canada post corporation

CANADA POST CORPORATION

PROPOSED PARKING LOT 2785 RIVERSIDE DRIVE

STORMWATER MANAGEMENT REPORT

Prepared by:

NOVATECH Suite 200, 240 Michael Cowpland Drive

Kanata, Ontario K2M 1P6

June 30, 2015 Revised: October 29, 2015

Ref: R-2015-112 Novatech File No. 114093

M:\2014\114093\DATA\Reports\SWM\CPC Parking Lot SWM Report_rev2.docx

Suite 200, 240 Michael Cowpland Drive, Ottawa ON K2M 1P6 Tel: 613.254.9643 Fax: 613.254.5867 www.novatech-eng.com

October 29, 2015 Jones Lang LaSalle Real Estate Services Inc. 275 Slater Street, Suite 1004 Ottawa, Ontario K1P 5H9 Attention: Mr. Peter Miller Dear Sir: Re: Stormwater Management Report

Canada Post Corporation Parking Lot 2785 Riverside Drive Ottawa, ON Our File No.: 114093

Enclosed is a copy of the revised ‘Stormwater Management Report’ for the proposed development. The site is located on the Canada Post Corporation (CPC) complex at 2785 Riverside Drive, in the City of Ottawa. This report addresses the approach to stormwater management for the subject site and is submitted in support of the Site Plan amendment application. Please contact the undersigned, should you have any questions or require additional information. Yours truly,

NOVATECH

François Thauvette, P. Eng. Project Manager cc: Cody Oram (City of Ottawa) Robert Turenne (CPC)

Proposed Parking Lot, 2785 Riverside Drive Canada Post Corporation – Stormwater Management Report

Novatech i

TABLE OF CONTENTS

1.0 INTRODUCTION ............................................................................................................. 1

1.1 Purpose ..................................................................................................................... 1

1.2 Location and Site Description ................................................................................. 1

1.3 Pre-Consultation Information .................................................................................. 2

1.4 Proposed Development ............................................................................................ 2

2.0 STORM DRAINAGE AND STORMWATER MANAGEMENT.......................................... 2

2.1 Stormwater Management Criteria and Objectives .................................................. 2

2.1.1 Allowable Release Rate .................................................................................... 2

2.2 Stormwater Quantity Control ................................................................................... 3

2.2.1 Area A-1 – Controlled Flow from Parking Lot ................................................. 3

2.2.2 Area A-2 – Direct Runoff ................................................................................... 3

2.2.3 Comparison of Site Flows (Allowable vs. Post-Development) ...................... 3

2.3 Stormwater Quality Control ..................................................................................... 4

2.4 Major System Overland Flow Route ........................................................................ 4

3.0 EROSION AND SEDIMENT CONTROL ......................................................................... 4

4.0 CONCLUSION ................................................................................................................ 5

LIST OF FIGURES

Figure 1 Aerial Plan

LIST OF APPENDICES

Appendix A: Correspondence

Appendix B: SWM Calculations, IDF Curves, Storm Sewer Design Sheet

Appendix C: CDS Treatment Unit Information

LIST OF DRAWINGS

114093-SGS – Site Servicing, Grading and Stormwater Management Plan


Novatech 1

1.0 INTRODUCTION

The owner is proposing to construct a new parking lot at the Canada Post Corporation (CPC) Head Office complex in Ottawa. The proposed parking lot will replace the recently demolished Building ‘F’ located near the south west corner of the property. Novatech has been retained to complete the stormwater management design for this project.

1.1 Purpose

This report outlines the approach to site drainage and stormwater management. This report is being submitted in support of the site plan amendment application for the subject property.

1.2 Location and Site Description

The Canada Post Corporation (CPC) Head office in Ottawa is bordered by Heron Road to the north, Brookfield Road to the south, the Airport Parkway to the east and Riverside Drive to the west. The parking lot to be constructed will be located at 2785 Riverside Drive, south of Building ‘B’, west of Building ‘C’, near the southwest corner of the property. The proposed parking lot will replace the recently demolished Building ‘F’ and covers an approximate area of 0.777 hectares.

Figure 1 – Aerial Plan provides an aerial view of the site.


