PROPOSED RESIDENTIAL TOWERS AND COMMERCIAL SPACE 2418 Khalsa Gate, Oakville

FUNCTIONAL SERVICING AND STORMWATER MANAGEMENT REPORT

prepared for:

Golden Archtech Investment Corp.

prepared by:

MGM Consulting Inc. 400 Bronte Street South Suite 201 Milton, Ontario L9T 0H7

File No. 2015-017

Date: November 17, 2015

Functional Servicing and Stormwater Management Report Page 1 of 6 Proposed Residential Towers with Commercial Space, 2418 Khalsa Gate, Oakville, Ontario November 17, 2015

1.0 Purpose of Report

MGM Consulting Inc. has been retained by Golden Archtech Investment Corp. to prepare a Functional Servicing and Stormwater Report to address the site-specific infrastructure and grading required to support construction of the proposed ten storey residential and commercial building located at 2418 Khalsa Gate in the Town of Oakville. The site is approximately 0.515 ha in area and the legal description is Part of Lot 31, Concession 1, South of Dundas Street in the Town of Oakville in the Regional Municipality of Halton.

2.0 Existing Conditions

The site is currently developed with one single family residence located in the north corner of the site. The remaining portion of the site is undeveloped and composed of gravel and grassed areas with a gravel driveway access off of Khalsa Gate. The existing ground elevations within the site range from 147.92 m. in the south east portion of the site up to 151.48 m. in the north-west corner of the site abutting intersection of Pine Glen Road and Khalsa Gate. Based on the existing topography, site drainage currently flows towards the south and is captured by an existing catchbasin on Bronte Road municipal right of way.

The existing site is indicated in Figure No. 1.

3.0 Existing Municipal Infrastructure

The site abuts a developing commercial area along southeast and fronting three municipal road right of ways including Bronte Road to the west, Pine Glen Road to the nort and Khalsa Gate to the east. Bronte Road is currently a four lane roadway developed with an urban cross section. Left and right turning lanes to assist turning movements onto Glen Pine Road to the east. Pine Glen road is a two lane roadway with urban cross section of paved asphalt, curb and gutter with asphalt sidewalk Boulevard. Low traffic movement is controlled by stop sign at the intersection of Khalsa Gate and Pine Glen Road. Khalsa Gate is a two lane roadway with rural cross section of paved asphalt and drainage ditch along north and south side boulevard. There is currently street light located along north and west boulevards of the property, and hydro transformer at the east corner of the property. Details of servicing information on municipal right of way indicated on record drawings provided by Town of Oakville and Region of Halton are as follows:

Functional Servicing and Stormwater Management Report Page 2 of 6 Proposed Residential Towers with Commercial Space, 2418 Khalsa Gate, Oakville, Ontario November 17, 2015

Bronte Road • A 1200 mm diameter storm sewer along the west side of Bronte Road • A 450mm diameter tees off from 1200mm storm main line to provide storm servicing for

a limited portion of Pine Glen road. Pine Glen Road • A 300mm diameter storm sewer along the north side of the road, • A 200 mm diameter sanitary sewer alone the center line of road to the west property limit

which terminated with plug at intersection to Khalsa Gate, • A 400 mm diameter watermain terminated with plug at intersection to Khalsa Gate,

Khalsa Gate • A 825 mm diameter trunk sanitary sewer located within the right of way, • A 300mm diameter sanitary sewer to provide sanitary service to local residential,

commercial and industrial areas on Khalsa Gate, • A 300mm diameter watermain extending from Pine Glen Road after a 90 degree bend

which provides the feed to a fire hydrant located at the west corner of the intersection of Khalsa Gate and Pine Glen Road.

4.0 Proposed Site Development

The proposed site development includes the construction of a ten storey commercial & residential building, with vehicular access off of Pine Glen road at the north and Khalsa Gate at the east, surface parking, and two levels of underground parking. The proposed building footprint is 1,791.6 m2 with a total gross floor area of 20,582 m2. Landscape buffers are proposed along all sides of the property. As part of the development, three 2.5m wide new concrete sidewalks will be constructed within the municipal right of way that abut the north, east and west frontage of the site. The proposed site development is indicated in Figure No. 2.

5.0 Proposed Site Grading

The proposed site grading will take into account the existing topography, perimeter elevations, the proposed two vehicular accesses off of Pine Glen Road and Khalsa Gate, safe vehicular and pedestrian movements and access within the site. Grading will also be completed such that the majority of drainage is contained within the site and conveyed to the proposed internal storm system and proposed stormwater management features (area drains). Slopes within the paved areas of the site will typically be set between 1% and 4%. During a major storm event, storm water will overflow through the proposed vehicular access, to the Pine Glen right of way.

Functional Servicing and Stormwater Management Report Page 3 of 6 Proposed Residential Towers with Commercial Space, 2418 Khalsa Gate, Oakville, Ontario November 17, 2015

A preliminary design for site grading is indicated on Drawing No. CV- 1.

