.2 10-YR Rainfall=4.86" 0.19 0.18 0.17 Runoff Area=2,345 sf 0.16 0.15 Runoff Volume=457 cf 0.14 0.13 Runoff Depth=2.34" 0.12 Flow (cfs) 0.11 0.1 Tc=5.0 min 0.09 0.08 CN=75/0 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 28

Hydrograph for Subcatchment EX: EX

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 0.88 0.01 0.00 0.00 20.00 4.63 2.15 0.00 0.00 30.00 4.86 2.34 0.00 0.00 40.00 4.86 2.34 0.00 0.00 50.00 4.86 2.34 0.00 0.00 60.00 4.86 2.34 0.00 0.00 70.00 4.86 2.34 0.00 0.00 80.00 4.86 2.34 0.00 0.00 90.00 4.86 2.34 0.00 0.00 100.00 4.86 2.34 0.00 0.00 110.00 4.86 2.34 0.00 0.00 120.00 4.86 2.34 0.00 0.00 130.00 4.86 2.34 0.00 0.00 140.00 4.86 2.34 0.00 0.00 150.00 4.86 2.34 0.00 0.00 160.00 4.86 2.34 0.00 0.00 170.00 4.86 2.34 0.00 0.00 180.00 4.86 2.34 0.00 0.00 190.00 4.86 2.34 0.00 0.00 200.00 4.86 2.34 0.00 0.00 210.00 4.86 2.34 0.00 0.00 220.00 4.86 2.34 0.00 0.00 230.00 4.86 2.34 0.00 0.00 240.00 4.86 2.34 0.00 0.00 250.00 4.86 2.34 0.00 0.00 260.00 4.86 2.34 0.00 0.00 270.00 4.86 2.34 0.00 0.00 280.00 4.86 2.34 0.00 0.00 290.00 4.86 2.34 0.00 0.00 300.00 4.86 2.34 0.00 0.00 PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 29

Summary for Subcatchment PR: Bypass

Runoff = 0.22 cfs @ 11.96 hrs, Volume= 435 cf, Depth= 2.48"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 10-YR Rainfall=4.86"

Area (sf) CN Description * 61 98 Impervious * 2,039 76 Gravel (Site Restoration) 2,100 77 Weighted Average 2,039 76 97.10% Pervious Area 61 98 2.90% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment PR: Bypass Hydrograph

0.24 Runoff 0.23 0.22 cfs 0.22 0.21 Type II 24-hr 0.2 0.19 10-YR Rainfall=4.86" 0.18 0.17 Runoff Area=2,100 sf 0.16 0.15 0.14 Runoff Volume=435 cf 0.13 0.12 Runoff Depth=2.48" 0.11 Flow (cfs) 0.1 Tc=5.0 min 0.09 0.08 0.07 CN=76/98 0.06 0.05 0.04 0.03 0.02 0.01 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 30

Hydrograph for Subcatchment PR: Bypass

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 0.88 0.02 0.67 0.00 20.00 4.63 2.23 4.39 0.00 30.00 4.86 2.42 4.62 0.00 40.00 4.86 2.42 4.62 0.00 50.00 4.86 2.42 4.62 0.00 60.00 4.86 2.42 4.62 0.00 70.00 4.86 2.42 4.62 0.00 80.00 4.86 2.42 4.62 0.00 90.00 4.86 2.42 4.62 0.00 100.00 4.86 2.42 4.62 0.00 110.00 4.86 2.42 4.62 0.00 120.00 4.86 2.42 4.62 0.00 130.00 4.86 2.42 4.62 0.00 140.00 4.86 2.42 4.62 0.00 150.00 4.86 2.42 4.62 0.00 160.00 4.86 2.42 4.62 0.00 170.00 4.86 2.42 4.62 0.00 180.00 4.86 2.42 4.62 0.00 190.00 4.86 2.42 4.62 0.00 200.00 4.86 2.42 4.62 0.00 210.00 4.86 2.42 4.62 0.00 220.00 4.86 2.42 4.62 0.00 230.00 4.86 2.42 4.62 0.00 240.00 4.86 2.42 4.62 0.00 250.00 4.86 2.42 4.62 0.00 260.00 4.86 2.42 4.62 0.00 270.00 4.86 2.42 4.62 0.00 280.00 4.86 2.42 4.62 0.00 290.00 4.86 2.42 4.62 0.00 300.00 4.86 2.42 4.62 0.00 PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 31

Summary for Pond 2P: Dry Well 1

Inflow Area = 180 sf,100.00% Impervious, Inflow Depth = 4.62" for 10-YR event Inflow = 0.03 cfs @ 11.96 hrs, Volume= 69 cf Outflow = 0.00 cfs @ 7.00 hrs, Volume= 69 cf, Atten= 99%, Lag= 0.0 min Discarded = 0.00 cfs @ 7.00 hrs, Volume= 69 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf

Routing by Stor-Ind method, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Peak Elev= 11.18' @ 18.86 hrs Surf.Area= 28 sf Storage= 47 cf

Plug-Flow detention time= 1,275.0 min calculated for 69 cf (100% of inflow) Center-of-Mass det. time= 1,275.0 min ( 2,018.4 - 743.5 )

Volume Invert Avail.Storage Storage Description #1 9.50' 84 cf Custom Stage Data (Prismatic) Listed below (Recalc)

Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 9.50 28 0 0 12.50 28 84 84

Device Routing Invert Outlet Devices #1 Primary 12.05' 3.0" Vert. Orifice/Grate C= 0.600 #2 Discarded 9.50' 0.500 in/hr Exfiltration over Surface area

Discarded OutFlow Max=0.00 cfs @ 7.00 hrs HW=9.53' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.00 cfs)

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=9.50' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 32

Pond 2P: Dry Well 1 Hydrograph

Inflow 0.03 cfs Outflow Discarded Primary 0.032 Inflow Area=180 sf 0.03 Peak Elev=11.18' 0.028 0.026 Storage=47 cf 0.024 0.022 0.02 0.018 0.016

Flow (cfs) 0.014 0.012 0.01 0.008 0.006 0.00 cfs 0.004 0.00 cfs

0.0020.00 cfs 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 33

Hydrograph for Pond 2P: Dry Well 1

Time Inflow Storage Elevation Outflow Discarded Primary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 9.50 0.00 0.00 0.00 10.00 0.00 3 9.60 0.00 0.00 0.00 20.00 0.00 47 11.18 0.00 0.00 0.00 30.00 0.00 39 10.89 0.00 0.00 0.00 40.00 0.00 27 10.47 0.00 0.00 0.00 50.00 0.00 16 10.06 0.00 0.00 0.00 60.00 0.00 4 9.64 0.00 0.00 0.00 70.00 0.00 0 9.50 0.00 0.00 0.00 80.00 0.00 0 9.50 0.00 0.00 0.00 90.00 0.00 0 9.50 0.00 0.00 0.00 100.00 0.00 0 9.50 0.00 0.00 0.00 110.00 0.00 0 9.50 0.00 0.00 0.00 120.00 0.00 0 9.50 0.00 0.00 0.00 130.00 0.00 0 9.50 0.00 0.00 0.00 140.00 0.00 0 9.50 0.00 0.00 0.00 150.00 0.00 0 9.50 0.00 0.00 0.00 160.00 0.00 0 9.50 0.00 0.00 0.00 170.00 0.00 0 9.50 0.00 0.00 0.00 180.00 0.00 0 9.50 0.00 0.00 0.00 190.00 0.00 0 9.50 0.00 0.00 0.00 200.00 0.00 0 9.50 0.00 0.00 0.00 210.00 0.00 0 9.50 0.00 0.00 0.00 220.00 0.00 0 9.50 0.00 0.00 0.00 230.00 0.00 0 9.50 0.00 0.00 0.00 240.00 0.00 0 9.50 0.00 0.00 0.00 250.00 0.00 0 9.50 0.00 0.00 0.00 260.00 0.00 0 9.50 0.00 0.00 0.00 270.00 0.00 0 9.50 0.00 0.00 0.00 280.00 0.00 0 9.50 0.00 0.00 0.00 290.00 0.00 0 9.50 0.00 0.00 0.00 300.00 0.00 0 9.50 0.00 0.00 0.00 PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 34

Summary for Pond 5P: Dry Well 2

Inflow Area = 80 sf,100.00% Impervious, Inflow Depth = 4.62" for 10-YR event Inflow = 0.01 cfs @ 11.96 hrs, Volume= 31 cf Outflow = 0.00 cfs @ 10.67 hrs, Volume= 31 cf, Atten= 97%, Lag= 0.0 min Discarded = 0.00 cfs @ 10.67 hrs, Volume= 31 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf

Routing by Stor-Ind method, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Peak Elev= 10.57' @ 13.89 hrs Surf.Area= 28 sf Storage= 16 cf

Plug-Flow detention time= 380.7 min calculated for 31 cf (100% of inflow) Center-of-Mass det. time= 380.8 min ( 1,124.2 - 743.5 )

Volume Invert Avail.Storage Storage Description #1 10.00' 84 cf Custom Stage Data (Prismatic) Listed below (Recalc)

Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 10.00 28 0 0 13.00 28 84 84

Device Routing Invert Outlet Devices #1 Primary 12.55' 3.0" Vert. Orifice/Grate C= 0.600 #2 Discarded 10.00' 0.565 in/hr Exfiltration over Surface area

Discarded OutFlow Max=0.00 cfs @ 10.67 hrs HW=10.03' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.00 cfs)

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=10.00' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 35

Pond 5P: Dry Well 2 Hydrograph

Inflow 0.01 cfs Outflow Discarded Inflow Area=80 sf Primary 0.014 0.013 Peak Elev=10.57' 0.012 0.011 Storage=16 cf 0.01 0.009 0.008 0.007

