addendum to environmental study report – ottawa combined ... · addendum to environmental study...

Addendum to Environmental Study Report – Ottawa Combined Sewage Storage Tunnel (CSST)

Revised Alternative North-South Tunnel Construction Staging Area

Prepared for:

City of Ottawa

Prepared by:Stantec Consulting Ltd.

March 31, 2014 Insert revision record

Sign-off Sheet

This document entitled Addendum to Environmental Study Report – Ottawa Combined Sewage Storage Tunnel (CSST) was prepared by Stantec Consulting Ltd. for the account of City of Ottawa. The material in it reflects Stantec’s best judgment in light of the information available to it at the time of preparation. Any use which a third party makes of this report, or any reliance on or decisions made based on it, are the responsibilities of such third parties. Stantec Consulting Ltd. accepts no responsibility for damages, if any, suffered by any third party as a result of decisions made or actions based on this report.

Prepared by (signature)

Loretta Hardwick

Reviewed by (signature)

Adrien Comeau

ADDENDUM TO ENVIRONMENTAL STUDY REPORT – OTTAWA COMBINED SEWAGE STORAGE TUNNEL (CSST)

Table of Contents

EXECUTIVE SUMMARY ............................................................................................................... I

1.0 INTRODUCTION ...........................................................................................................1.11.1 ENVIRONMENTAL STUDY REPORT FOR CSST................................................................ 1.11.2 PURPOSE OF ADDENDUM ............................................................................................. 1.21.3 CONSULTATION .............................................................................................................. 1.2

2.0 ALTERNATE STAGING AREAS AND LAUNCH SITES......................................................2.12.1 ALTERNATE STAGING AREAS......................................................................................... 2.1

2.1.1 Alternate Launch Sites ................................................................................ 2.1

3.0 DESCRIPTION OF THE REVISED ALTERNATIVE..............................................................3.13.1 DESCRIPTION OF THE NST ALIGNMENT EXTENSION..................................................... 3.13.2 SITE DESCRIPTION ........................................................................................................... 3.2

3.2.1 Geotechnical............................................................................................... 3.23.2.2 Environmental .............................................................................................. 3.33.2.3 Archaeological............................................................................................ 3.3

4.0 EVALUATION OF REVISED PREFERRED ALTERNATIVE ..................................................4.14.1 TECHNICAL EVALUATION .............................................................................................. 4.14.2 NATURAL ENVIRONMENT EVALUATION ....................................................................... 4.24.3 SOCIO-CULTURAL EVALUATION ................................................................................... 4.24.4 ECONOMIC EVALUATION............................................................................................. 4.3

5.0 POTENTIAL IMPACTS AND MITIGATION MEASURES ...................................................5.1

6.0 PREFERRED ALTERNATIVE.............................................................................................6.1

LIST OF TABLES Table 1: Summary of Advantages and Disadvantages...................................................... 6.1

LIST OF FIGURES Figure 1: CSST Alignment and Proposed NST Extension....................................................... 1.1Figure 2: Alignment of NST Extension ..................................................................................... 3.1Figure 3: Staging Area Site Plan.............................................................................................. 3.2

my c:\users\mayoung\desktop\nst_extension\report.docx i


LIST OF APPENDICES

APPENDIX A TECHNICAL MEMORANDUM: ALTERNATIVE CONSTRUCTION STAGING AREAS FOR NST - JANUARY 10, 2014........................................................A.1

APPENDIX B TECHNICAL MEMORANDUM: POTENTIAL ALTERNATIVE TUNNEL LAUNCHING SITES FOR NST – FEBRUARY 23, 2014 (REV 2) ....................................... B.1

APPENDIX C TECHNICAL MEMORANDUM: REVIEW OF POTENTIAL NST EXTENSION ALONG CHAMBERLAIN AVE – MARCH 28, 2014 (REV 4)......................C.1

APPENDIX D CONSULTATION.........................................................................................D.2

my c:\users\mayoung\desktop\nst_extension\report.docx ii


Executive Summary

This addendum to the 2013 Combined Sewage Storage Tunnel (CSST) Environmental Study Report (ESR) has been prepared to revise the previous recommended alternative for the staging area and launch site of the north-south tunnel (NST). During preliminary design of the CSST, consultation with PWGSC identified potential conflicts for the original (as documented in the ESR) preferred alternative in terms of construction schedule and space requirements at St. Laurent Square immediately south of the Supreme Court of Canada.

The revised recommended preferred location for the staging and launch site for the NST is a land parcel owned by the Ministry of Transportation (MTO) at 605 Bronson Avenue. Using this site will require the NST to be extended by approximately 625 m along Chamberlain Avenue on the south side of Highway 417. However, the site is large enough to accommodate both tunnel launch staging and launch operations without the need for remote staging areas. The site will be available by the start of 2015 and will be returned to the MTO by the start of 2018 in order to coordinate with other planned projects in the area.

Despite the additional tunneling costs involved with extending the NST, this option is similar in overall costs as compared to the previously recommended option. The NST extension effectively leads to offsetting cost savings through the replacement and either the elimination or deferral of other planned works (sanitary and storm sewers in the area).

It is recommended that the City proceed with using the Chamberlain Avenue site as the staging and launch site for the NST construction. This will require additional geotechnical and environmental studies as well as reaching an agreement with the MTO regarding land use and schedule. This site provides greater advantages over the other options identified.

my c:\users\mayoung\desktop\nst_extension\report.docx i


Introduction April 2, 2014

1.0 Introduction

1.1 ENVIRONMENTAL STUDY REPORT FOR CSST

In 2013, the City of Ottawa completed the Combined Sewage Storage Tunnel (CSST) Environmental Study Report (ESR) to identify the preferred design for the CSST. The purpose of the ESR was to identify and evaluate alternatives for the collection of sewage from the combined sewers within the study area during storm events, storing it temporarily, and then releasing it in a controlled manner into the sanitary trunk sewers for treatment at ROPEC and its discharge to the Ottawa River.

The ESR identified the preferred route as an east-west tunnel (EWT) through the downtown core from LeBreton Flats to New Edinburgh Park, and a north-south tunnel (NST) along Kent Street from Catherine Street to the existing outfall north of Wellington Street. The 2013 ESR concluded that the preferred design for the NST would include a construction staging and tunnel launch area at St. Laurent Square immediately south of the Supreme Court of Canada. Figure 1 shows the general vicinity of the project within the City of Ottawa and the approximate alignment of the tunnels.

Figure 1: CSST Alignment and Proposed NST Extension

my c:\users\mayoung\desktop\nst_extension\report.docx 1.1


Introduction April 2, 2014

The Notice of Completion was posted on January 25, 2013. The ESR was placed on the public record for review by the public and review agencies over a period of 30 calendar days. No requests for a Part II Order were received during the review period.

1.2 PURPOSE OF ADDENDUM

During stakeholder consultations held in late December 2013 and early January 2014, the design team (Stantec Consulting Ltd as lead Consultant) for this project was advised by Public Works and Government Services Canada (PWGSC) that there were potential conflicts regarding the use of St. Laurent Square as the NST’s launch site and staging area. The design team was notified that PWGSC has plans for a future project at St. Laurent Square. While the details of this PWGSC project are still being defined, it was recommended by PWGSC that use of this site be minimized, both in terms of the space required and the construction duration. These constraints required the design team to revisit the NST recommendation included in the ESR.

As stated in the Municipal Class EA guide (MEA October 2000, as amended 2007 and 2011), under the Municipal Class EA process, “any significant modification to the project or change in environmental setting for the project which occurs after filing of the ESR shall be reviewed by the proponent and an addendum to the ESR shall be written.” This addendum has been prepared to document the evaluation of revised alternatives and is to be read in conjunction with the ESR. The scope of this Addendum to the ESR is limited to a change in the location of the preferred location for the NST primary staging area and tunnel launch shaft. Only the proposed changes to the recommended undertaking, as documented in the Addendum, are open for review.

1.3 CONSULTATION

A Notice of Filing of Addendum has been issued and a 30-day review period will be provided for the public and review agencies to review and respond to the Addendum. Emails to notify of the Addendum have been sent to potentially affected members of the public, Aboriginal organizations, review agencies, and all others notified during preparation of the ESR. A list of the review agencies and other groups that received notification of the addendum is provided in Appendix D. A generic copy of the email correspondence sent to all agencies, groups and individuals is provided in Appendix D.



Alternate Staging Areas and Launch Sites April 2, 2014

2.0 Alternate Staging Areas and Launch Sites

An initial screening of potential alternatives was conducted to identify a technically and economically feasible alternative location for the NST primary construction staging area and launch shaft.

2.1 ALTERNATE STAGING AREAS

The design team undertook a high-level review of alternative tunnel staging sites along the NST alignment. The January 10, 2014 technical memorandum entitled Alternative Construction Staging Areas for NST details the alternate staging areas that were considered. The memorandum is included in Appendix A and contains an evaluation of the following staging areas:

a) St. Laurent Square – the front lawn of the Supreme Court of Canada, the ESR’s preferred option;

b) East of the Library and Archives – immediately west of St. Laurent Square;

c) Kent Street Right-of-Way – area at the north end of Kent Street between Wellington Street and

Vittoria Street (adjacent roadway on the north side of St. Laurent Square);

d) East of the Supreme Court – existing parking area north of the Justice Building;

e) Northeast of the Supreme Court – western portion of the Court’s lower parking area along the Ottawa River;

f) Kent and Albert with Reduced Staging Area at/near Supreme Court – east of Kent Street between Queen Street and Albert Street, in addition to a smaller area near the Supreme Court.

The Technical Memorandum compared these options and identified a), d) and e) as favourable alternatives. All of the alternate staging areas would still require a construction area at or near St. Laurent Square to tie into the existing Kent Storm Tunnel as an overflow outlet.

2.1.1 Alternate Launch Sites

The design team also considered seven alternate tunnel launching sites. These sites are presented and evaluated in the February 23, 2014 technical memorandum entitled Potential Alternate Tunnel Launching Sites for NST (Rev 2). This memorandum is included in Appendix B. The alternate launch sites presented are:

a) ESR Preferred Alternative –Kent Street and Wellington Street in St. Laurent Square;

b) Alternative 1 Kent and Albert/Queen – in the south portion of a parking lot at 280 Queen Street;

c) Alternative 2 Kent & Arlington – an empty land parcel, a small restaurant, the Arlington Avenue road allowance, and a portion of a parking lot near the south end of the NST;

d) Alternative 3 Glashan Public School – open area adjacent to the school building in the northeast quadrant of the Kent Street and Catherine Street intersection;



Alternate Staging Areas and Launch Sites April 2, 2014

e) Alternative 4 Kent & Catherine West (Car Wash) – southwest quadrant of the intersection of Kent Street and Catherine Street containing an existing car wash facility that would need to be demolished;

f) Alternative 5 Paterson Park – open space south of Chamberlain Avenue, between Bank Street and Lyon Street South.

g) Alternative 6 Soccer Field – southwest quadrant of the intersection of Chamberlain Avenue and Lyon Street South.

h) Alternative 7 605 Bronson – bordered by Bronson Avenue, Chamberlain Avenue, Percy Street and Highway 417.

The sites were evaluated and Alternative 7 (605 Bronson) was ranked the highest. It is one of only two sites from the above list that meets the minimum required launch area of 0.5 hectares (0.8 to 1.6 hectares is preferable) and that would not require a remote staging area.