6.0 Proposed Site Servicing 6.1 Sanitary Servicing

Sanitary servicing is proposed with a connection to the existing 300 mm diameter sanitary sewer stub, located on Khalsa Gate. Based on the available invert elevation of 147.19 m on the sanitary main, and proposed grading indicating a finished first floor elevation of 149.75 m. a gravity sewer connection can be provided to service the floor drains installed on the first level underground parking garage. The drainage from floor drains on second level underground parking garage will require pumping which will be addressed during the detailed design by the mechanical engineer. As indicated on the sanitary sewer design sheet included in Appendix A, the expected post sanitary discharge from the site is approximately 7.71 L/s. The proposed sanitary drainage system is indicated on CV-2.

6.2 Water Servicing

A preliminary calculation for the required water demand for fire protection and domestic supply are included in Appendix B. The proposed water supply requirements are calculated in accordance with the Design Criteria Manual provided by the Region of Halton. As indicated, the estimated domestic water consumption is 7.25 L/s required to service the proposed development. The maximum daily demand plus fire flow is calculated as 207.25 L/sec which is the flow that is required to be available at a local hydrant at a minimum pressure of 150 KPa. At the time of the preparation of this report, a fire flow test had not been performed, but may be required to confirm there is adequate pressure and flow. A Siamese connection is to be installed along the face of the building and within 45m of the existing fire hydrant. The exact location of the water service connection will be provided in coordination with the mechanical engineer.

Proposed water servicing is indicated on Drawing CV-2.

7.0 Stormwater Management

7.1 Stormwater Peak Rate Controls Proposed stormwater management features are proposed as part of the redevelopment in order to control post-development flows to below allowable pre-development flow rates.

Peak rate controls are achieved through a series of on-site controls including;

Functional Servicing and Stormwater Management Report Page 4 of 6 Proposed Residential Towers with Commercial Space, 2418 Khalsa Gate, Oakville, Ontario November 17, 2015

• Roof top controls on roof areas (excluding balconies and terraces), • Garage roof controls achieved through the installation of an orifice plate, installed

below the grates of proposed area drains, • A 125 mm diameter orifice tube, installed at the outlet of a proposed cistern installed

in the first level of underground parking.

As indicated in the detailed stormwater management calculations included in Appendix C, the above features will control post development flows during the 2 and 100 year storm events to 0.0343 cms and 0.0629 cms respectively during the 2 and 100 year storm events. While the post development 2 year flow slightly exceeds the calculated allowable 2 year flow of 0.0335 cms, the exceeded flow is within the level of accuracy used in the modeling.

On-site storage required during storm events is provided underground, within two proposed cisterns, and aboveground on the garage roof through area drains, and on the controlled roof areas. The maximum depth of ponding on the garage roof is 130 mm.

During severe storm events, or when an outlet is blocked, overland flow will occur at the north entrance of the site, outletting to Pine Glen Road right of way. Stormwater management calculations have been included in Appendix A. 7.2 Water Quality As required by Ministry of Environment and Town of Oakville, level 1 quality protection will be implemented for the proposed redevelopment. An Oil/Grit Separator model STC-750 is recommended to meet the water quality objective for the site. This unit will be installed on the downstream end of the private side storm sewer prior to outletting into the municipal storm system. The proposed unit will be adequate to ensure 80% removal of Total Suspended Solids (TSS) and 93% of the runoff volume.

A detailed Sizing Report from the manufacturer’s modeling software is included in Appendix C. 7.3 Erosion & Sediment Control During Construction

In 2006, The Greater Golden Horseshoe Area Conservation Authorities prepared a guideline entitled "Erosion & Sediment Control Guideline for Urban Construction". Based on the guideline, all projects involving the removal of topsoil or site alteration require an ESC (Erosion and Sediment Control) Plan in place prior to commencing construction. Failure to adhere to the plan could lead to the potential for prosecution under the various pieces of environmental legislation. The following principles assist in creating an effective ESC Plan. (Ref. Erosion and Sediment Control Guidelines for Urban Construction)

Functional Servicing and Stormwater Management Report Page 5 of 6 Proposed Residential Towers with Commercial Space, 2418 Khalsa Gate, Oakville, Ontario November 17, 2015

• Adopt a multi-barrier approach to provide erosion and sediment control through erosion controls first.

• Retain existing ground cover and stabilize exposed soils with vegetation where possible.

• Limit the duration of soil exposure and phase construction where possible. • Limit the size of disturbed areas by minimizing nonessential clearing and

grading. • Minimize slope length and gradient of disturbed areas. • Maintain overland sheet flow and avoid concentrated flows. • Store/stockpile soil away (e.g. greater than 15 meters) from watercourses,

drainage features and top of steep slopes. • Ensure contractors and all involved in the ESC practices are trained in ESC Plan,

implementation, inspections, maintenance, and repairs. • Adjust ESC Plan at construction site to adapt to site features. • Assess all ESC practices before and after all rainfall and significant snowmelt

events. The guideline stresses that prevention of erosion is the preferred mitigation measure for reducing the potential for sedimentation. Erosion and sediment control measures can be categorized as Erosion prevention controls and Sediment controls. Erosion controls include minimizing the reduction in vegetative ground cover or immediate stabilization of disturbed areas by top soiling, seeding, sodding, mulching, erosion control blankets, etc. Sediment Controls are further broken down into Perimeter Controls, Settling Controls and Filtration Controls. Some major perimeter controls include silt fences, cut-off swales and mud-mats. Settling controls reduce run-off velocity allowing the soil particles to settle out. Settling controls include sediment traps, rock check dams, straw bales and sediment control ponds. Filtration controls are achieved by filtering silt laden water through the use of a filter media such as a geotextile or sand. Filtration controls include storm inlet filter cloths, sediment bags and filter rings.