Flow (cfs) 0.006 0.005 0.004 0.003 0.00 cfs 0.002 0.00 cfs 0.001 0.00 cfs 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 36

Hydrograph for Pond 5P: Dry Well 2

Time Inflow Storage Elevation Outflow Discarded Primary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 10.00 0.00 0.00 0.00 10.00 0.00 1 10.02 0.00 0.00 0.00 20.00 0.00 12 10.44 0.00 0.00 0.00 30.00 0.00 1 10.03 0.00 0.00 0.00 40.00 0.00 0 10.00 0.00 0.00 0.00 50.00 0.00 0 10.00 0.00 0.00 0.00 60.00 0.00 0 10.00 0.00 0.00 0.00 70.00 0.00 0 10.00 0.00 0.00 0.00 80.00 0.00 0 10.00 0.00 0.00 0.00 90.00 0.00 0 10.00 0.00 0.00 0.00 100.00 0.00 0 10.00 0.00 0.00 0.00 110.00 0.00 0 10.00 0.00 0.00 0.00 120.00 0.00 0 10.00 0.00 0.00 0.00 130.00 0.00 0 10.00 0.00 0.00 0.00 140.00 0.00 0 10.00 0.00 0.00 0.00 150.00 0.00 0 10.00 0.00 0.00 0.00 160.00 0.00 0 10.00 0.00 0.00 0.00 170.00 0.00 0 10.00 0.00 0.00 0.00 180.00 0.00 0 10.00 0.00 0.00 0.00 190.00 0.00 0 10.00 0.00 0.00 0.00 200.00 0.00 0 10.00 0.00 0.00 0.00 210.00 0.00 0 10.00 0.00 0.00 0.00 220.00 0.00 0 10.00 0.00 0.00 0.00 230.00 0.00 0 10.00 0.00 0.00 0.00 240.00 0.00 0 10.00 0.00 0.00 0.00 250.00 0.00 0 10.00 0.00 0.00 0.00 260.00 0.00 0 10.00 0.00 0.00 0.00 270.00 0.00 0 10.00 0.00 0.00 0.00 280.00 0.00 0 10.00 0.00 0.00 0.00 290.00 0.00 0 10.00 0.00 0.00 0.00 300.00 0.00 0 10.00 0.00 0.00 0.00 PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 37

Summary for Link 3L: PR

Inflow Area = 2,360 sf, 13.60% Impervious, Inflow Depth = 2.21" for 10-YR event Inflow = 0.22 cfs @ 11.96 hrs, Volume= 435 cf Primary = 0.22 cfs @ 11.96 hrs, Volume= 435 cf, Atten= 0%, Lag= 0.0 min

Primary outflow = Inflow, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs

Link 3L: PR Hydrograph

Inflow 0.24 0.22 cfs Primary 0.23 0.22 cfs 0.22 Inflow Area=2,360 sf 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 Flow (cfs) 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 10-YR Rainfall=4.86" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 38

Hydrograph for Link 3L: PR

Time Inflow Elevation Primary Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) (hours) (cfs) (feet) (cfs) 0.00 0.00 0.00 0.00 260.00 0.00 0.00 0.00 5.00 0.00 0.00 0.00 265.00 0.00 0.00 0.00 10.00 0.00 0.00 0.00 270.00 0.00 0.00 0.00 15.00 0.01 0.00 0.01 275.00 0.00 0.00 0.00 20.00 0.00 0.00 0.00 280.00 0.00 0.00 0.00 25.00 0.00 0.00 0.00 285.00 0.00 0.00 0.00 30.00 0.00 0.00 0.00 290.00 0.00 0.00 0.00 35.00 0.00 0.00 0.00 295.00 0.00 0.00 0.00 40.00 0.00 0.00 0.00 300.00 0.00 0.00 0.00 45.00 0.00 0.00 0.00 50.00 0.00 0.00 0.00 55.00 0.00 0.00 0.00 60.00 0.00 0.00 0.00 65.00 0.00 0.00 0.00 70.00 0.00 0.00 0.00 75.00 0.00 0.00 0.00 80.00 0.00 0.00 0.00 85.00 0.00 0.00 0.00 90.00 0.00 0.00 0.00 95.00 0.00 0.00 0.00 100.00 0.00 0.00 0.00 105.00 0.00 0.00 0.00 110.00 0.00 0.00 0.00 115.00 0.00 0.00 0.00 120.00 0.00 0.00 0.00 125.00 0.00 0.00 0.00 130.00 0.00 0.00 0.00 135.00 0.00 0.00 0.00 140.00 0.00 0.00 0.00 145.00 0.00 0.00 0.00 150.00 0.00 0.00 0.00 155.00 0.00 0.00 0.00 160.00 0.00 0.00 0.00 165.00 0.00 0.00 0.00 170.00 0.00 0.00 0.00 175.00 0.00 0.00 0.00 180.00 0.00 0.00 0.00 185.00 0.00 0.00 0.00 190.00 0.00 0.00 0.00 195.00 0.00 0.00 0.00 200.00 0.00 0.00 0.00 205.00 0.00 0.00 0.00 210.00 0.00 0.00 0.00 215.00 0.00 0.00 0.00 220.00 0.00 0.00 0.00 225.00 0.00 0.00 0.00 230.00 0.00 0.00 0.00 235.00 0.00 0.00 0.00 240.00 0.00 0.00 0.00 245.00 0.00 0.00 0.00 250.00 0.00 0.00 0.00 255.00 0.00 0.00 0.00 PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 39

Time span=0.00-300.00 hrs, dt=0.01 hrs, 30001 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method

Subcatchment 1S: Building - 10x8 Runoff Area=80 sf 100.00% Impervious Runoff Depth=6.63" Tc=5.0 min CN=0/98 Runoff=0.02 cfs 44 cf

Subcatchment 4S: Building - 12x15 Runoff Area=180 sf 100.00% Impervious Runoff Depth=6.63" Tc=5.0 min CN=0/98 Runoff=0.04 cfs 99 cf

Subcatchment EX: EX Runoff Area=2,345 sf 0.00% Impervious Runoff Depth=4.04" Tc=5.0 min CN=75/0 Runoff=0.40 cfs 789 cf

Subcatchment PR: Bypass Runoff Area=2,100 sf 2.90% Impervious Runoff Depth=4.21" Tc=5.0 min CN=76/98 Runoff=0.37 cfs 737 cf

Pond 2P: Dry Well 1 Peak Elev=12.05' Storage=72 cf Inflow=0.04 cfs 99 cf Discarded=0.00 cfs 96 cf Primary=0.00 cfs 3 cf Outflow=0.00 cfs 99 cf

Pond 5P: Dry Well 2 Peak Elev=10.89' Storage=25 cf Inflow=0.02 cfs 44 cf Discarded=0.00 cfs 44 cf Primary=0.00 cfs 0 cf Outflow=0.00 cfs 44 cf

Link 3L: PR Inflow=0.37 cfs 740 cf Primary=0.37 cfs 740 cf

Total Runoff Area = 4,705 sf Runoff Volume = 1,670 cf Average Runoff Depth = 4.26" 93.18% Pervious = 4,384 sf 6.82% Impervious = 321 sf PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 40

Summary for Subcatchment 1S: Building - 10x8

Runoff = 0.02 cfs @ 11.96 hrs, Volume= 44 cf, Depth= 6.63"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 50-YR Rainfall=6.87"

Area (sf) CN Description * 80 98 Building 80 98 100.00% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment 1S: Building - 10x8 Hydrograph

Runoff 0.02 0.02 cfs 0.019 0.018 Type II 24-hr 0.017 0.016 50-YR Rainfall=6.87" 0.015 0.014 Runoff Area=80 sf 0.013 0.012 Runoff Volume=44 cf 0.011 0.01 Runoff Depth=6.63"

Flow (cfs) 0.009 0.008 Tc=5.0 min 0.007 0.006 CN=0/98 0.005 0.004 0.003 0.002 0.001 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 41

Hydrograph for Subcatchment 1S: Building - 10x8

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 1.24 0.00 1.03 0.00 20.00 6.54 0.00 6.30 0.00 30.00 6.87 0.00 6.63 0.00 40.00 6.87 0.00 6.63 0.00 50.00 6.87 0.00 6.63 0.00 60.00 6.87 0.00 6.63 0.00 70.00 6.87 0.00 6.63 0.00 80.00 6.87 0.00 6.63 0.00 90.00 6.87 0.00 6.63 0.00 100.00 6.87 0.00 6.63 0.00 110.00 6.87 0.00 6.63 0.00 120.00 6.87 0.00 6.63 0.00 130.00 6.87 0.00 6.63 0.00 140.00 6.87 0.00 6.63 0.00 150.00 6.87 0.00 6.63 0.00 160.00 6.87 0.00 6.63 0.00 170.00 6.87 0.00 6.63 0.00 180.00 6.87 0.00 6.63 0.00 190.00 6.87 0.00 6.63 0.00 200.00 6.87 0.00 6.63 0.00 210.00 6.87 0.00 6.63 0.00 220.00 6.87 0.00 6.63 0.00 230.00 6.87 0.00 6.63 0.00 240.00 6.87 0.00 6.63 0.00 250.00 6.87 0.00 6.63 0.00 260.00 6.87 0.00 6.63 0.00 270.00 6.87 0.00 6.63 0.00 280.00 6.87 0.00 6.63 0.00 290.00 6.87 0.00 6.63 0.00 300.00 6.87 0.00 6.63 0.00 PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 42

Summary for Subcatchment 4S: Building - 12x15

Runoff = 0.04 cfs @ 11.96 hrs, Volume= 99 cf, Depth= 6.63"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 50-YR Rainfall=6.87"

Area (sf) CN Description * 180 98 Building 180 98 100.00% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment 4S: Building - 12x15 Hydrograph