Novatech 2

1.3 Pre-Consultation Information

A pre-consultation meeting was held with the City of Ottawa on June 5, 2015 at which time the client was advised of the general submission requirements. Subsequent discussions were held with the Rideau Valley Conservation Authority (RVCA) regarding the stormwater quality control requirements for this subject site. Refer to Appendix A for a summary of the correspondence with the City of Ottawa and the RVCA.

1.4 Proposed Development

The proposed development will consist of a new 175-spot surface parking lot with associated landscaping and storm drainage system. Stormwater runoff from the proposed parking lot will be collected by the proposed storm sewer system and flows will be controlled by an inlet control device (ICD) prior to being released into the existing on-site storm sewer system. The parking lot flows will also pass through an oil grit separator to achieve the required Enhanced level of stormwater quality control (80% TSS removal) prior to being directed towards the municipal storm sewer system, which in turn outlets into the Rideau River located approximately 1 km northwest of the subject site.

2.0 STORM DRAINAGE AND STORMWATER MANAGEMENT

The subject site covers approximately 0.777 hectares. As described above, the stormwater management design will include both on-site stormwater quantity and stormwater quality control. A detailed description of the sub-catchment areas and post-development flows are discussed in the subsequent sections of this report.

2.1 Stormwater Management Criteria and Objectives

The criteria and objectives for the proposed stormwater management design are as follows:

• Provide a dual drainage system (i.e. minor and major system flows).

• Maximize surface storage available on-site.

• Control post-development flow to the maximum 1:5 year allowable release rate specified by the City of Ottawa. Post-development runoff in excess of the allowable release rate will be stored and controlled on-site for storms up to and including the 1:100 year design event, prior to being released into the existing on-site storm sewer system.

• Provide an Enhanced level of on-site stormwater quality control (minimum 80% TSS removal) prior to releasing flows from the proposed parking lot.

• Provide guidelines to ensure that site preparation and construction is in accordance with the current Best Management Practices for Erosion and Sediment Control.

2.1.1 Allowable Release Rate

The allowable release rate for the 0.777 hectare site to be re-developed was calculated using the Rational Method to be 75.9 L/s. This release rate was based on an allowable runoff coefficient (Callow=0.5) and a 1:5 year rainfall intensity of 70.3 mm/hr (City of Ottawa IDF Curves) using a time of concentration (tc) of 20.0 minutes. Refer to Appendix A for correspondence from the City of Ottawa and to Appendix B for SWM calculations.


Novatech 3

2.2 Stormwater Quantity Control

The proposed parking lot will be serviced by the existing on-site storm sewer that previously serviced the recently demolished Building ‘F’ and associated parking lot. This storm sewer outlets into the municipal storm sewer in Riverside Drive, which in turn flows into the municipal storm sewer in Heron Road. Flows are ultimately discharged into the Rideau River located approximately 1 km northwest of the subject site. The CCTV inspection of the existing private storm sewer system is being completed and will be provided to the City of Ottawa under separate cover.

2.2.1 Area A-1 – Controlled Flow from Parking Lot

The post-development flow from this sub-catchment area will be attenuated by the use of an inlet control device (ICD) installed in the outlet pipe of CBMH 4. Stormwater runoff from this sub-catchment area will be temporarily stored on the surface of the paved parking lot prior to being discharged into the on-site storm sewer system. Table 1 summarizes the post-development design flow from the sub-catchment area as well as the type of ICD, the anticipated ponding elevations, storage volumes required and storage volume provided for both the 1:5 year and the 1:100 year design events.

Table 1: Design Flow and Inlet Control Device Table

Design Event

Sub-Catchment Area A-1

Post-Development Conditions

Orifice Plug Type ICD

Design Flow (L/s)

Ponding Depth (m)

Storage Vol. Required (m³)

Max Storage Provided (m³)

1:5 Year 126mm dia. 48.7 L/s 0.15 m 60.3 m³ 168.0 m³

1:100 Year 126mm dia. 49.5 L/s 0.24 m 166.4 m³

Refer to Appendix B for SWM calculations.

2.2.2 Area A-2 – Direct Runoff

The uncontrolled post-development flow from this very small sub-catchment area was calculated using the Rational Method to be 13.1 L/s for the 1:5 year design event and 26.4 L/s for the 1:100 year design event. Refer to Appendix B for SWM calculations.