8.0 Summary

The following summarizes the findings and recommendations related to required servicing and stormwater management controls:

• Sanitary servicing for the site can be provided by a gravity sanitary sewer system and

a connection to the existing 300 mm sanitary sewer on Khalsa Gate right of way. Sanitary drainage from the second level of underground parking will be required to be pumped,

• Water servicing as required for domestic supply and fire protection can be provided

with a connection to the existing 400 mm watermain on Pine Glen Road right of way,

Functional Servicing and Stormwater Management Report Page 6 of 6 Proposed Residential Towers with Commercial Space, 2418 Khalsa Gate, Oakville, Ontario November 17, 2015

• Storm servicing is provided along the north side of the site, which will convey site

flows to the existing 300 mm diameter municipal storm sewer on Pine Glen Road,

• Stormwater management rate controls can be provided on roof top areas, on the garage roof areas and at the outlet from a proposed cistern, as required to control flows during the 2 and 100 year storm events, to slightly above the allowable 2 year rate and below the allowable 100 year rate,

• Sufficient on-site storage as required, can be provided on controlled roof areas, on top

of the garage roof at ground level, and in two proposed cisterns in the first level of underground parking,

• Stormwater quality controls are proposed with the installation of an STC-750

treatment unit to provide 80% capture of the Total Suspended Solids which achieves Level One Quality control requirements as established by the MOECC,

• Sediment and erosion controls as indicated on the Removals/Sediment and Erosion

Control Plan are to be implemented prior to construction and maintained until the site is stabilized.

Based on our analysis, the site can be adequately serviced with municipal storm water, sanitary sewers and water without any adverse effects on the adjacent properties.

Prepared by: MGM CONSULTING INC.

M.L.Stairs, P. Eng.

FIGURE 1

SEPT-16-2015

1:500

2015-017-C2

RESIDENTIAL TOWERS WITH COMMERCIAL SPACE

2418 KHALSA GATE, OAKVILLE

EXISTING DRAINAGE AREAS

CNIGNITLUSNOC

www.mgm.on.ca

Email: mgm@mgm.on.ca

Suite 201 Fax: (905 )875-1339

Tel: (905 )567-8678

L9T 0H7

Milton, Ontario

400 Bronte Street South

Consulting Engineering & Project Management

DRAINAGE AREA (ha)

RUN-OFF CO-EFFICIENT

LEGEND

FIGURE 2

SEPT-16-2015

1:500

2015-017-C2

RESIDENTIAL TOWERS WITH COMMERCIAL SPACE

2418 KHALSA GATE, OAKVILLE

PROPOSED DRAINAGE AREAS

CNIGNITLUSNOC

www.mgm.on.ca

Email: mgm@mgm.on.ca

Suite 201 Fax: (905 )875-1339

Tel: (905 )567-8678

L9T 0H7

Milton, Ontario

400 Bronte Street South

Consulting Engineering & Project Management

DRAINAGE AREA (ha)

RUN-OFF CO-EFFICIENT

LEGEND

APPENDIX A

STORMWATER MANAGEMENT CALCULATIONS

Appendix ADetailed Stormwater Management Calculations

1.0 DRAINAGE CHARACTERISTICS

1.1 Existing Drainage Areas: (see Figure No. 1)"c" Area (ha)

Building Roofs 0.95 0.016

Asphalt Pavement 0.90 0.010

Wooden Deck 0.50 0.003

Soft Landscaping 0.25 0.486

Total 0.29 0.515

1.2 Proposed Drainage Areas (see Figure No. 2)"c" Area (ha)

Attenuated Areas:

Concrete ‐ Controlled 0.95 0.107

Conventional Roof ‐ Uncontrolled 0.95 0.097

Conventional Roof ‐ Controlled 0.95 0.158

Green Roof ‐ Controlled 0.60 0.024

Soft Landscaping 0.25 0.033

0.88 0.417

Unattenuated Areas:

Concrete 0.95 0.021

Soft Landscaping 0.25 0.076

Total 0.40 0.097

TOTAL SITE 0.79 0.515

2.0  Allowable Post Development Flows 

Post development flows are to be controlled to the existing condition flow rates for the 2 to 100 year storm events:

Tc =  10 minutes

2.1 2 Year Allowable Flow Rate

Rainfall Intensity 'I' = 725/(Tc+4.8)^.808 =  82.2 mm/hr

and Q allow = ciA/360 =  0.0335 cms.

2.2 100 Year Allowable Flow Rate

Rainfall Intensity 'I' = 2150/(Tc+5.7)^.861 =  200.8 mm/hr

and Q allow = ciA/360 =  0.0819 cms.