The viability of Alternative 7 as a tunnel launch and staging site was evaluated in the March 28, 2014 technical memorandum entitled Review of Potential NST Extension along Chamberlain Avenue (Rev 4). This memorandum is included in Appendix C. This site is large enough to include staging and launch operations without the need for remote sites. It also relocates the bulk of the construction activity away from the Supreme Court and thus alleviates PWGSC’s concerns. A more detailed description and evaluation of this site follows.



Description of the Revised Alternative April 2, 2014

3.0 Description of the Revised Alternative

3.1 DESCRIPTION OF THE NST ALIGNMENT EXTENSION

The revised preferred alternative (referred to as the Chamberlain Avenue site) includes the relocation of the NST launch and construction staging site to a property located at the corner of Bronson Avenue and Chamberlain Avenue. An additional 625 m of tunnel is added to the south end of the NST to join the recommended alignment with the land parcel at the Chamberlain Avenue site. The additional length begins at the Catherine Street tunnel termination, curves to the west, and continues along Chamberlain Avenue as shown in Figure 2.

Figure 2: Alignment of NST Extension

The tunnel will be located along the south side of Chamberlain Avenue to provide the greatest separation distance from an existing 1220-mm watermain located on the north side of the roadway and to provide a better curve radius from the Kent Street alignment.

The tunneling equipment would be launched from the staging area with a shaft north of Chamberlain Avenue. It is estimated that the entire NST, including the proposed extension, could be constructed over an 18 to 20 month period. An additional 4-month period would be required to construct a permanent access shaft and flush-water reservoir. The total construction period for this portion of the work is estimated to be 22 to 24 months.

This alternative will still require a staging area in the vicinity of the Supreme Court to construct a diversion chamber and connection to the existing sewer infrastructure at that site, and potentially to remove the tunnel boring machine.




3.2 SITE DESCRIPTION

The Chamberlain Avenue site is bordered by Highway 417 to the north, Percy Street to the east, Chamberlain Avenue to the south, and Bronson Avenue to the west. As shown in Figure 3, it comprises an abandoned building, a parking/loading area and a grassed area that becomes sloped closer to Percy Street. It is expected that up to 0.96 hectares (2.37 acres) could be available, of which 0.5 hectares (1.2 acres) currently consists of open area with the balance being the building. This is the largest available site currently identified and would not require remote, off-site staging areas.

Figure 3: Staging Area Site Plan

MTO recently acquired the property at 605 Bronson Ave (i.e., the Chamberlain Avenue site) and has confirmed that they plan to demolish the existing building on the western portion of the property. This work is expected to be completed by February of 2015. MTO is also the current owner of the east portion of the site (currently vegetated) as a part of the Highway 417 parcel.

3.2.1 Geotechnical

Overburden soil conditions at the Chamberlain Avenue site generally consist of fill, overlying sand and glacial till, overlying bedrock. Existing borehole information in the area of the NST extension shows that the extension would have approximately 7 to 10m of rock cover over the tunnel crown. In the event that a tunnel slope steeper than 0.1% is required for this section, the rock cover is not expected to be problematic as bedrock rises fairly significantly towards the west.




Additional geotechnical investigation with deep boreholes would be required along the tunnel alignment and at the proposed launching site to confirm subsurface conditions.

3.2.2 Environmental

A review of a previous ESA report and building plans for the Chamberlain Avenue site indicate the current and/or past existence of multiple underground fuel storage tanks. These tanks will likely be removed as part of the building demolition; however, residual contaminated soils may remain present.

Lab test results from this ESA report show levels of soil and groundwater contaminants that exceed the applicable standards. Additional assessment of soil and groundwater quality in this area is required. The vacant parcel closer to Percy Street, where the proposed tunnel launch shaft is proposed to be located, has not been assessed.

3.2.3 Archaeological

As an amendment to the current project area no further archaeological work is required for the Chamberlain Avenue site. No portions of the NST alignment extension, including the launch site and construction staging area, are within an area of archaeological potential as defined by the City of Ottawa eMap showing elevated archaeological potential within the city (City of Ottawa 21012 eMap available online at http://maps.ottawa.ca/geoOttawa/ - accessed on March 24, 2014).


http://maps.ottawa.ca/geoOttawa/


Evaluation of Revised Preferred Alternative April 2, 2014

4.0 Evaluation of Revised Preferred Alternative

The criteria used to evaluate the revised preferred alternative are as presented in the original ESR document. Comparisons are made below between the ESR’s recommended design and this alternative. Details and notable negative and positive aspects are identified.

4.1 TECHNICAL EVALUATION

A preliminary investigation indicated that there are no significant conflicts with existing infrastructure associated with the proposed NST extension. The additional tunnel length poses a construction risk due to additional subsurface work; however, the construction methods and conditions are similar to those required for the NST.

Extending the tunnel to the Chamberlain Avenue site will extend the construction schedule for this portion of the work as compared to the St. Laurent Square alternative. This schedule will need to be coordinated with the MTO’s planned work in the area: demolition of the site’s existing building, improvements to the eastbound off-ramp of Highway 417 at Bronson Avenue, reconfiguration of the Chamberlain/Bronson/eastbound off- ramp intersection, and bridge replacement/rehabilitation of the Bronson Avenue and Percy Street overpasses.

One of the major advantages of the Chamberlain Avenue site is the ability to house the NST launch and staging operations at one location. This will simplify construction management and will not require the shuttling of staff or materials between multiple locations. The site also has easy access to Highway 417. This will help to minimize truck traffic on local roads, particularly as compared to the St. Laurent Square site which would require truck traffic to pass through the city center.

Preliminary hydraulic modelling of the NST extension has been completed for the 1:100 year event. The modelling results produced the following findings:

• The Catherine West Trunk Level Measures (TLM) improvement would no longer be required;

• The proposed Percy Street TLM, a 1,050ømm trunk sewer, would need to be extended 135m south from Catherine Street to Chamberlain Avenue to maintain level of service against flooding;

• A future connection between the NST and the Bronson Avenue sewer would not be deemed necessary but may still be desirable in order to avoid an upgrade of the Bronson Avenue sewer between Imperial Avenue and Arlington Avenue by connecting the Bronson Avenue sewer to the NST as a part of a future realignment of Chamberlain Avenue;

• A connection between the NST and the Lyon Street sewer would not be deemed necessary;

• Connection of the Chamberlain Avenue storm sewer to the NST may offer local surcharge relief and presents an opportunity to replenish the NST’s flush-water storage.

These hydraulic benefits represent significant improvements to the level of service of the local sewer systems as well as potential for future flexibility.




4.2 NATURAL ENVIRONMENT EVALUATION

The eastern portion of the Chamberlain Avenue site is a grassy slope with mature and immature trees and shrubs between Chamberlain Avenue and the highway retaining wall. Most of the existing vegetation would need to be removed to allow for construction activities. The vegetation is not expected to be of significant environmental value. The St. Laurent Square alternative may also involve removal of mature trees.

4.3 SOCIO-CULTURAL EVALUATION

The socio-cultural impacts of extending the NST to the Chamberlain Avenue site can be considered to be less than those of the St. Laurent Square alternative:

• The green space on the eastern portion of the Chamberlain Avenue site is currently not accessible to the public.

• Although the Chamberlain Avenue site involves the removal of urban trees, the area is currently fenced and adjacent to Highway 417 and it not used for recreational activities or cultural events;

• The Chamberlain Avenue site is compatible with MTO planning and the reduced staging area requirements at the Supreme Court has greater compatibility with PWGSC plans and policies;

• There are expected to be fewer site access restrictions and site security requirements at the Chamberlain Avenue site compared to the St. Laurent Square site.

The launching shaft and associated activities (mucking, staging, storage, loading/unloading, etc.) may present an impact to the local residents in terms of noise, dust, traffic, and visual distraction. The Chamberlain Avenue site is located adjacent to Highway 417, on the fringe of the neighbourhood and adjacent to commercial, industrial, and transportation uses. The proximity of the staging and mucking location to Highway 417 is beneficial compared to the previous alternative at St. Laurent Square that would require more truck traffic along Kent Street, Lyon Street, and at the Supreme Court Site. In addition, the implementation of the proposed NST extension is expected to significantly reduce future disruptions along Catherine West since future upgrades may be conducted as simple integrated road works where the implementation of a large relief sewer is no longer necessary.




4.4 ECONOMIC EVALUATION

The cost implications of the NST extension and use of the Chamberlain Avenue staging area and launch site are similar to the overall costs associated with launching from the ESR selected site at St. Laurent Square (i.e., the net cost impacts, or total of the estimated additional costs combined with identified savings, is within the margin of error of the cost estimate). The NST extension, the use of the Chamberlain Avenue staging area and launch site, and the extension of the Percy TLM will result in an additional cost compared to the ESR preferred alternative; however, the additional cost will be largely offset by identified savings associated with reduced time working at the Supreme Court site and the elimination of the requirement of the Catherine West TLM. A more detailed summary of the cost implications is provided in Appendix C.



Potential Impacts and Mitigation Measures April 2, 2014

5.0 Potential Impacts and Mitigation Measures

The potential impacts and mitigation measures for the CSST are presented in Table 5-2 of the 2013 ESR. Construction at the Chamberlain Avenue site will result in an increase in truck traffic, and a potential increase in noise and dust in the vicinity of the site. It is anticipated there will be minimal disruption to traffic through the construction process other than equipment and haul trucks accessing and departing the site. Extension of sewer infrastructure along Percy Street will likely require the closure of Percy Street to motor vehicles during the excavation and placement of the sewer and chamber; however, it is anticipated that pedestrian and cycle movements along Percy St. will be maintained. The ESR included requirements to mitigate noise, traffic and dust impacts that may be expected during construction and these mitigation measures will apply to construction at the Chamberlain Avenue site. No additional mitigation measures have been identified for the Chamberlain Avenue alternative.

It is recommended that public consultations be held with the community surrounding the Chamberlain Avenue site to inform nearby residents and business owners of the proposed work.

An arrangement to lease the site from the MTO and coordinate with the planned work will be required. The MTO has suggested that a memorandum of understanding be developed between the City and the MTO to outline requirements and intent on both sides. Any requirements that the MTO may impose on the site, schedule, operational, or otherwise, may impact the NST construction.



Preferred Alternative April 2, 2014

6.0 Preferred Alternative

A summary of the advantages and disadvantages of using the Chamberlain Avenue site for the NST tunnel launching site and primary construction staging area is provided in Table 1.

Table 1: Summary of Advantages and Disadvantages

Advantages Disadvantages

Large launching site with all operations on single site. Additional geotechnical and environmental investigation required with impacts on design schedule and budget.

No need to secure and lease remote staging/storage site(s). Eliminates need to store material off-site and shuttle staff between sites.

Additional design efforts required with impacts on design schedule and budget.

Impacts to community expected to be moderate and can be mitigated.

Contaminated soils present on the site. Extents unknown in the east portion of the staging area.

Eliminates need for Catherine West TLM and related open trench disruptions on busy arterial.

Additional tunneling costs and tunnel drive time (estimated additional 2 months).

Staging and mucking operations would be located with easy access to /from Hwy 417.

Time constraint: site must be returned to the MTO by the start of 2018.

Potentially eliminates need for replacement and upsizing of the Bronson sewer between Imperial Avenue and Arlington Avenue and the related open trench disruptions.