2.2.3 Comparison of Site Flows (Allowable vs. Post-Development)

Table 2 compares the post-development flows from the site to be developed to the allowable flows for both the 1:5 year and 1:100 year design events.

Table 2: Comparison of Allowable Flows to Post-Development Flows

Design Event

Allowable Flow (L/s) Post-Development Flow (L/s)

Total Site Area (0.777 ha)

Area A-1 (0.621 ha)

Area A-2 (0.156 ha)

Total Site Area (0.640 ha)

1:5 Year 75.9 L/s 48.7 L/s 13.1 L/s 61.8 L/s

1:100 Year 75.9 L/s 49.5 L/s 26.4 L/s 75.9 L/s


Novatech 4

As indicated in the table above, the post-development flows from the site will not exceed the allowable release rates for the 1:5 and 1:100 year design events.

2.3 Stormwater Quality Control

The subject site is located within the jurisdiction of the Rideau Valley Conservation Authority (RVCA) and requires best efforts to achieve an ‘Enhanced’ level of protection (i.e. minimum long-term average of 80% Total Suspended Solids (TSS) removal and at least 90% of the total rainfall being captured and treated). In order to mitigate the stormwater-related impacts due to the proposed development, runoff from the paved parking lot will be directed through a CDS Model PMSU 20_20_5 type oil/grit separator prior to being conveyed to the on-site storm sewer system, municipal storm sewer and ultimately into the Rideau River. The target level of protection is a long-term average removal of 80% of total suspended solids (TSS). Echelon Environmental have modeled and analyzed the tributary area to provide a CDS unit capable of meeting the TSS removal requirements. The model parameters for the TSS removal were based on historical rainfall data for Ottawa from the Ontario Climate Centre. It was determined that a CDS Model PMSU 20_20_5 will meet the target removal rate, providing a net annual 80% TSS removal and will treat 90% of the net annual rainfall for the tributary area. The CDS unit has a treatment capacity of approximately 31 L/s, a sump volume of 1.67m3, a total holding volume capacity of 3.15m3 and a minimum oil storage capacity of 376 L. It is recommended that the client implement a maintenance and monitoring program for the on-site storm sewers and stormwater management system: The storm drainage system should be inspected routinely (at least annually); the ICD should be inspected to ensure it is fitted securely and free of debris; and the oil-grit separator should be inspected at regular intervals and maintained when necessary to ensure optimum performance. Refer to Appendix C for the CDS unit operation, design, performance and maintenance summary parameters as well as the annual TSS removal efficiency data.

2.4 Major System Overland Flow Route

In the case of a major rainfall event exceeding the 1:100 year design event accounted for, the stormwater located within the paved parking lot will pond to a maximum depth of 0.25m before spilling into the roadway to the east. The major system overland flow route is shown on the enclosed 114093-SGS plan.

3.0 EROSION AND SEDIMENT CONTROL

To mitigate erosion and prevent sediment from entering the storm sewer system, temporary erosion and sediment control measures will be implemented on-site during construction in accordance with the Best Management Practices for Erosion and Sediment Control. This includes the following temporary measures:

• Filter bags will be placed under the grates of nearby catchbasins and manholes, and will remain in place until vegetation has been established and construction is completed;

• Silt fencing will be placed as per OPSS 577 and OPSD 219.110 along the surrounding construction limits;


Novatech

APPENDIX A

Correspondence

Meters

© Rideau Valley Conservation Authority

Map produced by RVCA, under License with the Ontario Ministry of Natural Resources © Queen's Printer for Ontario, 2015. This map is the property of the RVCA, and the RVCA holds a copyright on them. These maps may be copied or reproduced, provided that the RVCA is properly acknowledged as the original source of the information and provided that no fee is charged (other than to cover handling charges). The RVCA cannot guarantee the accuracy of the mapping for all possible uses. End-users of the information contained herein must therefore determine if the information is of suitable accuracy for their purposes

Legend

6/10/2015

6,735.21

Parcel data is owned by Teranet Enterprises Inc and its suppliers. All rights reserved. May not be reproduced without permission.