0.046 Runoff 0.044 0.04 cfs 0.042 0.04 Type II 24-hr 0.038 0.036 50-YR Rainfall=6.87" 0.034 0.032 Runoff Area=180 sf 0.03 0.028 0.026 Runoff Volume=99 cf 0.024 0.022 Runoff Depth=6.63"

Flow (cfs) 0.02 0.018 Tc=5.0 min 0.016 0.014 0.012 CN=0/98 0.01 0.008 0.006 0.004 0.002 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 43

Hydrograph for Subcatchment 4S: Building - 12x15

Summary for Subcatchment EX: EX

Runoff = 0.40 cfs @ 11.96 hrs, Volume= 789 cf, Depth= 4.04"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 50-YR Rainfall=6.87"

Area (sf) CN Description * 257 76 Gravel (80%) * 64 30 Gravel (20%) * 2,024 76 Gravel (Site Restoration) 2,345 75 Weighted Average 2,345 75 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment EX: EX Hydrograph

0.44 Runoff 0.42 0.40 cfs 0.4 0.38 Type II 24-hr 0.36 0.34 50-YR Rainfall=6.87" 0.32 0.3 Runoff Area=2,345 sf 0.28 0.26 Runoff Volume=789 cf 0.24 0.22 Runoff Depth=4.04" 0.2 Flow (cfs) 0.18 Tc=5.0 min 0.16 0.14 CN=75/0 0.12 0.1 0.08 0.06 0.04 0.02 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 45

Hydrograph for Subcatchment EX: EX

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 1.24 0.09 0.00 0.00 20.00 6.54 3.75 0.00 0.00 30.00 6.87 4.04 0.00 0.00 40.00 6.87 4.04 0.00 0.00 50.00 6.87 4.04 0.00 0.00 60.00 6.87 4.04 0.00 0.00 70.00 6.87 4.04 0.00 0.00 80.00 6.87 4.04 0.00 0.00 90.00 6.87 4.04 0.00 0.00 100.00 6.87 4.04 0.00 0.00 110.00 6.87 4.04 0.00 0.00 120.00 6.87 4.04 0.00 0.00 130.00 6.87 4.04 0.00 0.00 140.00 6.87 4.04 0.00 0.00 150.00 6.87 4.04 0.00 0.00 160.00 6.87 4.04 0.00 0.00 170.00 6.87 4.04 0.00 0.00 180.00 6.87 4.04 0.00 0.00 190.00 6.87 4.04 0.00 0.00 200.00 6.87 4.04 0.00 0.00 210.00 6.87 4.04 0.00 0.00 220.00 6.87 4.04 0.00 0.00 230.00 6.87 4.04 0.00 0.00 240.00 6.87 4.04 0.00 0.00 250.00 6.87 4.04 0.00 0.00 260.00 6.87 4.04 0.00 0.00 270.00 6.87 4.04 0.00 0.00 280.00 6.87 4.04 0.00 0.00 290.00 6.87 4.04 0.00 0.00 300.00 6.87 4.04 0.00 0.00 PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 46

Summary for Subcatchment PR: Bypass

Runoff = 0.37 cfs @ 11.96 hrs, Volume= 737 cf, Depth= 4.21"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 50-YR Rainfall=6.87"

Area (sf) CN Description * 61 98 Impervious * 2,039 76 Gravel (Site Restoration) 2,100 77 Weighted Average 2,039 76 97.10% Pervious Area 61 98 2.90% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment PR: Bypass Hydrograph

0.4 Runoff 0.38 0.37 cfs 0.36 Type II 24-hr 0.34 0.32 50-YR Rainfall=6.87" 0.3 0.28 Runoff Area=2,100 sf 0.26 0.24 Runoff Volume=737 cf 0.22 0.2 Runoff Depth=4.21"

Flow (cfs) 0.18 0.16 Tc=5.0 min 0.14 0.12 CN=76/98 0.1 0.08 0.06 0.04 0.02 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 47

Hydrograph for Subcatchment PR: Bypass

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 1.24 0.10 1.03 0.00 20.00 6.54 3.85 6.30 0.00 30.00 6.87 4.14 6.63 0.00 40.00 6.87 4.14 6.63 0.00 50.00 6.87 4.14 6.63 0.00 60.00 6.87 4.14 6.63 0.00 70.00 6.87 4.14 6.63 0.00 80.00 6.87 4.14 6.63 0.00 90.00 6.87 4.14 6.63 0.00 100.00 6.87 4.14 6.63 0.00 110.00 6.87 4.14 6.63 0.00 120.00 6.87 4.14 6.63 0.00 130.00 6.87 4.14 6.63 0.00 140.00 6.87 4.14 6.63 0.00 150.00 6.87 4.14 6.63 0.00 160.00 6.87 4.14 6.63 0.00 170.00 6.87 4.14 6.63 0.00 180.00 6.87 4.14 6.63 0.00 190.00 6.87 4.14 6.63 0.00 200.00 6.87 4.14 6.63 0.00 210.00 6.87 4.14 6.63 0.00 220.00 6.87 4.14 6.63 0.00 230.00 6.87 4.14 6.63 0.00 240.00 6.87 4.14 6.63 0.00 250.00 6.87 4.14 6.63 0.00 260.00 6.87 4.14 6.63 0.00 270.00 6.87 4.14 6.63 0.00 280.00 6.87 4.14 6.63 0.00 290.00 6.87 4.14 6.63 0.00 300.00 6.87 4.14 6.63 0.00 PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 48

Summary for Pond 2P: Dry Well 1

Inflow Area = 180 sf,100.00% Impervious, Inflow Depth = 6.63" for 50-YR event Inflow = 0.04 cfs @ 11.96 hrs, Volume= 99 cf Outflow = 0.00 cfs @ 16.55 hrs, Volume= 99 cf, Atten= 99%, Lag= 275.9 min Discarded = 0.00 cfs @ 4.64 hrs, Volume= 96 cf Primary = 0.00 cfs @ 16.55 hrs, Volume= 3 cf

Routing by Stor-Ind method, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Peak Elev= 12.05' @ 16.55 hrs Surf.Area= 28 sf Storage= 72 cf

Plug-Flow detention time= 1,850.2 min calculated for 99 cf (100% of inflow) Center-of-Mass det. time= 1,850.3 min ( 2,588.4 - 738.1 )

Volume Invert Avail.Storage Storage Description #1 9.50' 84 cf Custom Stage Data (Prismatic) Listed below (Recalc)

Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 9.50 28 0 0 12.50 28 84 84

Device Routing Invert Outlet Devices #1 Primary 12.05' 3.0" Vert. Orifice/Grate C= 0.600 #2 Discarded 9.50' 0.500 in/hr Exfiltration over Surface area

Discarded OutFlow Max=0.00 cfs @ 4.64 hrs HW=9.53' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.00 cfs)

Primary OutFlow Max=0.00 cfs @ 16.55 hrs HW=12.05' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.00 cfs @ 0.23 fps) PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 49

Pond 2P: Dry Well 1 Hydrograph

Inflow 0.04 cfs Outflow Discarded 0.046 Inflow Area=180 sf Primary 0.044 0.042 Peak Elev=12.05' 0.04 0.038 0.036 Storage=72 cf 0.034 0.032 0.03 0.028 0.026 0.024 0.022

Flow (cfs) 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.00 cfs 0.006 0.004 0.00 cfs 0.002 0.00 cfs 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 50

Hydrograph for Pond 2P: Dry Well 1

Time Inflow Storage Elevation Outflow Discarded Primary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 9.50 0.00 0.00 0.00 10.00 0.00 6 9.73 0.00 0.00 0.00 20.00 0.00 71 12.05 0.00 0.00 0.00 30.00 0.00 64 11.80 0.00 0.00 0.00 40.00 0.00 53 11.39 0.00 0.00 0.00 50.00 0.00 41 10.97 0.00 0.00 0.00 60.00 0.00 29 10.55 0.00 0.00 0.00 70.00 0.00 18 10.14 0.00 0.00 0.00 80.00 0.00 6 9.72 0.00 0.00 0.00 90.00 0.00 0 9.50 0.00 0.00 0.00 100.00 0.00 0 9.50 0.00 0.00 0.00 110.00 0.00 0 9.50 0.00 0.00 0.00 120.00 0.00 0 9.50 0.00 0.00 0.00 130.00 0.00 0 9.50 0.00 0.00 0.00 140.00 0.00 0 9.50 0.00 0.00 0.00 150.00 0.00 0 9.50 0.00 0.00 0.00 160.00 0.00 0 9.50 0.00 0.00 0.00 170.00 0.00 0 9.50 0.00 0.00 0.00 180.00 0.00 0 9.50 0.00 0.00 0.00 190.00 0.00 0 9.50 0.00 0.00 0.00 200.00 0.00 0 9.50 0.00 0.00 0.00 210.00 0.00 0 9.50 0.00 0.00 0.00 220.00 0.00 0 9.50 0.00 0.00 0.00 230.00 0.00 0 9.50 0.00 0.00 0.00 240.00 0.00 0 9.50 0.00 0.00 0.00 250.00 0.00 0 9.50 0.00 0.00 0.00 260.00 0.00 0 9.50 0.00 0.00 0.00 270.00 0.00 0 9.50 0.00 0.00 0.00 280.00 0.00 0 9.50 0.00 0.00 0.00 290.00 0.00 0 9.50 0.00 0.00 0.00 300.00 0.00 0 9.50 0.00 0.00 0.00 PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 51

Summary for Pond 5P: Dry Well 2

Inflow Area = 80 sf,100.00% Impervious, Inflow Depth = 6.63" for 50-YR event Inflow = 0.02 cfs @ 11.96 hrs, Volume= 44 cf Outflow = 0.00 cfs @ 9.61 hrs, Volume= 44 cf, Atten= 98%, Lag= 0.0 min Discarded = 0.00 cfs @ 9.61 hrs, Volume= 44 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf

