Reference No

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Stoney Creek Regional Facility Environmental Assessment

Geology and Hydrogeology Detailed Impact Assessment Report DRAFT FOR DISCUSSION

65 Sunray Street, Whitby Ontario L1N 8Y3 Canada 11102771 | Report No 27 | June 198

Table of Contents 1.

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

Background and Purpose .................................................................................................. 1

1.2

Description of the Preferred Landfill Footprint ................................................................... 2

1.3

Facility Characteristic Report ............................................................................................. 4

1.4

Geology and Hydrogeology Study Team ........................................................................... 4

2.

Study Area .................................................................................................................................... 4

3.

Methodology ................................................................................................................................. 6

4.

Detailed Description of the Environment Potentially Affected ...................................................... 6 4.1.1 4.1.2 4.1.3 4.2

5.

Source Water Protection Area ......................................................................................... 12

Geology and Hydrogeology Net Effects ..................................................................................... 13 5.1

Potential Effects on Geology and Hydrogeology ............................................................. 13 5.1.1 5.1.2 5.1.3 5.1.4

6.

Leachate Generation ...................................................................................... 13 Leachate Leakage Through Liner................................................................... 14 Effects on Downgradient Water Quality ......................................................... 15 Effects on Source Water Protection ............................................................... 16

5.2

Groundwater Flow............................................................................................................ 16

5.3

Proposed Mitigation Measures ........................................................................................ 17

5.4

Net Effects ....................................................................................................................... 18

Climate Change Considerations ................................................................................................ 19 6.1

Potential Effects of the Undertaking on Climate Change ................................................ 19 6.1.1

6.2

Mitigation ........................................................................................................ 19

Effect of Climate Change on the Undertaking ................................................................. 19 6.2.1

7.

Potential Man-Made Influences on Groundwater Movement ........................... 7 Remedial Systems ............................................................................................ 8 Groundwater Flow .......................................................................................... 12

Adaptation....................................................................................................... 19

Environmental Monitoring .......................................................................................................... 19 7.1

Monitoring Strategy and Schedule ................................................................................... 19 7.1.1 7.1.2

Environmental Effects Monitoring ................................................................... 19 Development of an Environmental Management Plan ................................... 23

8.

Commitments ............................................................................................................................. 23

9.

Other Approvals ......................................................................................................................... 23

DRAFT FOR DISCUSSION GHD | Draft Geology and Hydrogeology Detailed Impact Assessment Report |11102771 | i

Figure Index Figure 1.1

Preferred Landfill Footprint ................................................................................................ 3

Figure 2.1

Stoney Creek Regional Facility Site Location and Study Area ......................................... 5

Figure 4.1

Geologic Sequence and Groundwater Control Features ................................................ 10

Figure 4.2

Site Plan and Monitoring Network ................................................................................... 11

Table Index Table 4.1

Groundwater Flow Zones .................................................................................................. 6

Table 5.1

Predicted Leachate Generation Rates ............................................................................ 14

Table 5.2

Predicted Leachate Leakage Rates ................................................................................ 14

Table 5.3

Predicted Downgradient Groundwater Quality ................................................................ 15

Table 7.1

Predicted Downgradient Groundwater Quality ................................................................ 21

Appendices Appendix A

Description of Methodology – HELP Modeling

Appendix B

Description of Methodology – Groundwater Quality and Flow Evaluation

DRAFT FOR DISCUSSION GHD | Draft Geology and Hydrogeology Detailed Impact Assessment Report |11102771 | ii

1.

Introduction This report documents the Geology and Hydrogeology impact assessment of the Preferred Landfill Footprint for the Environmental Assessment (EA) for landfill expansion at the Stoney Creek Regional Facility (SCRF). In the preceding Alternative Methods phase of the EA, a net effects analysis as well as a comparative evaluation of the Six Alternative Landfill Expansion Options was carried out in order to identify a Preferred Landfill Footprint. The Preferred Landfill Footprint was determined to be Option #5 – Reconfiguration and Height Increase. The potential environmental effects and impact management measures to address the potential adverse environmental effects and the remaining net effects following the application of the impact management measures were identified for the Preferred Landfill Footprint.

1.1

Background and Purpose

In March of 2018, the recommended landfill expansion option (Option # 5) was presented to the public, stakeholders and the Government Review Team (GRT) for comments and feedback. Following the stakeholder and agency engagement, the Recommended option was confirmed and Option # 5 became the ‘Preferred’ Landfill Footprint (also referred to as the Preferred Method). Following confirmation of the Preferred Landfill Footprint, a detailed impact assessment was carried out. The intent of the impact assessment is to allow for additional details to be developed on the Preferred Landfill Footprint from a design and operations perspective and to then review the impact management measures and resultant net effects described in the Alternative Methods stage within the context of the more detailed design for the Preferred Landfill Footprint. Specifically, the following can be accomplished: • • • • •

Potential environmental effects can be identified with more certainty. More site-specific impact assessment measures can be developed for application. Net environmental effects can be identified with more certainty. Appropriate monitoring requirements can be clearly defined. Specific approval/permitting requirements for the proposed undertaking can be identified.

At the completion of the impact assessment of the Preferred Landfill Footprint, the advantages and disadvantages to the environment of the Preferred Landfill Footprint were identified. Climate change mitigation and adaptation measures will also be reviewed as part of the detailed site design established for the Preferred Method. In addition, during the impact assessment stage of the SCRF EA, Terrapure will complete an assessment of the cumulative effects of the proposed undertaking and other non-SCRF projects/activities that are existing, planned/approved or reasonably foreseeable within the Study Area. A Facility Characteristics Report (FCR) for the SCRF has been prepared so that potential environmental effects and mitigation or compensation measures identified for the Preferred Landfill Footprint during the Alternative Methods phase of the EA could be more accurately defined, along with enhancement opportunities and approval requirements. The discipline-specific work plans developed during the Terms of Reference outlined how impacts associated with the Preferred Landfill Footprint would be assessed. The results of these assessments have been documented in the following nine standalone Draft Detailed Impact Assessment Reports:    

Atmospheric including; 1) Air Quality and Odour; and, 2) Noise, Geology and Hydrogeology Surface Water Terrestrial and Aquatic

   

Transportation Land Use and Economic Design and Operations Human Health

DRAFT FOR DISCUSSION GHD | Draft Geology and Hydrogeology Detailed Impact Assessment Report |11102771 | 1

1.2

Description of the Preferred Landfill Footprint

The proposed expansion of the SCRF will increase the overall size of the landfill. Vertical limits will extend higher increasing the peak height by approximately 2.5 m. Horizontal limits will extend further toward the north, back to original approved footprint of the SCRF. The area currently approved to accept industrial fill will be replaced with a base liner system to accept residual material. The proposed layout of the SCRF is presented in Figure 1.1 below. The limits of the base liner system will be expanded back to the original approved footprint of 59.1 ha. The overall Site area of 75.1 ha. will not change. The figure shows the final extent of the landfill area after the final cover has been installed (the Post-Closure phase). Minimum on-Site buffer distances of 30 m will be maintained around the perimeter of the residual material area throughout all phases. On-Site buffers currently extend to approximately 65 m in various areas along the east and south side of the Site, and up to approximately 130 m in the vicinity of the existing stormwater management facility in the northwest corner of the Site. These buffer distances will also be maintained. The proposed expansion of the SCRF will increase the approved capacity by 3,680,000 m 3, resulting in a total Site capacity of 10,000,000 1 m3 for post-diversion, solid, non-hazardous residual material. No changes are being proposed to the maximum approved fill rates of up to 750,000 tonnes of residual material in any consecutive twelve month period, or up to 8,000 tonnes per day. 0F

The SCRF will continue to accept post-diversion, solid, non-hazardous industrial residual material. The SCRF will no longer be approved to accept industrial fill material. The SCRF will continue to accept residual material from sources from within the Province of Ontario. The overall composition of the residual material is expected to remain relatively consistent as the main sources (i.e., steel making industry, soils from infrastructure development projects) will not change. Additional descriptive details on the design of the Preferred Landfill Footprint can be found in the detailed FCR.

1

The total Site capacity may increase to 10,180,000, pending the MOEEC approval of the current ECA Amendment Application noted in the Facility Characteristics Report.


Figure 1.1 Preferred Landfill Footprint


1.3

Facility Characteristic Report

The Facility Characteristic Report (FCR) presents preliminary design and operations information for the Preferred Landfill Footprint (Option #5) and provides information on all main aspects of landfill design and operations including: • • • • •

site layout design including existing and proposed site characteristics; stormwater management; leachate management; landfill gas management; and, landfill development sequence and daily operations.

The FCR also provides estimates of parameters relevant to the detailed impact assessment, including estimates of leachate generation, contaminant flux through the liner system, landfill gas generation, and traffic levels associated with waste and construction materials haulage.

1.4

Geology and Hydrogeology Study Team

The Geology and Hydrogeology study team consisted of GHD staff. The actual individuals and their specific roles are provided as follows:

• • •

2.

Ben Kempel – Team Lead Allan Molenhuis – Geologist/Hydrogeologist Brian Dermody – Engineer

Study Area The specific On-Site, Site-Vicinity, and Regional study areas for the Preferred Landfill Footprint at the SCRF are listed below: Site Study Area

including all the lands within the existing, approved boundaries of the SCRF, as defined by Environmental Compliance Approval (ECA) No. A181008, as amended. The Site retains an additional 18 ha for industrial fill area, as well as an additional 15 ha (approx.) of buffer zone; and;

Local Study Area including all lands within a 1.5 kilometer (km) radius of the Site Study Area boundaries. The Site location and setting is illustrated on Figure 2.1, below.


Figure 2.1 Stoney Creek Regional Facility Site Location and Study Area


3.

Methodology The assessment of impacts associated with the Preferred Landfill Footprint was undertaken through a series of steps that were based, in part, on a number of previously prepared reports (Geology and Hydrogeology Existing Conditions Report and the Geology and Hydrogeology Comparative Evaluation Technical Memorandum) and through modeling of the potential effects. The potential effects associated with the Six Alternative Landfill Footprint Options identified during the Alternative Methods phase of the EA were based on Conceptual Designs. These potential effects were reviewed and re-modeled within the context of the detailed design plans developed for the Preferred Landfill Footprint, as identified in the FCR. The potential impact on the geology and hydrogeology environment of the Preferred Landfill Footprint is discussed in Section 5 of this report. With a more detailed understanding of the geology and hydrogeology environment developed, the previously identified potential effects and recommended impact management measures associated with the Preferred Landfill Footprint (documented in the Geology and Hydrogeology Comparative Evaluation Technical Memorandum, March 2018) were reviewed to ensure their accuracy in the context of the preliminary design. Based on this review, the potential effects, mitigation measures, and net effects associated with the Preferred Landfill Footprint were further refined and quantified.

4.