WGS_1984_Web_Mercator_Auxiliary_Sphere

1:

Map Projection:

171.07342.1 342.10

Map created:

Map Title

Notes

OHN Watercourse

RVCA Sub-Watersheds

RVCA Catchments

Regulation Limit

100yr Floodline

Reg Limit Dominant Hazard

Floodplain

Geo-technical Hazard Limit

Meander Belt

Stable Slope

Top of Slope

Unstable Slope

Wetland

Ottawa Parcels

Storm Water Management

Storm Outlet

Storm Combined Pipe

Combined Pipe

Storm Pipe

Parcel Activity

Township Municipal

Parcel - Assesment

Lot

Geographic Township

Waterbody

Wetlands

Evaluated-Provincial

Evaluated-Other

Not evaluated per OWES

DRAPE 2014

Red: Band_1

Green: Band_2

Blue: Band_3


Novatech

APPENDIX B

SWM Calculations, IDF Curves, Storm Sewer Design Sheet


Novatech

RATIONAL METHOD The Rational Method was used to determine both the allowable release rate as well as the post-development runoff for the portion of the site to be developed. The equation is as follows: Q=2.78 CIA Where: Q is the runoff in L/s C is the weighted runoff coefficient* I is the rainfall intensity in mm/hr** A is the area in hectares *The weighted runoff coefficient is determined for each of the catchment areas as follows: C = (Aperv x Cperv) + (Aimp x Cimp) Atot Where: Aperv is the pervious area in hectares Cperv is the pervious area runoff coefficient (Cperv=0.20) Aimp is the impervious area in hectares Cimp is the impervious area runoff coefficient (Cimp=0.90) Atot is the catchment area (Aperv + Aimp) in hectares Note: Increase the C values above by 25% for the 1:100 year event (max. Cimp=1.0). ** The rainfall intensities used for the post-development flow calculations were taken from the City of Ottawa IDF curves. A time of concentration (tc) of 20 minutes was used for the allowable release rate calculation, resulting in a rainfall intensity of 70.3 mm/hr for the 1:5 year event. A time of concentration (tc) of 10 minutes was used for the post-development conditions, resulting in rainfall intensities of 104.2 mm/hr for the 1:5 year event and 178.6 mm/hr for the 1:100 year event. SAMPLE CALCULATIONS: ALLOWABLE FLOW CALCULATIONS – 0.777 ha SITE Drainage Area (A) = 0.777 ha Runoff Coefficient (C5) = 0.5 Intensity (I5) = 70.3 mm/hr Qallow= 2.78 CIA Qallow= 2.78 x 0.5 x 70.3 x 0.777 Qallow= 75.9 L/s POST-DEVELOPMENT FLOW CALCULATIONS – AREA A-2 Drainage Area (A) = 0.156 ha Impervious Area = 0.019 ha Pervious Area = 0.137 ha Runoff Coefficient (C5yr) = 0.29


Novatech

Runoff Coefficient (Cw100yr) = 0.34 Intensity (I5) = 104.2 mm/hr Intensity (I100) = 178.6 mm/hr

( ) ( )29.0

156.0

90.0019.020.0137.0

5=×+×=yrC

( ) ( )34.0

156.0

0.1019.025.0137.0

100=×+×=yrC

Q5= 2.78 CIA Q100= 2.78 CIA Q5= 2.78 x 0.29 x 104.2 x 0.156 Q100= 2.78 x 0.34 x 178.6 x 0.156 Q5= 13.1 L/s Q100= 26.4 L/s

ORIFICE CALCULATION – ICD WITHIN OUTLET PIPE OF CBMH 4 The ICD installed in the outlet pipe of CBMH 4 will control the flows from the parking lot. Iterative calculations were required to determine the storage, approximate design flow and head. The controlled flow through the orifice was calculated to be approximately 49.5 L/s for the 1:100 year design event. The head was calculated from the water elevation to the centerline of the orifice to be approximately 2.11m (78.34m – (76.04 + (0.381/2))). Q = 0.62 x A x (2gh)1/2 0.0495 = 0.62 x A x (2 x 9.81 x 2.11)1/2 A = 0.0124086 = 3.14 x r2 The diameter of the orifice was calculated to be 0.125694551 or 126 mm. Iterative calculations were done to determine the release rate for the 1:5 year design event. The same orifice, with a design head of 2.02m, will release the 1:5 year design event at the rate of approximately 48.7 L/s.