3.0 Rooftop Controlled Flow and Storage Calculations 

3.1 Building Roof Areas

Flow from new roof areas is to be controlled with the installation of Zurn " Control‐Flo" roof drains.

Controlled Roof Areas =  0.181 ha

Total No. of Hoppers= 8 each

1 weir per Hopper 1 each

Weir Rating= 0.015  l/sec/mm

Max ponding depth =  150 mm.

Peak Flow from roof =  0.0180 m3/sec.

Approx. Max Storage Provided 90.6 cu.m.

3.2 Garage Roof Areas

Page 1 of 3

Appendix ADetailed Stormwater Management Calculations

Flows conveyed to the roadway areas overtop of the garage roof are to be controlled with the installation of an orifice plate, installed underneath the grate of proposed area drains.

Controlled flow based on the orifice equation = CA*(2gh)^0.5

Total Area 0.107 ha

No. of Orifice Controls 4 each

Proposed Orifice Diameter = 75 mm

C =  0.62

A =  0.0044 sq.m.

g =  9.81 m/sec^2

h =  130 mm

Controlled Flow 0.0133 cms 

4.0 On‐Site Storage Required

4.1 Two Year Storage Calculation

2 Year Controlled Controlled  Remaining Unattenuated Controlled Aprox.

Rainfall Rainfall Building Garage Roof Attenuated Flow Flow From Detention

Duration Intensity (I) Roof Flow Flow Flow Site* Volumes

min. s mm/h m3/s m

3/s m

3/s m

3/s m

3/s m

3

10 600 82.2 0.0180 0.0133 0.0228 0.0089 0.0323 13.1

15 900 65.0 0.0180 0.0133 0.0180 0.0071 0.0323 15.3

20 1200 54.2 0.0180 0.0133 0.0150 0.0059 0.0323 16.8

25 1500 46.7 0.0180 0.0133 0.0130 0.0051 0.0323 17.9

30 1800 41.2 0.0180 0.0133 0.0114 0.0045 0.0323 18.7

35 2100 37.0 0.0180 0.0133 0.0103 0.0040 0.0323 19.4

40 2400 33.6 0.0180 0.0133 0.0093 0.0037 0.0323 19.9

45 2700 30.8 0.0180 0.0133 0.0086 0.0034 0.0323 20.3

50 3000 28.5 0.0180 0.0133 0.0079 0.0031 0.0323 20.7

55 3300 26.6 0.0180 0.0133 0.0074 0.0029 0.0323 20.9

60 3600 24.9 0.0180 0.0133 0.0069 0.0027 0.0323 21.2

65 3900 23.5 0.0180 0.0133 0.0065 0.0026 0.0323 21.4

70 4200 22.2 0.0180 0.0133 0.0062 0.0024 0.0323 21.5

75 4500 21.1 0.0180 0.0133 0.0058 0.0023 0.0323 21.6

80 4800 20.1 0.0180 0.0133 0.0056 0.0022 0.0323 21.7

85 5100 19.1 0.0180 0.0133 0.0053 0.0021 0.0323 21.8

90 5400 18.3 0.0180 0.0133 0.0051 0.0020 0.0323 21.9

95 5700 17.6 0.0180 0.0133 0.0049 0.0019 0.0323 21.9

100 6000 16.9 0.0180 0.0133 0.0047 0.0018 0.0323 21.9

105 6300 16.3 0.0180 0.0133 0.0045 0.0018 0.0323 21.9

The maximum 2 year storage required beyond building and garage roof areas  =  21.9 cu.m.

and the total post development flow from the site at peak storage =  0.0343 cms which slightly exceeds the allowable rate

4.2 One Hundred Year Storage Calculation

100 Year Controlled Controlled  Remaining Unattenuated Controlled Aprox.

Rainfall Rainfall Building Garage Roof Attenuated Flow Flow From Detention

Duration Intensity (I) Roof Flow Flow Flow Site* Volumes

min. s mm/h m3/s m3/s m3/s m3/s m3/s m3

10 600 200.8 0.0180 0.0133 0.0557 0.0219 0.0457 24.8

15 900 158.3 0.0180 0.0133 0.0439 0.0172 0.0457 26.5

20 1200 131.4 0.0180 0.0133 0.0365 0.0143 0.0457 26.4

25 1500 112.7 0.0180 0.0133 0.0313 0.0123 0.0457 25.3

30 1800 99.0 0.0180 0.0133 0.0275 0.0108 0.0457 23.5

35 2100 88.4 0.0180 0.0133 0.0245 0.0096 0.0457 21.2

The maximum 100 year storage required beyond building and garage roof areas  =  26.5 cu.m.

and the total post development flow from the site at peak storage =  0.0629 cms which is below the allowable rate

Page 2 of 3

Appendix ADetailed Stormwater Management Calculations

5.0 Controlled Flow Calculations

An orifice is proposed to control flows to the existing flow rates during the 2 to 100 year storm events

Orifice Equation: Q = CA*(2gh)^1/2

Orifice Diameter =  125 mm.