Detailed Description of the Environment Potentially Affected The existing SCRF is located within fractured bedrock of the Niagara Escarpment in a former quarry. The closed Terrapure landfill, historically referred to as the "West Landfill" (closed landfill), located to the west of the SCRF (across 1st Road West), is also located within a former quarry. The SCRF and closed landfill are underlain by a sequence of shale and dolostone of the Lockport and Clinton formations. A prominent geologic feature within the Local Study Area is a small escarpment known as the Eramosa Scarp, located along the northern extent of both the SCRF and closed landfill. The Eramosa Scarp was formed by the removal of some rock units at the surface during glacial advancement. Subsequent glacial activity has resulted in burial of the Eramosa Scarp beneath a veneer of overburden. Previous investigations have identified five distinct bedrock groundwater flow zones within the within the Local Study Area. Table 4.1 summarizes these flow zones by name and associated lithologic unit. Table 4.1 Groundwater Flow Zones Flow Zone Eramosa Flow Zone Vinemount Flow Zone

Lithology Unit Eramosa Dolostone Vinemount Shale

Goat Island Upper Flow Zone Goat Island Mid Flow Zone Goat Island Lower Flow Zone

Goat Island Dolostone Goat Island Dolostone Ancaster Chert Beds

Notes Water table aquifer within uppermost bedrock unit Upper 0.5 m of a 5 m thick shale to shaley dolostone unit is horizontally permeable. The upper 1m zone represents the Vinemount Flow Zone 1.5 m layer of interbedded dolostone and shale within the upper portion of Goad Island Unit Split into Upper Mid and Lower Mid Flow Zones


The flow zones and their respective lithologic units are also illustrated on Figure 4.1. To the north of the Eramosa Scarp, the Eramosa Dolostone, Vinemount and in places the Goat Island Shale units do not exist, as they were eroded by glacial advancement. Where these units/flow zones do not exist, the water table generally occurs within the overburden, however seasonal fluctuations have historically dropped the water table to within the Goat Island Dolostone during drier periods. The distribution of flow zones within bedrock on the north and south sides of the Eramosa Scarp is illustrated on Figure 4.1. Beneath the Ancaster Chert Beds lie the Gasport Dolostone and Decew Dolostones. These units are interpreted to be less than 2 m in thickness in the Site Study Area and do not represent significant groundwater flow zones. A Unit known as the Rochester Shale underlies the Decew Dolostone. Previous studies have determined that the Rochester Shale has a horizontal hydraulic conductivity of less than 10-8 cm/sec. Vertical hydraulic conductivities have been estimated between 10-8 and 10-10 cm/sec. On this basis, the Rochester Shale is interpreted to be an effective aquitard and represents the bottom of active groundwater flow within the Site Study Area. Natural groundwater flow direction in these flow zones within the Site Study Area is generally to the northwest towards the Niagara Escarpment; however there are several natural and man-made features that influence the movement of groundwater on-Site and in the Local Study Area. These features are discussed in detail in the following section. Prior to quarry development and construction of several subsurface infrastructure projects, groundwater flow was likely consistently northwest in all five flow zones. To the north of the Site, closer to the Niagara Escarpment, the rock units are more fractured and interconnected. This interconnecting of units results in a more vertical component of groundwater flow (downward) prior to reaching the Escarpment. As a result, groundwater springs along the Escarpment face are infrequent to the north of the Site. Beyond the Niagara Escarpment, groundwater flow discharges to Lake Ontario. 4.1.1

Potential Man-Made Influences on Groundwater Movement

Various construction and infrastructure projects in the Local Study Area have influenced local groundwater flow directions and/or gradients. For example, construction of sewers within or below groundwater flow zones can influence groundwater flow by creating preferential pathways for groundwater movement within the granular trench bedding. The following points summarize the construction projects that have intersected the groundwater flow zones and thus affected the movement of groundwater: •

A 2.1 m diameter storm sewer was installed within the median of Mud Street to the south of the landfill during 1994. Construction of this sewer involved removal of portions of the Eramosa Dolostone and the Vinemount Shale.

•

A 42.7 m deep vertical sanitary sewer drop shaft was constructed as part of the Upper Stoney Creek subdivision development. This drop shaft connects the sanitary sewer at the top of the Niagara Escarpment to the sanitary sewer system at the base of the Escarpment. Construction of this vertical shaft involved blasting and excavating through rock, and thus resulted in connection of the various groundwater flow zones in the immediate vicinity of the vertical shaft.

•

A similar vertical shaft was constructed in the vicinity of Green Mountain Road West and Highway 20, between 2011 and 2012. The Centennial Parkway Truck Sanitary Sewer was extended by boring into the base of the Niagara Escarpment. Three vertical shafts were required for this extension. The Centennial Parkway Trunk Sanitary Sewer construction has been ongoing, extending from Green Mountain Road to the south towards the Town of Binbrook. Ongoing monitoring will determine what effects this construction will have on the groundwater flow system.


•

A former quarry dewatering sump, referred to as the South Sump, was excavated into the Vinemount Shale within the footprint of the SCRF. The South Sump has been operating during construction of four of the landfill cells in order to keep conditions dry for construction. This sump is connected to a series of granular trenches constructed for the purpose of expanding groundwater collection below the SCRF liner system. It should be noted that this construction took place early on in the life of the Site.

•

A lower quarry excavation located within the footprint of the SCRF was completed into the Goat Island Dolostone for aggregate production in the early 1980s. The eastern portion of this excavation included a 9 m deep dewatering sump. At the completion of quarrying this lower portion, the excavation was backfilled with rubble and capped with a 3 m thick clay plug in 1991. The clay plug was placed at the elevation of the Vinemount shale. Despite placement of a clay plug, the perimeter of the excavation represents a vertical connection between the Upper and Lower flow zones. A pumping well (M4) was installed below the clay plug in 1993 in order to use the highly permeable lower excavation as a source of groundwater capture.

•

A series of Containment Wells are operated along the northern limit of the closed landfill for the purpose of groundwater collection. Operation of these wells affects groundwater flow.

•

A Perimeter Drain was installed between the closed landfill and the operating SCRF for the purpose of mitigating the movement of impacted groundwater from the closed landfill to the operating SCRF. Eastward movement of groundwater from the closed landfill to the operating SCRF is the result of active groundwater pumping at the South Sump and pumping well M4. The Perimeter Drain system includes groundwater collection trenches and a grout curtain installed to reduce movement of groundwater in the Vinemount and Upper Flow zones. 4.1.2

Remedial Systems

Previous investigations undertaken in the Site Study Area identified groundwater impacts related to the closed landfill to the west of the existing SCRF. The impacts are the result of infiltrated rainwater coming into direct contact with buried waste within the un-engineered landfill cells. No impacts to groundwater from the SCRF are evident, as the SCRF is fully lined and under-drained. Historically, impacts from the closed Site have been primarily noted within the Eramosa, Vinemount, Upper and Mid Flow Zones. In response to the identified impacts, several groundwater remediation strategies have been implemented. The principal groundwater remediation strategy is through active leachate or groundwater extraction and control in the areas of identified impact. The following points summarize the groundwater remediation systems currently in place at the closed landfill. •

A series of several Containment Wells are located along the northern boundary of the closed landfill. The locations of these wells correspond largely with the presence of the buried Eramosa Scarp. A total of seven Containment Wells have been installed and historically operated with groundwater pumped and discharged to the sanitary sewer system. With implementation of the Shatter Trench system (described below) and progressive closure of the closed landfill, decreases in available drawdown have been observed at the Containment Wells. These effects, combined with decreased performance due to mineral precipitation, have reduced the active network from 7 to 2 wells as of 2017. Currently, only CW3 and CW16 continue to actively pump.

•

A groundwater collection trench and grout curtain was constructed between the closed landfill and operating SCRF for the purpose of reducing migration of impacted water from the closed landfill to the east. The groundwater collection trench is part of a network of groundwater collection trenches that are constructed within shallow bedrock around and within the footprint of the SCRF. These shallow groundwater collection trenches are connected to a central groundwater pumping station and allow complete collection of groundwater from the Vinemount Flow Zone within the footprint of the SCRF.


•

Operation of pumping well M4, located within the lower excavation to the north of the operating SCRF. Operation of this pumping well controls groundwater impacts within the Vinemount Flow Zone, as well as the Upper and Mid Flow Zones.

•

Operation of pumping well L1 near the west side of the closed landfill. L1 was installed in 1995, and has been in continuous operation since, with the exception of interruptions for maintenance, etc. L1 draws water from the Lower Flow Zone.

•

Operation of pumping wells within a Shatter Trench located to the north of the closed landfill. The Shatter Trench pumping wells remove groundwater from the Upper Flow Zone and the Upper-Mid Flow Zone. Currently, two pumping wells actively remove groundwater from the Shatter Trench (M5A, M5R).

The locations of these measures are presented in profile on Figure 4.1 (where possible), and in plan view on Figure 4.2 (where possible).


SCRF

SCRF

Source: JACKMAN GEOSCIENCE INC., 2015. HAMILTON (STONEY CREEK) LANDFILL, PROVISIONAL CERTIFICATE OF APPROVAL No. A181008, ANNUAL REPORT 2014

TERRAPURE ENVIRONMENTAL

11102771-00 Jun 10, 2016

GEOLOGIC SEQUENCE AND GROUNDWATER CONTROL FEATURES STONEY CREEK REGIONAL FACILITY ENVIRONMENTAL ASSESSMENT CAD File: P:\drawings\11100000s\11102771\11102771 - PRES\11102771-00(PRES005)\11102771-00(PRES005)CI\11102771-00(PRES005)CI-WA001.dwg

FIGURE 4.1

SCRF

CLOSED TERRAPURE LANDFILL

Source: JACKMAN GEOSCIENCE INC., 2015. HAMILTON (STONEY CREEK) LANDFILL, PROVISIONAL CERTIFICATE OF APPROVAL No. A181008, ANNUAL REPORT 2014

TERRAPURE ENVIRONMENTAL

11102771-00 Jun 10, 2016

SITE PLAN AND MONITORING NETWORK STONEYCREEK REGIONAL FACILITY ENVIRONMENTAL ASSESSMENT CAD File: P:\drawings\11100000s\11102771\11102771 - PRES\11102771-00(PRES005)\11102771-00(PRES005)CI\11102771-00(PRES005)CI-WA002.dwg

FIGURE 4.2

4.1.3

Groundwater Flow

Due to the various influences on groundwater movement in the Site Study Area, groundwater flow is complex. The following description is taken from the 2016 Annual Report (Jackman, 2017) for the SCRF and provides a conceptual description of the movement of groundwater through the Site Study Area. Groundwater flow in the vicinity of the SCRF is generally from the southeast to the northwest towards the Niagara Escarpment. It is expected that as groundwater approaches the Niagara Escarpment, that downward movement between flow zones increases due to the presence of more and larger interconnected fractures which increase vertical permeability. This results in the groundwater flow moving into the deeper formations prior to reaching the edge of the escarpment. In the immediate vicinity of the SCRF, geologic evidence suggests that interconnections between the flow zones are less pronounced and the predominant direction of groundwater flow is interpreted to be horizontal within these flow zones. As discussed above, there are several man-made influences on groundwater flow that affect the horizontal and vertical movement of groundwater within the flow zones. The interpreted shallow groundwater flow in the immediate vicinity of the SCRF is affected by the absence of the upper rock units within the landfill footprint and by the active pumping of the M4 containment well. This containment well contributes inward flow of shallow groundwater to the lower excavation portion of the SCRF. The collected groundwater is pumped to the sanitary sewer connection located at the north side of the SCRF. Groundwater flow in the deeper bedrock flow zones within the Site Study Area is also largely affected by the groundwater remediation systems currently in operation, with some influences from off-Site infrastructure projects being apparent (e.g., vertical sewer shaft at Green Mountain West and Highway 20). The dominant horizontal hydraulic gradients in the lower flow zones indicate an overall groundwater flow direction from southeast to northwest towards the Niagara Escarpment.

4.2

Source Water Protection Area

Source Water Protection Areas (SWPAs) were developed to ensure drinking water sources, such as lakes, rivers, and well water are protected from activities with the potential to threaten drinking water quality. The purpose of the development of SWPAs is to maintain clean sources of municipal and private drinking water. Source Protection Regions and SWPAs are defined across Ontario under the Clean Water Act, 2016. Source Protection mapping obtained from the MOECC indicates the following about the area surrounding the Local Study Area: •

•

The Site is not within a wellhead protection area, nor an area with groundwater under the direct influence (GUDI) of surface water. o

Wellhead protection areas are designated around pumping wells based on the contaminant travel time.

o

It should be noted that the Municipal Water Supply is derived from an intake located within Lake Ontario, and not from the aquifers underlying the Local Study Area.

o

As the Site is not within a wellhead protection area, it is not assigned a vulnerability score.