Project: Canada Post Corporation - Parking Lot DATE: June 2015

Location: 2785 Riverside Drive REV: October 2015 by SM

Novatech Project No. 114093

Stormwater Management Summary Sheet

5 year 100 year 100 year Effective Available Required Available Required Head on

Sub Sub C = C = Combined Combined Outlet Controlled Top of Ponding 5 year 5 year 100 year 100 year Invert or Pipe dia Orifice Diameter

Area Area 0.2 0.9 Composite Composite Location Release Grate Depth volume volume volume volume Pan Elev. (if plug type) (if plug) of Orifice

I.D. (ha) C C (L/s) (m) (m) (cu.m) (cu.m) (cu.m) (cu.m) (m) (mm) (m) (mm)

A1 0.621 0.087 0.534 0.80 0.89 CBMH 4 49.5 78.10 0.24 60.3 60.3 168.0 166.4 76.04 381 2.11 126

A2 0.156 0.137 0.019 0.29 0.34 Free Flow 26.4 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A

0.777 0.224 0.553 75.9

Area

M:\2014\114093\DATA\Calculations\Sewer Calcs\SWM\114093 - SWM_rev2.xls

Project: Canada Post Corporation - Parking Lot

Location: 2785 Riverside Drive DATE: June 2015

Novatech Project No. 114093 REV: Oct. 2015 by SM

Storage Requirements for Area A1 (CBMH 4)

Area 0.621 hectares

5 Year Runoff Coefficient = 0.80 post development

100 Year Runoff Coefficient= 0.89 post development

Return Time Intensity Flow Controlled Net Runoff To Storage Req'd

Period (min) (mm/hr) Q (L/s) Release Be Stored (L/s) m3

10 104.19 144.25 48.7 95.6 57.3

5 Year 15 83.56 115.68 48.7 67.0 60.3

20 70.25 97.26 48.7 48.6 58.3

25 60.90 84.31 48.7 35.6 53.5

30 53.93 74.66 48.7 26.0 46.8

10 178.56 275.87 49.5 226.4 135.8

20 119.95 185.32 49.5 135.8 163.0

100 Year 25 103.85 160.44 49.5 110.9 166.4

35 82.58 127.58 49.5 78.1 164.0

45 69.05 106.68 49.5 57.2 154.4

Description

Pipe

Diameter

(mm)

Pipe

Length (m)

Depth to

Invert (m)

Storage

Volume (m3)

Cumulative

Volume (m3)*

381.0 59.0 N/A 6.72 6.72

CB 1 N/A N/A 1.58 0.57 7.29

CB 2 N/A N/A 1.58 0.57 7.86

CB 3 N/A N/A 1.58 0.57 8.43

CBMH 4 N/A N/A 2.06 2.33 10.76

10.76

*Cumulative Volume = Sum of all (Pipe Area x Pipe Length) + (CB Area x CB Depth) + (CBMH Area x CBMH Depth)

CB 1 246.9 0.15 12.35 481.7 0.24 38.54

CB 2 247.5 0.15 12.38 466.3 0.24 37.30

CB 3 248.1 0.15 12.41 499.1 0.24 39.93

CBMH 4 248.4 0.15 12.42 518.3 0.24 41.46

Sub Total 49.55 Sub Total 157.23

** Total storage available = Surface storage + pipe & structure storage

= 157.23 + 10.76

= 168.0 Cubic Metres

Pipe Storage

Pipe and Structure storage =

5 YEAR 100 YEAR

SURFACE STORAGE

Catchbasin

Manhole

Storage

Catchbasin

Storage

Stormwater Storage Volumes for Areas A1



Novatech

Project: Canada Post Corporation - Parking Lot DATE: June 2015

Location: 2785 Riverside Drive REV: Oct 2015 by SM

Novatech Project No. 114093

Table 2. Storm Sewer Design Sheet

TOTAL TIME RAINFALL PEAK PIPE PIPE FULL FLOW TIME OF EXCESS

FROM TO AREA R= R= INDIV ACCUM OF INTENSITY FLOW SIZE SLOPE LENGTH CAPACITY VELOCITY FLOW CAPACITY Q/Qfull

0.2 0.9 2.78 AR 2.78 AR CONC. I Q (l/s) (mm) (%) (m) (l/s) (m/s) (min.) (l/s)

