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Supporting Document 2 Alternative Methods Report – Assessment

of Landfill Footprint Alternatives

Waste Management of Canada Corporation

West Carleton Environmental Centre Landfill Footprint Expansion

ALTERNATIVE METHODS REPORT – ASSESSMENT OF LANDFILL FOOTPRINT ALTERNATIVES Prepared by: AECOM Canada Ltd. Project Number: 60242342-1 Date: August, 2012

Assessment of Landfill Footprint Alternatives West Carleton Environmental Centre

T a b l e o f C o n t e n t s Page

1. Introduction......................................................................................................... 1 1.1 Background.......................................................................................................... 1

2. Identification of the Envelopes for Potential Development ............................ 3 2.1 Land Ownership ................................................................................................... 3 2.2 Existing Natural Environment Features ................................................................ 3 2.3 Land Use Constraints .......................................................................................... 5

2.3.1 City of Ottawa Official Plan ....................................................................... 5 2.3.2 City of Ottawa Comprehensive Zoning By-Law (2008-250) ...................... 9

2.4 Perimeter Buffer Zones ...................................................................................... 10 2.5 Landfill Footprint Envelopes ............................................................................... 10

3. Generation and Evaluation of the Alternative Methods ................................ 11 3.1 Overview ............................................................................................................ 11 3.2 Generation of Landfill Footprint Options ............................................................. 11

3.2.1 Conceptual Design of Landfill Footprint Options ..................................... 14 3.2.2 Description of the Landfill Footprint Options ........................................... 22 3.2.3 Landfill Footprint Option 1 ...................................................................... 23 3.2.4 Landfill Footprint Option 2 ...................................................................... 25 3.2.5 Landfill Footprint Option 3 ...................................................................... 26 3.2.6 Landfill Footprint Option 4 ...................................................................... 28

3.3 Summary of Landfill Footprint Options ............................................................... 29 3.4 Assessment of the Alternative Methods ............................................................. 31

4. Net Effects Analysis ......................................................................................... 37 4.1 Landfill Footprint Option #1 ................................................................................ 37

4.1.1 Net Effects Analysis................................................................................ 37 4.2 Landfill Footprint Option #2 ................................................................................ 54



4.4.1 Net Effects Analysis................................................................................ 84 5. Comparative Evaluation Results ................................................................... 102

5.1 Overall Landfill Footprint Option Rankings ....................................................... 119 6. Summary ......................................................................................................... 121


List of Figures Figure 1.1 Study Area ........................................................................................................... 2 Figure 2.1 Study Area Constraints ........................................................................................ 4 Figure 2.2 Official Plan Designations .................................................................................... 6 Figure 2.3 Carp Road Corridor Community Design Plan ....................................................... 7 Figure 2.4 City of Ottawa Comprehensive Zoning By-Law (2008-250) .................................. 9 Figure 3.1 Landfill Footprint Option #1 ................................................................................ 12 Figure 3.2 Landfill Footprint Option #2 ................................................................................ 13 Figure 3.3 Landfill Footprint Option #3 ................................................................................ 15 Figure 3.4 Landfill Footprint Option #4 ................................................................................ 16 Figure 3.5 Cross Sections A-A’ (for Option #1) and B-B’ (for Option #2) ............................. 24 Figure 3.6 Cross Sections C-C’ (for Option #3) and D-D’ (for Option #4) ............................ 27 Figure 3.7 Alternative Methods Process.............................................................................. 31 Figure 4.1 Option #1 Impact on Vegetation Communities ................................................... 43 Figure 4.2 Option #1 Impact on Wildlife and Aquatic Features ............................................ 44 Figure 4.3 Option #1 Impact to Tributaries .......................................................................... 45 Figure 4.4 Option #1 Impact on Cultural Heritage Resources ............................................. 47 Figure 4.5 Option #1 Impact on Archaeological Resources ................................................. 48 Figure 4.6 Option #1 Impact on Agriculture ......................................................................... 51 Figure 4.7 Option #2 Impact on Vegetation Communities ................................................... 60 Figure 4.8 Option #2 Impact on Wildlife and Aquatic Features ............................................ 61 Figure 4.9 Option #2 Impact on Cultural Heritage Resources ............................................. 63 Figure 4.10 Option #2 Impact on Archaeological Resources ................................................. 64 Figure 4.11 Option #2 Impact on Agriculture ......................................................................... 67 Figure 4.12 Option #3 Impact on Vegetation Communities ................................................... 75 Figure 4.13 Option #3 Impact on Wildlife and Aquatic Features ............................................ 76 Figure 4.14 Option #3 Impact on Cultural Heritage Resources ............................................. 78 Figure 4.15 Option #3 Impact on Archaeological Resources ................................................. 79 Figure 4.16 Option #3 Impact on Agriculture ......................................................................... 82 Figure 4.17 Option #4 Impact on Vegetation Communities ................................................... 91 Figure 4.18 Option #4 Impact on Wildlife and Aquatic Features ............................................ 92 Figure 4.19 Option #4 Impact to Tributaries .......................................................................... 93 Figure 4.20 Option #4 Impact on Cultural Heritage Resources ............................................. 95 Figure 4.21 Option #4 Impact on Archaeological Resources ................................................. 96 Figure 4.22 Option #4 Impact on Agriculture ......................................................................... 99


List of Tables Table 2.1 Official Plan Designations and Permitted Uses .................................................... 8 Table 3.1 Comparison of Footprint Options ....................................................................... 29 Table 5.1 Comparative Evaluation Results ...................................................................... 103 Attachments Attachment A. Conceptual Design Report Attachment B. Landfill Footprint Net Effects Table Attachment C. Comparative Evaluation Technical Memorandums


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1. Introduction 1.1 Background Waste Management of Canada Corporation (WM) is preparing an Environmental Assessment (EA) for a proposed undertaking consisting of the provision of a new landfill footprint at the existing Ottawa Waste Management Facility (Ottawa WMF). WM has undertaken and received approval of a Terms of Reference (ToR) for identification and assessment of a new landfill footprint as part of the WCEC. From the analysis presented in Supporting Document #2 – Alternatives To the Undertaking, of the approved ToR, WM identified Alternative 3 – Close the current landfill and establish new landfill disposal capacity at the West Carleton Environmental Centre (WCEC) as the preferred Alternative To the Undertaking. Identification and evaluation of “Alternative Methods” or different ways that the project can be developed is a key element of the EA process. For example, the proposed new landfill footprint for residual waste could be constructed in different locations and configurations (size, height, etc.) at the WCEC. The new landfill footprint will be one component of the proposed WCEC. The approved ToR identified a study area, within which alternative methods would be identified for consideration in the EA. The study area is bounded on the southeast and southwest sides by Highway 417; on the northeast by Carp Road; and on the northwest by Richardson Side Road. The study area is bisected by William Mooney Road to the southwest of the existing Ottawa WMF (Figure 1.1). The existing Ottawa WMF landfill is located on Lots 3 and 4, Concession 3 in the former Township of Huntley, formerly in the Township of West Carleton, now the City of Ottawa near the intersection of Carp Road and Highway 417. The lands within the study area are contiguous with the existing Ottawa WMF, owned and operated by WM. The purpose of this document is to present the generation and evaluation of alternative landfill footprints and provide the rationale for the selection of the preferred landfill footprint.

Assessment of Landfill Footprint Alternatives

West Carleton Environmental Centre

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Figure 1.1 Study Area


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2. Identification of the Envelopes for Potential Development

During the ToR phase, preliminary development envelopes were identified within the study area within which landfill footprint alternatives and other non-landfill components of the WCEC could be located. Two distinct development envelopes, located North and West of the existing landfill, were included in the ToR, which was approved in November 2010. During Open House #1 of the EA, these footprint development envelopes were confirmed and presented to the public. WM considered the following constraints when determining appropriate landfill footprint envelopes:

WM ownership of land or option to purchase land; Existing natural environment features; Land use constraints; and, Perimeter buffer zones.