The Site is not considered an issue contributing area. o

Issue contributing areas are assigned based on exceedances of ODWS during treatment as a result of activities in a particular area.


•

5.

A small area in the northern portion of the Local Study Area is located within the limit of the Intake Protection Zone (IPZ) 2 and the Vulnerable Surface Water Area. o

IPZ 2 is designated based on potential influence on the City of Hamilton’s water intake in Lake Ontario. IPZ 2 is located on the lower level of the Niagara Escarpment.

o

The vulnerable surface water area is assigned based on the ability for contaminants to travel in surface water. The vulnerability score in the northern portion of the Local Study Area is 4.8. Vulnerability scores in IPZ 2 range between 3.5 to 6.3.

Geology and Hydrogeology Net Effects As mentioned, the previously identified potential effects and proposed mitigation measures associated with the Preferred Landfill Footprint were reviewed in greater detail to ensure their accuracy in the context of the preliminary design of the Preferred Landfill Footprint. This expanded review included: •

Updated modeling of the potential for leakage through the landfill liner using the Hydrologic Evaluation of Landfill Performance (HELP) model. The updated HELP modeling took into consideration the updated design details for the Preferred Landfill Footprint. The results were applied to the stages of landfill development in order to identify the worst-case scenario for leachate generation and potential liner leakage.

•

Updated modeling of the potential impact to downgradient groundwater quality from the predicted worst-case scenario leachate leakage modeling results. Background groundwater quality used in the assessment of potential effects was updated to include current upgradient groundwater quality in the various flow zones.

•

Leachate and downgradient water quality used in the assessment of potential effects was updated to include most current water quality data for the various flow zones.

•

Calculations of the potential effects of the Preferred Landfill Footprint on groundwater flow.

Appendix A summarizes the results of the updated HELP modeling, including a description of the input parameters and the conservative assumptions. Appendix A also provides the HELP model summary output files. Appendix B summarizes the modeling results for the predicted potential effects on downgradient groundwater quality and groundwater flow.

5.1

Potential Effects on Geology and Hydrogeology

This section discusses the evaluation results in terms of the predicted effects of the Preferred Landfill Footprint on groundwater quality and groundwater flow. Discussions of predicted leachate generation and leakage through the liner are included, as these are integral parts of the groundwater quality evaluation. 5.1.1

Leachate Generation

As discussed in Appendix A, the HELP model was used to predict leachate generation rates for the Preferred Landfill Footprint. Leachate generation rates are provided by the HELP model as leakage through the final cover system into the waste mound. Based on the HELP modeling conducted, Table 5.1 summarizes the predicted leachate generation rates under various stages of landfill development, including closure conditions for the Preferred Landfill Footprint, as well as the existing approved configuration.


Table 5.1 Predicted Leachate Generation Rates Landfilling Section

Active Landfilling Area (ha)

Existing Conditions

28.9

164,712

Phase 1

40.2

183,219

Phase 2

21.8

153,084

Phase 3

16.8

172,634

Phase 4

18.8

203,357

Post Closure

0

172,567

Existing Approved Post Closure

0

172,509

Leachate Generation Rate (m3/yr)

The results presented in Table 5.1 demonstrate that leachate generation rates vary during the different stages of landfill development. Leachate generation is highest during Phase 4, with 203,357 m3 of leachate generated per year. It is important to note that the predicted post-closure leachate generation for the Preferred Landfill Footprint is essentially the same as the predicted post-closure leachate generation for the existing approved landfill configuration. 5.1.2

Leachate Leakage Through Liner

To understand the potential impact of leachate leakage through the liner system, it is necessary to model the amount of leachate that could potentially leak through the liner. In order to ensure this step in the impact assessment is conservative, the leachate leakage modeling is undertaken as a “worst-case” scenario by excluding the additional protection resulting from the hydraulic control layer. The liner system incorporated into the landfill design is highly protective of the natural environment and the likelihood of leachate leakage is very remote. Notwithstanding, the following paragraphs describe the results of leachate leakage modeling undertaken for the purpose of this conservative assessment. The HELP model was used to predict the rates of leachate through the liner system for the Preferred Landfill Footprint during the stages of landfill development. Based on the HELP modeling conducted, Table 5.2 summarizes the predicted leachate leakage rates under existing conditions, four Phases of development and closure conditions for the Preferred Landfill Footprint. Table 5.2 Predicted Leachate Leakage Rates Leachate Leakage Rate (m3/yr)

Landfilling Section

Active Landfilling Area (ha)

Existing Conditions

28.9

34.679

Phase 1

40.2

38.391

Phase 2

21.8

32.347

Phase 3

16.8

36.656

Phase 4

18.8

43.202

Post Closure

0

37.026

Existing Approved Post Closure

0

34.71

The results presented in Table 5.2 demonstrate that the modeled leachate leakage rates are low (not actually occurring), with the highest rate modeled during Phase 4 of landfill development under the Preferred Landfill Footprint. In order to ensure a conservative approach to predicting the effects of landfill development on future groundwater


quality and flow, the Phase 4 leakage rates presented in Table 5.2 have been used for the purposes of the groundwater quality and flow assessments discussed below. It is important to note that the predicted post-closure leachate leakage rate for the Preferred Landfill Footprint is essentially the same as the predicted post-closure leachate leakage rate for the existing approved landfill configuration. 5.1.3

Effects on Downgradient Water Quality

A generalized water balance and mass balance approach was used to estimate groundwater quality at the downgradient Site boundary for the Preferred Landfill Footprint. The water balance considered the primary inputs, and movements of water across the Site using both Site hydrogeologic data and theoretical calculations. The water balance and groundwater flow beneath the landfill was estimated by using Site specific groundwater elevations, gradients, and hydraulic conductivities. Based on the groundwater flux and contaminant mass loadings from predicted leachate leakage, downgradient groundwater quality was then estimated. A detailed description of calculation methodology and individual parameter results is provided in Appendix B. Additional contaminant mass from leachate leakage marginally increases some contaminant concentrations at the downgradient boundary. For the purposes of comparing the effects of the preferred Landfill Footprint on downgradient groundwater quality, chloride has been selected as a surrogate for leachate impacts. Chloride is a contaminant species where changes in concentration are due to physical, non-destructive, processes (e.g., mechanical dispersion, dilution) and is not subject to biochemical breakdown, precipitation, or adsorption. Thus, chloride provides a conservative estimate of potential future impacts. Table 5.3 provides a summary of the forecasted chloride concentrations in monitoring wells located at the downgradient boundary under final development (closure conditions) for both the Preferred Landfill Footprint, as well as the existing approved final closure conditions. The table provides a summary of the monitoring wells within the Vinemount Flow Zone (VFZ). The VFZ directly underlies the landfill liner and has comparatively limited upgradient flux. Thus, the VFZ is anticipated to be most affected by leachate mass loading. In order to ensure the results of the projected concentrations are conservative and comparable, the projections have been made assuming all leachate leakage would enter the VFZ. Table 5.3 Predicted Downgradient Groundwater Quality Existing Approved

Preferred Landfill Footprint

Chloride

Chloride

Well ID (mg/L)

(mg/L)

47-III

300

320

48-V

880

890

60-III

400

420

61-III

550

570

Notes: all concentrations are in mg/L (m3/year / m3/day ) leachate leakage rate

As shown in Table 5.3, the predicted downgradient groundwater quality is very similar for the Preferred Landfill Footprint and the Existing Approved scenarios. The detailed results for predicted groundwater


quality, including general chemistry and metals leachate indicator parameters, are included in Tables B.1 through B.4 within Appendix B. The results included in this table show a consistent pattern in that the predicted downgradient groundwater quality is similar to, but slightly higher that existing water quality. This is not unexpected as the modeling has added contaminant mass to the flow zone. The most significant modeled increases in downgradient parameter concentrations noted are for chloride and sodium. Although the modeled parameter increases are relatively minor, it is important to note the following with respect to the results of the groundwater quality assessment: 1. The downgradient groundwater quality predictions have not taken into account any attenuation of leachate impacts. The modeling has maintained the contaminant mass from the point of discharge beneath the liner system to the downgradient boundary. 2. The HELP modeling that was used to estimate the liner leakage did not take into account the hydraulic control layer component of the liner system. 3. The downgradient groundwater quality predictions have not taken into account the groundwater control systems incorporated into the landfill design. These systems are currently in operation and will be expanded as part of continued landfill development. These systems are discussed further in Section 6 (Proposed Mitigation Measures). 4. The predicted downgradient groundwater quality for the Preferred Landfill Footprint is very similar to the predicted downgradient groundwater quality for the existing approval under closure conditions, modeled using the same methodology. 5.1.4

Effects on Source Water Protection

Any potential impacts to groundwater and/or surface water quality within the SWPA will be dependent on groundwater quality migrating into the IPZ for the City of Hamilton water intake. As detailed in Table 5.3, conservative predictions of downgradient groundwater quality show very similar results for the Preferred Landfill Footprint s and the existing approval. The modeling results show minimal effects on predicted groundwater quality prior to implementation of mitigation measures. It is important to note that these predictions to downgradient groundwater and/or surface water quality within the SWPA do not consider the use of the groundwater control systems (mitigation measures). These systems will be operated and expanded as part of the continued landfill development and will mitigate the migration of potentially contaminated groundwater offsite. With the continued operation of the groundwater control systems, it is anticipated there will be no impacts on groundwater quality entering the IPZ.

5.2

Groundwater Flow

The estimated leakage rate of leachate through the liner (which is not actually occurring but modeled), calculated using the HELP model, was used to determine the potential impacts of each alternatives on groundwater flow. The HELP outputs show that leakage from the landfill liner will contribute approximately 0.056 mm of hydraulic head each year. This leakage will predominantly enter the Vinemount Flow Zone (which directly underlies the base of the landfill footprint), which could increase the hydraulic head beneath the landfill footprint. The increase in hydraulic head could affect groundwater flow by altering horizontal hydraulic gradients. Based on the 2017 groundwater elevations measured at the Site, groundwater levels within the Vinemount Flow Zone are heavily influenced by groundwater extraction at M4, as well as the Phase One Centennial Parkway Trunk Sanitary Sewer (CPTSS) construction; however, historic reports (Taro East Quarry Environmental Assessment Hydrogeological, Impact Assessment Final Report, Gartner Lee, January 1995) show that the baseline potentiometric surface ranges from 201.0 to 192.6 mAMSL across DRAFT FOR DISCUSSION GHD | Draft Geology and Hydrogeology Detailed Impact Assessment Report |11102771 | 16

the Site. Thus, the change in hydraulic head across the Site is on the order of several metres across a distance of approximately 900 m (i.e., i = (201mAMSL – 192.6mAMSL) / 900 m = 0.093 m/m). Under the landfill expansion with the Preferred Landfill Footprint, landfill leakage contributes an additional hydraulic head of 0.056 mm/year. Thus, the maximum increase in hydraulic gradient due to leachate leakage is negligible. The change in hydraulic gradient will produce negligible changes to groundwater flow rate and no observable change in direction.