Routing by Stor-Ind method, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Peak Elev= 10.89' @ 15.25 hrs Surf.Area= 28 sf Storage= 25 cf

Plug-Flow detention time= 598.4 min calculated for 44 cf (100% of inflow) Center-of-Mass det. time= 598.4 min ( 1,336.5 - 738.1 )

Volume Invert Avail.Storage Storage Description #1 10.00' 84 cf Custom Stage Data (Prismatic) Listed below (Recalc)

Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 10.00 28 0 0 13.00 28 84 84

Device Routing Invert Outlet Devices #1 Primary 12.55' 3.0" Vert. Orifice/Grate C= 0.600 #2 Discarded 10.00' 0.565 in/hr Exfiltration over Surface area

Discarded OutFlow Max=0.00 cfs @ 9.61 hrs HW=10.03' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.00 cfs)

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=10.00' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 52

Pond 5P: Dry Well 2 Hydrograph

Inflow 0.02 cfs Outflow Discarded Primary 0.02 Inflow Area=80 sf 0.019 0.018 Peak Elev=10.89' 0.017 0.016 0.015 Storage=25 cf 0.014 0.013 0.012 0.011 0.01 0.009 Flow (cfs) 0.008 0.007 0.006 0.005 0.004 0.003 0.00 cfs 0.002 0.00 cfs 0.0010.00 cfs 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 53

Hydrograph for Pond 5P: Dry Well 2

Time Inflow Storage Elevation Outflow Discarded Primary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 10.00 0.00 0.00 0.00 10.00 0.00 1 10.03 0.00 0.00 0.00 20.00 0.00 23 10.82 0.00 0.00 0.00 30.00 0.00 12 10.43 0.00 0.00 0.00 40.00 0.00 0 10.00 0.00 0.00 0.00 50.00 0.00 0 10.00 0.00 0.00 0.00 60.00 0.00 0 10.00 0.00 0.00 0.00 70.00 0.00 0 10.00 0.00 0.00 0.00 80.00 0.00 0 10.00 0.00 0.00 0.00 90.00 0.00 0 10.00 0.00 0.00 0.00 100.00 0.00 0 10.00 0.00 0.00 0.00 110.00 0.00 0 10.00 0.00 0.00 0.00 120.00 0.00 0 10.00 0.00 0.00 0.00 130.00 0.00 0 10.00 0.00 0.00 0.00 140.00 0.00 0 10.00 0.00 0.00 0.00 150.00 0.00 0 10.00 0.00 0.00 0.00 160.00 0.00 0 10.00 0.00 0.00 0.00 170.00 0.00 0 10.00 0.00 0.00 0.00 180.00 0.00 0 10.00 0.00 0.00 0.00 190.00 0.00 0 10.00 0.00 0.00 0.00 200.00 0.00 0 10.00 0.00 0.00 0.00 210.00 0.00 0 10.00 0.00 0.00 0.00 220.00 0.00 0 10.00 0.00 0.00 0.00 230.00 0.00 0 10.00 0.00 0.00 0.00 240.00 0.00 0 10.00 0.00 0.00 0.00 250.00 0.00 0 10.00 0.00 0.00 0.00 260.00 0.00 0 10.00 0.00 0.00 0.00 270.00 0.00 0 10.00 0.00 0.00 0.00 280.00 0.00 0 10.00 0.00 0.00 0.00 290.00 0.00 0 10.00 0.00 0.00 0.00 300.00 0.00 0 10.00 0.00 0.00 0.00 PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 54

Summary for Link 3L: PR

Inflow Area = 2,360 sf, 13.60% Impervious, Inflow Depth = 3.77" for 50-YR event Inflow = 0.37 cfs @ 11.96 hrs, Volume= 740 cf Primary = 0.37 cfs @ 11.96 hrs, Volume= 740 cf, Atten= 0%, Lag= 0.0 min

Primary outflow = Inflow, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs

Link 3L: PR Hydrograph

Inflow 0.4 0.37 cfs Primary 0.38 0.37 cfs 0.36 Inflow Area=2,360 sf 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 Flow (cfs) 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 50-YR Rainfall=6.87" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 55

Hydrograph for Link 3L: PR

Time Inflow Elevation Primary Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) (hours) (cfs) (feet) (cfs) 0.00 0.00 0.00 0.00 260.00 0.00 0.00 0.00 5.00 0.00 0.00 0.00 265.00 0.00 0.00 0.00 10.00 0.00 0.00 0.00 270.00 0.00 0.00 0.00 15.00 0.01 0.00 0.01 275.00 0.00 0.00 0.00 20.00 0.00 0.00 0.00 280.00 0.00 0.00 0.00 25.00 0.00 0.00 0.00 285.00 0.00 0.00 0.00 30.00 0.00 0.00 0.00 290.00 0.00 0.00 0.00 35.00 0.00 0.00 0.00 295.00 0.00 0.00 0.00 40.00 0.00 0.00 0.00 300.00 0.00 0.00 0.00 45.00 0.00 0.00 0.00 50.00 0.00 0.00 0.00 55.00 0.00 0.00 0.00 60.00 0.00 0.00 0.00 65.00 0.00 0.00 0.00 70.00 0.00 0.00 0.00 75.00 0.00 0.00 0.00 80.00 0.00 0.00 0.00 85.00 0.00 0.00 0.00 90.00 0.00 0.00 0.00 95.00 0.00 0.00 0.00 100.00 0.00 0.00 0.00 105.00 0.00 0.00 0.00 110.00 0.00 0.00 0.00 115.00 0.00 0.00 0.00 120.00 0.00 0.00 0.00 125.00 0.00 0.00 0.00 130.00 0.00 0.00 0.00 135.00 0.00 0.00 0.00 140.00 0.00 0.00 0.00 145.00 0.00 0.00 0.00 150.00 0.00 0.00 0.00 155.00 0.00 0.00 0.00 160.00 0.00 0.00 0.00 165.00 0.00 0.00 0.00 170.00 0.00 0.00 0.00 175.00 0.00 0.00 0.00 180.00 0.00 0.00 0.00 185.00 0.00 0.00 0.00 190.00 0.00 0.00 0.00 195.00 0.00 0.00 0.00 200.00 0.00 0.00 0.00 205.00 0.00 0.00 0.00 210.00 0.00 0.00 0.00 215.00 0.00 0.00 0.00 220.00 0.00 0.00 0.00 225.00 0.00 0.00 0.00 230.00 0.00 0.00 0.00 235.00 0.00 0.00 0.00 240.00 0.00 0.00 0.00 245.00 0.00 0.00 0.00 250.00 0.00 0.00 0.00 255.00 0.00 0.00 0.00 PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 56

Time span=0.00-300.00 hrs, dt=0.01 hrs, 30001 points Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv. Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method

Subcatchment 1S: Building - 10x8 Runoff Area=80 sf 100.00% Impervious Runoff Depth=7.64" Tc=5.0 min CN=0/98 Runoff=0.02 cfs 51 cf

Subcatchment 4S: Building - 12x15 Runoff Area=180 sf 100.00% Impervious Runoff Depth=7.64" Tc=5.0 min CN=0/98 Runoff=0.05 cfs 115 cf

Subcatchment EX: EX Runoff Area=2,345 sf 0.00% Impervious Runoff Depth=4.93" Tc=5.0 min CN=75/0 Runoff=0.48 cfs 964 cf

Subcatchment PR: Bypass Runoff Area=2,100 sf 2.90% Impervious Runoff Depth=5.12" Tc=5.0 min CN=76/98 Runoff=0.44 cfs 897 cf

Pond 2P: Dry Well 1 Peak Elev=12.08' Storage=72 cf Inflow=0.05 cfs 115 cf Discarded=0.00 cfs 97 cf Primary=0.00 cfs 18 cf Outflow=0.00 cfs 115 cf

Pond 5P: Dry Well 2 Peak Elev=11.07' Storage=30 cf Inflow=0.02 cfs 51 cf Discarded=0.00 cfs 51 cf Primary=0.00 cfs 0 cf Outflow=0.00 cfs 51 cf

Link 3L: PR Inflow=0.44 cfs 914 cf Primary=0.44 cfs 914 cf

Total Runoff Area = 4,705 sf Runoff Volume = 2,026 cf Average Runoff Depth = 5.17" 93.18% Pervious = 4,384 sf 6.82% Impervious = 321 sf PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 57

Summary for Subcatchment 1S: Building - 10x8

Runoff = 0.02 cfs @ 11.96 hrs, Volume= 51 cf, Depth= 7.64"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 100-YR Rainfall=7.88"

Area (sf) CN Description * 80 98 Building 80 98 100.00% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment 1S: Building - 10x8 Hydrograph

Runoff 0.023 0.022 0.02 cfs 0.021 0.02 Type II 24-hr 0.019 0.018 100-YR Rainfall=7.88" 0.017 0.016 Runoff Area=80 sf 0.015 0.014 Runoff Volume=51 cf 0.013 0.012 Runoff Depth=7.64" 0.011

Flow (cfs) 0.01 0.009 Tc=5.0 min 0.008 0.007 CN=0/98 0.006 0.005 0.004 0.003 0.002 0.001 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 58