Cost of using the site is expected to be modest and the land is not in private ownership.

MTO will demolish the existing building.

Reduced construction duration at Supreme Court grounds - lower risk of delays in approvals and construction progress due to sensitive stakeholders.

Good rock cover along extension alignment.

The Chamberlain Avenue site is the preferred location for the NST launch and construction staging site. Taking into account net cost impacts (i.e . additional tunneling costs minus identified savings), this option is similar in cost to the ESR’s initial recommendation, and it provides the contractor with single staging location with nearby access to Highway 417. It also addresses PWGSC’s concerns by minimizing the scope and duration of the work required at St. Laurent Square. Extending the NST along Chamberlain Avenue provides the City with future flexibility in rerouting sewer flows from Bronson Avenue and the surrounding area, possibly eliminating or deferring significant infrastructure projects. This site is the best suited of the alternatives previously identified to meet the criteria for the NST construction with the fewest negative impacts.



Appendix A Technical Memorandum: Alternative Construction Staging Areas for NST - January 10, 2014April 2, 2014

Appendix A Technical Memorandum: Alternative Construction Staging Areas for NST - January 10, 2014

my c:\users\mayoung\desktop\nst_extension\report.docx A.1

Memo

To: Randy Dempsey, P.Eng. From: Stéphane D’Aoust, P.Eng.

City of Ottawa Stantec Ottawa

File: CSST Design (1634-01060) Date: January 10, 2014

Reference: Alternative Construction Staging Areas for NST

The purpose of this memo is to provide some additional details with respect to alternative construction staging areas for the North South Tunnel (NST) and necessary connections to existing infrastructure north of Wellington St.

BACKGROUND At the Stakeholder meeting of December 19th 2013, the City was asked by PWGSC to provide additional details about the alternative construction staging areas for the NST that were considered as part of the Environmental Assessment (EA). It was brought to the PWGSC’s attention that 2 alternatives were documented in the EA based on a review by the design team and discussions during the EA with staff from the PWGSC, Parliamentary Precinct and the Supreme Court.

Following the December 19th 2013, the design team has reviewed the NST alignment and prepared a list of 6 alternative construction staging areas. More details on these alternatives are provided below.

Note that the design team has not developed these alternative designs beyond the conceptual stage and therefore the feasibility of such alternatives may be influenced by information to come.

ALTERNATIVE STAGING AREAS The availability of a tunnel construction staging area is key in the effective delivery of a project. The staging area will need to accommodate:

• Site Office Facilities, Restrooms

• Maintenance Shop

• Power Substation

• Construction Equipment Storage & Staging

• Fixed Crane

• Tunnel Ventilation Infrastructure

• Tunnel Muck Handling, Stockpiling, Loading

• Haul Truck Ingress, Wheel Washing and Egress

• Construction Water Treatment and Discharge

• Shaft / Tunnel Lining (cast in place concrete and possibly precast concrete segments,)

• Concrete Truck Staging

sgd w:\active\1634_01060_ottawa combined sewage storage tunnel\preliminary\deliverables\tms\site 6 alternative staging areas\mem_nst staging areas 20140110_rev_3.docx

January 10, 2014 Randy Dempsey, P.Eng. Page 2 of 8


The following provides a brief description of alternative construction staging areas with Alternatives a) and b) being the same as those presented in the EA as Areas 1 and 2, respectively.

ST. LAURENT SQUARE (AREA A) Staging Area a) is located on the front lawn of the Supreme Court of Canada. Refer to Figure 1. The site is bounded by Wellington St. to the south, Kent St., to the east, the Supreme Court building to the north and an access road to the west. Two rows of mature trees line both the east and west edges of the lawn whereas a single sparser row of trees lines its southern edge. An existing access chamber is located in the southeast corner of this area to access the head of the existing Kent St. Storm Tunnel Outfall, to which to the NST must connect. This staging area could allow for a single site for the construction of both the tunnel and the overflow chamber including the connection to the Kent Street Storm Tunnel Outfall.


• Least-impact alternative in terms of Federal Government’s traffic/parking. • Single construction area: Overflow chamber and

connection to Kent Storm Tunnel built from same location. • Among least-impact alternative in terms of new

permanent encumbrances to Federal Land. Consolidates structures requiring occasional access by City crews to a single area at the site, by placing new access points adjacent to the existing access points for the existing regulator and Storm drop structure.

• In front of Supreme Court – temporary aesthetic impacts with presence of hoarding. • Coordination required with PWGSC tunnel

construction. • Construction schedule (time-of-day, time-of-year)

may be impacted by noise/vibration/traffic restrictions requested by federal government. • Un-planned shutdowns caused by federal

government needs/events will have to be accommodated. • Sesquicentennial restriction.




EAST OF THE LIBRARY AND ARCHIVES (AREA B) Staging Area b) is located along Wellington St. east of the Library and Archives Canada building and immediately west of Staging Area a). Refer to Figure 2. It is also a tree-lined lawn which is slightly smaller that Staging Area a). This staging area could allow for the construction of the tunnel where the tunnel would be launched in an east direction on a radius that would allow a connection to the overflow chamber. With the use of this area for the main staging area, the overflow chamber and connection to the Kent Street Storm Tunnel Outfall would have to be constructed from a smaller construction staging area in front of the Supreme Court (Staging Area a).


• Open area with little to no disruptions to traffic management or parking in area. • Located west of Supreme Court reducing the

duration of the disruption in St. Laurent Square. • Low-impact alternative in terms of new permanent

encumbrances to Federal Land. Consolidates structures requiring occasional access by City crews to a single area at the site, by placing new access points adjacent to the existing access points for the existing regulator and Storm drop structure.

• Two construction areas: Additional disruption required North of Wellington to connect to Kent Storm Tunnel – temporary aesthetic impacts with presence of hoarding. • Two construction areas to control with respect to

security; discussions with RCMP may be required. • Tight turning radius hindering production. • Additional cost associated with 110m of tunnel

necessary and mucking shaft that will be abandoned after construction. • 110m of abandoned tunnel will remain

encumbering Federal Land. • Construction schedule (time-of-day, time-of-year)


government needs/events will have to be accommodated. • Sesquicentennial restriction.




KENT ST. ROW (AREA C) Staging Area c) is located along the Kent St. right of way between Wellington St. and Vittoria St. Refer to Figure 3. The staging would utilize the entire right of way preventing access to Vittoria from Wellington via Kent. This area is congested with utilities (sewers and utilities known to the City are illustrated on Drawing 1, note that some PWGSC utilities are missing from this drawing) and will require infrastructure relocation to allow the implementation of a shaft. This staging area could allow for a single site for the construction of both the tunnel and the overflow chamber including the connection to the Kent Street Storm Tunnel Outfall.


• Single construction area: Overflow chamber andconnection to Kent Storm Tunnel built from samelocation. Extent of area on Figure 3 may be largerthan illustrated depending on necessary utilityrelocations.• Consolidates structures requiring occasional access

by City crews to a single area at the site, by placingnew access points adjacent to the existing accesspoints for the existing regulator and Storm dropstructure.

• Major traffic disruptions (RCMP has concerns, andpossibly objections to closing Kent north ofWellington to traffic).• ROW congested with utilities would require

relocations if possible. Construction period wouldlikely be longer due to utility relocations. And theaffected area would likely extend well beyond whatis shown in Figure 3, depending on where theseutilities would be relocated. These relocations mayfurther encumber federal land.• Impractical and very confined staging area which

will result in significant cost and scheduleimplications• In front of Supreme Court – temporary aesthetic

impacts with presence of hoarding.• May be impacted by ongoing PWGSC tunnel

construction.• Proximity to House of Commons heritage

structure will have significant cost andschedule impacts.• Construction schedule (time-of-day, time-of-year)

may be impacted by noise/vibration/trafficrestrictions requested by federal government.• Un-planned shutdowns caused by federal

government needs/events will have to beaccommodated.• Sesquicentennial restriction.




EAST OF THE SUPREME COURT (AREA D) Staging Area d) is located to the east of the Supreme Court and north of the Justice building. Refer to Figure 4. The staging area would utilize a significant amount of the existing parking area north of the Justice Building. This staging area could allow for a single site for the construction of both the tunnel and the overflow chamber including the connection to the Kent Street Storm Tunnel Outfall.


• Better aesthetically since site not very visible from Wellington St. • Single construction area: Overflow chamber and

connection to Kent Storm Tunnel built from same location. • Likely less impacted by sesquicentennial

restrictions.

• High-impact in terms of new encumbrance on Federal Land. • Creation of a new zone affected by occasional

maintenance by City crews, in addition to the existing regulator and storm sewer drop structure at South-East corner of the Supreme Court’s front lawn. • Confined staging area that will present more or less

difficulty depending on how much of the parking area can actually be used. • Disruption to parking east of Supreme Court to

provide construction staging area for approximately one year. • Requires temporary relocation of House of

Commons truck storage/parking area. • Affects exit route options for evacuation of vehicles

parked in Supreme Court’s underground parking (to be discussed with RCMP). • Additional 140m of tunnel necessary. Additional

cost. • Construction schedule (time-of-day, time-of-year)


government needs/events will have to be accommodated. • Will require consent from stakeholder, chiefly the

House of Commons. • Geotechnical conditions of rock slope will influence

location of the tunnel construction shaft.




NORTHEAST OF THE SUPREME COURT (AREA E) Staging Area e) is located to the northeast of the Supreme Court in the western portion of the lower parking lot. Refer to Figure 5. In this alternative, the tunnel would be initiated from a portal on the north face of the escarpment west of the parking lot. The staging area would utilize a significant amount of the existing parking lot and could allow for a single site for the construction of both the tunnel and the overflow chamber including the interconnection to the Kent Street Storm Tunnel Outfall.


• Better aesthetically since site not very visible from Wellington St. • Single construction area: Overflow chamber

and interconnection to Kent Storm Tunnel built from same location. • Likely less impacted by sesquicentennial

restrictions.

• Highest-impact in terms of new encumbrance on Federal Land. • Creation of a new zone affected by occasional

maintenance by City crews, in addition to the existing regulator and storm sewer drop structure at South-East corner of SC front lawn. • Highest impact on vegetation (tree survey would have

to be conducted, species at risk, etc.) • Impacts use of recreational pathway/road along the

River, and linkages between that pathway to the upper area of the Parliamentary Precinct. • Shuts down access road along River and entrance

linking parking lot to access road (RCMP to be consulted). • Confined staging area that will present more or less

difficulty depending on how much of the area can actually be used. • Disruption to lower parking east of Supreme Court to

provide construction staging area for approx. one year. • Additional 210m of tunnel necessary. Additional cost. • Construction schedule (time-of-day, time-of-year) may

be impacted by noise/vibration/traffic restrictions requested by federal government. • Un-planned shutdowns caused by federal government

needs/events will have to be accommodated. • Will require consent from stakeholder, chiefly the

House of Commons, RCMP, Supreme Court and other users of that parking. • Disruptions to vegetation on escarpment. • Disruptions to pathway users along river. • May require EA addendum since the works will impact

vegetation, pedestrians and possibly the river along the escarpment.