5.3

Proposed Mitigation Measures

The evaluation of potential environmental effects provided above has been completed without taking into consideration several environmental control systems incorporated into the landfill design. These control systems are important aspects of the Site’s groundwater protection strategy and accordingly they are being taken into consideration as mitigation measures for the Preferred Landfill Footprint. The following paragraphs describe the environmental control systems in place at the SCRF and their relevance to the predicted environment performance of the Preferred Landfill Footprint. Groundwater Extraction Well M4 Around 1985, the Lower Excavation portion of the active quarry (at the time), was made through the Vinemount Shale floor to allow access to the Goat Island Dolostone. Dewatering for this quarrying operation from the Lower Excavation created a draw of impacted groundwater from the closed landfill located immediately to the west. The Lower Excavation ceased to be used and was backfilled in 1990 with clean rock rubble with a 3m thick clay plug installed to simulate the low permeability of the former Vinemount Shale floor of the quarry. The contact between the clay plug was imperfect and flow from the VFZ and UFZ mixed within the rock rubble with groundwater from the lower flow zones. In order to control movement and extract contaminated groundwater migrating from the closed landfill, M4 extraction well was established in one corner of the former Lower Excavation. Based upon observations of the system performance, a target pumping level was set for the M4 pumping well as a means of maintaining inward gradients toward the pumping well. Monitoring well observations during initial testing indicated that monitors across the length of the north boundary responded to the pumping of M4. Potentiometric groundwater surfaces provided in the 2016 Annual Monitoring Report (Jackman, June 2017) show groundwater flow in each of the flow zones was heavily influenced by the operation of M4. Inwards, horizontal hydraulic gradients are shown across the northern Site boundary of both the SCRF and closed landfill. This observation is consistent with previous presentations of groundwater flow with extraction well M4 in operation. In 2016, M4 extracted an average of 70,000 L/day (when in operation) which is greater than the combined flux estimates for the VFZ, UFZ, and UMFZ/LMFZ. It should be noted that in 2016, groundwater levels at the SCRF were being affected by dewatering associated with sewer construction along Highway 20, which resulted in a historically low extraction volume from M4. Based on data presented in the 2016 Annual Monitoring Report (Jackman, June 2017) (extraction greater than estimated flux values and measured inward horizontal hydraulic gradients), operation of M4 will be sufficient to capture potential future landfill-related water quality impacts within the VFZ, UFZ, and UMFZ/LMFZ. On the basis of historical performance of this extraction well, potential leakage from the landfill under the scenario of Preferred Landfill Footprint development will be mitigated by operation of M4.


It is recommended that extraction well M4 is maintained and operated for the purpose of collecting potentially impacted groundwater and maintaining inward gradients under the scenario of landfill development with the Preferred Landfill Footprint. Groundwater Collection Trench Network The existing developed portion of the SCRF includes a network of shallow groundwater collection trenches that surround the landfill footprint and connect through a network of trenches underlying the landfill liner. These trenches are excavated through the VFZ and keyed into the underlying Vinemount Shale aquitard. The trenches are connected to a groundwater pumping station located at the southeast corner of the SCRF. Accordingly, the groundwater collection trench system is capable of containing all groundwater flow within the VFZ below the landfill footprint. As the VFZ would be the primary receptor of direct leachate leakage from the liner, this system is capable of mitigating leakage from the liner, should this condition be observed in the future. It is recommended that construction of the network of groundwater collection trenches is completed beneath the liner system as landfill cells are constructed (as per the existing design). Evacuation of these collection trenches via the groundwater pumping station will assist in controlling the lateral movement of potentially impacted shallow groundwater. Hydraulic Control Layer The liner system for the SCRF includes a hydraulic control layer (HCL) between the two 1 m sections of compacted clay liner. The HCL consists of a coarse granular material, which, once fully constructed, will be flooded and maintained at a specified hydraulic head to induce an upward vertical gradient across the upper portion of the compacted clay liner. Maintaining an upward hydraulic gradient across the clay liner will ensure that downward leaking of leachate across the clay cannot occur. Accordingly, operation of the HCL will provide a substantial degree of additional protection against discharge of leachate through the liner into the natural environment.

5.4

Net Effects

The net environmental effects of the Preferred Landfill Footprint on geology and hydrogeology have been determined through applying the mitigation measures described above (Section 5.3) to the potential environmental effects identified in Sections 5.1 and 5.2. In consideration of the minor variations in predicted downgradient groundwater quality between the Preferred Landfill Footprint and the Existing Approval, and the very conservative nature of the modeling performed to predict the potential environmental effects, the mitigation measures described in Section 5.3 will adequately negate any potential environmental effects related to Site development under the Preferred Landfill Footprint. On the basis of the above, it is concluded that there will be no net environmental effects from the Preferred Landfill Footprint on the geologic or hydrogeologic conditions within the Site Study Area.


6.

Climate Change Considerations 6.1

Potential Effects of the Undertaking on Climate Change 6.1.1

Mitigation

The current undertaking is not expected to have an impact on climate change from a Geology/ Hydrogeology discipline perspective.

6.2

Effect of Climate Change on the Undertaking 6.2.1

Adaptation

The principal way in which the geologic and hydrogeologic conditions could be affected by future climate change would be through changes in precipitation rates. Changes in precipitation rates could affect leachate generation and thus potential leakage through the liner system. Changes in precipitation can also affect groundwater recharge patterns, which can affect groundwater availability and flow patterns. Mitigation of potential changes to the hydrogeologic regime at the Site due to climate change will be through adapting leachate collection strategies to changing conditions. The design of the leachate collection system allows for responding to increases in leachate generation through additional pumping. Leachate levels are monitored within manholes throughout the developed portions of the landfill and through leachate monitoring wells. If the results of monitoring demonstrate that climate change is resulting in increases in leachate generation, the leachate management strategy can be modified to increase leachate removal from the waste mound to ensure continued beneficial performance of the landfill.

7.

Environmental Monitoring To ensure that the proposed mitigation measures identified in Section 5 are implemented as envisioned, a strategy and schedule was developed for monitoring environmental effects. With these mitigation or compensation measures and monitoring requirements in mind, commitments have also been proposed for ensuring that they are carried out as part of the construction, operation, and maintenance of the landfill.

7.1

Monitoring Strategy and Schedule

As mentioned, a monitoring strategy and schedule was developed based on the Surface Water Impact Assessment carried out for the Preferred Landfill Footprint Landfill Footprint to ensure that: 1) predicted net negative effects are not exceeded; 2) unexpected negative effects are addressed; and, 3) the predicted benefits are realized. 7.1.1

Environmental Effects Monitoring

The Site hydrogeologic environmental performance is currently monitored through a comprehensive longterm groundwater monitoring program. This monitoring program includes collection of static water levels and groundwater quality samples four times per year at an extensive network of monitoring wells screened within the various flow zones on-Site and in the Site Study Area. The monitoring well network has evolved through the many years of Site monitoring to provide a very detailed account of the distribution of hydraulic head (static groundwater conditions) and groundwater quality within the various flow zones.


Groundwater quality samples are collected for a comprehensive list of analytes to identify landfill-related alterations to groundwater quality. This monitoring program is currently in place and should be maintained through landfill development under the Preferred Landfill Footprint. The long-term groundwater monitoring program tracks changes in groundwater quality and flow over time and will be used to assess the validity of the model predictions regarding the performance of the Preferred Landfill Footprint. The results of longterm monitoring will be reviewed and interpreted in detail annually as part of the annual reporting process. Annual data interpretation and reporting is used to ensure any deteriorations in environmental performance are identified and addressed through changes in operational practices or implementation of augmented remedial responses. A complete summary of the 2017 groundwater monitoring program is provided in Table 7.1. As with any environmental monitoring program, modifications to the program are occasionally necessary to adapt the program to evolving conditions. Accordingly, the monitoring program will need to be reviewed, as part of the annual reporting process to ensure that the monitoring program is adequately characterizing Site conditions with respect to the presence and movement of landfill-related groundwater quality alterations.


2017 Groundwater Monitoring Program Terrapure Environmental Closed Stoney Creek Regional Facility

Table 7.1

Monitor Flow Zone

Monitoring Well Nest

Waste

Eramosa

VFZ

UFZ

UMFZ

LMFZ

LFZ

RS

Monitor Flow Zone Designation – e.g. 29-II = VFZ monitor 14 29* 30 31 32 33 35 36 40* 41 42 43 44 45 46R 47 48 49 50 51 52 55 56 57 58 59 60 61 62 67 68 69 70 72 74 75 76 P1 P3 P4 P5 P6,9 P7 P8/G27 P9 P10 P11 P12 P13 P14 P15 GHD 11103232 (RPT5)

I III I I

I

VII1 V III

IV1 III II

III

II

VI1 I I II1 I

II II II II II1

IV

I I V1 IV

OB III3

III1 II I1 II II1 II

1

IV IV IV II V1 III

1

III V V

IV1 II

IIR4 I1 II II

IIIR4 II1 III III I

I I1 I IR4 I IR4 VI

I I

II1 I1 III III

1

OB VI3

V

IV IV III

V

IV

IV IVR4 9-I IV II,G27 II V1

III IV1

II I1

I

II II IV III III1 III IIR III1 III IV

I I III II

III II II III I III I I III1 III I I I I

1

II II I II1 II III III1 III III II

III1

II1 IV

II I

I I1 I I1

I II II1 II I

I I1 I I I

II

IR4

II1 II

I1 I

I

2017 Groundwater Monitoring Program Terrapure Environmental Closed Stoney Creek Regional Facility

Table 7.1

Monitor Flow Zone

Monitoring Well Nest

Waste

P16 P17 North Sump GW-PS (S. Sump) Shatter Trench Shatter Trench Shatter Trench Shatter Trench Shatter Trench Shatter Trench Shatter Trench Shatter Trench Shatter Trench Lower Excavation

VFZ

UFZ

UMFZ

LMFZ

LFZ

RS

I I Sump Sump ST 1 ST 1-I ST 2 ST 2-I ST1-II ST 2-II M5 M 5R M 5a CW4,7,13, 11,16

CW 2, 3, 4, 5,11, 13,15, 16 L1 Perimeter Drain

NOTES VFZ UFZ UMFZ LMFZ LFZ RS 1) * 3) 4) III III M5 ST 2 M 5a

Eramosa

M4 CW2,3,5,10, 15 L1 PD1

PD

Vinemount Flow Zone Upper Flow Zone Upper-Mid Flow Zone Lower-Mid Flow Zone Lower Flow Zone Rochester Shale Misa Organic Group Analysis conducted in 2017 to collect baseline data Monitors will be decommissioned when liner construction reaches this location OB III, OB VI are overburden monitors and are not in waste Monitor has been replaced by a new installation at the same monitor nest location Closed Terrapure Environmental Closed Stoney Creek Regional Facility Operating Terrapure Environmental Closed Stoney Creek Regional Facility Water Level Measurements Only Permit To Take Water Monitors (monthly basis) Permit To Take Water Monitors (weekly basis)

FREQUENCY AND PARAMETERS Seep Monitoring – Closed LF requirement Private Well Monitoring – PTTW requirement

Parameter List A and B Frequency – A - Each Quarter, B - Biannual

GHD 11103232 (RPT5)

Frequency – Twice per year – Seeps 1, A1, A2, A3, A4, A5, A6, A7, A8, A9, TB – Sample parameters are – field Conductivity, pH, temperature and dissolved oxygen. Also include general chemistry for the surface water-monitoring program. Residence 1, Residence 2, – Quarterly water quality sampling for List A (with owner’s permission) List A - pH, Cond., Alk., Hard., TDS, Phenols, TKN, NH3-N, Ca, K, Mg, Na, Cl, F, Br. NO2-N, NO3-N, PO4, SO4, Al, Ba, Be, B, Cd, Cr, Co, Cu, Pb, Fe, Mn, Mo, Ni, Si, Sr, Ti, V, Zn, DOC, Field pH, Field Cond., and Water Temp Locations with ‘1’- List B - Misa Groups 16,17,18,19,20 and 22

7.1.2

Development of an Environmental Management Plan

An Environmental Management Plan (EMP) or Plans will be prepared following approval of the undertaking by the Minister of the Environment and prior to construction. The EMP will include a description of the proposed mitigation measures, commitments, and monitoring.

8.