Hydrograph for Subcatchment 1S: Building - 10x8

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 1.43 0.00 1.21 0.00 20.00 7.50 0.00 7.26 0.00 30.00 7.88 0.00 7.64 0.00 40.00 7.88 0.00 7.64 0.00 50.00 7.88 0.00 7.64 0.00 60.00 7.88 0.00 7.64 0.00 70.00 7.88 0.00 7.64 0.00 80.00 7.88 0.00 7.64 0.00 90.00 7.88 0.00 7.64 0.00 100.00 7.88 0.00 7.64 0.00 110.00 7.88 0.00 7.64 0.00 120.00 7.88 0.00 7.64 0.00 130.00 7.88 0.00 7.64 0.00 140.00 7.88 0.00 7.64 0.00 150.00 7.88 0.00 7.64 0.00 160.00 7.88 0.00 7.64 0.00 170.00 7.88 0.00 7.64 0.00 180.00 7.88 0.00 7.64 0.00 190.00 7.88 0.00 7.64 0.00 200.00 7.88 0.00 7.64 0.00 210.00 7.88 0.00 7.64 0.00 220.00 7.88 0.00 7.64 0.00 230.00 7.88 0.00 7.64 0.00 240.00 7.88 0.00 7.64 0.00 250.00 7.88 0.00 7.64 0.00 260.00 7.88 0.00 7.64 0.00 270.00 7.88 0.00 7.64 0.00 280.00 7.88 0.00 7.64 0.00 290.00 7.88 0.00 7.64 0.00 300.00 7.88 0.00 7.64 0.00 PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 59

Summary for Subcatchment 4S: Building - 12x15

Runoff = 0.05 cfs @ 11.96 hrs, Volume= 115 cf, Depth= 7.64"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 100-YR Rainfall=7.88"

Area (sf) CN Description * 180 98 Building 180 98 100.00% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment 4S: Building - 12x15 Hydrograph

Runoff 0.05 0.05 cfs

0.045 Type II 24-hr

0.04 100-YR Rainfall=7.88"

0.035 Runoff Area=180 sf

0.03 Runoff Volume=115 cf

0.025 Runoff Depth=7.64" Flow (cfs)

0.02 Tc=5.0 min

0.015 CN=0/98

0.01

0.005

0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 60

Hydrograph for Subcatchment 4S: Building - 12x15

Summary for Subcatchment EX: EX

Runoff = 0.48 cfs @ 11.96 hrs, Volume= 964 cf, Depth= 4.93"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 100-YR Rainfall=7.88"

Area (sf) CN Description * 257 76 Gravel (80%) * 64 30 Gravel (20%) * 2,024 76 Gravel (Site Restoration) 2,345 75 Weighted Average 2,345 75 100.00% Pervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment EX: EX Hydrograph

Runoff 0.5 0.48 cfs Type II 24-hr 0.45 100-YR Rainfall=7.88" 0.4

0.35 Runoff Area=2,345 sf

0.3 Runoff Volume=964 cf

0.25 Runoff Depth=4.93" Flow (cfs)

0.2 Tc=5.0 min

0.15 CN=75/0

0.1

0.05

Hydrograph for Subcatchment EX: EX

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 1.43 0.14 0.00 0.01 20.00 7.50 4.59 0.00 0.01 30.00 7.88 4.93 0.00 0.00 40.00 7.88 4.93 0.00 0.00 50.00 7.88 4.93 0.00 0.00 60.00 7.88 4.93 0.00 0.00 70.00 7.88 4.93 0.00 0.00 80.00 7.88 4.93 0.00 0.00 90.00 7.88 4.93 0.00 0.00 100.00 7.88 4.93 0.00 0.00 110.00 7.88 4.93 0.00 0.00 120.00 7.88 4.93 0.00 0.00 130.00 7.88 4.93 0.00 0.00 140.00 7.88 4.93 0.00 0.00 150.00 7.88 4.93 0.00 0.00 160.00 7.88 4.93 0.00 0.00 170.00 7.88 4.93 0.00 0.00 180.00 7.88 4.93 0.00 0.00 190.00 7.88 4.93 0.00 0.00 200.00 7.88 4.93 0.00 0.00 210.00 7.88 4.93 0.00 0.00 220.00 7.88 4.93 0.00 0.00 230.00 7.88 4.93 0.00 0.00 240.00 7.88 4.93 0.00 0.00 250.00 7.88 4.93 0.00 0.00 260.00 7.88 4.93 0.00 0.00 270.00 7.88 4.93 0.00 0.00 280.00 7.88 4.93 0.00 0.00 290.00 7.88 4.93 0.00 0.00 300.00 7.88 4.93 0.00 0.00 PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 63

Summary for Subcatchment PR: Bypass

Runoff = 0.44 cfs @ 11.96 hrs, Volume= 897 cf, Depth= 5.12"

Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Type II 24-hr 100-YR Rainfall=7.88"

Area (sf) CN Description * 61 98 Impervious * 2,039 76 Gravel (Site Restoration) 2,100 77 Weighted Average 2,039 76 97.10% Pervious Area 61 98 2.90% Impervious Area

Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry,

Subcatchment PR: Bypass Hydrograph

0.48 Runoff 0.46 0.44 cfs 0.44 0.42 Type II 24-hr 0.4 0.38 100-YR Rainfall=7.88" 0.36 0.34 Runoff Area=2,100 sf 0.32 0.3 0.28 Runoff Volume=897 cf 0.26 0.24 Runoff Depth=5.12" 0.22 Flow (cfs) 0.2 Tc=5.0 min 0.18 0.16 0.14 CN=76/98 0.12 0.1 0.08 0.06 0.04 0.02 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 64

Hydrograph for Subcatchment PR: Bypass

Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 10.00 1.43 0.16 1.21 0.01 20.00 7.50 4.71 7.26 0.00 30.00 7.88 5.05 7.64 0.00 40.00 7.88 5.05 7.64 0.00 50.00 7.88 5.05 7.64 0.00 60.00 7.88 5.05 7.64 0.00 70.00 7.88 5.05 7.64 0.00 80.00 7.88 5.05 7.64 0.00 90.00 7.88 5.05 7.64 0.00 100.00 7.88 5.05 7.64 0.00 110.00 7.88 5.05 7.64 0.00 120.00 7.88 5.05 7.64 0.00 130.00 7.88 5.05 7.64 0.00 140.00 7.88 5.05 7.64 0.00 150.00 7.88 5.05 7.64 0.00 160.00 7.88 5.05 7.64 0.00 170.00 7.88 5.05 7.64 0.00 180.00 7.88 5.05 7.64 0.00 190.00 7.88 5.05 7.64 0.00 200.00 7.88 5.05 7.64 0.00 210.00 7.88 5.05 7.64 0.00 220.00 7.88 5.05 7.64 0.00 230.00 7.88 5.05 7.64 0.00 240.00 7.88 5.05 7.64 0.00 250.00 7.88 5.05 7.64 0.00 260.00 7.88 5.05 7.64 0.00 270.00 7.88 5.05 7.64 0.00 280.00 7.88 5.05 7.64 0.00 290.00 7.88 5.05 7.64 0.00 300.00 7.88 5.05 7.64 0.00 PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 65

Summary for Pond 2P: Dry Well 1

Inflow Area = 180 sf,100.00% Impervious, Inflow Depth = 7.64" for 100-YR event Inflow = 0.05 cfs @ 11.96 hrs, Volume= 115 cf Outflow = 0.00 cfs @ 12.91 hrs, Volume= 115 cf, Atten= 95%, Lag= 57.4 min Discarded = 0.00 cfs @ 3.78 hrs, Volume= 97 cf Primary = 0.00 cfs @ 12.91 hrs, Volume= 18 cf

Routing by Stor-Ind method, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Peak Elev= 12.08' @ 12.91 hrs Surf.Area= 28 sf Storage= 72 cf

Plug-Flow detention time= 1,624.7 min calculated for 115 cf (100% of inflow) Center-of-Mass det. time= 1,624.6 min ( 2,360.9 - 736.2 )

Volume Invert Avail.Storage Storage Description #1 9.50' 84 cf Custom Stage Data (Prismatic) Listed below (Recalc)

Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 9.50 28 0 0 12.50 28 84 84

Device Routing Invert Outlet Devices #1 Primary 12.05' 3.0" Vert. Orifice/Grate C= 0.600 #2 Discarded 9.50' 0.500 in/hr Exfiltration over Surface area

Discarded OutFlow Max=0.00 cfs @ 3.78 hrs HW=9.53' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.00 cfs)

Primary OutFlow Max=0.00 cfs @ 12.91 hrs HW=12.08' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.00 cfs @ 0.59 fps) PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 66

Pond 2P: Dry Well 1 Hydrograph

Inflow 0.05 cfs Outflow Discarded Inflow Area=180 sf Primary 0.05 Peak Elev=12.08' 0.045 Storage=72 cf 0.04

0.035

0.03

0.025 Flow (cfs) 0.02

0.015

0.01 0.00 cfs

0.00 cfs 0.005 0.00 cfs

Hydrograph for Pond 2P: Dry Well 1

Time Inflow Storage Elevation Outflow Discarded Primary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 9.50 0.00 0.00 0.00 10.00 0.00 9 9.81 0.00 0.00 0.00 20.00 0.00 71 12.05 0.00 0.00 0.00 30.00 0.00 65 11.80 0.00 0.00 0.00 40.00 0.00 53 11.39 0.00 0.00 0.00 50.00 0.00 41 10.97 0.00 0.00 0.00 60.00 0.00 30 10.55 0.00 0.00 0.00 70.00 0.00 18 10.14 0.00 0.00 0.00 80.00 0.00 6 9.72 0.00 0.00 0.00 90.00 0.00 0 9.50 0.00 0.00 0.00 100.00 0.00 0 9.50 0.00 0.00 0.00 110.00 0.00 0 9.50 0.00 0.00 0.00 120.00 0.00 0 9.50 0.00 0.00 0.00 130.00 0.00 0 9.50 0.00 0.00 0.00 140.00 0.00 0 9.50 0.00 0.00 0.00 150.00 0.00 0 9.50 0.00 0.00 0.00 160.00 0.00 0 9.50 0.00 0.00 0.00 170.00 0.00 0 9.50 0.00 0.00 0.00 180.00 0.00 0 9.50 0.00 0.00 0.00 190.00 0.00 0 9.50 0.00 0.00 0.00 200.00 0.00 0 9.50 0.00 0.00 0.00 210.00 0.00 0 9.50 0.00 0.00 0.00 220.00 0.00 0 9.50 0.00 0.00 0.00 230.00 0.00 0 9.50 0.00 0.00 0.00 240.00 0.00 0 9.50 0.00 0.00 0.00 250.00 0.00 0 9.50 0.00 0.00 0.00 260.00 0.00 0 9.50 0.00 0.00 0.00 270.00 0.00 0 9.50 0.00 0.00 0.00 280.00 0.00 0 9.50 0.00 0.00 0.00 290.00 0.00 0 9.50 0.00 0.00 0.00 300.00 0.00 0 9.50 0.00 0.00 0.00 PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 68