Figure 2.1 shows the application of these site-specific factors within the study area. The following sections describe the application of the site-specific factors within the development envelopes.

2.1 Land Ownership WM owns or has options to purchase a large portion of the lands within the study area. These lands are shaded in grey on Figure 2.1, and include land to the northeast and southwest immediately adjacent to the existing Ottawa WMF (hereafter referred to as the “north envelope” and “west envelope” respectively). The land within the study area that WM does not own or have the option to purchase is shaded in red on Figure 2.1.

2.2 Existing Natural Environment Features A preliminary inventory of existing natural heritage features within the study area was carried out to determine any land that should be excluded from potential development. The desktop inventory of existing natural features was completed using interpretation of aerial photography, existing natural environment information, and other baseline studies.



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Figure 2.1 Study Area Constraints


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Of note, the Goulbourn Wetland Complex is a provincially significant wetland (PSW) complex in the southwestern portion of the Study Area. This wetland is protected under the provincial Planning Act and the Provincial Policy Statement (2005, Section 2.1) from any development or site alteration. In addition, the City of Ottawa Official Plan (2003, Consolidated 2007) requires that any development within 120 metres (m) of the boundary of a designated wetland undertake an Environmental Impact Statement (EIS). Existing databases show that there are butternut trees (Juglans cinerea) within the study area. Butternut is listed as an endangered species under the provincial Endangered Species Act and the federal Species at Risk Act. A number of ditches and channels exist within the Study Area. Under the federal Fisheries Act, no project may create a “harmful alteration, disruption or destruction” (also known as a HADD) of fish habitat, unless authorized by the Minister. Further in relation to watercourses, under the generic regulations of the Conservation Authorities Act, incompatible development is normally prohibited within 15 m of any floodplain, wetland, river valley, or meander belt. To the north of the existing Ottawa WMF, there are two on-line (i.e., connected to other tributaries) unevaluated wetlands.

2.3 Land Use Constraints 2.3.1 City of Ottawa Official Plan

The existing Ottawa WMF lands are designated Solid Waste Disposal Site, Sand and Gravel Resource Area, and Carp Road Corridor Rural Employment Area in the City of Ottawa Official Plan (2003, Consolidated 2007) (see Figure 2.2). Within the Carp Road Corridor Community Design Plan (CDP), these lands are designated as Heavy Industrial Area and Solid Waste Disposal Site (see Figure 2.3). The north development envelope is designated as Carp Road Corridor Rural Employment Area. Within the Carp Road Corridor CDP, this land is designated as Light Industrial Area. Most of the west development envelope is designated General Rural Area, and the Goulbourn Wetland Complex is designated Significant Wetlands. Uses permitted within these designations are outlined in Table 2.1.


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Figure 2.2 Official Plan Designations


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Figure 2.3 Carp Road Corridor Community Design Plan


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Table 2.1 Official Plan Designations and Permitted Uses

Designation Permitted Uses Existing

Ottawa WMF Carp Road Rural Employment Area Rural industrial and commercial uses. Heavy Industrial Area (Carp Road

Corridor CDP) Heavy industrial uses involving the manufacturing of

products from local primary materials, quarry, abattoirs, salvage yards, sawmills.

Sand and Gravel Resource Area Pits and wayside pits and related uses such as portable asphalt plants.

Solid Waste Disposal Site Solid waste disposal sites. North

Development Envelope

Carp Road Rural Employment Area Rural industrial and commercial uses. Light Industrial Area (Carp Road

Corridor CDP) May include light manufacturing plants, distribution,

recycling and assembly plants, warehouses, service and repair shops, research, design and testing facilities, storage uses, transportation depots, contractor or construction related uses, and compatible public and institutional uses.

West Development

Envelope

General Rural Area Without a Zoning By-law Amendment: Agricultural uses, forestry and conservation, and natural resource management activities; Residential uses; Animal boarding, breeding, and training facilities, including stables; Bed and breakfast establishments; Open space; Cemeteries.

With a Zoning By-law Amendment: New industrial and commercial uses, such as farm equipment and supply centres, machine and truck repair shops, building products yards, landscape contractors, and nurseries; Uses that are noxious, such as salvage or recycling yards, composting or transfer facilities, concrete plants, the treatment of aggregate products, and abattoirs; New recreational commercial and non-profit uses, such as golf courses, driving ranges, mini putt operations, campgrounds, outdoor theme parks, and sports fields; New sand and gravel pits and underground mining for any mineral resources; Other new non-residential uses which are in keeping with the rural character or those uses that meet the needs of the traveling public, such as a restaurant, gas station, motel, and retail (up to 1,000 m2 gross leasable area); New institutional uses such as places of worship and schools; Country lot subdivision.

Significant Wetlands No development or site alteration is permitted except for open air recreation; scientific, educational, or conservation uses associated with the environmental features; existing agricultural operations; forestry. Single detached dwelling and accessory building, subject to conditions.


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2.3.2 City of Ottawa Comprehensive Zoning By-Law (2008-250)

The lands within the study area have eight different zonings under the City of Ottawa Comprehensive Zoning By-law (2008-250). These zonings are shown in Figure 2.4, and are described in the following subsections for the existing Ottawa WMF lands, the west development envelope, and the north development envelope.

Zoning Legend1

RH Rural Heavy Industrial Zone RG5[275r]-h Rural General Industrial Zone, subzone 5, with Exceptions, with a Holding provision

RH1[270r] Rural Heavy Industrial Zone, subzone 1, with Exceptions RU Rural Countryside Zone RH1[269r]-h Rural Heavy Industrial Zone, subzone 1, with

Exceptions, with a Holding provision EP3 Environmental Protection Zone, subzone 3

Figure 2.4 City of Ottawa Comprehensive Zoning By-Law (2008-250)

1. Permitted Uses for each Zone is described in the Land Use Existing Conditions Report located in Supporting

Document #1 to this EA Report


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Both landfill envelopes would require an amendment to the Official Plan and zoning by-law for the landfill footprint component of the WCEC.

2.4 Perimeter Buffer Zones If the EA is approved, WM must ensure the landfill area is completely surrounded by a buffer area. A proposed buffer from property lines of 100 m is shown in Figure 2.1.

2.5 Landfill Footprint Envelopes As previously mentioned, two distinct development envelopes within the study area in relation to the existing Ottawa WMF were identified during the ToR stage. These envelopes are referred to by their proximity to the Ottawa WMF, namely to the west of William Mooney Road and to the north of the existing Ottawa WMF. As a result of the constraints review, the north and west envelopes were identified in the ToR as the areas within which the “Alternative Methods for Carrying out the Undertaking” would be analyzed in the EA. In the ToR, WM proposed to complete a comparative evaluation with respect to the landfill footprint envelopes and then generate landfill footprint options within the preferred envelope:

“Once the selection of the preferred landfill envelope has been determined in the EA, alternatives will be identified during the EA within the preferred envelope.” (Approved ToR, Section 6.5, pp. 35).

After reviewing the initial information collected and reviewed as part of identifying the study area constraints/ potential landfill envelopes, WM determined that both envelopes were suitable for identifying potential landfill footprints. Locating a potential landfill footprint is possible for both envelopes, as no discernible differences between the two envelopes that would prevent development of a landfill footprint were identified. Therefore, WM embarked on generating potential landfill footprint options within each of the envelopes. This approach was presented at Open House #1 and Workshop #1 of the EA. Further discussion on the generation of landfill footprint options is provided in Section 3 of this report.