Commitments The commitments to be made as part of landfill development under the Preferred Landfill Footprint can be stated in two broad categories: commitments related to mitigation strategies; and, commitments related to monitoring of future potential environmental effects. The mitigation strategies to be implemented as part of the Preferred Landfill Footprint are described in detail in Section 5.3 and include the following: 1. Operation of the M4 extraction well to control hydraulic gradients beneath and immediately surrounding the SCRF. Historical performance monitoring has confirmed that operation of the M4 well is effective at controlling the migration of potential landfill-related water quality impacts through inducing preferential horizontal hydraulic gradients. Operation of this extraction well should continue with regular maintenance to ensure longevity and annual review of performance monitoring data to ensure continued effectiveness. 2. Completion of the network of shallow groundwater collection trenches. The existing design incorporates a network of shallow groundwater collection trenches underlying the base liner system and keyed into an underlying aquitard. Portions of the collection trench network is already existing where landfill cells have already been constructed. The remaining trenches should be installed beneath the liner as future cells are developed. The groundwater collection trenches should be evacuated through pumping at the groundwater pumping station, as possible. 3. The hydraulic control layer is an important component of the base liner system. By flooding this layer (once fully constructed), an upward hydraulic gradient can be induced across the upper/primary compacted clay base liner. This upward hydraulic gradient will ensure leakage across the liner is not possible. As a double check against liner leakage, the hydraulic control layer water should be sampled and tested for landfill indicator parameters as part of the regular long-term environmental monitoring program for the Site. As described in Section 7, the Site currently has a comprehensive groundwater monitoring program to monitor for landfill-related water quality alterations. This monitoring program should be maintained throughout the Site operations and post closure in order to track performance of the landfill’s environmental control systems related to groundwater. The environmental monitoring program results should be reviewed and reported along with detailed interpretations and recommendations annually. In addition, the monitoring program should be reviewed as part of the annual reporting process to ensure that it is sufficient for identifying and tracking potential future landfill-related water quality alterations.

9.

Other Approvals Additional approvals that may be required for the Geology/ Hydrogeology management of the Site include: • •

Permit/approval from the City of Hamilton Environmental Compliance Approval (ECA) amendment from the Ministry of the Environment and Climate Change (MOECC).


Appendices

GHD | Draft Geology and Hydrogeology Impact Assessment Technical Report | 11102771

Appendix A Description of Methodology - HELP Modeling


Appendix A: Detailed Description of Methodology – HELP Modelling The following provides a discussion on the detailed methodology for estimating leachate generation and leachate leakage through the liner for the preferred alternative.

1.

Leachate Generation and Leakage Rate

The Hydrologic Evaluation of Landfill Performance (HELP) model version 3.07 (Schroeder, et al., 1994a and 1994b) has been used to provide an assessment of leachate generation for the preferred alternative under various stages of development, including final closure. The HELP model was developed specifically to simulate the hydrologic components related to the operation of a landfill. Therefore, the HELP model is well suited for the purpose of this assessment. The following description of the HELP model, taken directly from Schroeder, et al., (1994a), provides an overview of both the landfill design parameters and hydrologic processes that can be simulated by the model: The Hydrologic Evaluation of Landfill Performance (HELP) computer program is a quasi-twodimensional hydrologic model of water movement across, into, through and out of landfills. The model accepts weather, soil and design data and uses solution techniques that account for the effects of surface storage, snowmelt, runoff, infiltration, evapotranspiration, vegetative growth, soil moisture storage, lateral subsurface drainage, leachate recirculation, unsaturated vertical drainage, and leakage through soil, geomembrane or composite liners. Landfill systems including various combinations of vegetation, cover soils, waste cells, lateral drain layers, low permeability barrier soils, and synthetic geomembrane liners may be modeled. The program was developed to conduct water balance analyses of landfills, cover systems, and solid waste disposal and containment facilities. As such, the model facilitates rapid estimation of the amounts of runoff, evapotranspiration, drainage, leachate collection, and liner leakage that may be expected to result from the operation of a wide variety of landfill designs. The primary purpose of the model is to assist in the comparison of design alternatives as judged by their water balances. The model, applicable to open, partially closed, and fully closed sites, is a tool for both designers and permit writers. The HELP model was developed by the United States Army Corps of Engineers under endorsement from the United States Environmental Protection Agency (USEPA). 1.1

Model Input Parameters

The HELP model requires two generalized groups of input parameters: •

Weather/Climatic and General Design Data

•

Soil & Design Data

Weather/Climatic and General Design Data The HELP model allows for manual input of weather/climatic and general design data, or use of default data for a specific geographical location based on historical results. The user can choose whether to Appendix A - Description of Methodology - HELP Modelling - NS.docx

Page 1

utilize manual data, default data, or a combination to generate synthetic weather/climatic data. The weather/climatic and general design data used in this assessment is SCRF specific manually input data obtained from the Environment and Climate Change Canada 1981-2010 Climate Normals & Averages database (Environment Canada, 2018), specifically the Hamilton A, Ontario station, Climate ID 6153194. All weather/climatic input parameters are summarized in the HELP model output files provided in in this Appendix.

Soil & Design Data The HELP model allows for manual input of soil and design data, or it can use default soil and design data based on material type. The soil and design data include soil layer type and the associated layer properties. The soil profile for the approved existing conditions and expansion options are as follows: Table A.1 Final Cover Material Properties Layer Topsoil Clay Cap Waste Leachate Collection HDPE Clay Liner

Layer Type Vertical Percolation Barrier Soil Liner Vertical Percolation Lateral Drainage Geomembrane Barrier Soil Liner

Layer Thickness

HELP Material Texture No.

USCS Description

Saturated Hydraulic Conductivity (cm/s)

15 cm

4

SM

1.7 x 10-3

60 cm

User Specified

-

1.0 x 10-5

Varies

User Specified

-

1.0 x 10-4

35 cm

21

Clear Stone

3.0 x 10-1

0.2 cm

35

2.0 x 10-13

200 cm

28

HDPE C (compacted)

1.2 x 10-6

The HELP model was used to estimate leachate generation for two types of landfill cover as follows: •

Open Active Cell

•

Final Cover

Two models were produced for each of the above noted cover types to determine leachate generation rates for the top of the landfill (3 percent) and the side slopes of the landfill (4H:1V). The models also include the waste layer, leachate collection layer, and landfill liner to determine the rate at which leachate percolated through the base of the landfill and potential leachate collection rates. Waste thicknesses were based on waste thickness under the scenario of full development, varying depending on model (i.e., top vs. side slope). For modeling purposes, the landfill liner is comprised of compacted clay with an estimated saturated hydraulic conductivity of 1.2 x 10-6 cm/s. In reality, the compacted clay liner is divided by a 50 cm thick hydraulic control layer consisting of 50 mm clear stone. Given the difficulty of incorporating the hydraulic control layer into the HELP model, the compacted clay liner layers were combined and modeled as a 200 cm thick layer. The hydraulic control layer represents an additional protection against potential leachate leakage for the following reasons: 1. The hydraulic control layer, once fully constructed, will be charged with clean water to a static elevation above the invert elevation of the leachate collection system. This will result in a Appendix A - Description of Methodology - HELP Modelling - NS.docx

2

“hydraulic trap” by inducing an inward gradient from the hydraulic control layer into the waste mound. 2. The hydraulic control layer water quality will be monitored regularly to ensure that the primary liner is functioning and provide advance warning of potential leakage. For these reasons, excluding the hydraulic control layer represents a conservative approach to modelling the potential for leachate leakage through the base liner system. The results of the modelling of leachate generation under the various stages of development for the Preferred Alternative are presented in Table A.2. The results of the modelling of leachate leakage under the various stages of development for the Preferred Alternative are presented in Table A.3.

Appendix A - Description of Methodology - HELP Modelling - NS.docx

3

Phase Existing Conditions Area ‐ Active Landfilling (ha) Area ‐ Final Cover (ha) Cover Status Annual Leachate Generation (m3) 3 Annual Leachate Generation (m /day) Cover Status 3 Annual Leachate Generation (m ) 3 Annual Leachate Generation (m /day) 3 Total Leachate Generation (m ) 3 Total Leachate Generation (m /day)

28.9 11.3 Active (Daily Cover) 131717 360.9 Final Cover 32995 90.4 164712 451.3

Phase 1

Table A.2 Modelled Leachate Generation Rates SCRF Terrapure Inc. Phase 2 Phase 3

40.2 0 Active (Daily Cover) 183219 502.0 Final Cover 0 0.0 183219 502.0



Phase 4

Post‐Closure


0 59.1 Active (Daily Cover) 0 0.0 Final Cover 172567 472.8 172567 472.8

Existing Approved (Post‐Closure) 0 59.1 Active (Daily Cover) 0 0.0 Final Cover 172509 472.6 172509 472.6

Phase Existing Conditions Area ‐ Active Landfilling (ha) Area ‐ Final Cover (ha) Cover Status Annual Leachate Infiltration (m3) 3 Annual Leachate Infiltration (m /day) Cover Status 3 Annual Leachate Infiltration (m ) 3 Annual Leachate Infiltration (m /day) 3 Total Leachate Infiltration (m ) 3 Total Leachate Infiltration (m /day)

28.9 11.3 Active (Daily Cover) 27.600 0.076 Final Cover 7.079 0.019 34.679 0.095

Phase 1

Table A.3 Modelled Leachate Infiltration Rates SCRF Terrapure Inc. Phase 2 Phase 3

40.2 0 Active (Daily Cover) 38.391 0.105 Final Cover 0.000 0.000 38.391 0.105



Phase 4

Post‐Closure


0 59.1 Active (Daily Cover) 0.000 0.000 Final Cover 37.026 0.101 37.026 0.101

Existing Approved (Post‐Closure) 0 59.1 Active (Daily Cover) 0.000 0.000 Final Cover 37.085 0.102 37.085 0.102

Appendix B Description of Methodology - Groundwater Quality and Flow Evaluation


Appendix B: Detailed Description of Methodology – Groundwater Quality and Flow Evaluation The following provides a discussion on the detailed methodology for approximating the effects of leachate leakage through the liner on groundwater quality and groundwater flow.

1.

Effects on Downgradient Water Quality

In order to estimate groundwater quality at the downgradient Site boundary under the preferred alternative scenario, a generalized water balance and mass balance approach has been used. For comparison, a similar approach has been utilized to assess downgradient water quality under the current, approved (post-closure) scenario. The following sections provide discussion of the calculations and assumptions used to assess future groundwater quality at the downgradient Site boundary. 1.1

Water Balance

A generalized water balance has been developed for the Site to characterize the basic hydrogeologic functioning in the vicinity of the Landfill. The water balance considers the primary inputs, and movement of water across the Site using both empirically derived data and theoretical calculations where data is unavailable (e.g., leachate leakage from the landfill after closure). These inputs are then used in combination with current contaminant mass inputs to derive the predicted future groundwater concentrations at the downgradient Site boundary. The inputs to the water balance are as follows: •

Groundwater flow into the landfill area, below the liner, from upgradient sources, in each of the flow zones that have the potential to receive leachate impacts after landfill closure (i.e. Vinemount Flow Zone [VFZ], Upper Flow Zone [UFZ], Upper Mid Flow Zone [UMFW], Lower Mid Flow Zone [LMFZ], and the Lower Flow Zone [LFZ])

•

Precipitation over the landfill area that results in: -

Leachate generation, which, in turn, results in leachate leakage into the underlying flow zones

-

Leachate generation under various scenarios of Site development were considered and the worst case (i.e. largest leachate infiltration estimates) have been used in the mass balance

In addition to using the largest leakage rates through the landfill liner, runoff from the final cap (which will ultimate infiltrate into the shallow flow zones providing dilution of impacts) has not been included in the mass balance equation. Infiltration of precipitation falling over the downgradient buffer zone will also provide dilution of landfill derived impacts in the shallow flow zones; however, the area downgradient of the landfill footprint is limited and has not been included in the water balance model. Utilizing the worst-case leakage rates while discounting runoff and downgradient precipitation ensures that the mass balance approach provides a conservative estimate of downgradient water quality under the scenario of landfill development with the preferred alternative.