KENT AND ALBERT (AREA F) + REDUCED STAGING AREA AT/NEAR SUPREME COURT Staging Area f) is located east of Kent St. between Queen and Albert Streets. Refer to Figure 6 and Figure 7. This site is currently being used to provide a temporary shaft (to 2017) for the construction of the LRT. The site is privately owned (Brookfield) and is slated for development. Assuming that the site is available for the NST construction, the tunnel boring machine would be launched from a new shaft at this location heading north and subsequently heading south toward Catherine St. With the use of this area for the main staging area, the overflow chamber and connection to the Kent Street Storm Tunnel Outfall would have to be constructed from a smaller construction staging area either in front of the Supreme Court (Staging Area a) (Figure 6) or to the east of the Supreme Court (Staging Area d) (Figure 7).


• Located away from Supreme Court reducing the duration of the disruption in St. Laurent Square or East of Supreme Court for connection to Kent Storm Tunnel. • Should Area A be selected for connection of the

new Tunnel to the existing Storm sewer: o Least-impact alternative in terms of new

permanent encumbrances to Federal Land. o Consolidates structures requiring

occasional access by City crews to a single area at the site, by placing new access points adjacent to the existing access points for the existing regulator and Storm drop structure.

o Least-impact alternative in terms of traffic/parking.

• Should Area D be selected: o Low aesthetic impact.

• Confined staging area that will present more or less difficulty depending on how much of the area can actually be used. • Two construction areas: Additional disruption

required North of Wellington to connect to Kent Storm Tunnel and extract Tunnel Boring Machine – temporary aesthetic impacts with presence of hoarding. This comes with ALL the other disadvantages noted for a) and b) above. • Potential for conflicts with LRT construction (RTG)

during construction including constructor issue. • Loss of income to the landowner due to elimination

of revenue stream (paid parking). • Should Area D be selected for connection of the

new Tunnel to the existing Storm sewer: o High-impact in terms of new encumbrance

on Federal Land. o Creation of a new zone affected by

occasional maintenance by City crews, in addition to the existing regulator and storm sewer drop structure at South-East corner of SC front lawn.

o Requires temporary relocation of House of Commons truck storage/parking area.

• Should Area A be selected: o Aesthetic impact to front lawn of Supreme

Court (albeit shorter duration and extent).




SUMMARY A comparison of the advantages and disadvantages of the alternative staging areas is provided herein. Based on this comparison, alternatives a), d) and e) are favored over the other alternatives since all of the construction necessary for the NST may be done from a single staging area minimizing traffic disruptions or any throw away infrastructure. These sites do not have the potential to conflict with LRT projects. If Area a) or d) is selected, the construction schedule may be impacted by the on-going PWGSC tunnel construction.

Stantec Consulting Ltd.

Stéphane D’Aoust, P.Eng. Practice Leader - Water Phone: (613) 725-5558 [email protected]

Attachment: Figure 1 to 7: Alternative Construction Staging Areas for North South Tunnel Drawing 1: Site 6 Existing Utilities Known to City

c. Adrien Comeau, P.Eng. - Stantec


mailto:[email protected]

Temporary Hoarding around Proposed Tunnel Construction Staging Area

Permanent CSST Connection to Existing Storm Tunnel Access Manhole

TBM Launch and Ultimate Access to Underground Structure

Approx. Proposed Tunnel Alignment

Figure 1: NST Construction Staging Area - Alternative a) Existing Kent Storm Tunnel Proposed North-South Tunnel

Temporary Hoarding around Construction Area for Connection to Kent Storm Tunnel

Permanent CSST Connection to Existing Storm Tunnel Access Manhole

TBM Launch and Temporary Hoarding around Proposed Tunnel Construction Staging Area

Permanent Access Manhole to Underground Structure

Figure 2: NST Construction Staging Area - Alternative b) Existing Kent Storm Tunnel Proposed North-South Tunnel


Permanent Connection to Existing Storm Manholes Tunnel Access

TBM Launch and Permanent Access Manhole to Underground Structure

Minimum Temporary Hoarding around Proposed Tunnel Construction Staging Area (utility relocations may necessitate a larger area)

Figure 3: NST Construction Staging Area - Alternative c) Existing Kent Storm Tunnel Proposed North-South Tunnel


Existing Storm Tunnel Access Manhole


TBM Launch and Permanent Access Manhole to Underground Structure with Connection to Existing Storm Tunnel

Figure 4: NST Construction Staging Area - Alternative d) Existing Kent Storm Tunnel Proposed North-South Tunnel


TBM Launch and Permanent Access Manhole to Underground Structure New Outlet to River

Existing Storm Tunnel Access

Figure 5: NST Construction Staging Area - Alternative e) Existing Kent Storm Tunnel Proposed North-South Tunnel

TBM Launch and Temporary Hoarding around Proposed Tunnel

Construction Staging Area


Connection to and Temporary Hoarding around Construction Area for Connection to Kent Storm Tunnel

Approx. Tunnel Alignment


Figure 6: NST Construction Staging Area - Alternative f-1) Existing Kent Storm Tunnel Proposed North-South Tunnel

TBM Launch and Temporary Hoarding around Proposed

Tunnel Construction Staging

Connection to and Temporary Hoarding around Construction Area for Connection to Kent Storm Tunnel



Figure 7: NST Construction Staging Area - Alternative f-2) Existing Kent Storm Tunnel Proposed North-South Tunnel

-

0

0

\

b "

"I

D

r "

0

71

0 "

c

c1 J

-

I

I

Cl

I

(

I

I ~

\

-·

0

--------------....,,---

!

,/ 37M1m WA1ERMAIN

- Ir-= Lf-~

I 0

D 0

L__ PROPOr, )E~ 3.Dm DIA KENT In STREEf SEW. ,GE TUNNEL

WITH APPROX. 22m COVER

'1cl

' \ ' II ,

. I

.-

µ Cl)

1z w ~

;;

( (~

i)' I -i / I I I I

'

I '·

\\---- ------

I~

12/imm WATERMlolN AIMHD

'----,1111. . I (QJ ---<

I ~, >---"

)

OTTAWA COMBINED SEWAGE STORAGE TUNNEL

Civil SITE6

KENT TUNNEL OVERFLOW

Contract No.

15013-2033 1

Sheet 1 of 1

Asset No.

W. Newell, P. Eng. R. Dempsey, P. Eng. General Manager, Project Manager, Asset Group

1==~=m~tra~structu~~ra~S~e/VICe.S~-~~='=~~m~frastru~ctu~ra~S~eJV1COS~-~~=

~Stantec CH2MHILL. Des. Ch~d.

l---------~-----------1 Dwn. Chk'd.

Utility Circ. No. Index No.

Const. Inspector

Scale: 1:200

NOTE: The location of utilities is approximate only, the exact location should be detennined by consulting the municipal authorities and utility companies coocemed. The contractor shall prove the location of utilities and shall be responslble for adequate protection from damage.

No. Deacrtptlon By Date (ddlmm/yy)

~ 1--1----------------------1----+-----1

~ 1--1---------------------+---+------1 ~ 1--1----------------------l----L-----1

\ jv I

,--- -I

I /

I

0

/~ ''rI @J ) -I )c-

·~

ii 4f= ® '1 "" IF° 1(~ @ii ,CJ ~

r ,/ -- i:O LJ "-'--\ //- ~ I

I

u 0 p ~ ~ ~ _____ ! ----- -- ---- -- ---- ----- ----- ----- ~~

0 2 • • 12 16m

--------- 478477

z

~ :::J (.) a:::-(.)

~ ...J-1:::J

0


Appendix B Technical Memorandum: Potential Alternative Tunnel Launching Sites for NST – February 23,2014 (Rev 2)April 2, 2014

Appendix B Technical Memorandum: Potential Alternative Tunnel Launching Sites for NST – February 23, 2014 (Rev 2)

my c:\users\mayoung\desktop\nst_extension\report.docx B.1

Technical Memorandum: Review of Potential NST Extension along Chamberlain Avenue

Ottawa Combined Sewer Storage Tunnel (CSST)

City of Ottawa Contract No. ISD13-2033

Prepared for: City of Ottawa

Prepared by:


CH2M HILL

March 28, 2014 Revision Record

Revision Description Prepared By Checked By Approved By Rev 0 Draft P.Pitre/S.D’Aoust Mar 5 A.C. Mar 5 Rev 1 Draft P.Pitre Mar 12 Rev 2 Draft P.Pitre Mar 14 Rev 3 Submitted P.Pitre Mar 19 Rev 4 Rev Final P.Pitre Mar 28 A.C. Mar 28

Sign-off Sheet

This document entitled Technical Memorandum: Review of Potential NST Extension along Chamberlain Avenue was prepared by Stantec Consulting Ltd. and CH2M HILL for the account of the City of Ottawa. The material in it reflects Stantec’s and CH2M HILL’s best judgment in light of the information available to it at the time of preparation. Any use which a third party makes of this report, or any reliance on or decisions made based on it, are the responsibilities of such third parties. Stantec Consulting Ltd. and its sub-consultant CH2M HILL accept no responsibility for damages, if any, suffered by any third party as a result of decisions made or actions based on this report.


Pascal Pitre


Adrien Comeau

TECHNICAL MEMORANDUM: REVIEW OF POTENTIAL NST EXTENSION ALONG CHAMBERLAIN AVENUE

March 28, 2014

Table of Contents

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

2.0 BACKGROUND.............................................................................................................. 1SITE DESCRIPTION ...................................................................................................................... 1TUNNEL ALIGNMENT DESCRIPTION ........................................................................................ 2

3.0 HYDRAULIC CONSIDERATIONS..................................................................................... 3

4.0 GEOTECHNICAL CONSIDERATIONS ............................................................................. 5

5.0 ENVIRONMENTAL CONSIDERATIONS ........................................................................... 5

6.0 CLASS ENVIRONMENTAL ASSESSMENT CONSIDERATIONS.......................................... 6

7.0 COORDINATION WITH THE MTO ................................................................................... 7

8.0 COSTS IMPLICATIONS ................................................................................................... 9

9.0 SUMMARY & RECOMMENDATION.............................................................................. 10

LIST OF EXHIBITS

Exhibit 1: Site Plan ......................................................................................................................... 2Exhibit 2: 1958 Image ................................................................................................................... 2Exhibit 3: Alignment of NST Extension......................................................................................... 3Exhibit 4: Elimination of Catherine West TLM............................................................................. 4Exhibit 5: Cost Comparison Relative to Launching at ESR Site at Supreme Court (Site 6) . 9Exhibit 6: Summary of Advantages and Disadvantages ...................................................... 10

my c:\users\mayoung\desktop\nst_extension\csst_tm_605bronsonsite_rev4.docx i


March 28, 2014

1.0 Introduction

The purpose of this technical memorandum is to document a review of the feasibility of extending the NST south and west along Chamberlain Ave., in order to take advantage of the vacant site at 605 Bronson Ave. for construction staging and tunnel launching. The following assessment will review the viability of this option, local hydraulic improvements offered by the NST extension, and will provide an overview of potential capital cost and constructability implications.

2.0 Background

During stakeholder consultations held in late December 2013 and early January 2014, the design team was advised by the PWGSC that the Supreme Court of Canada site could not be used for the NST tunnel launching and staging. Subsequently, the design team has undertaken a high-level review of alternative tunnel staging sites along the NST alignment (documented in TM – “Potential Alternative Tunnel Launching Sites for NST”, February 2014). One of the sites identified involves the use of a vacant property northeast of the Bronson and Chamberlain intersection.