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3. Generation and Evaluation of the Alternative Methods

3.1 Overview The methodology for generating and evaluating the Alternative Methods is composed of the following:

Generate Alternative Methods Assessment of the Alternative Methods (including a Comparative Evaluation

of the Alternative Methods) Identification of the Preferred Alternative Method

3.2 Generation of Landfill Footprint Options Using the existing conditions information collected as part of identifying the envelopes for potential development, alternative landfill footprints were generated at a conceptual level of design. Initially, two alternative landfill footprint options were generated and developed for presentation to the public. These alternative landfill footprint options were presented to the Public at Workshop #1. WM developed preliminary options for landfill footprints within each of the envelopes for discussion (see Figures 3.1 and 3.2). The footprints were generated using the following basic design parameters:

Size ................... 6.5 million cubic metres (m3) (as per the approved ToR) Height ............... Between approximately 27 and 33 m Side Slopes ...... 4:1

For comparison purposes, the existing Ottawa WMF has the following design parameters:

Size ................... 8.7 million m3 Height ............... Approximately 47 m Side Slopes ...... 3:1



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Figure 3.1 Landfill Footprint Option #1



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After presenting the initial two landfill footprint options at Workshop #1, WM received feedback from the public that two additional footprints should be considered in the comparative evaluation. One option was a variation on the northern footprint and the other was presented as a hybrid between the two landfill envelopes, or a “wrap-around” to the existing Ottawa WMF. Both of these landfill footprint options (see Figures 3.3 and 3.4) were accepted by WM as potentially viable options to be carried forward in the assessment of alternative landfill footprint options.

3.2.1 Conceptual Design of Landfill Footprint Options

Once WM confirmed that the 4 options would be carried forward for evaluation, further details were completed with respect to each of the landfill footprint options. This detail was contained within a Conceptual Design Report (See Attachment A). The four alternative landfill footprint options have been developed to a conceptual level of detail to enable a comparative analysis. The conceptual design focused on identifying characteristics that could be used to differentiate the footprints from one another. At this stage, limited work was undertaken on identifying the characteristics that would reasonably be similar for all footprints. The footprint characteristics that were developed and utilized for comparative evaluation purposes included the following:

Location within the development envelopes including buffer zones to property boundaries and sensitive environmental features;

Configuration of side slopes and height; Estimated traffic levels; Leachate generation rate; and, Other design and operational assumptions.

A series of criteria and assumptions were established to guide the development of footprint options within the West and North envelopes. These include WM’’s projected residual waste disposal capacity requirements (as approved in the ToR), regulatory requirements relating to landfill design geometry, as well as some of the constraints used in the ToR for identifying the development envelopes. In addition, assumptions were made relating to operational traffic levels, leachate generation rates, and aspects of site design and operations based on the existing site, other WM sites and professional judgement.



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3.2.1.1 Landfill Capacity

The landfill airspace requirement has been estimated at 6.5 million m3, which includes daily cover material, as noted in the approved ToR. The airspace requirement estimate is the same for all footprints considered and is based on the following:

400,000 tonnes (T) per year over a 10 year period equates to a total waste tonnage of 4,000,000 T.

In-place waste density has been estimated as 0.725 T/m3. Waste density is influenced by numerous factors including waste type and operating methods, although this value is considered reasonable for a large, modern landfilling facility. At this density 4,000,000 T corresponds to a waste volume of 5,517,000 m3.

A waste to daily cover ratio of 6:1 (approximately 15%) based on WM operating experience which provides a balance between the efficient use of cover material and the appropriate amount for managing potential nuisance effects. At this ratio the total volume of daily cover soil would be 920,000 m3.

The total volume of waste and daily cover based on these parameters is 6,437,000 m3. For planning purposes the required airspace requirement was approximated as 6,500,000 m3.

Additional airspace will be required for the final cover material used to close the landfill site.

3.2.1.2 Footprint Geometry and Location

O. Reg. 232/98 (amended to O. Reg. 483/98), Landfilling Sites and the accompanying Landfilling Standards Guideline specify requirements and/or provide recommendations for key landfill design parameters. The parameters identified in the regulation relevant to the development of footprint options include the following. Buffer Zones The regulatory requirements specify a 100 m wide buffer area between the edge of the waste footprint and the site boundary, but allow this to be reduced to a minimum of 30 m if it is shown to be appropriate based on a site specific assessment (e.g., if the buffer provides adequate space for vehicle movements, ancillary facilities, and ensures that potential effects from the landfill operation do not have unacceptable impacts outside of the site). The footprint options were developed maintaining 100 m buffers between the edge of the footprint and the boundaries of WM


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owned/optioned property, but were reduced to 30 m in some specific cases. The basis for applying a 30 m buffer is provided as part of the description for each landfill footprint. The Goulbourn Wetland Complex is a PSW located in the southwestern portion of the West Envelope. This wetland is protected under the provincial Planning Act and the Provincial Policy Statement from any development or site alteration. In addition, the City of Ottawa Official Plan (2003, Consolidated 2007) requires that any development within 120 m of the boundary of a designated wetland undertake an EIS. As such, 120 m was used as a minimum buffer between the landfill footprint and the wetland complex in the West Envelope. This buffer requirement is also regulated under the Conservation Authorities Act and managed by the Mississippi Valley Conservation Authority. For all footprints considered it has been assumed that WM will acquire all of the lands that it currently has an option to purchase. Final Slopes The regulatory requirements specify a maximum slope of four units horizontal to one unit vertical (4H to 1V) and a minimum slope of 20H to 1V (5%) but allow variance where it can be shown to be appropriate. The footprint options were developed in adherence to the specified maximum/minimum slope requirements. Landfill Height There are no regulatory requirements specifically constraining landfill height, although maximum height is indirectly governed by regulatory requirements to ensure that adequate foundation conditions exist and that slopes are stable. In developing footprint options, WM initially assumed the top of waste elevation to be approximately 153 metres above sea level (mASL) (which is approximately 28 m above existing surrounding grade) in order to minimize the visual and other impacts of the new landfill. By comparison, the maximum elevation of the existing Ottawa WMF landfill is approximately 172 mASL or approximately 47 m above the surrounding ground surface. However, landfill height is also influenced by assumed depth of excavation, as discussed below. Subsurface conditions will be evaluated in more detail and confirmed once a preferred footprint is chosen. Depth of Excavation There are no regulatory requirements specifically constraining landfill excavation depth, although subsurface conditions (e.g., shallow bedrock and high water table) in the study area dictate a relatively shallow base excavation. Initially it was assumed that that the base of the


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landfill (e.g., bottom of waste) would be at grade, and that the liner and leachate collection system would be situated below grade. It is assumed that the liner and collection system will consist of the O. Reg. 232/98 Generic II cross-section (discussed further below) which is 3.1 m thick, and thus it was anticipated that the excavation depth would be at least 3.1 m. Additional information regarding groundwater conditions in the north and west footprint envelopes has been obtained since initial landfill concept development. Water table elevations in the north and west footprint envelopes vary but in many places are close to grade. Consequently the depth of excavation will be less than initially anticipated, which in turn influences landfill height. Subsurface conditions (including potential excavation depth) will be evaluated and confirmed once a preferred footprint is identified.

3.2.1.3 Traffic Levels

Truck traffic associated with the landfill facility is important in assessing the potential impacts of the site on various receptors. For the purposes of this comparative analysis the traffic levels have been estimated as follows:

Each footprint option is projected to have waste receipts of up to 400,000 T/ year for a 10 year period. As such the traffic associated with waste and daily cover loads would be equal for all options. A traffic analysis was conducted for the existing WMF landfill in 2006. WMF landfill operations in 2005 reflected receipt of approximately 400,000 T of waste, including daily cover, and thus the 2005 traffic levels are seen as generally comparable to a future landfill operation of this magnitude.