A =  0.0123 m2

g =  9.81 m/sec2

C= 0.62 co‐efficient of dischargeh (2 year) =  0.92 m.

2 year controlled flow =  0.0323 cms

2 year + Unattenuated Flow = 0.0343 cms

h (100 year) =  1.84 m.

100 year controlled flow =  0.0457 cms

100 year + Unattenuate flow = 0.0629 cms

6.0 Proposed Cistern Sizing

First cistern is proposed to provide on‐site storage as required.Length Width Max. height

Proposed Cistern Dimensions 5.5 2.5 1.83

Base Elevation 148.50

2 Year Storage 149.42 12.6 cu.m100 Year Storage 150.34 25.3 cu.m

Page 3 of 3

AREA1

Page 1

MGM CONSULTING Inc.STORM SEWER DESIGN SHEET

2418 Khalsa Gate By: Calvin DangDate: November 13, 2015

Location Areas A * C Rainfall Flow Sewer DesignManhole Invert Manhole Invert Area Cumulative Weighted Incremental Cumulative Time Intensity Pipe Slope Max. Flow Max Velocity Length Time in

from to Area Coefficent A * C A * C I2 Q Size Q max V max Sectionm. m. ha ha C min mm/hr. cms mm. % cms m./sec. m. min.

CISTERN 2 MH3 0.417 0.417 0.88 0.367 0.367 10 88.2 0.090 375 1.0 0.176 1.59 1.0 0.01

MH3 OGS 0.417 0.367 10.0 88.1 0.090 375 0.50 0.124 1.12 26.0 0.39

OGS CISTERN 1 0.417 0.367 10.4 85.6 0.087 300 2.10 0.140 1.99 5.0 0.04

CISTERN 1 MH1 0.417 0.367 10.4 85.3 *0.0629 300 1.00 0.097 1.37 1.0 0.01

MH1 CBMH2 0.417 0.367 10.5 85.2 *0.0629 300 0.50 0.068 0.97 6.3 0.11

CBMH2 EX.MH 0.417 0.367 10.6 84.5 *0.0629 300 0.50 0.068 0.97 13.5 0.23

* Controlled flow obtained from SWM design calculationn = 0.013

APPENDIX B

WATER DEMAND CALCULATIONS

Water Demand Calculation Residential Towers with Commercial Space 2418 Khalsa Gate Date: November 13, 2015 According to Table 2-1 and Table 2-2, Design Criteria Region of Halton Commercial Residential

Apartments over 6 stories

Total equivalent population to be serviced

8 persons 560 persons

Average Day Service Demand (L/ha/day)

24750 78375

Total Lands to be Serviced 0.0791 ha 1.9708 ha 2.0499 ha

No. Water Demands

Demand type Demand (units)

Commercial Residential Total 1 Average day flow 0.023 L/s 1.788 L/s 1.81 L/s 2 Maximum day flow 0.056 L/s 4.005 L/s 4.06 L/s 3 Peak hour flow 0.056 L/s 7.25 L/s 7.25 L/s 4 Fire Flow 200.00 L/s 200.00 L/s Analysis 5 Maximum day plus fire flow 207.25 L/s 6 Peak hour flow 7.25 L/s 7 Maximum demand flow 207.25 L/s

Fire Flow Calculation

The FUS requires that a minimum water supply source 'F' be provided at 150 kPaThe min flow 'F' can be calculated as such:

F=220C√Awhere:F- Required fire flow in L/minC- Coefficient related to constructionA- Total area in sq.m

C = 0.8 (Non-combusitble construction )

For non-combustible construction, the area shall be a total of all floors (excluding basementsat least 50 percent below grade) in the building being considered.

A = 20496 sq.m

Therefore,

F= 25196.91 L/min

Reduction Factors:

F'=F*f1*f2

where:f1- Occupancy factorf2- Sprinkler protection factorFor low hazard occupancies, f1 = 0.75Assuming that the units will be sprinklered f2= 0.5

F' = 9448.84 L/min

Exposure Factors:F" = F'*f3where:f3- Exposure factor not to exceed 75%

Separation between subject building and other structures, and associated charges are as follows:

Distance (m) Charge

North Side 30 10%South Side 25 10%East Side Road 0%West Side Road 0%

Total 20%

The total increase for exposures is 20%

Therefore the increase due to exposures = 1889.768 l/minF" = 11338.61 L/min

Therefore a minimum flow of approximately 12000 L/min must be available at the nearest hydrant with a minimum pressure of 150 kPa.

Note: This fireflow calculation has been prepared as a guide only. Confirmation of adquate flowand pressure is required from a Fire Protection professional.