Site Description

The site at 605 Bronson Ave consists of a property owned by the Ontario Ministry of Transportation (MTO), located approximately 625m from the Catherine Street tunnel termination. The site is bordered by Highway 417 to the north, Percy St to the east, Chamberlain St to the south and Bronson Ave to the west. As illustrated on Exhibit 1, it is comprised of an abandoned building, a parking/loading area and a grassed area that becomes sloped closer to Percy St. It is expected that up to 0.96 hectare (2.37 acres) could be available, of which 0.5 hectare (1.2 acre) currently consists of open area, with the balance being the building. It is the largest available site and would not require additional remote (off-site) staging area.

The MTO recently acquired the property at 605 Bronson (west portion of the site illustrated below containing the building and parking area), but already owned the east portion of the site (currently vegetated) as part of the Highway 417 parcel.

The MTO plans to tender the demolition of the existing building in the Spring of 2014 in order to realign Chamberlain Ave with the Highway 417 W-NSE ramp at Bronson Ave. Improvements of the Hwy 417 off-ramp are also planned. The road realignment, ramp improvements and intersection reconfiguration were planned for 2016, but the MTO would be willing to postpone the road work east of Bronson Ave (realignment of Chamberlain St) to accommodate the tunneling work. The MTO stipulated that the building needs to be demolished as soon as possible (by the MTO) or assumed by the City as part of the construction site and subsequently demolished by the City. Primary immediate concern of the MTO is to verify the structural stability of the communication tower on the roof, which would impact the Queensway if it fell to the north.

Prior to being acquired by the MTO, the west portion of the site (where building is located) was owned by the Ottawa-Carleton District School Board, and used as shops. Prior to this, the site was a Coca-Cola plant adjacent to rail yards as depicted in the 1958 photo (Exhibit 2).

my c:\users\mayoung\desktop\nst_extension\csst_tm_605bronsonsite_rev4.docx 1


March 28, 2014

Exhibit 1: Site Plan

Exhibit 2: 1958 Image

Tunnel Alignment Description

Being launched from 605 Bronson, the NST would follow Chamberlain Ave and pass under Highway 417 near the Kent St overpass. The tunnel boring machine (TBM) would be extracted at the Supreme Court site. As previously indicated, the Hwy417/Kent overpass will be under construction from late 2014 until probably 2016. The tunnel extension would pass under this construction site and approval from the MTO would be required. Consultation with the MTO suggests that, provided the tunnel is well into the bedrock and will not affect the bridge foundations, approval should be granted. The length of the NST included in



March 28, 2014

the Functional Design (from Supreme Court to Catherine St) is approximately 1580m. The extension of the NST would add another 625m (approx.), or an additional 40% to the length. The total revised NST length would be approximately 2,205 m.

Exhibit 3 illustrates the proposed extension of the NST along Chamberlain Ave and the approximate location of the proposed tunnel launching shaft, west of Percy St. It is expected that the tunnel would be located along the south side of Chamberlain Ave to provide the greatest separation distance from the existing 1220 mm watermain located along the north side of Chamberlain and also to provide a better radius at the Kent St curve. This radius at Kent St may be 150 m if an open face tunnel boring machine (TBM) is used or 220 m if an earth pressure balance machine (EPBM) is used. Which tunneling technique is specified will be dependent on the risk associated with dewatering of the overburden clay and is still to be confirmed. Both radii are shown on Exhibit 3 below. If the 150 m radius is used, the alignment would pass under the west abutment of the Kent St overpass. If the 220 m radius is used, the alignment would have a greater encroachment onto private property.

Exhibit 3: Alignment of NST Extension

3.0 Hydraulic Considerations

The InfoWorks model developed as part of the O’Connor Trunk Level Measures (TLM) Preliminary Design (Stantec, 2012) was used to assess the hydraulic performance of the proposed NST extension and the ability to adjust the proposed TLMs in the area.

Simulations of the 1:100-yr event indicate that a 625 m extension of the NST to the west side of Percy St provides the ability to eliminate the Catherine West TLM. In order to maintain the level of service (LOS) against flooding offered by the Catherine West TLM, the proposed Percy St TLM (1050mm diam.) will need to be extended an additional 135 m south along Percy from Catherine to Chamberlain. Refer to Exhibit 4 for an illustration of the proposed extension of the Percy St TLM to the NST and the elimination of the Catherine West TLM. The elimination of the Catherine West TLM avoids significant traffic disruptions associated with an open trench excavation along this busy arterial road.



March 28, 2014

The model results indicate that there is no need for a connection between the future NST and the Bronson sewer since this connection would only relieve approximately 40 L/s. However, it may be beneficial to provide a shallow (standard depth) sewer connection to the NST from Bronson as part of the Chamberlain Ave realignment project, as it could possibly replace the proposed Bronson sewer upgrade (from 600mm diam. to 900mm) between Imperial and Arlington (not modeled). The sewer connection from Bronson would be approximately 250 m in length. This opportunity would have to be reviewed with ISD to assess whether it offers advantages with respect to the planned Bronson sewer reconstruction. Hence, the NST does not need to extend past Percy St for hydraulics purposes.

The model results also indicate that there is no need for a connection between the NST and the Lyon St sewer.

Chamberlain Ave is serviced by a local storm sewer which accepts drainage from Highway 417 (flows into the municipal storm system at Percy St). This sewer is subject to LOS issues (LOS estimated at between 1:2-yr and 1:10-yr). It is suspected that this is not overly problematic as there are likely no basement connections to this sewer. A connection to the NST from the Chamberlain storm sewer may offer some local surcharge relief and an opportunity to replenish a flushwater storage compartment for periodic sediment flushing of the NST. Note that the Implementation Plan from the O'Connor Drainage Area Flood Control Study (Delcan, 2006) recommended inflow control along Chamberlain combined with overland flow diversions to Central Park (Head of Paterson Creek). A more detailed review of the local storm sewer system is required to determine the best location for a relief connection(s).

Exhibit 4: Elimination of Catherine West TLM



March 28, 2014

4.0 Geotechnical Considerations The design team has existing borehole information (a combination of boreholes completed by Golder and McRostie) for the overpasses at Bronson Avenue, Percy Street, Lyon Street, and Kent Street. These boreholes indicate that the bedrock surface elevation increases to the west, as indicated below: • At the Kent overpass, the bedrock is approximately 13 m deep (elevation 56 m) • At the Percy overpass, the bedrock is approximately 7 to 8 m deep (elevation 60 to 61 m) • At the Bronson overpass, the bedrock is approximately 1 to 2 m deep (elevation 68 to 69 m)

The NST will have an invert elevation of 45.74m at the Kent/Catherine intersection, which implies an approximate crown of tunnel bore elevation of 49.09m (allowing for 350mm for shotcrete and final lining). Therefore, the rock cover over the NST tunnel bore near the Kent Street overpass is expected to be in the 7 m range based on the rock elevations reported above.

With an approximate length of 625 m between the Kent/Catherine intersection and the proposed launching shaft, and with a tunnel slope of 0.1%, the invert elevation at the launching shaft would be 46.36 m, with a tunnel crown elevation of 49.72 m. The rock cover over the tunnel near the Percy St overpass would be in the range of 10-11 m. In the event that a steeper slope is adopted for this section of the tunnel, the rock cover would not be problematic as it rises fairly significantly towards the west.

The overburden soil conditions generally consist of fill overlying sand and glacial till. Clay is also present between Lyon St and Kent St, and to the south of Chamberlain Ave. The potential for contaminants along Chamberlain should be considered. There is anecdotal evidence that there may be some buried waste materials and contaminated fill in this area.

Additional geotechnical investigations with deep boreholes would be required along Chamberlain Ave tunnel alignment and at the proposed launching site. It is expected that the NST extension would require seven to eight boreholes plus a pumping test.

5.0 Environmental Considerations A review of the following documents provided by the MTO was conducted by the design team’s environmental group:

• Phase II ESA report (SLR, 2008), • Environmental Summary and Remedial Estimates (SLR, June 2010), • Building plans

The building plans showed details of an underground storage tank (UST) for gasoline and indicated the presence of a waste oil UST. The Phase II ESA reports that the gasoline UST was removed from the property in the 1990s. There is no mention in the SLR reports of the waste oil UST. It may have been removed from the property at some point or could potentially still be present. Historical fire insurance plans (FIPs) were also reviewed. These FIPs indicate the presence of another UST south of the building, dating back to the mid-1950s.

The Phase II ESA indicates that there are petroleum hydrocarbon impacts in the soil and groundwater on both the north side and east side of the building. Comparison of the lab results from the Phase II ESA to the current soil and groundwater quality standards applicable in Ontario indicates that:

1. There is soil and groundwater in the northwest corner of the property (between the building and the highway embankment) that fails the standards applicable to the Site.

2. There is soil and groundwater east of the building that fails the standards applicable to the Site. 3. Soil in three locations on the property (northwest corner of the property, east of the building, and

beneath the south side of the building) fails the background quality standards and would have to be disposed at a landfill if generated as excess material.



March 28, 2014

It is possible that additional soil and groundwater impacts exist at the Site. Site concerns that have not been well assessed in the Phase II ESA include:

1. Waste oil UST east of the building; 2. Former rail lines northeast of the building; 3. Area of the gasoline UST; 4. UST south of the building, noted on FIPs; 5. Off-site gasoline retail outlets and automotive service garages.

Additional assessment of the soil and groundwater condition in these areas of the site are recommended. Also, the SLR Phase II ESA assesses solely the 275 Chamberlain Avenue property (605 Bronson Avenue). The vacant parcel closer to Percy St (where the tunnel launching shaft is proposed to be located) was not assessed. Additional assessment of soil and groundwater quality on the vacant parcel would be required.

It is recommended that the additional environmental screening program be coordinated with the additional geotechnical investigation.

6.0 Class Environmental Assessment Considerations

In order to launch from the MTO property west of Percy St, the tunnel would have to be extended south of Highway 417, outside the study area considered in the Municipal Class Environmental Assessment (EA). The launching shaft and part of the tunnel alignment are located on property owned by a third party public agency (MTO) and the construction activities would be potentially impacting a broader area of the community, as well as a different neighborhood, than originally anticipated. Consequently, the tunnel extension can be considered as having a greater social impact than that considered in the EA. It is our understanding and expectation that an amendment to the EA would need to be prepared to document this tunnel extension and assess the added impacts. It is expected that impacts associated with the tunnel portion of the work would be minimal and/or easily mitigated due to the depth and trenchless nature of the work. The launching shaft and associated activities (mucking, staging, storage, loading/unloading, etc.) may present a greater impact to the local community (visual, noise, dust, traffic, etc.) However, due to the location of the site (between Chamberlain and Highway 417), being on the fringe of the neighborhood and adjacent to commercial/industrial/transportation uses, it is expected that impacts to the community would be relatively modest and easily mitigated. The proximity of the staging and mucking location to Hwy417 can also be seen as beneficial compared to the previous alternative that would require more truck traffic along Kent St, Lyon St and at the Supreme Court site.

In order to mitigate risks of further extensions to the project schedule, it is recommended that this EA amendment process be commenced as soon as a decision is made with respect to using this site.



March 28, 2014

7.0 Coordination with the MTO

The MTO has indicated their willingness to work with the project team to accommodate the tunnel launching and mucking operation at this site. The following sections highlight items that will require consideration by the City and/or coordination with the MTO in the immediate/near future.