Soil and granular materials will need to be imported to the site to construct the base liner, leachate collection system, and final cover. Volumes of construction material will vary somewhat for each footprint because the footprint sizes vary. A preliminary estimate was made of the truck traffic associated with the importation of construction materials for each footprint.

Estimated traffic levels for each footprint option are presented in Section 3.2.2 and are supported by calculations summarized in Attachment A. Other site traffic will be considered in the detailed impact assessment of the preferred landfill footprint alternative.

3.2.1.4 Leachate Generation Rate

Leachate generation rate is an important parameter used in assessing the operational and environmental performance of a landfill site. It will vary over the operational and post-closure


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period of the facility and is influenced by factors including precipitation, degree of landfill development (e.g., area of landfill that is actively undergoing development versus areas where final cover has been placed), final cover design, and other factors. For the purposes of facilitating a comparative analysis of the proposed landfill footprints, an approximate range of leachate generation rates for each footprint have been calculated based on the following:

Leachate generation rates will vary according to the size of the landfill footprint;

The landfill footprint is assumed to have been fully closed; The final cover design is reflective of the minimum design specified in O.

Reg. 232/98, consisting of 0.6 m of compacted fine-grained soil overlain by a 0.15 m thick vegetative layer; and,

Post closure leachate generation rates for each footprint were estimated using the Hydrologic Evaluation of Landfill Performance (HELP) model.

It is recognized that leachate generation rates during the operating period will vary and will be higher than in the closed state. This generation rate is influenced by the phasing of landfill development and timing of final cover construction. This is consistent with approaches used in other landfill EAs. Leachate generation rates for each option in the post closure period are presented in Section 3.2.2 and are supported by calculations summarized in Attachment A.

3.2.1.5 Other Assumptions

There are characteristics of a landfill operation that would be common to all footprints. While these would not significantly influence the comparative analysis they should nevertheless be considered in reviewing the footprint alternatives. These facility characteristics are summarized as follows and discussed in the Conceptual Design Report within Attachment A. Leachate Management The landfill leachate control system will be designed in compliance with the requirements of O. Reg. 232/98 such that the Ontario Ministry of the Environment’s (MOE) Reasonable Use Policy is met. The regulations allow two approaches for designing a landfill to protect groundwater quality – a site specific design, or a generic design. The site specific approach allows a proponent to design the leachate controls to suit the site setting provided that the Reasonable


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Use limits are met. The generic approach allows the proponent to select one of two generic designs which have been developed such that the Reasonable Use limits are met within a broad range of hydrogeologic settings. At this time WM is planning to design the site with the Generic II – Double Liner system as specified in the regulations. This consists of (from top down):

0.3 m thick granular/perforated pipe primary leachate collection system; 0.75 m thick geomembrane/engineered clay primary liner; 0.3 m thick granular/perforated pipe secondary leachate collection system; 0.75 m thick geomembrane/engineered clay secondary liner; 1 m thick natural or constructed soil attenuation layer.

Collected leachate will be removed from the site for treatment and/or disposal in accordance with applicable regulations (method to be determined). Consideration of leachate treatment alternatives and the identification of a preferred approach will be the subject of a separate evaluation process as part of the EA. The preferred leachate treatment alternative will be considered in conjunction with the preferred landfill footprint during the detailed impact assessment. Gas Controls O. Reg. 232/98 requires the mandatory collection of landfill gas for sites with a waste capacity greater than 1.5 million m3, and as such a gas collection system will be required for the proposed landfill footprint. This is expected to include both horizontal and vertical collection piping that will be developed progressively through the operating period. WM currently operates a landfill gas recovery system at the existing Ottawa WMF landfill which supplies gas to an on-site electricity generation and gas flaring facility.

Surface Water Management O. Reg. 232/98 requires that landfill sites be designed to protect surface water to specified performance standards. Design practices that will be followed in developing the surface water management system include:

divert or control clean surface water flowing onto the site; and control quality and quantity of runoff discharging from the site to control

erosion, sediment transport, and flooding.


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Landfill Operations O. Reg. 232/98 requires the landfill be designed and operated to ensure that nuisance impacts are minimized, and the regulation requires that the proponent prepare a report describing all aspects of the operation as well as maintenance procedures that will be followed. A key objective in planning landfill operations is to minimize nuisance impacts including noise, litter, vectors, dust, and odour. Typical operating practices relating to these issues include:

Landfill development sequence is planned to allow the progressive closure of the landfill, including commencing construction of the final cover as early as possible.

Site design includes screening features such as berms and tree plantings which can attenuate visual impact and noise, and permanent litter fences to reduce blowing litter.

Site haul roads are paved, are of sufficient length to minimize mud trackout, and are routinely cleaned to minimize dust generation.

Daily operations are planned such that: the size of the working face is kept to a minimum in order to minimize

the area of exposed waste; working face location is adjusted as required and seasonally to provide

shelter from prevailing winds; portable litter fences are routinely used around the working face to

capture blowing litter; waste compaction commences immediately after placement and

spreading; and cover material is readily available and the working face is fully covered

at the end of each operating day. A comprehensive monitoring and maintenance program is implemented

which addresses all aspects of the landfill operation. This includes a routine waste inspection program and monitoring for landfill odour.

3.2.2 Description of the Landfill Footprint Options

Four landfill footprints have been developed for comparative analysis, consisting of two in the West development envelope and two in the North development envelope. The footprints were identified respecting the criteria and assumptions described in Section 3.2.1 and based on public input. These options are illustrated in Figures 3.1 to 3.4.


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3.2.3 Landfill Footprint Option 1

Landfill Footprint Option 1 is shown in Figure 3.1, and is located within the West Envelope. This footprint was identified by the project team and reflects the following:

The footprint is on lands that WM does not currently own but has options to purchase.

A 100 m buffer is maintained between the north limit of the footprint and the private lands to the north (e.g., which front onto Richardson Side Road), and between the east limit (in northeast corner of the footprint) and the private lands to the east of William Mooney Road.

For the remainder of the east limit a 30 m buffer is maintained between the footprint and William Mooney Road. This buffer distance is considered reasonable since it supports a lower landfill height which is an important consideration received from the community, there are no identifiable receptors of concern on the opposite side of William Mooney Road, allows sufficient area to monitor the operation and performance of the landfill, and there is no requirement for ancillary facilities within this buffer area. In addition, WM expects to acquire the lands on the east side of William Mooney Road.

A minimum 150 m distance is maintained between the western limit of the footprint and the Goulbourn Wetland Complex. This respects the minimum 120 m buffer distance required around the wetland and provides a minimum 30 m wide access/maintenance corridor.

The south limit of the footprint is determined by maintaining the noted buffers and providing the required 6,500,000 m3 capacity while observing a maximum waste elevation of approximately 156 mASL (or 157 mASL allowing for the final cover) and side slopes varying from 4H to 1V to 5%. The maximum height of the landfill is approximately 31 m above the existing ground surface, as shown in Section A-A’’ on Figure 3.5. The south limit of the footprint is over 500 m from the south property boundary.

The south portion of the envelope provides limited area for disposal capacity due to the relatively narrow area between the Goulbourn PSW and William Mooney Road.

This option requires truck traffic to travel west from Carp Road across the northern limit of the existing Ottawa WMF landfill to access the footprint. For safety and access control WM would seek to purchase and close William Mooney Road.



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Figure 3.5 Cross Sections A-A’ (for Option #1) and B-B’ (for Option #2)


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Landfill Footprint Option 2 is shown in Figure 3.2, and is generally centred within the North Envelope. This footprint was identified by the project team and reflects the following:

The southern half of the footprint is on WM-owned lands and the northern half is on lands that WM has options to purchase. A light industrial building (e.g., the Laurysen building) is situated in the eastern portion of WM optioned lands.