CB 1 CBMH 4 0.621 0.087 0.534 1.38 1.38 10.00 104.19 144.25 381.0 0.80 59.0 163.77 1.43 0.69 19.52 0.88

CBMH 4 OGS 0.000 0.000 0.000 0.00 1.38 10.69 100.71 139.42 381.0 0.80 1.5 163.77 1.43 0.02 24.34 0.85

OGS EX MH 0.000 0.000 0.000 0.00 1.38 10.70 100.62 139.31 381.0 0.80 6.0 163.77 1.43 0.07 24.46 0.85

Definitions Notes:

Q = 2.78 AIR 1) Ottawa Rainfall-Intensity Curve

Q = Peak Flow, in Litres per second (L/s) 2) Min Velocity = 0.76 m/sec.

A = Area in hectares (ha)

I = Rainfall Intensity (mm/h)

R = Runoff Coefficient

LOCATION AREA (Ha) UNCONTROLLED FLOW PROPOSED SEWER



Novatech

APPENDIX C

CDS Treatment Unit Information

505 Hood Road Unit 26 Markham ON L3R 5V6

Tel: (905) 948-0000 Fax: (905) 948-0577 E-mail: [email protected]

June 25, 2015

Novatech Engineering Consultants Ltd 240 Michael Cowpland Drive, Suite 200 Ottawa, ON K2M 1P6 Tel: 613.254.9643 Fax: 613.254.5867 Attention: Mr. Larry Colbran RE: Submittal for Approval for the CDS PMSU 20_20_5 for the Canada Post, Brookfield Rd, Ottawa, ON Mr. Colbran, Echelon Environmental is pleased to offer this detailed submittal package for approval of the CDS PMSU 20_20_5 stormwater treatment system on the Canada Post, Brookfield Road, Ottawa, ON.

The proposed CDS PMSU 20_20_5 was designed based on the following parameters: Design Parameters

Drainage Area: 0.64 ha

Imperviousness: 89-percent (calculated) Runoff Coefficient: 0.83

Time of Concentration: 10 minutes (Assumed) Target Particle Size Distribution: Fine

MOE Treatment Level: Normal (80% TSS Removal, 90% of flow treated) Peak Flow to OGS: TBD ( 51.9 l/sec based upon upstream ICD and

100 year storm)

Our TSS removal calculation can be found in Appendix I. As indicated on the calculation, the CDS PMSU 20_20_5 has been selected to capture 80-percent TSS on an average annual basis and treat 90-percent of the site runoff. As noted on the calculation, the TSS removal efficiency was based on a Fine PSD and weather station 6105976 (downtown) Appendix II shows the validation against a Fine PSD, as well as the anticipated grit load/cleaning cycle.

TSS Removal Calculation

Detailed submittal drawings will follow upon request. PMSU 20_20_5 cut sheet is in Appendix III. Detailed Submittal Drawings

The proposed CDS PMSU 20_20_5 has been is designed to Canadian Highway Bridge Design Code (CHBDC) loadings. All concrete components are manufactured at an OPS pre-qualified plant.

Structural Design

Currently over 2000 CDS units installed throughout Ontario with single units treating drainage areas ranging from 0.1 ha to 50 ha. The CDS Stormwater Treatment System is an approved product in Ontario and is servicing various jurisdictions throughout the province.

Approval Background

Approval of the CDS Technology for TSS Removal NJDEP – CDS has met NJDEP’s testing requirements and is a re-certified product as of January, 2015. It is also the only Oil/Grit Separator to have achieved Tier One and Tier Two testing with approved scour testing as of January, 2015. Ministry of Environment - The Ministry of Environment (MOE) has reviewed the system and has provided Certificate of Approval/Environmental Compliance, (see Appendix IV). Approvals are for sites using CDS units to achieve Level 1 (80% TSS Removal, 90% Runoff Treated) treatment. Ontario Provincial Standards – Ontario Provincial Standards’ (OPS) Special Review Committee for the approval of oil/grit separators in municipal roadway applications, standardized a review process for all municipalities. CDS has been reviewed and approved by OPS. Certification is attached, Appendix IV.