Appendix B - Description of Methodology - GW Quality & Flow.docx

Page 1

1.1.1

Groundwater Flow Beneath Landfill

Groundwater flow beneath the landfill footprint was estimated using the groundwater elevations reported in the 2015 and 2016 Annual Monitoring Reports (Jackman Geoscience Inc., June 30, 2016, and June 30, 2017), as well as the flow zone characteristics reported by Gartner Lee Limited in the Taro East Quarry Environmental Assessment, Hydrogeologic Impact Assessment, Final Report (Gartner Lee Limited, 1995c). The Site-wide groundwater flow direction and gradients were estimated using an average of the 2015 through 2017 hydraulic data. A general southeast to northwest flow direction has been used and a gradient of 0.01 m/m has been estimated based on the available data. Individual flow zone thicknesses were estimated using details from Gartner Lee Limited. Geometric mean hydraulic conductivity values were applied to each flow zone. To determine cross-sectional area through which groundwater flow occurs in each flow zone beneath the landfill a line perpendicular to the direction of groundwater flow (southwest to northeast), approximately 910 m in length, is multiplied by the thickness of each flow zone. The groundwater flow passing through the cross-sectional area can be calculated using Darcy’s Law and is expressed with the following equation: Equation 1:

Darcy’s Law

Where,

𝑄𝑄 = 𝐾𝐾𝐾𝐾𝐾𝐾

Q = groundwater flow rate, flux, passing through cross-sectional area, A A = cross-sectional area though which groundwater is flowing i = hydraulic gradient K = geometric mean hydraulic conductivity of the individual flow zone through which groundwater is flowing

The cross-sectional area for groundwater flow is calculated as follows: Equation 2:

Cross-Sectional Area

Where,

𝐴𝐴 = 𝐿𝐿𝑥𝑥 × 𝑑𝑑

Lx = source length perpendicular to groundwater flow (910 m) d = thickness

The majority of groundwater flow in each unit would occur through zones of higher hydraulic conductivity. Thus, using the geometric mean of hydraulic conductivity ranges provides a groundwater flux estimate that is likely low. 1.1.2

Potential Leachate Leakage

Leachate generation rates were estimated using the Hydrologic Evaluation Landfill Performance (HELP) model, as discussed in Appendix A. Separate HELP models were created to simulate differing landfill development stages under the scenario of the preferred alternative. Leachate leakage rates from the


2

worst-case development stage were used to represent the leachate mass loading and potential impacts to groundwater quality under the preferred alternative landfill development configuration. In order to estimate contaminant mass loading, recent (2017) measured concentrations in leachate were used. Leachate concentrations were multiplied by individual leakage rates to derive masses to be added to the underlying aquifer(s) from leachate leakage. 1.2

Contaminant Mass Balance

To assess the future potential groundwater quality and identify potential compliance issues at the downgradient Site boundary, future contaminant concentrations need to be calculated to compare against established Reasonable Use Concentration (RUC) trigger levels for the Site. In order to predict future groundwater contaminant concentrations, a generalized mass balance approach has been utilized to estimate contaminant mass inputs. As RUC trigger levels have been prepared on a well by well basis, changes in groundwater contaminant concentrations must also be estimated on a well by well basis. Theoretical contaminant masses within the discrete flow zones have been estimated at individual monitoring wells by multiplying flux estimates for each flow zone by the 2017 groundwater quality at downgradient monitoring wells. Leakage rates and current measured leachate characteristics were used to estimate total contaminant mass loading that will be added to the underlying flow zones. The sum of these contaminant mass inputs (from individual monitoring wells added with leachate leakage) can then be divided over the total flux input (groundwater flux from that flow zone added to leachate leakage rates) to derive future groundwater concentrations at specific monitoring wells along the downgradient Site boundary. In order to apply the results in a ‘worst-case’ scenario, the total contaminant mass from the estimated leachate leakage was added to each individual flow zone flux estimate. This provides a very conservative estimate of downgradient groundwater concentrations given that all leachate leakage has been projected into each individual flow zone. Realistically, the additional contaminant mass resulting from leachate leakage will be distributed amongst the various flow zones, thus reducing the contaminant mass loading in comparison to this ‘worst-case’ scenario. Current downgradient groundwater quality was determined using the median 2017 concentrations. Multiplying the median concentration by the groundwater flux provides an existing contaminant mass for each parameter. For example: Equation 3:

Mass Balance

Where,

𝑀𝑀𝐶𝐶𝐶𝐶 𝑖𝑖𝑖𝑖 𝑉𝑉𝑉𝑉𝑉𝑉 = 𝐶𝐶̅ × 𝑄𝑄𝑉𝑉𝑉𝑉𝑉𝑉

MCL in VFZ = mass of chloride in VFZ C = median 2017 measured chloride concentration in the VFZ (mg/L) Qin VFZ = estimated flux through the VFZ (L/day)

Similarly, the mass discharge resulting from leachate leakage can be calculated. Adding the mass discharge from each of the groundwater flow inputs and dividing by the total volume provides an estimate of the final concentration of each parameter. For example:


3

Equation 4:

Forecasted Groundwater Concentration

Where,

𝐶𝐶𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓 =

𝑀𝑀𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙 + 𝑀𝑀𝑖𝑖𝑖𝑖 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 𝑄𝑄𝑖𝑖𝑖𝑖 𝑉𝑉𝑉𝑉𝑉𝑉 + 𝑄𝑄𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙

C forecasted = forecasted concentration in a VFZ monitoring well (mg/L) M leakage = contaminant mass from leachate leakage (mg/day) Min monitor = contaminant mass in individual monitoring well (mg/day) Qin VFZ = flux through flow zone (VFZ) (L/day) Qin VFZ = estimated flux through the VFZ (L/day) Q leakage = landfill leachate leakage rate (L/day)

Table B.1 provides a summary of the forecasted final contaminant concentrations at the downgradient Site boundary under the preferred alternative. Table B.2 provides a summary under the existing, approved (post-closure) conditions. 1.2.1

Confirmatory Comparison

The water balance method, discussed above was used to compare forecasted concentrations with the current, 2017, concentrations and established trigger levels for the Site. Tables B.3 and B.4 provide a summary of the forecasted concentrations for the preferred alternative and existing, approved conditions (post-closure). Both tables provide a comparison of forecasted concentrations in comparison with established trigger levels. As expected, adding contaminant mass from leachate leakage to the existing mass increases the current concentrations. Contaminant concentrations are increased more significantly in flow zones with lower estimated flux values. This is particularly apparent in the VFZ. Forecasted concentrations result in several exceedances of the established trigger levels in the downgradient monitoring wells. It should be noted that the predicted water quality in downgradient monitoring wells is similar to the current groundwater quality demonstrating that the additional contaminant mass added to each flow zone will have a minimal effect on groundwater quality. Where trigger level exceedances are noted in the forecasted concentrations, trigger level exceedances are also generally noted in the current groundwater quality dataset. 1.2.2

Additional Assumptions

In addition to the assumptions described above which ensure a ‘worst-case’ or conservative estimate of water quality, the forecast concentration model does not include an estimate of shallow or Eramosa Flow Zone water quality. It is assumed that the majority of this groundwater flux originating from this unit will be extracted prior to flowing beneath the landfill footprint. The 2016 Annual Report (Jackman Geoscience Inc., June 30, 2017) and 2017 hydraulic data shows that groundwater elevations at the Site have been influenced/lowered notably by dewatering activities associated with the sewer construction along Hwy. 20. This lowering of elevations may have influenced hydraulic gradient estimates and thus, influenced the flux estimates listed above. Flux estimates are likely lower as a result.


4

Contaminant mass from leachate leakage will flow downward into the VFZ; downward vertical hydraulic gradients between the VFZ and underlying flow zones show that flow (and contaminant mass) will likely mix with the lower flow zones. The lower excavation in the northwest corner of the Site also provides a conduit for downward migration. Combining the entire contaminant mass from leachate to a single flow zone provides a very conservative estimate as this mass will be distributed amongst the various flow zones.

2.

Groundwater Flow

As discussed in Section 5.1, leachate generation has been estimated for the preferred alternative using HELP modeling. The results of the HELP modeling have also been used to estimate the leakage rates of leachate through the liner system. The HELP outputs show that leakage from the landfill liner under ‘worst-case’ will contribute an average of 626.5 mm per hectare each year. This leakage will predominantly enter the VFZ (which directly underlies the base of the landfill footprint), which will increase the hydraulic head beneath the landfill footprint. Horizontal groundwater flow is determined by hydraulic conductivities, saturated thicknesses, and hydraulic gradients (i.e., the change in hydraulic head over a horizontal length). Given that the VFZ is approximately 1 m thick and is entirely saturated, the only component of the horizontal groundwater flow subject to alteration due to additional leachate leakage is the hydraulic gradient. The equation describing the hydraulic gradients is presented as Equation 5. Equation 5:

Hydraulic Gradient

Where,

𝑖𝑖 =

ℎ1 − ℎ2 𝑙𝑙

i = hydraulic gradient h1 = the hydraulic head or potential groundwater surface at point 1 h2 = the hydraulic head or potential groundwater surface at point 2 l = the distance between points 1 and 2

Based on the 2017 groundwater elevations measured at the Site, groundwater levels within the VFZ are heavily influenced by groundwater extraction at M4; however, historic reports (Taro East Quarry Environmental Assessment Hydrogeological, Impact Assessment Final Report, Gartner Lee, January 1995) show that the baseline potentiometric surface ranges from 201 to 192.6 mAMSL across the Site. Thus, the change in h1-h2 is on the order of several metres across a distance of approximately 900 m (i.e. i = (201mAMSL – 192.6mAMSL) / 900 m = 0.0093 m/m). Under the scenario of landfill expansion under the preferred alternative, landfill leakage contributes, an average additional hydraulic head of 0.056 mm/year. Conservatively assuming the additional hydraulic head happens instantaneously, the change in hydraulic gradient under the preferred alternative is negligible. As shown in the calculation below, the hydraulic influence of an additional 0.056mm of head will have no observable effect on horizontal gradients and thus will have no effect on groundwater flow patterns.