A 100 m buffer is maintained between the north limit of the footprint and the private lands to the north (e.g., which front onto Richardson Side Road). An unevaluated Wetland with a 10 m buffer exists within this north buffer zone.

A 328 m buffer is maintained between the east limit of the footprint and Carp Road. This reflects avoiding an existing topographic low area (former gravel pit) in this part of the site which could complicate landfill development in this area.

A 30 m buffer is maintained between the east limit of the footprint and the Laurysen building. WM considers that the existing Laurysen building may have several beneficial uses including equipment storage/maintenance or waste diversion activities in the future.

A 30 m buffer is maintained between the south limit of the footprint and the perimeter roadway of the existing landfill at the WMF. This allows sufficient area for site access, maintenance and monitoring activities.

The location of the west limit of the footprint was determined by maintaining the noted buffers and providing the required 6,500,000 m3 capacity while observing a maximum waste elevation of approximately 157 mASL (or 158 mASL allowing for the final cover) and side slopes varying from 4H to 1V to 5%. The maximum height of the landfill is approximately 33 m above the existing ground surface as shown in Section B-B’’ on Figure 3.5.

A 216 m buffer is maintained between the west limit of the footprint and William Mooney Road.

The west limit of the footprint allows preservation of the majority of the existing woodlot within the west part of the WM-owned lands.

This option confines truck traffic to the North envelope and does not impact William Mooney Road. Trucks will enter the footprint area from the on-site road between the existing landfill and the proposed footprint.


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Landfill Footprint Option 3 is shown in Figure 3.3. This option was developed at the request of public stakeholders through the EA consultation process for a footprint that minimizes the visual impact of a landfill in the North Envelope by reducing its height. Option 3 is summarized as follows:

The southern half of the footprint is on WM-owned lands and the northern half is on lands that WM has options to purchase.

A 100 m buffer is maintained between the north limit of the footprint and the private lands to the north. An unevaluated Wetland with a 10 m buffer exists within this north buffer zone.

A 328 m buffer is maintained between the east limit of the footprint and Carp Road. This reflects avoiding an existing topographic low area (former gravel pit) in this part of the site which could complicate landfill development in this area.

A 30 m buffer is maintained between the east limit of the footprint and the Laurysen building. WM considers that the existing Laurysen building may have several beneficial uses including equipment storage/maintenance or waste diversion activities in the future.

A 30 m buffer is maintained between the south limit of the footprint and the perimeter roadway of the existing landfill at the WMF. This allows sufficient area for site access, maintenance and monitoring activities.

The west limit of the footprint is extended to the maximum possible within the North Envelope with a 30 m buffer maintained between the west limit and William Mooney Road. In addition, WM expects to acquire the lands on the west side of William Mooney Road.

Providing a landfill capacity of 6,500,000 m3 and maintaining side slopes between 4H to 1V and 5% results in a maximum waste height of approximately 151 mASL (or 152 mASL allowing for the final cover). The maximum height of the landfill is approximately 27 m above the existing ground surface as shown in Section C-C’’ on Figure 3.6.

This option confines truck traffic to the North envelope and does not impact William Mooney Road. Trucks will enter the footprint area from the on-site road between the existing landfill and the proposed footprint.



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Figure 3.6 Cross Sections C-C’ (for Option #3) and D-D’ (for Option #4)


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Landfill Footprint Option 4 is shown in Figure 3.4. This option was developed at the request of public stakeholders through the EA consultation process for a footprint that maximizes distance to residences located northwest of the West Envelope, and minimizes the visual impact of the landfill by minimizing its height and locating it as close to the existing WMF landfill as possible. Option 4 is summarized as follows:

The ‘‘L-shaped’’ footprint straddles the West and North envelopes, and is situated on WM-owned lands and on lands that WM has options to purchase. This option requires the closure and purchase of William Mooney Road as the footprint is built over a section of William Mooney Road.

For the portion within the North envelope: A 30 m buffer is maintained between the north limit of the footprint and

the existing limit of WM–owned lands. This buffer distance is considered reasonable since it supports a lower landfill height overall (otherwise the western portion would be higher to provide the required capacity) which is an important consideration received from the community, there are no identifiable receptors of concern to the immediate north, allows sufficient area to monitor the operation and performance of the landfill, and there is no requirement for ancillary facilities within this buffer area. In addition, WM expects to acquire the lands to the immediate north of the existing limit of WM – owned lands.

A 30 m buffer is maintained between the south and east limits of the footprint and the perimeter roadway of the existing landfill at the WMF. This allows sufficient area for site access, maintenance and monitoring activities.

A 260 m buffer (approximate) is maintained between the east limit of the footprint and Carp Road. This buffer width reflects avoiding an existing topographic low area (former gravel pit) in this part of the site which could complicate landfill development in this area.

The maximum height of the waste for the portion within this area is approximately 149 mASL (or 150 mASL allowing for the final cover) and is approximately 25 m above the existing ground surface.

For the portion within the West envelope: A minimum 150 m distance is maintained between the west limit of

the footprint and the Goulbourn PSW Complex. This respects the minimum 120 m buffer distance required around the wetland and provides a minimum 30 m wide access/maintenance corridor.


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The south limit shown results from provision of 6,500,000 m3 capacity and side slopes between 4H to 1V and 5%. The maximum height of the waste within this area is approximately 154 mASL (or 155 mASL allowing for the final cover) and is approximately 30 m above the existing ground surface as shown in Section D-D’’ on Figure 3.6.

Trucks will enter the footprint area from the on-site road between the existing landfill and the proposed footprint.

3.3 Summary of Landfill Footprint Options The key attributes of the four landfill footprint alternatives are summarized in Table 3.1. These attributes are provided at a conceptual level of detail/design, which is appropriate for completing a comparative evaluation of the landfill footprint alternatives.

Table 3.1 Comparison of Footprint Options

Attribute Option 1 Option 2 Option 3 Option 4 General Description

and Location Irregular shaped

footprint in northern portion of West

Envelope. Provides required volume

capacity of 6,500,000 m3.

Rectangular footprint in ‘‘centre’’ of North Envelope. Provides

required volume capacity of

6,500,000 m3.

Rectangular footprint in ‘‘west-central’’ part of North Envelope. Provides required volume capacity of

6,500,000 m3.

Irregular footprint straddling West and

North Envelope. Provides required volume capacity of

6,500,000 m3.

Land Ownership On WM-Optioned Lands (with exception

of William Mooney Road)

On WM-Owned and Optioned Lands

On WM-Owned and Optioned Lands

On WM- Owned and Optioned Lands (with exception of William

Mooney Road) Footprint Size 384,800 m2 357,400 m2 442,400 m2 476,800 m2

Approximate Elevation of Top of Landfill

(including final cover)

157 mASL

158 mASL 152 mASL 155 mASL (in West Envelope); 150 mASL (in North Envelope)

Approximate Height of Landfill Above Existing

Grade

31 m 33 m 27 m 30 m (in West Envelope); 25 m (in

North Envelope) Operational Impact to William Mooney Road

Yes, necessitates closure and WM

acquisition of William Mooney Road

No, operation confined to North Envelope

No, operation confined to North Envelope

Yes, necessitates closure and WM

acquisition of William Mooney Road

Minimum Distance to Privately –Owned

Lands (reflecting WM acquisition of all optioned lands)

Approx. 100 m Approx. 100 m Approx. 100 m Approx. 320 m


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Table 3.1 Comparison of Footprint Options

Attribute Option 1 Option 2 Option 3 Option 4 Minimum Distance to

Carp Road Approx. 1,375 m Approx. 330 m Approx. 330 m Approx. 280 m

Minimum Distance to Richardson Side Road


Minimum Distance to Hwy 417


Longest Internal Haul Distance Internal to

Site(1)