APPENDIX C

STORMCEPTOR REPORT

1

Stormceptor Sizing Detailed Report

PCSWMM for Stormceptor

Project Information Date 11/6/2015

Project Name 2418 Khalsa Gate

Project Number N/A

Location Oakville

Stormwater Quality Objective This report outlines how Stormceptor System can achieve a defined water quality objective through the removal of total suspended solids (TSS). Attached to this report is the Stormceptor Sizing Summary. Stormceptor System Recommendation The Stormceptor System model STC 750 achieves the water quality objective removing 80% TSS for a Fine (organics, silts and sand) particle size distribution and 93% runoff volume. The Stormceptor System The Stormceptor oil and sediment separator is sized to treat stormwater runoff by removing pollutants through gravity separation and flotation. Stormceptor’s patented design generates positive TSS removal for all rainfall events, including large storms. Significant levels of pollutants such as heavy metals, free oils and nutrients are prevented from entering natural water resources and the re-suspension of previously captured sediment (scour) does not occur. Stormceptor provides a high level of TSS removal for small frequent storm events that represent the majority of annual rainfall volume and pollutant load. Positive treatment continues for large infrequent events, however, such events have little impact on the average annual TSS removal as they represent a small percentage of the total runoff volume and pollutant load. Stormceptor is the only oil and sediment separator on the market sized to remove TSS for a wide range of particle sizes, including fine sediments (clays and silts), that are often overlooked in the design of other stormwater treatment devices.

2

Small storms dominate hydrologic activity, US EPA r eports

“Early efforts in stormwater management focused on flood events ranging from the 2-yr to the 100-yr storm. Increasingly stormwater professionals have come to realize that small storms (i.e. < 1 in. rainfall) dominate watershed hydrologic parameters typically associated with water quality management issues and BMP design. These small storms are responsible for most annual urban runoff and groundwater recharge. Likewise, with the exception of eroded sediment, they are responsible for most pollutant washoff from urban surfaces. Therefore, the small storms are of most concern for the stormwater management objectives of ground water recharge, water quality resource protection and thermal impacts control.”

“Most rainfall events are much smaller than design storms used for urban drainage models. In any given area, most frequently recurrent rainfall events are small (less than 1 in. of daily rainfall).” “Continuous simulation offers possibilities for designing and managing BMPs on an individual site-by-site basis that are not provided by other widely used simpler analysis methods. Therefore its application and use should be encouraged.” – US EPA Stormwater Best Management Practice Design Guide, Volume 1 – General Considerations, 2004

Design Methodology Each Stormceptor system is sized using PCSWMM for Stormceptor, a continuous simulation model based on US EPA SWMM. The program calculates hydrology from up-to-date local historical rainfall data and specified site parameters. With US EPA SWMM’s precision, every Stormceptor unit is designed to achieve a defined water quality objective. The TSS removal data presented follows US EPA guidelines to reduce the average annual TSS load. Stormceptor’s unit process for TSS removal is settling. The settling model calculates TSS removal by analyzing (summary of analysis presented in Appendix 2):

• Site parameters • Continuous historical rainfall, including duration, distribution, peaks (Figure 1) • Interevent periods • Particle size distribution • Particle settling velocities (Stokes Law, corrected for drag) • TSS load (Figure 2) • Detention time of the system

The Stormceptor System maintains continuous positive TSS removal for all influent flow rates. Figure 3 illustrates the continuous treatment by Stormceptor throughout the full range of storm events analyzed. It is clear that large events do not significantly impact the average annual TSS removal. There is no decline in cumulative TSS removal, indicating scour does not occur as the flow rate increases.

3

Figure 1. Runoff Volume by Flow Rate for TORONTO C ENTRAL – ON 100, 1982 to 1999 for 0.515 ha, 88% impervious. Small frequent storm events represent the majority of annual rainfall volume. Large infrequent events have little impact on the average annual TSS removal, as they represent a small percentage of the total annual volume of runoff.

Figure 2. Long Term Pollutant Load by Flow Rate fo r TORONTO CENTRAL – 100, 1982 to 1999 for 0.515 ha, 88% impervious. The majority of the annual pollutant load is transported by small frequent storm events. Conversely, large infrequent events carry an insignificant percentage of the total annual pollutant load.

4

Stormceptor Model TSS Removal (%)

STC 750 80

Drainage Area (ha) Impervious (%)

0.515 88

Figure 3. Cumulative TSS Removal by Flow Rate for TORONTO CENTRAL – 100, 1982 to 1999. Stormceptor continuously removes TSS throughout the full range of storm events analyzed. Note that large events do not significantly impact the average annual TSS removal. Therefore no decline in cumulative TSS removal indicates scour does not occur as the flow rate increases.

5

Appendix 1 Stormceptor Design Summary Project Information Date 11/6/2015

Project Name 2418 Khalsa Gate

Project Number N/A

Location Oakville

Designer Informat ion Company MGM

Contact Calvin D

Rainfall Name TORONTO CENTRAL

State ON

ID 100

Years of Records 1982 to 1999

Latitude 45°30'N

Longitude 90°30'W

Notes N/A

Water Quality Objective

TSS Removal (%) 80

Runoff Volume (%) 90

Drainage Area

Total Area (ha) 0.515

Imperviousness (%) 88

The Stormceptor System model STC 750 achieves the water quality objective removing 80% TSS for a Fine (organics, silts and sand) particle size distribution and 93% runoff volume.