Building Demolition

If the City wishes to proceed with the option of launching from this MTO site, a decision was to be made as soon as possible as to whether the City would assume the existing building or let the MTO demolish it in 2014. The MTO had indicated that the existing rooftop communication tower presents a hazard due to its proximity to the Queensway and the uncertainty with respect to its structural stability and anchoring. The MTO indicated that a structural condition assessment was conducted on the tower during the week of March 3, 2014, and revealed that the tower must be taken down as soon as possible. The MTO is proceeding with removing the tower as an urgent project. The MTO also reported that all services to the building and utility connections have been disconnected. As a result, the sprinkler system is reported to have suffered damage due to frozen pipes. It is also unclear as to the amount of work that would be required to refurbish the building for use as office/storage facility for the CSST project.

The MTO believes they would be ready to tender the demolition by late March / early April 2014. It is expected that tendering would extend over one month and the demolition would take 6 to 8 months. If the demolition work was to commence in June (conservative start date), six months would extend to December 2014 while eight months would extend to February 2015.

It is estimated that the 2200 m long NST could be constructed over a 18-20 month period, including setting up the site, excavating the shaft, setting up the TBM in the shaft, building the tail tunnel, driving the tunnel, removing the TBM, delay associated with configuring the tunnel intersection at Slater, lining the tunnel and removing all equipment. If an EPBM is used in lieu of a TBM, it is expected that the duration would be similar since the drive progress is slower, despite the fact that it would be a one-pass operation (no need to line the tunnel afterwards). It is estimated that after the tunnel is completed, the permanent structure (including the access shaft and flush-water reservoir) would be constructed over a 4 month period, resulting in an overall construction period of 22-24 months at this site.

There is a risk that the MTO demolition contract could slip and take longer than the anticipated 6-8 months and go beyond February 2015. Of the 18-20 month period for the NST construction, it is expected that the first 4 to 4.5 months would be for the site preparation, excavation of the shaft, and setting up the shaft for the TBM/EPBM. A temporary and smaller construction site could be configured during this period if required to maintain a separation from the MTO demolition contract at 605 Bronson and satisfy MOL requirements. Furthermore, the 22-24 month period for the NST & site facilities construction would be shorter than the overall CSST project schedule, which should be able to accommodate some minor delays associated with this launch if necessary.

As the City may not be in a position to assume the building until project funding has been confirmed, the City has instructed the MTO on March 5, 2014 to proceed with the demolition of the building. The MTO has since confirmed that they are proceeding with the finalization of the building demolition tender.



March 28, 2014

Road Works

The MTO had planned to construct the realignment of Chamberlain Ave, improve the W-NSE ramp of Highway 417 and reconfigure the Chamberlain/Bronson/W-NSE Ramp intersection in 2016. However, they have indicated that they would accept postponement of the road works east of Bronson Ave (Chamberlain Ave realignment) to accommodate the City’s tunneling project. The MTO still intends to proceed with the intersection and off-ramp improvements in 2016. Adjacent construction zones will need to be clearly delineated. The MTO also indicated that minor alignment modifications may be made to Chamberlain Ave if needed for the CSST project, provided that it remains within the original concept presented during public consultation and would have no property impacts. The City may wish to install a sanitary sewer along Chamberlain Ave between Bronson and the NST to provide relief.

The MTO wishes to retain the design and construction of the Chamberlain Ave realignment for reasons related to the Bronson Ave overpass replacement project, as explained below.

Bridge Works

The MTO is planning bridge replacement/rehabilitation for the structures at the Bronson Ave overpass, to proceed to construction in 2018. The site at 605 Bronson is to be used for construction staging, hence the further postponement of the Chamberlain Ave realignment work. The MTO requires that the site be available for their use (CSST construction completed) by the beginning of 2018. As reported above, it is estimated that the NST and related structures could be constructed in a 24 month period. If construction commences in the summer of 2015, that would provide a 30-month window before 2018. The MTO is looking for assurances that the CSST construction would be completed and the site would be returned to the MTO for the start of 2018.

The MTO is also planning the future replacement/rehabilitation of the Percy St overpass. The structures to be constructed for the NST must be coordinated with the MTO to ensure they will not impact planned MTO projects. It will be critical for the NST structures to be located as close to an edge of the site as practical in order to mitigate encumbrances that may impact staging operations for the planned MTO projects. The structural stability of the bridge foundations and highway retaining walls must also be protected.

Memorandum of Understanding

The MTO suggested that a memorandum of understanding be developed as soon as possible between the City and the MTO to outline requirements and intent on both sides.



March 28, 2014

8.0 Costs Implications The following table provides a summary of the cost implications with the NST extension in comparison with launching from the ESR-selected site at the Supreme Court (Site 6).

Exhibit 5: Cost Comparison Relative to Launching at ESR Site at Supreme Court (Site 6)

Description Capital Costs 32% Delivery Cost Table Note 1

ADDITIONAL COSTS NST extension (3000mm diam. x 625m conventional CIP liner, $9,000/m)

$5.6M $1.8M

Additional Shaft $1.0M $0.3M Extension of Percy TLM from Catherine St to Chamberlain Ave (1050mm diam. x 110m microtunnel, $7,000/m)

$0.8M $0.2M

Cost to lease MTO land --- Unknown Sub-totals $7.4M $2.3M

30% Contingency Table Note 1 $2.9M Additional Costs $12.6M

SAVINGS/CREDITS Credit: Site 6 nighttime work premium (assumed 50% credit) Table Note 3

-$1.5M n/a

Credit: Elimination of Catherine West TLM (Stantec, 2012) Table Note 4

-$2.9M -$0.9M

Credit: Eliminate the premium that would have applied to an undersized site such as within the hoarding at Site 6 – Supreme Court (i.e. the need to pay for a remote staging/storage site and to bullgang material and shuttle staff between sites) Table Note 5

-$5.3M n/a

Sub-totals -$9.7M -$0.9M 30% Contingency Table Note 2 -$1.1M

Savings/Credits -$11.7M

Total $0.9M additional cost

Table Notes: 1. With reference to the City of Ottawa’s Capital Cost Estimates Components table, this

cost estimate is considered a Class C estimate with a contingency of 30% of capital cost, while delivery (incl. engineering, EA amendment, geotechnical & environmental investigations, utility adjustments/relocates & City internal costs) is estimated at 32% of capital cost. The contingency is applied to the capital cost and also to the delivery cost. The foregoing is consistent with the Functional Design Report (FDR) cost estimate.

2. The contingency allowance for the savings/credits is only applied to the Catherine West TLM item (capital cost and delivery cost) since the allowances for premiums for nighttime work and small sites already include contingencies.

3. In the Opinion of Probable Cost prepared in support of the Functional Design (2012), a



March 28, 2014

premium of $3M was added to the construction cost of the NST to account for delays and inconvenience of nighttime work expected to be required for construction activities in the vicinity of the Supreme Court of Canada and the Justice Building. Although work in that area will still be required for the TBM/EPBM extraction shaft and construction of the NST overflow chamber and related connections, this work would occur over a much reduced timeline when compared to a tunnel mucking operation. Therefore, it is estimated that perhaps 50% of the nighttime work premium could be credited.

4. The Opinion of Probable Cost prepared in support of the FDR (2012) did not includethis value. The credit amount was derived from the O’Connor Trunk Level Measures(TLM) PDR (2012).

5. The Opinion of Probable Cost prepared in support of the FDR (2012) did not includethis premium for launching from a site of insufficient size. Although the boundaries ofthe site (0.5 ha) would in theory be large enough to support a tunnel launchingoperation (including staging & storage), the usable space confirmed by PWGSC (0.3 ha)is a 40% reduction from the theoretical size of the site. The reduction is to protect theexisting trees and root system. The cost associated with a launching site of insufficient size was determined by Jim Peregoy (consulting former tunnel contractor, member of the design team) and is documented in the CSST TM titled Potential Alternative Tunnel Launching Sites for NST (Rev March 28, 2014).

The Savings/Credits outlined in the above table indicate values for some items that were not included in the 2012 Functional Design Report (FDR) or its supporting cost estimate. Extending the tunnel to the Percy/Chamberlain intersection would advance the benefits from two planned projects (credit for eliminating the Catherine West TLM less the Percy TLM extension) and thus would provide an improved level of flood protection to the Percy/Catherine West area much earlier than scheduled in the O’Connor Flood Control Pre-Design. To the CSST project itself, the actual short-term cost increase (when compared to the FDR cost estimate) will be $12.6M – $1.3M [consisting of ($0.8+$0.2)*1.3 contingency for the Percy TLM] - $1.5M [nighttime premium] = $9.8M, the bulk of which is offset by advancing future flood control works and using them with a dual purpose to further reduce CSOs in the short term.

It should be noted that the cost impact identified in the above table is less than the level of accuracy of the estimate at this stage of the project (7%).

9.0 Summary & Recommendation A summary of advantages and disadvantages to use the MTO property at 605 Bronson for the NST tunnel launching site is provided below:

Exhibit 6: Summary of Advantages and Disadvantages


Large launching site with all operations on single site. An EA amendment would be required.

No need to secure and lease remote staging/storage site and eliminate need to bull gang material and shuttle staff between sites (potential saving of $5-6M).

Additional geotechnical and environmental investigation would be required with impacts to design schedule and budget.



March 28, 2014


Although EA amendment is required, it is anticipated that impacts to community would be modest and can be suitably mitigated.

Additional design efforts would be required with impacts to design schedule and budget.

Eliminates need for Catherine West TLM ($7.3M saving) and related open trench disruptions on busy arterial. Presents opportunity to cost-effectively provide flood relief to area with less disruption to the community.

Contaminated soils present on the site (well characterized in the west portion of the site, but extents unknown in the east portion).

Staging and mucking operations would be located with easy access to/from Hwy 417.

Additional tunneling costs and tunnel drive time (estimated additional 2 months).

Potentially eliminates need for replacement and upsizing of the Bronson sewer between Imperial and Arlington and related open trench disruptions on busy arterial (cost not factored in above table as this elimination has not been confirmed).

Site must be returned to the MTO by the start of 2018, which presents a time constraint.

Cost of using the site is expected to be modest and the land is not in private ownership.

MTO will be demolishing existing building.

Lower risk of approval and construction delays due to sensitive stakeholders by reducing construction duration at Supreme Court.

Good rock cover along alignment.

Based on the foregoing, it is recommended that the City selects the 605 Bronson tunnel launching site for the NST and proceed with the Class EA amendment and memorandum of understanding with the MTO to formalize the scope and agreement.



Appendix C Technical Memorandum: Review of Potential NST Extension along Chamberlain Ave – March 28, 2014 (Rev 4) April 2, 2014

Appendix C Technical Memorandum: Review of Potential NSTExtension along Chamberlain Ave – March 28, 2014 (Rev 4)

my c:\users\mayoung\desktop\nst_extension\report.docx C.1

Technical Memorandum: Potential Alternative Tunnel Launching Sites for NST

Ottawa Combined Sewer Storage Tunnel (CSST)

City of Ottawa Contract No. ISD13-2033

Prepared for: City of Ottawa

Prepared by:


CH2M HILL

February 23, 2014

Revision Record Revision Description Prepared By Checked By Approved By

Rev 0 Draft P.Pitre Jan 29 S.D’Aoust Rev 1 Draft P.Pitre Feb 3 S.D’Aoust Rev 2 Draf P.Pitre Feb 23 S.D’Aoust

Sign-off Sheet

This document entitled Technical Memorandum: Potential Alternative Tunnel Launching Sites for NST was prepared by Stantec Consulting Ltd. and CH2M HILL for the account of the City of Ottawa. The material in it reflects Stantec’s and CH2M HILL’s best judgment in light of the information available to it at the time of preparation. Any use which a third party makes of this report, or any reliance on or decisions made based on it, are the responsibilities of such third parties. Stantec Consulting Ltd. and its sub-consultant CH2M HILL accept no responsibility for damages, if any, suffered by any third party as a result of decisions made or actions based on this report.