2,700 m 1,900 m 2,100 m 2,100 m

Waste Haulage Traffic – Loads per Day(2)

180 – 230 180 – 230 180 – 230 180 – 230

Waste Haulage Traffic – Trips per AM peak

hour(2)

25 – 35 25 – 35 25 – 35 25 – 35

Waste Haulage Traffic – Trips per PM peak

hour(2)

25 – 50 25 – 50 25 – 50 25 – 50

Construction Traffic (Scenario 1)

– Loads per Day(3)

Up to 123 Up to 115 Up to 142 Up to 153


– Trips per Hour(3)



– Loads per Day(3)



– Trips per Hour(3)

40 37 46 49

Leachate Generation Rate(4)

1.8 to 2.9 L/s 1.7 to 2.7 L/s 2.1 to 3.3 L/s 2.3 to 3.6 L/s

Notes: 1. Measured as maximum distance from site entrance to furthest point of landfill footprint, reflecting: a. Access to site remains through existing site entrance; b. Truck traffic utilizes existing internal road along north perimeter of existing landfill mound for greatest distance possible, then

crosses into footprint area. 2. Data taken from, 2006 study undertaken by WM and considered to reflect waste and daily cover haulage for future 10 year

operating period. 3. Construction traffic estimated as per Appendix A, reflecting:

a. Includes importation of soil and granular materials for Ont. Reg. 232/98 Double Generic Liner System; b. Scenario 1 reflects construction of one base liner and leachate collection system cell, and one phase of final cover (each

totalling approximately one eighth of landfill area) over a 6 month period. This scenario is intended to represent a ‘‘typical’’ construction season;

c. Scenario 2 reflects construction of two base liner and leachate collection system cells but no final cover over a 6 month period. This scenario is intended to represent the construction required to prepare the site to accept waste at the start of the operation period.

4. Leachate generation rate estimated as per Appendix B, reflecting: a. Estimated using HELP model reflecting landfill footprint fully closed; b. Landfill final cover consisting per Ont. Reg. 232/98 minimum design of 0.6 m soil overlain by 0.15 m vegetated topsoil.


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3.4 Assessment of the Alternative Methods Following the identification of the alternative landfill footprints, a detailed assessment and evaluation of the four footprints was undertaken. As identified in Figure 3.7, the multi-step process began with confirming the evaluation criteria and indicators proposed in the approved ToR and confirmed at public meetings, including Open House #1 and #2 and Workshop #1 and #2. With a final list of evaluation criteria and indicators established, they were applied to each of the four footprint options through a “net effects analysis” to determine the net positive or negative environmental effects. Next, a Reasoned Argument or Trade-off method was carried out using this information to determine a preferred landfill footprint.

Figure 3.7 Alternative Methods Process


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The assessment and evaluation of the alternative landfill footprints was conducted in three steps:

Step 1 – Confirm Evaluation Criteria and Indicators/Measures Step 2 – Undertake the Net Effects Analysis Step 3 – Carry out the Comparative Evaluation

Step 1: Confirm Evaluation Criteria and Indicators/Measures Prior to undertaking the net effects analysis, the evaluation criteria, indicators, and measures previously developed in the ToR were reviewed with the public during Open House events and confirmed for application to each of the landfill footprint alternatives. With regard to the evaluation criteria, the following Environmental Components were utilized:

Atmospheric Environment Geology and Hydrogeology Surface Water Biology – Terrestrial and Aquatic Cultural Heritage Resources Transportation Land Use Agriculture Socio-economic Aboriginal Site Design and Operations

By establishing evaluation criteria in relation to these Environmental Components, the WCEC EA addresses each aspect of the “environment” as defined in the Ontario EA Act (OEAA). The approved WCEC ToR set out the draft criteria and indicators for evaluating the ‘‘alternative methods’’ (i.e., alternative landfill footprint options) in the EA. As a result, the draft criteria, indicators, and measures provided for in the ToR were reviewed and modified appropriately to suit the evaluation of the landfill footprint alternatives. Specifically, the criteria, indicators and measures were modified in consultation with review agencies and the public to ensure that an appropriate level of scrutiny and rigour was applied in evaluating the landfill footprint alternatives. In doing so, the results of the evaluation phase will consist of clearly defined net effects for each landfill footprint alternative.


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Step 2: Undertake the Net Effects Analysis With the evaluation criteria, indicators and measures confirmed through the preceding step, a net effects analysis of the alternative landfill footprint options was carried out consisting of the following activities:

Identify potential effects (based on measures) on the environment; Develop and apply avoidance/mitigation/compensation/enhancement measures;

and Determine net effects on the environment.

Each of these activities will be documented in a separate table for each alternative landfill footprint options. Identify the Potential Effects Potential effects on the environment will be based on the information contained in the Existing Conditions reports. After determining the alternatives, the evaluation criteria will be applied to each alternative landfill footprint option to determine the potential environmental effects. Specifically, this will be accomplished by applying the indicators to each alternative landfill footprint option. The results of applying these indicators will be expressed in the context of their corresponding measures, either quantitatively or qualitatively, as appropriate, in the potential effects column of the net effects table. Develop and Apply the Avoidance / Mitigation / Compensation / Enhancement Measures Once the potential effects on the environment have been identified for each alternative landfill footprint options, the appropriate avoidance/ mitigation/ compensation/ enhancement measures will be developed and documented in the net effects table for each indicator. The intent of these measures is as follows:

Avoidance: .......... The first priority is to prevent the occurrence of negative effects (adverse environmental effects) associated with implementing an alternative.

Mitigation: ........... Where adverse environmental effects cannot be avoided, it will be necessary to develop the appropriate measures to remove or alleviate to some degree the negative effects associated with implementing the alternative.


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Compensation: ... In situations where appropriate mitigation measures are not available, or significant net adverse effects will remain following the application of mitigation, compensation measures may be required to counterbalance the negative effect through replacement in kind, or provision of a substitute or reimbursement.

Enhancement: ..... Wherever possible, the opportunity should be taken to enhance the positive environmental effects associated with implementing an alternative rather than simply mitigate and/or compensate.

With these intentions in mind, the avoidance/ mitigation/ compensation/ enhancement measures will be developed based on the professional expertise of the Project Team reflecting current procedures, historical performance, and existing environmental conditions. These developed measures will be documented in the avoidance/ mitigation/ compensation/ enhancement measures column of the net effects table. Determine the Net Effects Once the appropriate avoidance/ mitigation/ compensation/ enhancement measures have been developed and applied to the potential environmental effects of each alternative landfill footprint option, the remaining net negative or net positive effect will be determined and documented by the Project Team members in the “net effects” column of the net effects table. In cases where the net negative or net positive effect cannot be addressed through the application of avoidance/ mitigation/ compensation/ enhancement measure(s), the potential net effect will remain unchanged and therefore, will still be identified as the “net effect”. The net effects associated with each alternative landfill footprint option will be identified and carried forward to Step 3. Step 3: Carry Out the Comparative Evaluation In Step 3, the net effects identified for each alternative landfill footprint option in Step 2 will be compared to one another in order to identify a “recommended landfill footprint. The comparison of net effects will be completed using a “Reasoned Argument” or “Trade-off” method, as provided for in the approved WCEC EA ToR.


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This method is based on the following two activities:

1st Activity .... Identify the level of effect (‘‘No’’, ‘‘Low’’, ‘‘Moderate’’ or ‘‘High’’) associated with each alternative landfill footprint option for each indicator

2nd Activity.... Rank each alternative landfill footprint option from most preferred to least preferred (in this example case, since four are being compared, either first, second, third, fourth or tied for first, etc.) based on the identified level of effect from each indicator: Criteria rankings for each landfill footprint option; Factor specific rankings for each landfill footprint option; and, Overall landfill footprint rankings.