Upstream Storage Storage Discharge (ha-m) (L/s)

0 0

Stormceptor Sizing Summary

Stormceptor Model TSS Removal Runoff Volume

% % STC 300 72 85 STC 750 80 93

STC 1000 80 93 STC 1500 81 93 STC 2000 85 97 STC 3000 86 97 STC 4000 89 99 STC 5000 90 99 STC 6000 92 99 STC 9000 94 100

STC 10000 94 100 STC 14000 95 100

6

Particle Size Distribution Removing silt particles from runoff ensures that the majority of the pollutants, such as hydrocarbons and heavy metals that adhere to fine particles, are not discharged into our natural water courses. The table below lists the particle size distribution used to define the annual TSS removal.

Fine (organics, silts and sand)

Particle Size Distribution Specific Gravity

Settling Velocity

Particle Size Distribution Specific Gravity

Settling Velocity

µm % m/s µm % m/s 20 20 1.3 0.0004 60 20 1.8 0.0016

150 20 2.2 0.0108 400 20 2.65 0.0647

2000 20 2.65 0.2870

Stormceptor Design Notes • Stormceptor performance estimates are based on simulations using PCSWMM for Stormceptor version 1.0

• Design estimates listed are only representative of specific project requirements based on total suspended solids (TSS) removal.

• Only the STC 300 is adaptable to function with a catch basin inlet and/or inline pipes.

• Only the Stormceptor models STC 750 to STC 6000 may accommodate multiple inlet pipes.

• Inlet and outlet invert elevation differences are as follows:

Inlet and Outlet Pipe Invert Elevations Differen ces

Inlet Pipe Configuration STC 300 STC 750 to STC 6000

STC 9000 to STC 14000

Single inlet pipe 75 mm 25 mm 75 mm

Multiple inlet pipes 75 mm 75 mm Only one inlet pipe.

• Design estimates are based on stable site conditions only, after construction is completed.

• Design estimates assume that the storm drain is not submerged during zero flows. For submerged applications, please contact your local Stormceptor representative.

• Design estimates may be modified for specific spills controls. Please contact your local Stormceptor representative for further assistance.

• For pricing inquiries or assistance, please contact Imbrium Systems Inc., 1-800-565-4801.

7

Appendix 2 Summary of Design Assumptions

SITE DETAILS

Site Drainage Area Total Area (ha) 0.515 Imperviousness (%) 88

Surface Characteristics Width (m) 144

Slope (%) 2

Impervious Depression Storage (mm) 0.508

Pervious Depression Storage (mm) 5.08

Impervious Manning’s n 0.015

Pervious Manning's n 0.25

Maintenance Frequency Sediment build-up reduces the storage volume for sedimentation. Frequency of maintenance is assumed for TSS removal calculations.

Maintenance Frequency (months) 12

Infiltration Parameters Horton’s equation is used to estimate infiltration

Max. Infiltration Rate (mm/h) 61.98

Min. Infiltration Rate (mm/h) 10.16

Decay Rate (s-1) 0.00055

Regeneration Rate (s-1) 0.01

Evaporation Daily Evaporation Rate (mm/day) 2.54

Dry Weather Flow Dry Weather Flow (L/s) No

Winter Months Winter Infiltration False

Upstream Attenuation Stage-storage and stage-discharge relationship used to model attenuation upstream of the Stormceptor System is identified in the table below.

Storage Discharge ha-m L/s

0 0

8

PARTICLE SIZE DISTRIBUTION

Particle Size Distribution Removing fine particles from runoff ensures the majority of pollutants, such as heavy metals, hydrocarbons, free oils and nutrients are not discharged into natural water resources. The table below identifies the particle size distribution selected to define TSS removal for the design of the Stormceptor System.

Fine (organics, silts and sand)

Particle Size Distribution Specific Gravity

Settling Velocity

Particle Size Distribution Specific Gravity

Settling Velocity

µm % m/s µm % m/s 20 20 1.3 0.0004 60 20 1.8 0.0016

150 20 2.2 0.0108 400 20 2.65 0.0647

2000 20 2.65 0.2870

Figure 1. PCSWMM for Stormceptor standard design grain size distributions.

9

TSS LOADING

TSS Loading Parameters TSS Loading Function Buildup / Washoff

Buildup/Washoff Parameters Target Event Mean Concentration (EMC) (mg/L) 125

Exponential Buildup Power 0.4

Exponential Washoff Exponential 0.2

TSS Availability Parameters

Availability = A + BiC

Availability Constant A 0.057

Availability Factor B 0.04

Availability Exponent C 1.1

Min. Particle Size Affected by Availability (µm) 400

HYDROLOGY ANALYSIS

PCSWMM for Stormceptor calculates annual hydrology with the US EPA SWMM and local continuous historical rainfall data. Performance calculations of the Stormceptor System are based on the average annual removal of TSS for the selected site parameters. The Stormceptor System is engineered to capture fine particles (silts and sands) by focusing on average annual runoff volume ensuring positive removal efficiency is maintained during all rainfall events, while preventing the opportunity for negative removal efficiency (scour). Smaller recurring storms account for the majority of rainfall events and average annual runoff volume, as observed in the historical rainfall data analyses presented in this section.