Pascal Pitre


Stephane D’Aoust

TECHNICAL MEMORANDUM: POTENTIAL ALTERNATIVE TUNNEL LAUNCHING SITES FOR NST

February 23, 2014

Table of Contents

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

2.0 ALTERNATIVE NST LAUNCHING SITES............................................................................ 1EA & FUNCTIONAL DESIGN PREFERRED SITE: ST. LAURENT SQUARE (SUPREME

COURT OF CANADA) ........................................................................................................ 4ALTERNATIVE SITE 1: KENT & ALBERT/QUEEN...................................................................... 5ALTERNATIVE SITE 2: KENT & ARLINGTON ............................................................................ 6ALTERNATIVE SITE 3: GLASHAN SCHOOL SITE ...................................................................... 7ALTERNATIVE SITE 4: KENT & CATHERINE WEST (CAR WASH)........................................... 8ALTERNATIVE SITE 5: PATERSON PARK................................................................................... 8ALTERNATIVE SITE 6: SOCCER FIELD .................................................................................... 10ALTERNATIVE SITE 7: 605 BRONSON (MTO SITE)................................................................. 11

3.0 EVALUATION AND RANKING FROM A CONTRACTOR’S PERSPECTIVE...................... 12

LIST OF FIGURES : Site Plan.......................................................................................................................... 2Figure 1

Table 2: NST Alternative Tunnel Launching Site Evaluation and Ranking Table ................ 12

my c:\users\mayoung\desktop\nst_extension\csst_tm_nst_launchsites_20140223_rev2.docx i


February 23, 2014

1.0 Introduction

This technical memorandum describes the evaluation of alternative launching sites for the North-South Tunnel (NST) of the Ottawa CSST project. The city was asked by PWGSC to review potential relocation options for the tunnel launching and mucking site proposed in the St. Laurent Square, south of the Supreme Court of Canada. This review includes sites that were not considered as part of the Environmental Assessment and that are not located within Federal lands.

Seven potential alternative launching sites have been identified to be subject to this review.

This evaluation includes a review conducted by Jim Peregoy from a contractor’s perspective, especially to assist with estimating the costs implications of relocating the tunnel launching site.

2.0 Alternative NST Launching Sites

In the EA and functional design, the tunnel launching shaft at St. Laurent Square (front lawn of the Supreme Court of Canada) would be reconfigured and repurposed as an overflow and diversion chamber at the north end of the NST. Even if the NST was launched from a different location, the overflow chamber would still be required at this location.

The seven potential alternative tunnel launching sites are described as follows. These seven potential sites are identified on Figure 1 and illustrated in greater details herein.

1. Kent & Albert/Queen

2. Kent & Arlington

3. Glashan School Site

4. Kent & Catherine West (Car Wash)

5. Paterson Park

6. Soccer Field

7. 605 Bronson

my c:\users\mayoung\desktop\nst_extension\csst_tm_nst_launchsites_20140223_rev2.docx 1


February 23, 2014

Figure 1: Site Plan



February 23, 2014

The ideal size for a tunnel launching site is between 0.8 to 1.6 hectares (2 to 4 acres). The minimum size (workable) for a tunnel launching site is generally considered to be 0.5 hectares (1.25 acres). The launching/staging area needs to include:

• Site office Facilities, Restrooms • Construction Equipment Storage & Staging

• Maintenance Shop • Tunnel Muck Handling, Stockpiling, Loading

• Power Substation • Haul Truck Ingress, Wheel Washing, Egress

• Fixed Crane • Construction Water Treatment and Discharge

• Tunnel Ventilation Infrastructure • Concrete Truck Staging

• Shaft / Tunnel Lining (cast in place concrete and possibly precast concrete segments)

Sites that do not meet the 0.5 hectare minimum size will not offer enough space for much more than the crane, muck handling and truck loading/unloading, and are expected to require a remote staging area.

The following sections presents descriptions and discussions for the various sites. The appended table presents the perspective of a contractor (as prepared by Jim Peregoy), including some advantages and disadvantages and his high-level estimated cost implication for relocating the launching site.



February 23, 2014

EA & Functional Design Preferred Site: St. Laurent Square (Supreme Court of Canada)

The St. Laurent Square, which is located north of Wellington and forms a front lawn to the Supreme Court of Canada, is currently used as a tunnel launching site and staging area for the Public Works Governmental Services Canada (PWGSC) tunnel. The intent would be to continue to use the site for a similar function for the CSST project. The total St. Laurent Square site is approximately 0.5 hectare in size, but only approximately 0.3 hectare (0.74 acres) would be considered usable space since PWGSC stipulated that the permissible site use would be limited to the extent of the current construction project hoarding limits. It is reported that the existing hoarding was located to avoid the root system of the existing rows of mature trees that are to be preserved. PWGSC also stipulated that tree removal would not be permitted. This site is smaller than the minimum desired size of 0.5 hectares for a tunnel launching site. This implies that this site would likely require a small remote storage/staging area for some of the equipment. As indicated above, this site was identified in the Environmental Assessment as the preferred location for the tunnel launching site for the NST, and its configuration was developed through the Functional Design. The overflow connection of the NST to an existing storm outfall would be configured at this location. Therefore, even if the tunnel launching and mucking is relocated to a different site, the overflow chamber would still need to be constructed at the St. Laurent Square.

It has also been stipulated by PWGSC that construction activities would be limited to night work to avoid disruptions to the Supreme Court sessions. A $3 million premium has been added to the cost estimate to reflect the added inconvenience and loss of productivity.



February 23, 2014

Alternative Site 1: Kent & Albert/Queen

The Kent & Albert/Queen site (280 Queen Street) is located two blocks from St. Laurent Square. On the east side of Kent St, between Queen St and Albert St, there is a surface parking lot. The total parcel is approximately 0.5 hectares. However, the north portion of the parcel is currently being used for a temporary shaft for the OLRT project (until 2017). This would leave approximately 0.225 hectares (0.6 acres) for the NST launching site.

Advantages and disadvantages are outlined in the appended table. Although the site does not require building demolition or an extension to the tunnel, it is approximately half of the minimum required size for a tunnel launching site. As such, an additional site for remote staging and storage will be required. The estimated additional rental and operation costs are also presented in the appended table. The contractor’s table outlines the presence of an adjacent high rise building as a disadvantage, but this is less of an issue if there are no residential uses. In this case, 255 Albert St is an office building. This site would require tunnel launching in two different directions (towards the north and towards the south) and turning the muck retrieval system for off-line extraction (shaft being beside alignment).

It is expected that this site may not remain available if not secured quickly.



February 23, 2014

Alternative Site 2: Kent & Arlington

The Kent & Arlington site is located one block north of the proposed tunnel termination at Catherine Street. As illustrated below, the site located on the west side of Kent St would be comprised of four distinct components. These would consist of an empty parcel (506 Kent), a small restaurant (504 Kent), the Arlington St road allowance and a portion of the parking lot associated with the bus depot in the southwest quadrant of the intersection.

Refer to the appended table for a summary of advantages, disadvantages and estimated cost. The estimated cost is comprised of additional rental and operation (no added length of tunnel). Even with the compounding of the parcels, this would present the smallest of the six possible sites. It would require the largest remote staging area, hence the higher additional cost. It is also immediately adjacent to residential uses, which would be non-desirable. This site would also require launching in two directions with off-line muck removal as it is located one block short of the proposed tunnel termination point (Catherine St).



February 23, 2014

Alternative Site 3: Glashan School Site

Site 3 is proposed on the property of the Glashan Public School (28 Arlington). It is also approximately half the minimum size required for launching and staging operation and will therefore require a sizable remote staging site. Working on a school site would be far from ideal and the acquisition of institutional property may prove more difficult. Construction noise, and the risks associated with construction activities and moving equipment could be more challenging to mitigate. The estimated cost is comprised of additional rental and operation (no added length of tunnel).



February 23, 2014

Alternative Site 4: Kent & Catherine West (Car Wash)

The Kent & Catherine West site is located in the southwest quadrant of the Kent/Catherine intersection. The property at 270 Catherine includes a strip commercial building and associated parking area.

This is the largest alternative site, but would require demolishing a commercial building. The site would still be deemed inadequately sized to accommodate the full launching and staging operation and would therefore require a remote staging site (only half an acre in this case).

The tunnel would only need to be launched in one direction from this site, but it presents a minor increase in length. Although adjacent to Highway 417, there is no MTO property encroachment on the site. The estimated cost included in the appended contractor’s table includes additional site rental (for remote site) and operation costs and an extension of the tunnel.

Alternative Site 5: Paterson Park

Paterson Park is located south of Highway 417, approximately 250m from the Catherine Street tunnel termination. It is a passive use park at a lower elevation than surrounding land and is used for stormwater ponding during large storm events. It is expected that up to 0.66 hectares (1.6 acres) could be available, and therefore would not require additional remote (off-site) staging area. This is reflected in the lower estimated cost implication. The additional cost listed in the table is comprised of the cost to extend the tunnel approximately 250m. No additional site rental or lease cost is included.



February 23, 2014

The tunnel extension would pass under Highway 417 and under commercial and residential properties since the Kent St ROW does not extend past Chamberland Ave. As previously indicated, the Hwy417/Kent overpass will be under construction from late 2014 until probably 2016.

The tunnel extension would pass under this construction site and approval from the MTO would be required. The tunnel will have 15-20m of total cover at this crossing.

Limited geotechnical information from shallow boreholes indicate that the area is underlain by 1 to 3 metres of fill over 1 to 2.5 metres of peat over either weathered clay crust or sand and gravel. Open hole water levels were recorded near ground surface. Published drift thickness mapping indicates bedrock to be at about 10 to 15 metres depth along the alignment of Kent Street in the area from Catherine to Patterson Creek. This corresponds with the findings from the CSST boreholes at Kent and Catherine. Mapping indicates that the depth to bedrock in the area generally increases from west to east (i.e. rock is likely shallower closer to Lyon than closer to Bank). Additional geotechnical investigation would be required to confirm that the dropping rock elevation does not become problematic further south. Structural distress (e.g. tilting of benches, light standards, retaining walls) has occurred in this area, likely resulting from ongoing decay and compression of the organic peat and miscellaneous fills. The impacts of dewatering at this site would need to be considered carefully so as not to impact the adjacent structures and services.

Patterson Creek is a former landfill site and the potential for contamination would need to considered at this The use of Paterson Park for a launching site would require an amendment to the Environmental Assessment Report. Public consultation and an evaluation of social impacts would need to be done. It is expected that the social impact may be deemed to be considerable by the community that would lose access to this community green space. Opposition to the use of this site could be strong.



February 23, 2014

Alternative Site 6: Soccer Field

There is a soccer field located at 78/80 Chamberlain Ave, in the southwest quadrant of the Chamberlain/Lyon intersection. The soccer field, which is partially owned by the City, is used by the Glashan Public School. This alternative launching site is located west of Paterson Park and approximately 290 m from the Catherine Street tunnel termination. It is expected that up to 0.38 hectares (0.94 acres) could be available, which implies that additional remote (off-site) storage/staging area would be required. This additional property requirement and the tunnel extension are reflected in the estimated cost.