The process followed in Step 3 and the results of these two activities are described in further detail in the following sections. Level of Effect Determination of the Alternative Landfill Footprint Options As mentioned, the “Reasoned Argument” or “Trade-off” method will be used to highlight the relative level of effect of each landfill footprint option based on the net effects determined in Step 2. More specifically, a level of effect ranging from ‘‘No effect’’, ‘‘Low effect’’, ‘‘Moderate effect’’ or ‘‘High effect’’ will be determined for each landfill footprint option by each indicator. Ranking of the Alternative Landfill Footprint Options The net effects identified for each alternative in the previous step will then be compared to one another in order to identify a “recommended” footprint location. The comparison of net effects will be completed using a “Reasoned Argument” or “Trade-off” method, as provided for in the approved ToR. Under the Reasoned Argument approach, the difference in net effects associated with the various alternatives is highlighted. Based on these differences, the advantages and disadvantages of each alternative are identified according to the evaluation of trade-offs between the various evaluation criteria and indicators. The relative significance of potential impacts is examined to provide a clear rationale for the selection of a preferred alternative. The term Trade-offs is defined as “things of value given up in order to gain different things of value”. Each alternative will be compared against the others to distinguish relative differences in impacts to the environment, taking into account possible mitigation measures.


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For example, during the detailed Comparative Evaluation of the alternative landfill footprints, the rankings will be combined (aggregated) for each Environmental Indicator and Criteria into a single preference rating (‘‘No’’, ‘‘Low’’, ‘‘Medium’’, or ‘‘High’’) for each environmental component. These results will be aggregated further into a single preference rating for each alternative landfill footprint in order to rank the alternatives (incorporating trade-offs and professional judgement) and identify a preferred alternative landfill footprint. This method is based on the following two activities (example provided below):

1st Activity .... Identify the level of effect (‘‘No Effect’’, ‘‘Low’’, ‘‘Medium’’ or ‘‘High’’) associated with each alternative for each indicator

2nd Activity.... Rank each alternative from most preferred to least preferred based on the identified level of effect from each indicator; Criteria rankings for each alternative landfill footprint option; component specific rankings for each alternative landfill footprint option; and, overall alternative landfill footprint option rankings.

Each team member first assigned rankings for each individual Criteria based on the level of effect determined for each Indicator under that Criteria. For example, the “Atmospheric Environment” Environmental Component has three Criteria, each of which have two Indicators that will be given a level of effect (‘‘No’’, ‘‘Low’’, ‘‘Medium’’ or ‘‘High’’) and then consolidated to determine an overall Criteria ranking. After each Criteria are ranked, ranking will then occur for each Environmental Component (i.e., Atmospheric Environment, Land Use, Geology and Hydrogeology, etc.) based on the rankings from each evaluation criteria. For example, in the case of the Atmospheric Environment component, the Technical Consultant will consider the identified rankings for an alternative corresponding to their evaluation criteria (incorporating trade-offs and their professional judgment) in determining the Atmospheric Environment component ranking. Following this, the Project Team determined an overall ranking of each alternative based on the individual Environmental Component rankings. With this in mind, the Team will then assign an overall ranking of ‘‘First’’ for an alternative having a greater number of higher placed individual Component rankings (e.g., more ‘‘First’’ and ‘‘Second’’ place rankings). The Comparative Evaluation in the following sections has been prepared as per the steps outlined above so that a clear, traceable, and replicable process is provided.


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4. Net Effects Analysis Now that the methodology of the Assessment of Alternative Methods has been presented, the following sections will review the net effects analysis for each of the Landfill footprint options.

4.1 Landfill Footprint Option #1 4.1.1 Net Effects Analysis

The following provides the key net effects for landfill footprint option #1 as illustrated in Figure 3.1. Please refer to Attachment B for the overall net effects tables and Attachment C for the discipline specific memos. Atmospheric With respect to the Odour criteria, the assessment of Option #1 resulted in predicted concentrations less than 1 Odour Unit (OU) over a 10-minute averaging period, at 99.5% of the time (provided the assumptions detailed in Appendix C). The net effects are based on implementing the following key mitigation measures:

the landfill gas collection and utilization system is incorporated and implemented progressively over the lifespan of Option #1; and,

Best Management Practices (BMPs) are incorporated to reduce the potential for odour to occur during the normal operation of the landfill.

The net effects determination considered all 24 receptors identified in the Odour existing conditions report. Based on the modelling completed, no off-site receptors are affected. Odours are more likely to impact receptor areas closer to the landfill based on the nature of the sources. With respect to Air Quality, landfill gas emissions were modelled for vinyl chloride, benzene and hydrogen sulphide. These compounds were evaluated to determine the potential to exceed any air quality standards or guidelines at the property line and at all sensitive receptors (24) identified in the Odour existing conditions report. All receptors are expected to be within compliance (provided the assumptions detailed in Appendix C). The net effects are based on implementing the following key mitigation measures:

the landfill gas collection and utilization system is incorporated and implemented progressively over the lifespan of Option #1; and,

BMPs are incorporated to reduce the potential for landfill gas releases to occur during the normal operation of the landfill.


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Also reviewed as part of the Air Quality criteria were combustion emissions, including oxides of nitrogen and carbon monoxide and particulate emissions. For Option #1, the predicted concentrations for combustion emissions were predicted to be within compliance at all 24 receptors identified in the Air Quality existing conditions report for both nitrogen and oxides and carbon monoxide. This estimate is based on all assumptions provided in Appendix C above and that mitigation measures allowing for the efficient traffic flow on-site (no holder periods or prolonged idling) and BMPs are put in place to control emissions for the vehicles allowed to entire the site. For dust emissions, TSP, PM10 and PM2.5 were considered. Predicted concentrations for 24-hour periods for each type of particulate were assessed at all 24 receptors. For Option #1, the results assumed all of the assumptions provided in Appendix C and that each alternative would incorporate efficient traffic flow movements on-site (no holding periods or prolonged idling periods) and that BMPs for dust would be incorporated. The maximum concentrations were predicted to exceed at two off-site receptors for Option 1. Additional mitigation measures/ strategies focused on dust reduction will be outlined to minimize dust to all receptors, should Option #1 be identified as the preferred alternative. With respect to the Noise criteria, the predicted sound levels for Option #1 at each of the 24 receptors were assessed to determine if the predicted noise levels would be less than 55 dBA (MOE Noise Guideline for Landfills) or within 3 dB of the background noise levels. As an example, a 3 dB change in noise levels is the level where the human ear can detect a change in the sound levels. Option 1 has a total of five receptors that were either greater than 55 dBA or greater than 3 dB above background levels. Results are provided in Appendix C. All results were based on the assumptions provided in Appendix C and the proposed mitigation measures that each alternative would include the following:

maintenance to keep haul trucks and construction trucks in good working conditions;

screening berms to provide noise reduction for specific operations; noise BMPs to minimize the potential for noise levels in excess during normal

operations; and efficient traffic flow of on-site vehicles to ensure that vehicles are moving and

are not sitting idle for prolonged periods of time. Once a preferred option is selected, specific details regarding berming and noise reduction strategies will be outlined to minimize noise to all receptors.