Rainfall Station Rainfall Station TORONTO CENTRAL

Rainfall File Name ON100.NDC Total Number of Events 3020

Latitude 45°30'N Total Rainfall (mm) 13190.7

Longitude 90°30'W Average Annual Rainfall (mm) 732.8

Elevation (m) 328 Total Evaporation (mm) 1166.4

Rainfall Period of Record (y) 18 Total Infiltration (mm) 1574.7

Total Rainfall Period (y) 18 Percentage of Rainfall that is Runoff (%)

79.9

10

Rainfall Event Analysis

Rainfall Depth No. of Events Percentage of Total Events

Total Volume Percentage of Annual Volume

mm % mm % 6.35 2398 79.4 3626 27.5

12.70 346 11.5 3182 24.1

19.05 130 4.3 2037 15.4

25.40 66 2.2 1432 10.9

31.75 38 1.3 1075 8.2

38.10 16 0.5 545 4.1

44.45 7 0.2 292 2.2

50.80 13 0.4 611 4.6

57.15 2 0.1 106 0.8

63.50 2 0.1 121 0.9

69.85 0 0.0 0 0.0

76.20 0 0.0 0 0.0

82.55 1 0.0 79 0.6

88.90 1 0.0 85 0.6

95.25 0 0.0 0 0.0

101.60 0 0.0 0 0.0

107.95 0 0.0 0 0.0

114.30 0 0.0 0 0.0

120.65 0 0.0 0 0.0

127.00 0 0.0 0 0.0

133.35 0 0.0 0 0.0

139.70 0 0.0 0 0.0

146.05 0 0.0 0 0.0

152.40 0 0.0 0 0.0

158.75 0 0.0 0 0.0

165.10 0 0.0 0 0.0

171.45 0 0.0 0 0.0

177.80 0 0.0 0 0.0

184.15 0 0.0 0 0.0

190.50 0 0.0 0 0.0

196.85 0 0.0 0 0.0

203.20 0 0.0 0 0.0

209.55 0 0.0 0 0.0

>209.55 0 0.0 0 0.0

11

Pollutograph

Flow Rate

Influent Mass

Effluent Mass

Total Mass

Cumulative Mass

L/s kg kg kg % 1 14084 12350 26403 53.3 4 22171 4239 26403 84.0 9 24599 1807 26403 93.2

16 25560 844 26403 96.8 25 26036 367 26403 98.6 36 26246 157 26403 99.4 49 26333 69 26403 99.7 64 26371 32 26403 99.9 81 26390 13 26403 100.0

100 26395 8 26403 100.0 121 26397 5 26403 100.0 144 26399 4 26403 100.0 169 26399 3 26403 100.0 196 26400 2 26403 100.0 225 26401 2 26403 100.0 256 26402 1 26403 100.0 289 26403 0 26403 100.0 324 26403 0 26403 100.0 361 26403 0 26403 100.0 400 26403 0 26403 100.0 441 26403 0 26403 100.0 484 26403 0 26403 100.0 529 26403 0 26403 100.0 576 26403 0 26403 100.0 625 26403 0 26403 100.0 676 26403 0 26403 100.0 729 26403 0 26403 100.0 784 26403 0 26403 100.0 841 26403 0 26403 100.0 900 26403 0 26403 100.0

12

Cumulative Runoff Volume by Runoff Rate

Runoff Rate Runoff Volume Volume

Overflowed Cumulative

Runoff Volume L/s m³ m³ %

1 18341 35921 33.8 4 38502 15759 71.0 9 46795 7467 86.2

16 50206 4056 92.5 25 51953 2308 95.7 36 52951 1311 97.6 49 53512 750 98.6 64 53835 427 99.2 81 53998 263 99.5 100 54054 208 99.6 121 54092 170 99.7 144 54127 135 99.8 169 54150 112 99.8 196 54174 87 99.8 225 54200 61 99.9 256 54228 33 99.9 289 54254 8 100.0 324 54262 0 100.0 361 54262 0 100.0 400 54262 0 100.0 441 54262 0 100.0 484 54262 0 100.0 529 54262 0 100.0 576 54262 0 100.0 625 54262 0 100.0 676 54262 0 100.0 729 54262 0 100.0 784 54262 0 100.0 841 54262 0 100.0 900 54262 0 100.0

Project No. 2015-017THE REGIONAL MUNICIPALITY OF HALTON Subdivision:

SANITARY SEWER DESIGN SHEET Date: 13-Nov-15

Des. By: CD Chk. By: MLS

Tributary Area Hectare Population Tributary Average Average SEWER PIPEIncrement Total Increment Total Increment Total Peaking Max. Infiltration Max. Flow Q V m/S

Res. Comm. Ind. Res. Comm. Ind.Street ha ha ha ha L/s L/s Factor m3/s L/s L/s mm. % L/s Full Flow Act. Flow Type n Class REMARKS

Residential 1.971 1.97 560 560 1.782 1.782 3.948 7.038 0.564 7.601Commercial 0.0791 0.08 8 8 0.025 0.025 3.539 0.090 0.023 0.113

Total 7.714 200 2.00 46.403 1.48 PVC 0.013 SDR35

2418 Khalsa Gate