Summary for Pond 5P: Dry Well 2

Inflow Area = 80 sf,100.00% Impervious, Inflow Depth = 7.64" for 100-YR event Inflow = 0.02 cfs @ 11.96 hrs, Volume= 51 cf Outflow = 0.00 cfs @ 8.98 hrs, Volume= 51 cf, Atten= 98%, Lag= 0.0 min Discarded = 0.00 cfs @ 8.98 hrs, Volume= 51 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf

Routing by Stor-Ind method, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs Peak Elev= 11.07' @ 15.77 hrs Surf.Area= 28 sf Storage= 30 cf

Plug-Flow detention time= 714.9 min calculated for 51 cf (100% of inflow) Center-of-Mass det. time= 715.0 min ( 1,451.2 - 736.2 )

Volume Invert Avail.Storage Storage Description #1 10.00' 84 cf Custom Stage Data (Prismatic) Listed below (Recalc)

Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 10.00 28 0 0 13.00 28 84 84

Device Routing Invert Outlet Devices #1 Primary 12.55' 3.0" Vert. Orifice/Grate C= 0.600 #2 Discarded 10.00' 0.565 in/hr Exfiltration over Surface area

Discarded OutFlow Max=0.00 cfs @ 8.98 hrs HW=10.03' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.00 cfs)

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=10.00' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 69

Pond 5P: Dry Well 2 Hydrograph

Inflow 0.02 cfs Outflow Discarded Inflow Area=80 sf Primary 0.022 Peak Elev=11.07' 0.02 0.018 Storage=30 cf 0.016

0.014

0.012

Flow (cfs) 0.01

0.008

0.006

0.004 0.00 cfs 0.00 cfs 0.002 0.00 cfs 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 70

Hydrograph for Pond 5P: Dry Well 2

Time Inflow Storage Elevation Outflow Discarded Primary (hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs) 0.00 0.00 0 10.00 0.00 0.00 0.00 10.00 0.00 1 10.04 0.00 0.00 0.00 20.00 0.00 29 11.02 0.00 0.00 0.00 30.00 0.00 18 10.64 0.00 0.00 0.00 40.00 0.00 5 10.17 0.00 0.00 0.00 50.00 0.00 0 10.00 0.00 0.00 0.00 60.00 0.00 0 10.00 0.00 0.00 0.00 70.00 0.00 0 10.00 0.00 0.00 0.00 80.00 0.00 0 10.00 0.00 0.00 0.00 90.00 0.00 0 10.00 0.00 0.00 0.00 100.00 0.00 0 10.00 0.00 0.00 0.00 110.00 0.00 0 10.00 0.00 0.00 0.00 120.00 0.00 0 10.00 0.00 0.00 0.00 130.00 0.00 0 10.00 0.00 0.00 0.00 140.00 0.00 0 10.00 0.00 0.00 0.00 150.00 0.00 0 10.00 0.00 0.00 0.00 160.00 0.00 0 10.00 0.00 0.00 0.00 170.00 0.00 0 10.00 0.00 0.00 0.00 180.00 0.00 0 10.00 0.00 0.00 0.00 190.00 0.00 0 10.00 0.00 0.00 0.00 200.00 0.00 0 10.00 0.00 0.00 0.00 210.00 0.00 0 10.00 0.00 0.00 0.00 220.00 0.00 0 10.00 0.00 0.00 0.00 230.00 0.00 0 10.00 0.00 0.00 0.00 240.00 0.00 0 10.00 0.00 0.00 0.00 250.00 0.00 0 10.00 0.00 0.00 0.00 260.00 0.00 0 10.00 0.00 0.00 0.00 270.00 0.00 0 10.00 0.00 0.00 0.00 280.00 0.00 0 10.00 0.00 0.00 0.00 290.00 0.00 0 10.00 0.00 0.00 0.00 300.00 0.00 0 10.00 0.00 0.00 0.00 PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 71

Summary for Link 3L: PR

Inflow Area = 2,360 sf, 13.60% Impervious, Inflow Depth = 4.65" for 100-YR event Inflow = 0.44 cfs @ 11.96 hrs, Volume= 914 cf Primary = 0.44 cfs @ 11.96 hrs, Volume= 914 cf, Atten= 0%, Lag= 0.0 min

Primary outflow = Inflow, Time Span= 0.00-300.00 hrs, dt= 0.01 hrs

Link 3L: PR Hydrograph

Inflow 0.48 0.44 cfs Primary 0.46 0.44 cfs 0.44 Inflow Area=2,360 sf 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 Flow (cfs) 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Time (hours) PECO Type II 24-hr 100-YR Rainfall=7.88" Prepared by JMT Printed 9/24/2020 HydroCAD® 10.00-20 s/n 08514 © 2017 HydroCAD Software Solutions LLC Page 72

Hydrograph for Link 3L: PR

Time Inflow Elevation Primary Time Inflow Elevation Primary (hours) (cfs) (feet) (cfs) (hours) (cfs) (feet) (cfs) 0.00 0.00 0.00 0.00 260.00 0.00 0.00 0.00 5.00 0.00 0.00 0.00 265.00 0.00 0.00 0.00 10.00 0.01 0.00 0.01 270.00 0.00 0.00 0.00 15.00 0.01 0.00 0.01 275.00 0.00 0.00 0.00 20.00 0.00 0.00 0.00 280.00 0.00 0.00 0.00 25.00 0.00 0.00 0.00 285.00 0.00 0.00 0.00 30.00 0.00 0.00 0.00 290.00 0.00 0.00 0.00 35.00 0.00 0.00 0.00 295.00 0.00 0.00 0.00 40.00 0.00 0.00 0.00 300.00 0.00 0.00 0.00 45.00 0.00 0.00 0.00 50.00 0.00 0.00 0.00 55.00 0.00 0.00 0.00 60.00 0.00 0.00 0.00 65.00 0.00 0.00 0.00 70.00 0.00 0.00 0.00 75.00 0.00 0.00 0.00 80.00 0.00 0.00 0.00 85.00 0.00 0.00 0.00 90.00 0.00 0.00 0.00 95.00 0.00 0.00 0.00 100.00 0.00 0.00 0.00 105.00 0.00 0.00 0.00 110.00 0.00 0.00 0.00 115.00 0.00 0.00 0.00 120.00 0.00 0.00 0.00 125.00 0.00 0.00 0.00 130.00 0.00 0.00 0.00 135.00 0.00 0.00 0.00 140.00 0.00 0.00 0.00 145.00 0.00 0.00 0.00 150.00 0.00 0.00 0.00 155.00 0.00 0.00 0.00 160.00 0.00 0.00 0.00 165.00 0.00 0.00 0.00 170.00 0.00 0.00 0.00 175.00 0.00 0.00 0.00 180.00 0.00 0.00 0.00 185.00 0.00 0.00 0.00 190.00 0.00 0.00 0.00 195.00 0.00 0.00 0.00 200.00 0.00 0.00 0.00 205.00 0.00 0.00 0.00 210.00 0.00 0.00 0.00 215.00 0.00 0.00 0.00 220.00 0.00 0.00 0.00 225.00 0.00 0.00 0.00 230.00 0.00 0.00 0.00 235.00 0.00 0.00 0.00 240.00 0.00 0.00 0.00 245.00 0.00 0.00 0.00 250.00 0.00 0.00 0.00 255.00 0.00 0.00 0.00

POST CONSTRUCTION STORMWATER5 MANAGEMENT REPORT

Appendix E Drainage Area Plans

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POST CONSTRUCTION STORMWATER6 MANAGEMENT REPORT

Appendix F Infiltration Testing Reports

August 26 , 2020

GEOTECHNICAL ENGINEERING REPORT

ADELPHIA GATEWAY, LLC PECO STATION INFILTRATION TESTING REPORT DELAWARE COUNTY, PENNSYLVANIA

Submitted to: Hunt, Guillot and Associates (HGA) One Metroplex Drive, Suite 100 Birmingham, Alabama 35209

August 26, 2020

Mr. Bill Freeman Hunt, Guillot and Associates (HGA) One Metroplex Drive, Suite 100 Birmingham, Alabama 35209

Reference: Geotechnical Engineering Report for Infiltration Testing at PECO Station Delaware County, Pennsylvania JMT Job No. 18-00672-06A

Dear Mr. Freeman:

Johnson, Mirmiran & Thompson, Inc. (JMT) is pleased to submit this geotechnical engineering analysis for the above-referenced project. This report contains a discussion of our understanding of the project, exploration procedures, the exploration results, and our recommendations for the design of the vegetated roof and either rain barrel or dry well best management practice (BMP) stormwater management (SWM) facility for the proposed Adelphia Gateway, LLC, PECO Station project in Delaware County, Pennsylvania.

It has been our pleasure to be of service to you. If you have any questions or require any additional information, please do not hesitate to contact this office.

Very truly yours,

JOHNSON, MIRMIRAN AND THOMPSON, INC.