5

Equation 6:

Revised Hydraulic Gradient with Leakage

h2(new) = h2 + leakage rate = 192.6 mAMSL + 0.056 mm = 192.6 mAMSL

It follows that: 𝑖𝑖 =

201 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚−192.66 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 900 𝑚𝑚

= 0.0093 m/m


6

Table B.1

pg 1 of 1

Groundwater Compliance Forecast - Mass Balance Alternative 5 Detailed Impact Assessment Environmental Assessment for the Stoney Creek Regional Facility (SCRF) Landfill Expansion Terrapure Environmental

Parameters

Units

Landfill Leachate Concentrations (measured ranges)

Mass and Source Volumes WELL NEST 46

Minimum

pH Conductivity TOC Measured Alkalinity Measured Hardness Phenols Ca Mg Na K Cl F SO4 Ammonia‐N TKN NO3‐N NO2‐N Al Ba Be B Br Cd Cr Co Cu Pb Fe Mn Mo Ni Sr Ti V Zn

std. units uS/cm mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L

7.2 2650 10 169 220 0.002 20 15 1 9.56 280 0 25 0.22 1.08 0 0 0 0.025 0 0.41 0 0 0 0 0.0025 0.00125 0.01 0 0.01 0.03 0.3 0 0 0

Maximum

11 21620 1420 3800 340 8.5 777 498 4250 2800 5010 6.4 6190 270 310 45.3 12 110 0.43 0.0005 8.7 150 0.01 0.06 1.017 0.3 0.23 15.5 0.98 5.68 0.6 11 1.55 0.2 0.5

Current (2017)

8.48 14000 537.5 3150 322.5 3.275 46.5 56.75 2100 1250 2625 3.525 172.5 187.5 197.5 0 0 0.131 0.2 0 3.5 67 0 0.0135 0.00485 0.038125 0.006025 0.85 0.165 0.4725 0.185 5.275 0.084 0.1125 0

NOTES: 0.0 mg/L has been used where concentrations are below reporting levels Leachate loading mass is worst case (Maximum measured concentrations * flux) Mass balanace approach is inappropriate for forecastings pH values. A range of 6.5 - 8.5 is estimated

GHD 11102771 (12)

Units

WELL NEST 56

WELL NEST 60

WELL NEST 47

WELL NEST 61

WELL NEST 48

Flux from Landfill Leakage

m3/day L/day

0.12 118

mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day

Mass from Leakage 63425 371700 38055 386 5487 6697 247800 147500 309750 416 20355 22125 23305 0 0 15 24 0 413 7906 0 2 1 4 1 100 19 56 22 622 10 13 0

2017 Median Concentration

46‐I/IR LFZ 7.685 5800 4.3 230 1800 0.016 605 72 620 37.5 955 0.89 1600 13.5 14 0 0 0.00285 0.0225 0 0.8 0 0 0 0 0 0 0.065 0.17 0 0 9.45 0 0 0

46‐IIIR UFZ

46‐II/IIR UMFZ

7.65 3450 4.3 260 1150 0.0036 330 72 350 24.5 405 0.665 1100 4.05 4.3 0 0 0 0.0225 0 0.835 0 0 0 0 0 0 0.05 0.0835 0 0 5.1 0 0 0

Flux (L/day) 7.825 1800 2.6 345 740 0 165 79.5 88 4.65 180 0.31 360 0.16 0.47 0 0 0.00565 0.048 0 0.165 0 0 0 0 0 0 0.175 0.11 0 0 1.65 0 0 0

Forecasted Concentration


46‐I/IR LFZ

46‐IIIR UFZ

46‐II/IIR UMFZ

56‐I UMFZ

74,000 6.5 - 8.5 6030 5.1 230 1800 0.02 600 70 620 39.4 960 0.9 1600 13.8 10 0 0 0.003 0.023 0 0.804 0.107 0 0 0 0.0001 0 0.066 0.17 0.0008 0.0003 9.44 0.0001 0.0002 0

4,300 6.5 - 8.5 4020 18.5 340 1130 0.09 320 70 400 57.2 460 0.7 1080 8.9 10 0 0 0.003 0.027 0 0.906 1.789 0 0.0004 0 0.001 0.0002 0.071 0.0857 0.0126 0.0049 5.1 0.0022 0.003 0

25,000 6.5 - 8.5 1840 5.1 360 740 0.02 160 80 100 10.5 190 0.3 360 1 0 0 0 0.006 0.049 0 0.181 0.315 0 0.0001 0 0.0002 0 0.178 0.1103 0.0022 0.0009 1.67 0.0004 0.0005 0

Flux (L/day) 7.53 3350 3.2 310 1400 0 345 130 205 14.5 480 0.35 945 1.115 1.25 0 0 0 0.0455 0 0.325 0 0 0 0 0 0 0.475 0.145 0 0.0017 5.75 0 0 0

Forecasted Concentrations

56‐I UMFZ 25,000 6.5 - 8.5 3570 5.7 320 1390 0.02 340 130 210 20.3 490 0.4 940 2 0 0 0 0.001 0.046 0 0.34 0.315 0 0.0001 0 0.0002 0 0.477 0.1451 0.0022 0.0026 5.75 0.0004 0.0005 0

2017 Median Concentrations

60‐IV LFZ 7.525 7650 4.6 160 2300 0.027 725 130 825 36 1600 0.915 1800 5.55 5.2 0 0 0 0.0145 0 1.5 7.5 0 0 0 0 0 0 0.11 0 0 9.55 0 0 0

60‐II UFZ 7.62 3250 4.6 285 1100 0 300 81.5 275 23.5 385 0.91 890 4.25 4.5 0 0 0 0.021 0 0.62 0 0 0 0 0 0 0.375 0.115 0.00175 0.00275 3.2 0 0 0

60‐I UMFZ 7.65 3450 3.55 260 1150 0.0036 330 76.5 350 24.5 405 0.64 1100 4.05 4.3 0 0 0 0.0175 0 0.835 0 0 0 0 0 0 0 0.064 0 0 5.1 0 0 0


60‐III VFZ

Flux (L/day) 7.61 2750 4.7 390 1090 0 330 61 240 13.5 325 0.665 650 0.73 0.94 0 0 0 0.027 0 0.875 0 0 0 0 0 0 0.05 0.0835 0.000285 0 3.85 0 0 0.016


60‐IV LFZ

60‐II UFZ

60‐I UMFZ

60‐III

74,000 6.5 - 8.5 7708 5.4 160 2300 0.03 720 130 830 37.9 1600 0.9 1800 5.8 10 0 0 0 0.015 0 1.503 7.595 0 0 0 0.0001 0 0.001 0.1101 0.0008 0.0003 9.54 0.0001 0.0002 0

4,300 6.5 - 8.5 3568 18.8 360 1080 0.09 290 80 320 56.3 440 1 870 9.1 10 0 0 0.003 0.026 0 0.697 1.789 0 0.0004 0 0.001 0.0002 0.388 0.1163 0.0143 0.0076 3.26 0.0022 0.003 0

25,000 6.5 - 8.5 3795 6.1 270 1150 0.02 330 80 360 30.3 420 0.7 1100 4.9 10 0 0 0.001 0.018 0 0.848 0.315 0 0.0001 0 0.0002 0 0.004 0.0645 0.0022 0.0009 5.1 0.0004 0.0005 0

2,800 6.5 - 8.5 3430 26.2 500 1060 0.13 320 60 320 63.5 420 0.8 630 8.3 10 0 0 0.005 0.034 0 0.981 2.709 0 0.0005 0 0.0015 0.0002 0.082 0.0868 0.0194 0.0075 3.91 0.0034 0.0045 0.0154

VFZ

47‐III VFZ 7.66 2750 3.7 345 1250 0.00175 390 67 145 15.5 225 0.65 825 1.2 1.55 0 0 0 0.016 0 1.6 0 0 0 0 0 0 0 0.05 0 0 5.85 0 0 0

47‐IV Water Table 7.82 1600 5.1 275 535 0 145 42 137 2.9 160 0.54 315 0.08 0.345 0 0 0 0.0585 0 0.1145 0 0.000405 0 0 0.0035 0 0.085 0.09 0.00285 0.0026 1.6 0 0 0.345

47‐II UFZ 7.755 1650 4.35 245 460 0 125 35 155 2.5 175 0.505 260 0.0265 0.28 0 0 0 0.072 0 0.1045 0 0.000305 0 0 0.0008 0 0 0.103 0.00285 0.0024 1.35 0 0 0.55


47‐I UMFZ Flux (L/day) 7.675 4250 3.85 250 1800 0 560 92.5 300 25 480 0.885 1600 5 5 0 0 0 0.017 0 0.965 0 0 0 0 0 0 0.16 0.13 0 0.00065 4.5 0 0 0

47‐III VFZ 2,800 6.5 - 8.5 3436 25.3 460 1210 0.13 380 70 220 65.4 320 0.8 800 8.7 10 0 0 0.005 0.023 0 1.677 2.709 0 0.0005 0 0.0015 0.0002 0.034 0.0547 0.0191 0.0075 5.83 0.0034 0.0045 0

47‐IV Water Table 40,000 6.5 - 8.5 1590 6.7 280 530 0.01 140 40 140 6.6 170 0.5 310 0.6 0 0 0 0 0.059 0 0.124 0.197 0.0004 0 0 0.0036 0 0.087 0.0902 0.0042 0.0031 1.61 0.0002 0.0003 0.344

47‐II UFZ 4,300 6.5 - 8.5 1832 18.6 320 460 0.09 120 40 210 35.8 240 0.6 260 5 10 0 0 0.003 0.075 0 0.195 1.789 0.0003 0.0004 0 0.0018 0.0002 0.023 0.1047 0.0154 0.0073 1.45 0.0022 0.003 0.5353

47‐I UMFZ 25,000 6.5 - 8.5 4870 6.4 260 1790 0.02 560 90 310 30.8 490 0.9 1590 5.9 10 0 0 0.001 0.018 0 0.977 0.315 0 0.0001 0 0.0002 0 0.163 0.1302 0.0022 0.0015 4.5 0.0004 0.0005 0

2017 Median Concentrations 61-II 61-I 61-III UFZ UMFZ VFZ Flux (L/day) 7.66 7.755 7.675 2750 1650 4250 3.7 4.35 3.85 345 245 250 1250 460 1800 0.00175 0 0 390 125 560 67 35 92.5 145 155 300 15.5 2.5 25 225 175 480 0.65 0.505 0.885 825 260 1600 1.2 0.0265 5 1.55 0.28 5 0 0 0 0 0 0 0 0 0 0.016 0.072 0.017 0 0 0 1.6 0.1045 0.965 0 0 0 0 0.000305 0 0 0 0 0 0 0 0 0.0008 0 0 0 0 0 0 0.16 0.05 0.103 0.13 0 0.00285 0 0 0.0024 0.00065 5.85 1.35 4.5 0 0 0 0 0 0 0 0.55 0

Forecasted Concentrations 61-II 61-I 61-III UFZ UMFZ VFZ 4,300 25,000 2,800 6.5 - 8.5 6.5 - 8.5 6.5 - 8.5 3280 1521 5235 18 6.9 25.4 420 260 370 1230 460 1740 0.09 0.02 0.13 380 120 540 70 40 90 200 160 370 48.5 8.4 74.5 290 190 570 0.7 0.5 1 810 260 1540 6.2 0.9 12.4 10 0 10 0 0 0 0 0 0 0.003 0.001 0.005 0.021 0.073 0.024 0 0 0 1.651 0.12 1.068 1.789 0.315 2.709 0 0.0003 0 0.0004 0.0001 0.0005 0 0 0 0.001 0.001 0.0015 0.0002 0 0.0002 0.023 0.004 0.188 0.0531 0.1033 0.1314 0.0126 0.0051 0.0191 0.0049 0.0033 0.0081 5.83 1.37 4.53 0.0022 0.0004 0.0034 0.003 0.0005 0.0045 0 0.5474 0

2017 Median Concentrations 48-I 48-II 48-V LFZ UMFZ VFZ Flux (L/day) 7.395 7.62 7.64 8600 5350 5000 1.8 3.15 3.35 280 345 350 2950 1850 1950 0.0235 0 0 865 600 650 195 88.5 88 780 520 460 28 13 10.5 1950 1005 820 0.745 0.7 0.62 1500 1400 1400 2.85 0.995 0.78 3 1.25 1.1 0 0 0 0 0 0 0 0 0 0.0185 0.031 0.034 0 0 0 1.9 0.465 0.355 21.5 0 0 0 0 0.00016 0 0 0 0 0 0 0 0 0 0 0 0 0 0.12 0.43 0.11 0.13 0.105 0 0 0.00025 0 0.00055 0.00135 12 3.9 3.45 0 0 0 0 0 0 0 0 0

Forecasted Concentrations 48-I 48-II 48-V LFZ UMFZ VFZ 74,000 25,000 2,800 6.5 - 8.5 6.5 - 8.5 6.5 - 8.5 8162 5815 5887 2.7 5.7 25 280 360 460 2950 1840 1880 0.03 0.02 0.13 860 600 630 190 90 90 780 530 530 29.9 18.8 60.6 1950 1010 890 0.7 0.7 0.7 1500 1390 1350 3.1 1.9 8.3 0 0 10 0 0 0 0 0 0 0 0.001 0.005 0.019 0.032 0.041 0 0 0 1.903 0.479 0.482 21.572 0.315 2.709 0 0 0.0002 0 0.0001 0.0005 0 0 0 0.0001 0.0002 0.0015 0 0 0.0002 0.001 0.123 0.447 0.1101 0.1302 0.1074 0.0008 0.0022 0.0193 0.0003 0.0014 0.0088 11.99 3.91 3.52 0.0001 0.0004 0.0034 0.0002 0.0005 0.0045 0 0 0