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Geology & Hydrogeology The net effects relating to the Geology and Hydrogeology for all Options considered the following criteria and indicators:

Groundwater Quality ...... predicted effects to groundwater quality at property boundaries and off-site;

Groundwater Flow .......... predicted groundwater flow characteristics. With respect to Groundwater Quality, various considerations were reviewed when considering the net effects, including leachate generation rates at closure, existing groundwater quality, monitorability of the site, and number and type of downgradient receptors. In regard to Groundwater Flow, considerations included overburden type, depth to groundwater table, hydraulic characteristics and modelled results of groundwater flow change. These considerations assisted in framing what mitigation measures would be required and the resultant net effects. At closure, leachate generated from Option #1 is expected to be 1.8 to 2.9 L/s, which is the second lowest of all alternatives. The existing groundwater quality is generally within the range of background concentrations. The existing groundwater flow regime is well understood and monitorable, which is a key component of ensuring that the mitigation measures related to the design of the landfill and liner system are operating as intended. In terms of receptors, there are 13 residential properties and 1 institutional property within 500 m downgradient of Option #1. These properties utilize private wells for their water supplies. This surface geology in the Option #1 area is largely fine sand to silty sand and sand-gravel, with overburden thickness ranging from 2.6 to 9.2 m, with the thinnest area along the northern side of the footprint area. The predominant underlying bedrock is the Bobcaygeon Formation, with Gull River Formation underlying the overburden to the extreme west side of the footprint area. The bedrock slopes gradually to the north-northeast. The water table is relatively shallow and is generally found between <1 m to 2.5 m below ground surface. The overburden-shallow bedrock is the primary groundwater flow zone, with good connection to the deeper bedrock. The flow is northward on the south side of the footprint, becoming northeastward along the north side of the footprint. The results of the numerical flow modelling revealed that the simulated drawdown is predicted to be 0.11 m at downgradient property boundaries, with no effects to off-site groundwater flow directions.


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For the purpose of the Net Effects Analysis, it is important to recognize that the generic design options for groundwater protection as developed by the MOE and specified in O. Reg. 232/98 are considered to be protective of the groundwater environment. That is, the generic design options have been developed to ensure that the Groundwater Protection Standards (Reasonable Use Limits) are met at the base of the leachate containment system. Further contaminant attenuation in the buffer area is not required (MOE Landfill Standards Guideline, May 1998; revised June 2010). A Generic Design Option II – Double Composite Liner System will be used for the West Carleton Environmental Centre regardless of the landfill footprint alternative selected. The existing conditions for groundwater flow and groundwater quality have been determined and are predictable. The existing hydrogeologic conditions are suitable for effectively monitoring groundwater flow and quality around landfill footprint Option #1. It is noted that development of a landfill with a Generic Design Option II leachate containment and collection system will eliminate recharge to the aquifer from any precipitation within the area of the footprint. This will result in a minor amount of localized drawdown of the water table in the area. Numerical modelling of groundwater flow indicates that the predicted drawdowns at the property boundaries are on the order of 0.1 to 0.2 m (at full landfill development). This amount is an order of magnitude less than the natural seasonal variations in the water table, and is not expected to affect off-site groundwater supplies. With the use of a Generic Design Option II leachate containment and collection system, no mitigation measures are required beyond the implementation of an Environmental Monitoring Plan (EMP) that is appropriate to the landfill footprint option. The result of the Net Effects Analysis is that no off-site groundwater receptors are anticipated to be affected by landfill footprint Option #1. The key factors leading to this result are:

the use of the Generic Design Option II leachate containment and collection system, which is protective of the groundwater environment, and

the hydrogeologic conditions are suitable for effectively monitoring groundwater flow and quality around the landfill footprint.

Surface Water Resources With respect to surface water quality, Option #1 has the potential for water quality impacts due to accidental leachate seeps to the surface and/or increases in Total Suspended Solids (TSS) concentration due to runoff from the internal gravelled access roadways. These water quality impacts can be mitigated by a two staged Stormwater Management (SWM) facility to remove


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larger particle size TSS and provide for emergency leachate containment in a Stage 1 sediment forebay, with a Stage 2 providing extended control for additional TSS removal. SWM facility outflow would then be to South Huntley Creek. The resultant net effect would be discharging to surface water with no increase in TSS and related parameter concentrations in Huntley Creek (South Branch) at William Mooney Road. From a water quantity perspective, the upstream wetland drainage pattern would be blocked by the proposed landfill with a potential impact on the existing wetland natural environment due to increased water levels. This would be mitigated by diverting the wetland flow around the landfill and back to South Huntley Creek using an open channel and culverts for roadway crossings. Therefore, there would be no increase in wetland water levels. Due to the change in local topography provided by the relatively steep-sloped (from a hydrologic perspective) landfill configuration, a reduction in travel time (as a result of increased flow velocities) would create an increase in peak flows with potential to increase downstream water levels and flood damages. This impact could be mitigated by the recommended Stage 1 and Stage 2 of the SWM facility providing attenuation of post-development flows to pre-development levels with outflow to South Huntley Creek. Therefore, there would be no increase in peak flows at William Mooney Road. Terrestrial Environment With respect to impacts on vegetation communities, Option #1 results in 16.7 ha of vegetation being removed, including 8.2 ha of meadow communities, 2.2 ha of thicket communities, 3.0 ha of forest communities and 3.3 ha of wetland communities which are associated with the adjacent PSW (see Figure 4.1). Some of the vegetation being removed is early successional that could be considered less significant because of its age and simpler structure. BMPs will be implemented on-site during construction (i.e., installation of protective fencing, access restrictions, use of dust suppressants, etc.) to reduce the overall net effect. Further, compensation for the loss of vegetation communities will occur elsewhere on-site where there are areas that could be revegetated. A Compensation and Restoration Plan will be developed during detailed design to address the exact location of these areas. With respect to impacts on wildlife habitat, Option #1 has the greatest impact on area sensitive species (5 bird territories) criteria because of the presence of four territories of Eastern Meadowlark in the rather extensive meadow (see Figure 4.2). Further, because of the loss of 16.7 ha of vegetated habitat, there is an increased effect on observed area sensitive bird species such as the black and white warbler.


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The wetland that would be removed with Option #1 were found to be deciduous swamp with shallow ponding that mostly did not appear to provide amphibian breeding function. Option #1 would create a barrier to wildlife movement between core habitat areas on the two sides of William Mooney Road. While there will be a permanent interruption of wildlife movement between core woodlots; wildlife will adapt to move in areas of contiguous vegetation. Similar to mitigation measures for effects on vegetation communities, revegetation in adjacent areas could compensate for the loss of bird habitat. The removal of vegetation should occur outside of breeding bird season (May-July). A Compensation and Restoration Plan will be developed during detailed design to address the exact location of these areas. Installation of a fence along the perimeter will deter species from entering the landfill. By implementing buffers between footprint and existing vegetation, Construction disturbance to breeding birds and wildlife will be minimized. There are no impacts on rare, threatened or endangered species within the area. Aquatic Environment With respect to impacts on water quality and impacts to aquatic habitat/biota, Option #1 will impact Tributary C (see Figure 4.3) and require removal of part (878 m) of the channel. This watercourse is an intermittent drain that supports flow for only a few months a year. Fish have been observed in this channel in May, therefore the Tributary does provide seasonal fish habitat. Most likely these fish move upstream from Tributary D of the South Huntley Creek during periods of high flow. Removal of the section of Tributary C will permanently remove this seasonal fish habitat, but the species present are common and tolerant of a wide range of environmental conditions, therefore this effect is classified as low. There is the opportunity to realign Tributary C to Tributary D to maintain the seasonal connectivity, or else to enhance or create fish habitat elsewhere in the South Huntley Creek to compensate for any loss of habitat. If work is carried out in the dry, then the effects to aquatic habitat are completely mitigated. Archaeology & Cultural Heritage The evaluation of cultural and heritage resources relied on mapping produced by Archaeological Services Inc. (ASI) in 2006 of the study area. Built heritage features and cultural landscapes within the study area were identified using both the Ministry of Tourism, Culture and Sport (MTC)guidelines and past experience, and informed through research into the history of the region. It should be noted that that no structures designated under Part IV of the Ontario Heritage Act are present within the study area.

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