Michael E. Leffler, P.E. Mark R. Stouffer, P.E. Vice President Geotechnical Engineer

1.0 INTRODUCTION

This memorandum was prepared for the Adelphia Gateway, LLC in accordance with our agreement. Johnson, Mirmiran & Thompson, Inc. (JMT) has completed the Geotechnical Engineering Report for the design of the proposed PECO Station vegetated roof and either rain barrel or dry well best management practice (BMP) stormwater management (SWM) facility in Delaware County, Pennsylvania.

2.0 SUBSURFACE EXPLORATION

A total of two test pits were excavated by JMT’s subconsultant American Geotech, Inc. (AGI) using JCB 8029 CTS mini excavator on July 24, 2020 to investigate the soil and groundwater conditions and perform Double Ring Infiltration Tests. Both test pits, identified as Test Pits TP-1 and TP-2, were approximately 2 feet wide by 15 to 20 feet long and excavated to a depth of about 7 feet deep. The two double ring infiltration tests were both conducted at depths of about 5 feet below existing grade. Existing grade at both test pits was approximately elevation (EL) 14 feet above Mean Sea Level (MSL), so the tests were performed at approximate EL 9 feet. The test pits were extended two feet deeper or to approximate EL 7 feet to investigate the presence of limiting layers below the anticipated infiltration depth.

The locations of the two test pits and infiltration tests with respect to the green roofs and rain barrels are displayed on the plan view included as Appendix A. The soil in the test pits was tested and classified using the USCS Textural and Plasticity Classification System. The laboratory test results, and the test pit logs are included in Appendix B. The Double Ring Infiltration Test results are provided in Appendix C.

3.0 GEOLOGIC SETTING

The project site is in Delaware County, in southeast Pennsylvania at the northwest corner of the PECO Station that is located on the northwest side of the Delaware River. The PECO Station lies to the northeast of USR 22; and the northwest corner is just on the other side of the gravel road that runs alongside the railroad tracks. The PECO Station lies within the Atlantic Coastal Plain Physiographic Province. Topography is low relief and surface drainage is southeasterly towards the Delaware River.

The surface materials on site are mapped as the Quaternary Trenton Gravel which is a product of Delaware River deposits. It is described in the literature as gray or pale-reddish-brown very

PECO Site – Vegetated Roof and Rain 1 Johnson, Mirmiran & Thompson, Inc. Barrel/Dry Well SWM Facility

gravelly sand interstratified with cross bedded sand and clay-silt beds, and it includes areas of Holocene alluvium and swamp deposits. The Trenton overlies crystalline rock of lower Paleozoic age with outcrops to the west.

4.0 SOIL CONDITIONS

The subsurface conditions at the site were evaluated by using the data from the two test pits. At the staked location of Test Pit TP-1, an 8-inch thick concrete slab was encountered at a depth of about 0.5 feet, and it was underlain by 1.5 feet of brick fragments. The edge of the concrete slab was about 5.5 feet south of the fence line. Therefore, the test pit was excavated just to the south of the edge of the concrete slab and the brick fragments. The test pits indicated two strata consisting of gravel surface materials designated as Stratum A, and natural soils consisting of Sandy LEAN CLAY (CL) and Sandy SILT (ML) designated as Stratum B.

The surface conditions on the project site consisted of about 0.5 feet of Sandy Gravel. In Test Pit TP-1, the gravel was underlain by the natural soil, but in TP-2 it was underlain by about 1.5 feet of asphalt millings. In TP-1, Stratum B consisted of Sandy LEAN CLAY (CL) from about 0.5 to 2.0 feet deep and Sandy Silt (ML) to the maximum depth investigated of 7 feet deep. In TP-2, the Sandy LEAN CLAY (CL) was not encountered, but the Stratum B Sandy SILT (ML) was encountered from 2.0 to 7.0 feet deep. Please see Appendix B for two test pit logs, and the laboratory test results for the two samples that were tested.

5.0 GROUNDWATER CONDITIONS

On the day of the infiltration testing, seepage was observed in Test Pit TP-1 at about the bottom of the test pit of about 7 feet deep. Groundwater was not observed in Test Pit TP-2. It should be noted that the tests were conducted during the dry season in late July prior to hurricane season, and there was no rain on the day of testing.

The recorded water levels in the test pits reflect the conditions at the time of this infiltration testing only. Fluctuations in the location of hydrostatic groundwater level and perched water levels can occur as a result of seasonal variations in evaporation, precipitation, surface water runoff, leaking utilities and other factors.

6.0 ANALYSIS AND RECOMMENDATIONS

Two vegetated roofs with either rain barrels or dry wells are being considered for stormwater management to handle increased runoff created by proposed site improvements at the northwest corner of the PECO Station. The two vegetated roofs are to be installed on top of a 12 by 15 foot building and an 8 by 10 foot building. The BMP 6.5.1 Vegetated Roofs and BMP 6.5.2 Rain Barrels will be installed to manage any increase in runoff volume and rate, and to improve

PECO Site – Vegetated Roof and Rain 2 Johnson, Mirmiran & Thompson, Inc. Barrel/Dry Well SWM Facility

water quality. Dry wells are also being considered in place of the rain barrels. In this case, the dry wells will provide temporary storage and infiltration of the rooftop runoff. Once all the site features are constructed, grading will be performed to restore the ground surface to the existing contours, and gravel will be placed at the surface to match the existing gravel that is there now.

Soil Infiltration testing was performed on July 24, 2020 by American Geotech, Inc. (AGI) using the Double Ring Infiltration Test method in accordance with PA Code 73.15 and ASTM D3385-94. The locations of the infiltration tests are shown in Appendix A. The results are as follows:

Infiltration Approx. Test Depth (ft) USCS Textural & Average Test Ground / Elevation Plasticity Class. Infiltration Surface Elev. Rate (in./hr.)

TP-1 14 5 / EL 9.0 Sandy Silt (ML) 1.00

TP-2 14 5 / EL 9.0 Sandy Silt (ML) 1.25

The test pits revealed Sandy Silt soil with an average infiltration rate of 1.13 inches per hour with no limiting layers such as impervious clay, bedrock, or groundwater. Based on the Pennsylvania Department of Environmental Protection (DEP) 2006 Pennsylvania Stormwater Best Management Practices Manual, the use of infiltration in SWM facilities is permissible only when the soils will provide infiltration rates between 0.1 and 10 inches per hour. Furthermore, infiltration is generally permissible when there is a two-foot clearance above the regularly occurring seasonally high groundwater table, and there is a minimum depth to bedrock of two feet. Therefore, based on the infiltration rates, the use of infiltration should be feasible at this site. However, the groundwater data was collected in late July during the dry season, and the seasonally high groundwater table may be higher in the springtime. Given water seepage was noted at the bottom of Test Pit TP-1, depending on the seasonally high groundwater table in the Spring, dry wells may not be feasible in this location, or the bottom elevations of the dry wells should be limited to a depth that is 2 feet higher than the seasonally high groundwater table. The seasonally high groundwater table depth in this location should be investigated.

7.0 DESIGN AND CONSTRUCTION CONSIDERATIONS The test pit exploration revealed the presence of the concrete slab along the north fence line. Other existing slabs or foundations may be encountered during construction. If dry wells are selected to be installed, they will need to be located not only so as to avoid the slabs or footings, but also such that they will be 10 feet away from the building foundations per BMP 6.4.6. Of course, an alternative would be to remove the existing slabs or footings and backfill with suitable borrow.

PECO Site – Vegetated Roof and Rain 3 Johnson, Mirmiran & Thompson, Inc. Barrel/Dry Well SWM Facility

APPENDICES

APPENDIX A

• Vegetated Roof and Rain Barrel/Infiltration Test Plan View

LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD

LOD LOD

LOD

LOD LOD LOD

LOD LOD

TP-2 LOD

LOD LOD LOD LOD LOD LOD LOD LOD

LOD

LOD LOD LOD LOD LOD LOD

LOD LOD LOD LOD FIGURE 1 - TEST PIT AND DOUBLE RING INFILTRATION LOCATIONS

LOD

LOD LOD LOD

LOD LOD LOD LOD LOD

TP-1 LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD LOD

LOD

LOD LOD LOD LOD LOD LOD LOD LOD

APPENDIX B

• Test Pit Logs • Laboratory Test Results

Johnson Mirmiran & Thompson, Inc. TEST PIT NUMBER: TP-1 40 Wight Avenue PAGE 1 OF 1 Hunt Valley, Maryland 21030 CLIENT PECO PROJECT NAME Tilghman Lateral PROJECT NUMBER 18-00672-06A PROJECT LOCATION Chester, PA

GROUND ELEVATION SIZE " GROUND WATER & CAVED DEPTH LEVELS DATE STARTED 7/24/20 COMPLETED 7/24/20 AT TIME OF EXCAVATION --- EXCAVATION CONTRACTOR / RIG AGI / JCB 8029CTS AT END OF EXCAVATION --- EXCAVATION METHOD LOGGED BY PEO AUGERS PULLED EXCAVATION --- CAVED EXCAVATION --- NORTH - 191691.36 EAST - 2634808.76 2 HOURS AFTEREXCAVATION 7.0 ft CAVED EXCAVATION 7.0 ft

MATERIAL DESCRIPTION REMARKS (ft) DEPTH U.S.C.S. SAMPLE STRATUM GRAPHIC LOG STRATA DEPTH 0.0 TYPE / NUMBER 0' GP Sandy GRAVEL, Trace Organics, Moist, Gray and Black A 0.5' Sandy LEAN CLAY, Moist, Orangish Brown