Conventional oil-grit separators rely solely on gravity for grit separation. By contrast, CDS units utilize multiple hydraulic techniques to allow large flows to be processed in a compact footprint. These processes include gravity, swirl concentration and a patented inertial based screening process. In a CDS system, the energy in the storm flow is used to enhance separation, thereby allowing for a much more compact treatment chamber.

System Features

The CDS system removes 100% of the buoyant and neutrally buoyant material larger than 2.4mm up to the treatment flowrate. The system also incorporates a riser tube on top of the treatment chamber that extends beyond the high water condition to maintain the capture of buoyant material during peak events and temporary backwater conditions.

Floatables Containment

CDS units are capable of capturing and retaining hydrocarbons with its integral oil baffle design. CDS units were tested and demonstrated to be greater than 99% effective in controlling dry-weather accidental oil spills.

Hydrocarbon Capture

CDS units have an internal by-pass weir and are capable of by-passing peak design storm events. CDS units are custom designed for each site based on the specific hydraulic requirements.

Internal High Flow By-Pass Capability

CDS units have a separate treatment chamber and grit storage sump chamber. With this design feature, the geometry of the treatment chamber is not impacted by accumulated grit, and the independent sump chamber volume can be optimized to capture the estimated accumulated grit in between maintenance cycles.

Sump is Separate from the Treatment Chamber

Echelon Environmental provides a full Operations and Maintenance Manual with as-built drawings included for all CDS units. Echelon Environmental also offers a comprehensive Inspection and Maintenance Program to assist owners in establishing long term maintenance for their separators.

Inspection and Maintenance

We trust this submittal fully addresses all the tender requirements for the oil-grit separator. Yours Truly, Echelon Environmental Inc. George Gebara, B.Eng - Project Manager

APPENDIX I CDS TSS REMOVAL CALCULATIONS

Project Name: Canada Post, Brookfield Engineer: Novatech

Location: Ottawa, On. Contact: Mr. Larry ColbranOGS #: OGS Report Date: 25-Jun-15

Area 0.64 ha 215Weighted C 0.83 (assumed) (select from Rainfall Data column D)Tc 10 minutes (assumed) Particle Size Distribution FINECDS Model 2020 (select from pulldown) 31 l/s

Rainfall

Intensity1

(mm/hr)

Percent

Rainfall

Volume1

Cumulative

Rainfall

Volume

Total

Flowrate

(l/s)

Treated

Flowrate (l/s)

Operating

Rate (%)

Removal

Efficiency

(%)

Incremental

Removal (%)

0.5 9.2% 9.2% 0.7 0.7 2.4 98.2 9.01.0 10.6% 19.8% 1.5 1.5 4.7 97.5 10.41.5 9.9% 29.7% 2.2 2.2 7.1 96.8 9.62.0 8.4% 38.1% 3.0 3.0 9.5 96.1 8.12.5 7.7% 45.8% 3.7 3.7 11.9 95.5 7.33.0 5.9% 51.7% 4.4 4.4 14.2 94.8 5.63.5 4.4% 56.1% 5.2 5.2 16.6 94.1 4.14.0 4.7% 60.7% 5.9 5.9 19.0 93.4 4.44.5 3.3% 64.0% 6.6 6.6 21.3 92.7 3.15.0 3.0% 67.1% 7.4 7.4 23.7 92.1 2.86.0 5.4% 72.4% 8.9 8.9 28.4 90.7 4.97.0 4.4% 76.8% 10.3 10.3 33.2 89.3 3.98.0 3.5% 80.3% 11.8 11.8 37.9 88.0 3.19.0 2.8% 83.2% 13.3 13.3 42.7 86.6 2.410.0 2.2% 85.3% 14.8 14.8 47.4 85.3 1.915.0 7.0% 92.3% 22.2 22.2 71.1 78.5 5.520.0 4.5% 96.9% 29.5 29.5 94.8 71.7 3.325.0 1.4% 98.3% 36.9 31.2 100.0 59.2 0.930.0 0.7% 99.0% 44.3 31.2 100.0 49.4 0.335.0 0.5% 99.5% 51.7 31.2 100.0 42.3 0.240.0 0.5% 100.0% 59.1 31.2 100.0 37.0 0.245.0 0.0% 100.0% 66.5 31.2 100.0 32.9 0.050.0 0.0% 100.0% 73.8 31.2 100.0 29.6 0.0

90.86.5%84.3%

98.6%

1 - Based on 42 years of hourly rainfall data from Canadian Station 6105976, Ottawa ON2 - Reduction due to use of 60-minute data for a site that has a time of concentration less than 30-minutes.