The tunnel extension would pass under Highway 417. As previously indicated, the Hwy417/Kent overpass will be under construction from late 2014 until probably 2016. The tunnel extension would pass under this construction site and approval from the MTO would be required. The tunnel will have 15-20m of total cover at this crossing.

The site is located west of Kent Street and higher than Paterson Park. The rock elevation is known to rise towards the west along Catherine Ave. It is expected that rock cover would be adequate (at least similar to or greater than the rock cover at Catherine/Kent).



February 23, 2014

Alternative Site 7: 605 Bronson (MTO Site)

Alternative Site 7 consists of a property owned by the MTO, approximately 630m from the Catherine Street tunnel termination. The site is bordered by Highway 417 to the north, Percy St to the east, Chamberlain St to the south and Bronson Ave to the west. As illustrated on the figure below, it is comprised of an abandoned building planned to be demolished, a parking/loading area and a grassed area that becomes sloped closer to Percy St. It is expected that up to 0.86 hectare (2.1 acres) could be available, of which 0.5 hectare (1.2 acre) would consist of open area, with the balance being the building. It is the largest available site and would not require additional remote (off-site) staging area. The additional cost listed in the table is comprised of the cost to extend the tunnel approximately 630m. No additional site rental or lease cost is included.

The tunnel extension would follow Chamberlain Avenue and pass under Highway 417 near the Kent St overpass. As previously indicated, the Hwy417/Kent overpass will be under construction from late 2014 until probably 2016. The tunnel extension would pass under this construction site and approval from the MTO would be required. The tunnel will have 15-20m of total cover at this crossing. Rock elevation is reported to be rising towards the west along Catherine Street and be approximately 10m higher at this site than at the intersection of Kent/Catherine.

Consultation with the MTO revealed that they are willing to let the City use the site for tunnel launching purposes, with a caveat that the City takes over responsibility for the building and its demolition.

Another benefit of this site would be the provision of sewer overflow relief opportunity at Percy Street, which may also result in the cancellation of a separate flood relief project planned for the area. A quick review of this potential suggests that the hydraulics would work. The cost presented in the appended contractor’s table does not include any potential savings from other projects.



February 23, 2014

3.0 Evaluation and Ranking from a Contractor’s Perspective

The appended table was prepared by Jim Peregoy, to present an evaluation from a contractor’s perspective. The estimated cost implications are high level and based on the following components:

• Additional cost for a rental site for remote (off-site) storage/staging for the term of the project (estimated requirement to be 26 months).

• Additional cost for a “bull gang” to move resources between the sites.

• Additional cost to shuttle crews between sites since change trailer would be on the remote site.

• Additional cost for required tunnel extensions.

The table also offers a ranking from a contractor’s perspective. But it should be noted that Mr. Peregoy also indicated that none of the alternative sites along Kent Street are desirable. The preferred site in his perspective is by far the site at 605 Bronson. It is the largest site amongst the reviewed options and includes a building for storage/offices.

It should also be noted that not all constraints and opportunities identified in the text above by the design team are necessarily reflected in the contractor’s table.

The contractor’s comparison of prices in the appended table also does not include any costs associated with acquiring or leasing the main launching site, or the preparation of this site (i.e. demolishing existing buildings, etc). The only property costs included are for additional property requirements for remote (off-site) space when the main launching site is inadequately sized for the operation.



February 23, 2014

Table 2: NST Alternative Tunnel Launching Site Evaluation and Ranking Table Shaft Location Shaft Type Shaft

Compound Area Available

Advantages of Potential Site

Disadvantages of Potential Site

Additional Area Needed Beyond Area Available on Site

Cost Implications of Additional Area or Additional Tunnel Length

Site Preference Ranking (from a contractor's perspective)

St. Laurent Construction 3,000 m2 / Construction ops on Site too small for full +/- 1 acre $8.25 - $8.50 M 4 Square Shaft 0.74 acre one site

Most of drive is uphill operations Still need 1/2 to 3/4 acre elsewhere. Night work only ($3M premium).

1 - Kent & Construction 2,250 m2 / No structure High rise buildings in +/- 1 acre $5.25 to $5.50 M 7 Albert/Queen Shaft 0.56 acre demolition

Limited ops on site Main yard elsewhere

proximity

2 - Kent & Arlington

Construction Shaft

1,500m2 / 0.37 acre

Limited ops on site Main yard elsewhere

Much too small Immediately adjacent to multi-storey residential

1+ acre $5.75 - $6.45 M 8

3 - Glashan Construction 2,500m2 / Construction ops on Drive downhill for most of +/- 1 acre $5.50 - $6.00 M 6 School Site Shaft 0.62 acre one site

Maintenance elsewhere

tunnel School adjacent to site

4 - Kent & Construction 4,200m2+ / Construction ops on +/- 40 m additional tunnel +/- 1/2 acre $5.50 - $6.00 M 5 Catherine Shaft 1.0 acre one site Driving downhill for most of (Car Wash) Maintenance

elsewhere tunnel Existing building to demolish

5 – Paterson Park

Construction Shaft

6,600 m2 / 1.6 acre

Everything on one site +/- 250 m additional tunnel Driving downhill for most of tunnel

none $2.50 - $ 3.00 M 2

6 – Soccer Field Construction 3,800 m2 / Construction ops on +/- 290 m additional tunnel +/- 1/2 acre $8.50 - $ 9.00 M 3 Shaft 0.94 acre one site

Maintenance elsewhere

Driving downhill for most of tunnel

7 – 605 Bronson Construction 8,600m2+ / Everything on one site. +/- 630 m additional tunnel None $7,50 - $ 8.00 M 1 Shaft 2.1 acre Building available on

site for offices/storage Driving downhill for most of tunnel. Existing building to demolish.

Assumptions: Rock tunneling, non-segment construction, single shift work. Does not include costs to acquire and prepare the main launching site (demolish

buildings, etc) – assumes site is in hand.



Appendix D - Consultation April 2, 2014

Appendix D - Consultation

my c:\users\mayoung\desktop\nst_extension\report.docx D.2

CITY OF OTTAWACLASS ENVIRONMENTAL ASSESSMENTCOMBINED SEWAGE STORAGE TUNNEL

NOTICE OF FILING OF ADDENDUM

In February 2013, the City of Ottawa completed a Schedule C Class Environmental Assessment (EA) to identify and develop a preferred solution and functional design for additional storage of combined sewage in the ultimate combined sewer area of Ottawa. In the 2013 Combined Sewage Storage Tunnel (CSST) Environmental Study Report (ESR), the preferred design of the CSST consists of an east-west tunnel (EWT) through the downtown core from LeBreton Flats to New Edinburgh Park and a north-south tunnel (NST) along Kent Street from Catherine Street to the existing outfall north of Wellington Street. The 2013 ESR concluded that the preferred design for the NST would include a construction staging area in St. Laurent Square.

As a result of consultation during preliminary design of the CSST in 2014, it was determined that the CSST could be extended south to Chamberlain Street for an alternative construction staging area for the NST. The resulting change in the preferred construction staging area requires additional property. An addendum is required to evaluate the potential environmental implications.

By this Notice, the Addendum is being placed on the public record in accordance with the requirements of the Municipal Engineers Association Municipal Class Environmental Assessment (2000, as amended 2007 and 2011). Please note that only the changes proposed in the Addendum are open for review.

A copy of the Addendum report, and the 2013 ESR, will be available for viewing at the following locations:

http://ottawa.ca/en/city-hall/public-consultations/sewers-and-wastewater/combined-sewer-overflows City of Ottawa, Client Service Centre: 110 Laurier Avenue West Ottawa Public Library, Hazeldean: 50 Castlefrank Road Ottawa Public Library, Ruth E. Dickinson: 100 Malvern Drive Ottawa Public Library, Main: 120 Metcalfe Street Ottawa Public Library, Orléans: 1705 Orléans Boulevard

The 30-day public review period begins April 4, 2014. Written comments* may be submitted until May 4, 2014 to:

Randy Dempsey, Project Manager Infrastructure Services Dept. 100 Constellation Cres. Ottawa, ON K2G 6J8 Phone: 613-580-2424 ext 14102 Fax: 613-560-6064 E-mail: [email protected]

If concerns arise during the prescribed review period that cannot be resolved through discussions with the City of Ottawa, a person or party may request that the Minister of Environment make an order for the project to comply with Part II of the Environmental Assessment Act (referred to as a Part II Order). This request must be received by the Minister, at the address listed below, prior to May 4, 2014. A copy of the request must also be sent to the City of Ottawa at the address listed above. If no request is received on or before the end of the review period, the City will proceed with detailed design and construction as presented in the Addendum.

Minister of the Environment 77 Wellesley Street West 11th Floor, Ferguson Block Toronto, ON M7A 2T5

This Notice issued April 4, 2014.

*Information will be collected in accordance with Ontario’s Freedom of Information and Protection of Privacy Act. With the exception of personal information, all comments will become part of the public record.

http://ottawa.ca/en/city-hall/public-consultations/sewers-and-wastewater/combined-sewer-overflows

mailto:[email protected]

Circulation List

Adopt a River Bank (NGO) Bank Street Promenade BIA Britannia Yacht Club Byward Market BIA Canada Lands Corporation Canadian Environmental Assessment Agency Canadian Environmental Network (NGO) Canadian Parks & Recreation CanoeKayak Canada Capital Cruises Central Park Community Centretown Citizens Community Association City Centre Coalition (Residents Association) City of Gatineau City of Ottawa Downtown Rideau BIA Eastern Ottawa CoC Environment Canada Federal Heritage Building Review Office Fisheries and Oceans Canada Friends of Bytown Friends of Petrie Island Friends of the Rideau Greenspace Alliance of Canada's Capital (NGO) Haunted Walks Inc. Hydro Ottawa Lady Dive Amphibus Landowner Resource Centre Le Conseil régional de l'environnement et du développement durable de l'Outaouais Le Regroupement des gens d'affairs de la Capital Lowertown Community Association LRT Office Ministry of Aboriginal Affairs Ministry of Environment Ministry of Municipal Affairs and Housing Ministry of Natural Resources Ministry of Tourism and Culture Ministry of Transportation National Arts Centre National Capital Business Alliance National Capital Commission Nature Conservancy of Ottawa Ontario Environmental Network Ottawa Chamber of Commerce Ottawa New Edinburg Club (Yacht) Ottawa Region Landlords Association (NGO) Ottawa River Canoe Club Ottawa River Institute

Circulation List

Ottawa River Keeper Ottawa River Runners Ottawa Rowing Club Ottawa Taxpayer Advocacy Group Paddle Canada Parks Canada Pauls Boat Lines Ltd. Preston Street BIA Public Works and Government Services Canada Rideau CoC Rideau Valley Conservation Authority River Management Society Rockcliffe Park Residents Association: Environment Committee Somerset Street Chinatown BIA Somerset Village BIA Sparks Street BIA The Heritage Canada Foundation (NGO) The Ottawa Field‐Naturalists' Club University of Ottawa Vanier BIA Water, Soil, Air Environmental Advisory Council (NGO) Westboro Beach Community Association

addendum to environmental study report – ottawa combined ... · addendum to environmental study...

Documents