CL B

2' Sandy SILT, Moist, Orangish Brown 2.5

ML B

5.0 5' Sandy SILT, Moist, Orangish Brown

ML B

Bottom of test pit at 7.0 feet TEST PITS 2 TILGHMAN LATERAL TEST PITS.GPJ GINT US.GDT 7/30/20 US.GDT GINT TEST PITS.GPJ LATERAL 2 TILGHMAN TEST PITS Johnson Mirmiran & Thompson, Inc. TEST PIT NUMBER: TP-2 40 Wight Avenue PAGE 1 OF 1 Hunt Valley, Maryland 21030 CLIENT PECO PROJECT NAME Tilghman Lateral PROJECT NUMBER 18-00672-06A PROJECT LOCATION Chester, PA

GROUND ELEVATION SIZE " GROUND WATER & CAVED DEPTH LEVELS DATE STARTED 7/24/20 COMPLETED 7/24/20 AT TIME OF EXCAVATION --- EXCAVATION CONTRACTOR / RIG AGI / JCB 8029CTS AT END OF EXCAVATION --- EXCAVATION METHOD LOGGED BY PEO AUGERS PULLED EXCAVATION --- CAVED EXCAVATION --- NORTH - 191644.39 EAST - 2634812.08 2 HOURS AFTEREXCAVATION DRY CAVED EXCAVATION 7.0 ft

MATERIAL DESCRIPTION REMARKS (ft) DEPTH U.S.C.S. SAMPLE STRATUM GRAPHIC LOG STRATA DEPTH 0.0 TYPE / NUMBER 0' GP Sandy GRAVEL, Trace Organics, Moist, Gray and Black A 0.5' Asphalt Millings, Moist, Black

GP A

2' Sandy SILT, Moist, Orangish Brown 2.5

ML B

5.0 5' Sandy SILT, Moist, Orangish Brown

ML B

Bottom of test pit at 7.0 feet TEST PITS 2 TILGHMAN LATERAL TEST PITS.GPJ GINT US.GDT 7/30/20 US.GDT GINT TEST PITS.GPJ LATERAL 2 TILGHMAN TEST PITS AMERICAN GEOTECH, INC. Engi neers, Consul tants, and M ateri al Testi ng L aboratori es Main Office: 1801 Penn Ave., Wyomissing Hills, PA 19609; Tel.: (610) 670-9055 / Fax: (610) 678-2719 Branch Office: 209 Main Street, Woodbridge, NJ 07095; Tel.: (732) 750-1668

Particle Size Analysis of Soils (In accordance with ASTM D 422)

Boring Client: JMT Number: TP-1 Sample Project: TILGHMAN LATERAL Number: TP-1 Sample Depth Location: CHESTER. PA (Ft.): 5

AGI Project #.: Date(s) Tested: 7/28/20

TEST DATA:

Sieve Opening U.S. Weight Cumulative Cumulative Percent Total Sieve Inches Millimeter Standard Retained Weight Percent Finer by Weight of Weight Sieve Size on Sieve Retained Retained Weight Sieve + or Number Soil

3.00 76 3" 0.0 0.0 0.0 100.0 0.0 0.0 1.50 38 1 1/2" 0.0 0.0 0.0 100.0 0.0 0.0 0.75 19.1 3/4" 0.0 0.0 0.0 100.0 0.0 0.0 0.375 9.52 3/8" 0.0 0.0 0.0 100.0 518.8 518.8 0.187 4.76 No. 4 0.0 0.0 0.0 100.0 770.2 770.2 0.079 2 No. 10 0.7 0.7 0.8 99.2 446.0 445.3 0.033 0.84 No.20 1.4 2.1 2.3 97.7 430.6 429.2 0.0165 0.42 No.40 5.8 7.9 8.5 91.5 354.6 348.8 0.0098 0.25 No. 60 11.1 19.0 20.4 79.6 340.0 328.9 0.0059 0.149 No. 100 13.4 32.4 34.7 65.3 341.0 327.6 0.0029 0.074 No. 200 11.9 44.3 47.5 52.5 335.1 323.2 1.4 344.1 342.7 Pan 47.6

Total Sample Weight in Grams 93.3

Gradation Curve

100.0

80.0

60.0

40.0

20.0 Percent Finer by Weight Finer by Percent

0.0 1000 100 10 1 0.1 0.01 0.001 Grain Size in Millimeters

Gradation by Descriptive Component: ML " Sandy SILT"

Boulders Cobbles Gravel Sand Silt and Clay Coarse Fine Coarse Medium Fine Sieve Range > 12" 12" - 3" 3" - 3/4" 3/4" - #4 #4 - #10 #10 - #40 #40 - #200 < #200 % of Sample 0.0 0.0 0.0 0.0 0.8 7.7 39.0 52.5

D10= D30= D60=

Cu= Cc= LL: NP PL: NP Tested By: Date: PI: NP Reviewed By: Date: AMERICAN GEOTECH, INC. Engi neers, Consul tants, and M ateri al Testi ng L aboratori es Main Office: 1801 Penn Ave., Wyomissing Hills, PA 19609; Tel.: (610) 670-9055 / Fax: (610) 678-2719 Branch Office: 209 Main Street, Woodbridge, NJ 07095; Tel.: (732) 750-1668

Particle Size Analysis of Soils (In accordance with ASTM D 422)

Boring Client: JMT Number: TP-2 Sample Project: TILGHMAN LATERAL Number: TP-2 Sample Depth Location: CHESTER. PA (Ft.): 5

AGI Project #.: Date(s) Tested: 7/28/20

TEST DATA:

3.00 76 3" 0.0 0.0 0.0 100.0 0.0 0.0 1.50 38 1 1/2" 0.0 0.0 0.0 100.0 0.0 0.0 0.75 19.1 3/4" 0.0 0.0 0.0 100.0 0.0 0.0 0.375 9.52 3/8" 0.0 0.0 0.0 100.0 518.8 518.8 0.187 4.76 No. 4 0.0 0.0 0.0 100.0 770.2 770.2 0.079 2 No. 10 0.4 0.4 0.3 99.7 445.7 445.3 0.033 0.84 No.20 1.8 2.2 1.9 98.1 431.0 429.2 0.0165 0.42 No.40 6.2 8.4 7.3 92.7 355.0 348.8 0.0098 0.25 No. 60 12.1 20.5 17.7 82.3 341.0 328.9 0.0059 0.149 No. 100 15.0 35.5 30.7 69.3 342.6 327.6 0.0029 0.074 No. 200 12.8 48.3 41.7 58.3 336.0 323.2 1.0 343.7 342.7 Pan 66.4

Total Sample Weight in Grams 115.7

Gradation Curve

100.0

80.0

60.0

40.0

20.0 Percent Finer by Weight Finer by Percent

0.0 1000 100 10 1 0.1 0.01 0.001 Grain Size in Millimeters

Gradation by Descriptive Component: ML " Sandy SILT"

Boulders Cobbles Gravel Sand Silt and Clay Coarse Fine Coarse Medium Fine Sieve Range > 12" 12" - 3" 3" - 3/4" 3/4" - #4 #4 - #10 #10 - #40 #40 - #200 < #200 % of Sample 0.0 0.0 0.0 0.0 0.3 6.9 34.5 58.3

D10= D30= D60=

Cu= Cc= LL: NP PL: NP Tested By: Date: PI: NP Reviewed By: Date:

APPENDIX C

• Double Ring Infiltration Test Results

AMERICAN GEOTECH, INC. Ci vi l /Geotechni cal Engi neers and M ateri al Testi ng L aboratori es Main Office: 1801 Penn Ave., Wyomissing Hills, PA 19609; Tel.: (610) 670-9055 / Fax: (610) 678-2719 Branch Office: 209 Main Street, Woodbridge, NJ 07095; Tel.: (732) 750-1668

INFILTRATION RATE (PA CODE 73.15) (ASTM D 3385-94

Client: JMT Date: 7/24/2020 (7/30/2020 REVISED)

Project: TILGHMAN LATERAL Surface Condition: FILL MATERIALS ( GRAVEL)

Location: CHESTER, PA AGI Project No.:

SOIL DESCRIPTION: Weather Conditions: Cloudy TP-1 TP-2 Temperature: 83 0 feet TO 2 feet Sandy Clay 0 feet To 2 feet Fill meterials 2 feet TO 5 feet Brown Sandy 2 feet To 5 feet Brown Sandy SILT SILT

TEST PIT LOCATIONS SEE FIGURE 1 ONE SOIL SAMPLE AT BOTTOM OF EACH TEST` PIT WAS COLLECTED AND SENT TO AGI'S LABORATORY FOR SIEVE ANALYSES. TEST RESULTS ARE PRESENTED IN ATTACHMENT 1.

INFILTRATION TEST: (ASTM D3385-94)

TEST READING OUTER RING INNNER RING DEPTH OF THE READING NO. READING NO. READING NO. READING NO. LOCATION INTERVAL DIAMETER DIAMETER TEST 1 2 3 4 (MIN.) (INCHES) (INCHES) (FEET) INCHES OF DROP INCHES OF DROP INCHES OF DROP INCHES OF DROP TP- 1 30 24.00 12.00 5.0 1.00 0.50 0.50 0.50 TP-2 30 24.00 12.00 5.0 1.00 0.63 0.63 0.63

NOTE:

CALCULATION OF AVERAGE INFILTRATION RATE:

DROP DURING INFILTRATIO TEST HOLE FINAL PERIOD N RATE NO. INCHES/30 MIN IN/HOUR

TP - 1 0.50 1.00 TP- 2 0.63 1.25

Infiltration Rates vary from 1.0 to 1.25 in/hour with an avg Infiltration rate of

AVG INFILTRATION RATE = 1.13 in/hour 28.6 mm/hour

INSPECTOR : AT DATE: 7/28/2020 CHECKED BY : KC DATE: 7/30/2020

1600 Market Street, Suite 520 Philadelphia, PA 19103 P. 267-256-0300 www.jmt.com