CDS ESTIMATED NET ANNUAL SOLIDS LOAD REDUCTION

Rainfall Station #

CDS Treatment Capacity

Removal Efficiency Adjustment2 =

Predicted % Annual Rainfall Treated =

BASED ON THE RATIONAL RAINFALL METHOD

Predicted Net Annual Load Removal Efficiency =

BASED ON A FINE PARTICLE SIZE DISTRIBUTION

APPENDIX II PSD VALIDATION AND ANTICIPATED GRIT

LOAD/CLEANING CYCLE

Engineer: Novatech Project: Canada Post, Brookfield RdContact: Larry Colbran CDS Model: 20_20_5

Report Date: 24-Jun-15 OGS Location: Ottawa, ON

0.64 ha89 %

0.83

Assumptions:

1. Annual Rainfall 700 mm2. Typical Grit Concentration 250 mg/l3. Apparent Grit Density 1.4 kg/l (estimated)4. Grit Capture Efficiency 80%

Runoff Volume = Area x Rainfall Depth x Runoff Coefficient = 3,718 cu.m

Grit Collected = Grit Concentration x Runoff Volume x Grit Capture Efficiency = 744 kg

Grit Volume = Mass / Apparent Density = 531 litres or 0.531 cu.m

Therefore it can be expected that this site will generate approximately 0.531cu.m of grit annually.

1.749 cu.m

Therefore the design sump capacity will accommodate a cleaning frequency of one time per 20 to 24 months.

Estimate of Annual Grit Collection

Area :

Imperviousness :

Runoff Coefficient :

Sump Capacity of CDS unit =

of 2

CDS Stormwater Treatment Unit Performance

Table 1. Fine Particle Size Distribution (PSD)

Particle Size (μm)

% of Particle Mass

< 20 20 20 – 40 10 40 – 60 10 60 – 130 20

130 – 400 20 400 – 2000 20

Removal Efficiencies – CDS Unit Testing Under Various Flow Rates The following performance curves are based on controlled tests using a full scale CDS Model PMSU20_20 (2400 micron screen), 1.1-cfs (494-gpm) capacity treatment unit.

CDS Unit Performance Curve for Ecology PSDFine Distribution

0.00

20.00

40.00

60.00

80.00

100.00

0% 20% 40% 60% 80% 100% 120% 140%% Design Flow Rate

TSS

Rem

oval

%

Figure 1. CDS Unit Performance for Fine PSD

of 2

CDS Unit Performance Testing Protocol

Tests were conducted using two types of sand – U.S. Silica OK-110 and UF sediment (a mixture of U.S. Silica sands). Particle size gradations for the two types of sand are illustrated in Figure 2.

0.010.020.030.040.050.060.070.080.090.0

100.0

1 10 100 1000 10000Particle Size (µm)

Per

cent

Fin

er

UF Mix Avg.OK 110 Avg.

Figure 2. Test material particle size gradations - CDS Model PMSU20_20 test

(Analytical results provided by MACTEC Engineering and Consulting Inc. FL ASTM D-422 with Hydrometer method)

The influent concentration (mg/L) for the test was set at 200-mg/L and verified from slurry feeding. Effluent samples were taken at fixed time intervals during each test run at various flow rates. The composite effluent samples were sent to Test American Analytical Testing Lab, OR for TSS analysis (ASTM D3977-97). TSS removal rates for the specified PSD (d50 of 90 µm) under various flow rates were calculated from Figure 2 shows the removal efficiency as a function of operating flow rate. This removal efficiency curve as a function of percent flow rate can be applied to all CDS unit models.

APPENDIX III CDS PMSU 20_20_5 CUTSHEET

APPENDIX IV

Ontario Provincial Standards Approval MOE Certificate

canada post corporation

Documents