Table B.2

pg 1 of 1

Groundwater Compliance Forecast - Mass Balance - Approved Scenario (Post-Closure) Detailed Impact Assessment Environmental Assessment for the SCRF Landfill Expansion Terrapure Environmental

Parameters

Units

Landfill Leachate Concentrations (measured ranges)

Mass and Source Volumes WELL NEST 46

Minimum

pH Conductivity TOC Measured Alkalinity Measured Hardness Phenols Ca Mg Na K Cl F SO4 Ammonia‐N TKN NO3‐N NO2‐N Al Ba Be B Br Cd Cr Co Cu Pb Fe Mn Mo Ni Sr Ti V Zn

std. units uS/cm mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L

7.2 2650 10 169 220 0.002 20 15 1 9.56 280 0 25 0.22 1.08 0 0 0 0.025 0 0.41 0 0 0 0 0.0025 0.00125 0.01 0 0.01 0.03 0.3 0 0 0

Maximum

11 21620 1420 3800 340 8.5 777 498 4250 2800 5010 6.4 6190 270 310 45.3 12 110 0.43 0.0005 8.7 150 0.01 0.06 1.017 0.3 0.23 15.5 0.98 5.68 0.6 11 1.55 0.2 0.5

Current (2017)

8.48 14000 537.5 3150 322.5 3.275 46.5 56.75 2100 1250 2625 3.525 172.5 187.5 197.5 0 0 0.131 0.2 0 3.5 67 0 0.0135 0.00485 0.038125 0.006025 0.85 0.165 0.4725 0.185 5.275 0.084 0.1125 0

NOTES: 0.0 mg/L has been used where concentrations are below reporting levels Leachate loading mass is worst case (Maximum measured concentrations * flux) Mass balanace approach is inappropriate for forecastings pH values. A range of 6.5 - 8.5 is estimated

GHD 11102771 (12)

Units

WELL NEST 56

WELL NEST 60

WELL NEST 47

WELL NEST 61

WELL NEST 48

Flux from Landfill Leakage

m3/day L/day

0.10 95

mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day mg/day

Mass from Leakage 51114 299552 30668 311 4422 5397 199701 118870 249627 335 16404 17830 18781 0 0 12 19 0 333 6371 0 1 0 4 1 81 16 45 18 502 8 11 0


46‐I/IR LFZ 7.685 5800 4.3 230 1800 0.016 605 72 620 37.5 955 0.89 1600 13.5 14 0 0 0.00285 0.0225 0 0.8 0 0 0 0 0 0 0.065 0.17 0 0 9.45 0 0 0

46‐IIIR UFZ

46‐II/IIR UMFZ

7.65 3450 4.3 260 1150 0.0036 330 72 350 24.5 405 0.665 1100 4.05 4.3 0 0 0 0.0225 0 0.835 0 0 0 0 0 0 0.05 0.0835 0 0 5.1 0 0 0

Flux (L/day) 7.825 1800 2.6 345 740 0 165 79.5 88 4.65 180 0.31 360 0.16 0.47 0 0 0.00565 0.048 0 0.165 0 0 0 0 0 0 0.175 0.11 0 0 1.65 0 0 0

Forecasted Concentration


46‐I/IR LFZ

46‐IIIR UFZ

46‐II/IIR UMFZ

56‐I UMFZ

74,000 6.5 - 8.5 6030 5 230 1800 0.02 600 70 620 39.1 960 0.9 1600 13.7 10 0 0 0.003 0.023 0 0.803 0.086 0 0 0 0 0 0.066 0.17 0.0006 0.0002 9.44 0.0001 0.0001 0

4,300 6.5 - 8.5 3950 15.8 320 1130 0.07 320 70 390 51 450 0.7 1080 8 10 0 0 0.003 0.026 0 0.893 1.45 0 0.0003 0 0.0008 0.0001 0.067 0.0853 0.0102 0.004 5.1 0.0018 0.0024 0

25,000 6.5 - 8.5 1840 4.6 360 740 0.01 160 80 100 9.4 190 0.3 360 0.9 0 0 0 0.006 0.049 0 0.178 0.254 0 0.0001 0 0.0001 0 0.178 0.1102 0.0018 0.0007 1.66 0.0003 0.0004 0

Flux (L/day) 7.53 3350 3.2 310 1400 0 345 130 205 14.5 480 0.35 945 1.115 1.25 0 0 0 0.0455 0 0.325 0 0 0 0 0 0 0.475 0.145 0 0.0017 5.75 0 0 0


56‐I UMFZ 25,000 6.5 - 8.5 3570 5.2 320 1400 0.01 340 130 210 19.2 490 0.4 940 1.8 0 0 0 0 0.046 0 0.337 0.254 0 0.0001 0 0.0001 0 0.476 0.1451 0.0018 0.0024 5.75 0.0003 0.0004 0


60‐IV LFZ 7.525 7650 4.6 160 2300 0.027 725 130 825 36 1600 0.915 1800 5.55 5.2 0 0 0 0.0145 0 1.5 7.5 0 0 0 0 0 0 0.11 0 0 9.55 0 0 0

60‐II UFZ 7.62 3250 4.6 285 1100 0 300 81.5 275 23.5 385 0.91 890 4.25 4.5 0 0 0 0.021 0 0.62 0 0 0 0 0 0 0.375 0.115 0.00175 0.00275 3.2 0 0 0

60‐I UMFZ 7.65 3450 3.55 260 1150 0.0036 330 76.5 350 24.5 405 0.64 1100 4.05 4.3 0 0 0 0.0175 0 0.835 0 0 0 0 0 0 0 0.064 0 0 5.1 0 0 0


60‐III VFZ

Flux (L/day) 7.61 2750 4.7 390 1090 0 330 61 240 13.5 325 0.665 650 0.73 0.94 0 0 0 0.027 0 0.875 0 0 0 0 0 0 0.05 0.0835 0.000285 0 3.85 0 0 0.016


60‐IV LFZ

60‐II UFZ

60‐I UMFZ

60‐III

74,000 6.5 - 8.5 7708 5.3 160 2300 0.03 720 130 830 37.6 1600 0.9 1800 5.8 10 0 0 0 0.015 0 1.503 7.576 0 0 0 0 0 0.001 0.1101 0.0006 0.0002 9.54 0.0001 0.0001 0

4,300 6.5 - 8.5 3509 16.1 350 1080 0.07 290 80 310 50 430 1 870 8.2 10 0 0 0.003 0.025 0 0.682 1.45 0 0.0003 0 0.0008 0.0001 0.385 0.1161 0.0119 0.0067 3.24 0.0018 0.0024 0

25,000 6.5 - 8.5 3777 5.6 270 1150 0.02 330 80 360 29.1 410 0.7 1100 4.7 10 0 0 0 0.018 0 0.845 0.254 0 0.0001 0 0.0001 0 0.003 0.0644 0.0018 0.0007 5.1 0.0003 0.0004 0

2,800 6.5 - 8.5 3321 22.2 480 1060 0.11 320 60 300 54.1 400 0.8 630 6.9 10 0 0 0.004 0.033 0 0.961 2.201 0 0.0004 0 0.0013 0.0002 0.076 0.0862 0.0158 0.0061 3.9 0.0028 0.0037 0.0155

VFZ

47‐III VFZ 7.66 2750 3.7 345 1250 0.00175 390 67 145 15.5 225 0.65 825 1.2 1.55 0 0 0 0.016 0 1.6 0 0 0 0 0 0 0 0.05 0 0 5.85 0 0 0

47‐IV Water Table 7.82 1600 5.1 275 535 0 145 42 137 2.9 160 0.54 315 0.08 0.345 0 0 0 0.0585 0 0.1145 0 0.000405 0 0 0.0035 0 0.085 0.09 0.00285 0.0026 1.6 0 0 0.345

47‐II UFZ 7.755 1650 4.35 245 460 0 125 35 155 2.5 175 0.505 260 0.0265 0.28 0 0 0 0.072 0 0.1045 0 0.000305 0 0 0.0008 0 0 0.103 0.00285 0.0024 1.35 0 0 0.55


47‐I UMFZ Flux (L/day) 7.675 4250 3.85 250 1800 0 560 92.5 300 25 480 0.885 1600 5 5 0 0 0 0.017 0 0.965 0 0 0 0 0 0 0.16 0.13 0 0.00065 4.5 0 0 0

47‐III VFZ 2,800 6.5 - 8.5 3341 21.2 440 1220 0.11 380 70 210 56 300 0.7 800 7.3 10 0 0 0.004 0.022 0 1.662 2.201 0 0.0004 0 0.0013 0.0002 0.028 0.0538 0.0155 0.0061 5.83 0.0028 0.0037 0

47‐IV Water Table 40,000 6.5 - 8.5 1588 6.4 280 530 0.01 140 40 140 5.9 170 0.5 310 0.5 0 0 0 0 0.059 0 0.123 0.159 0.0004 0 0 0.0036 0 0.087 0.0902 0.004 0.003 1.61 0.0002 0.0003 0.3442

47‐II UFZ 4,300 6.5 - 8.5 1759 15.9 310 460 0.07 120 40 200 29.5 230 0.6 260 4.1 0 0 0 0.003 0.075 0 0.178 1.45 0.0003 0.0003 0 0.0016 0.0001 0.018 0.1043 0.013 0.0064 1.43 0.0018 0.0024 0.5381

47‐I UMFZ 25,000 6.5 - 8.5 4867 5.9 260 1790 0.01 560 90 310 29.6 490 0.9 1590 5.7 10 0 0 0 0.018 0 0.975 0.254 0 0.0001 0 0.0001 0 0.163 0.1301 0.0018 0.0013 4.5 0.0003 0.0004 0

2017 Median Concentrations 61-II 61-I 61-III UFZ UMFZ VFZ Flux (L/day) 7.66 7.755 7.675 2750 1650 4250 3.7 4.35 3.85 345 245 250 1250 460 1800 0.00175 0 0 390 125 560 67 35 92.5 145 155 300 15.5 2.5 25 225 175 480 0.65 0.505 0.885 825 260 1600 1.2 0.0265 5 1.55 0.28 5 0 0 0 0 0 0 0 0 0 0.016 0.072 0.017 0 0 0 1.6 0.1045 0.965 0 0 0 0 0.000305 0 0 0 0 0 0 0 0 0.0008 0 0 0 0 0 0 0.16 0.05 0.103 0.13 0 0.00285 0 0 0.0024 0.00065 5.85 1.35 4.5 0 0 0 0 0 0 0 0.55 0

Forecasted Concentrations 61-II 61-I 61-III UFZ UMFZ VFZ 4,300 25,000 2,800 6.5 - 8.5 6.5 - 8.5 6.5 - 8.5 3221 1503 5155 15.2 6.4 21.4 410 260 350 1230 460 1750 0.07 0.01 0.11 380 120 540 70 40 90 190 160 360 42.2 7.2 65.2 280 180 550 0.7 0.5 1 810 260 1550 5.2 0.7 11 10 0 10 0 0 0 0 0 0 0.003 0 0.004 0.02 0.072 0.023 0 0 0 1.641 0.117 1.048 1.45 0.254 2.201 0 0.0003 0 0.0003 0.0001 0.0004 0 0 0 0.0008 0.0009 0.0013 0.0001 0 0.0002 0.018 0.003 0.183 0.0525 0.1032 0.1311 0.0102 0.0046 0.0155 0.004 0.0031 0.0067 5.84 1.36 4.53 0.0018 0.0003 0.0028 0.0024 0.0004 0.0037 0 0.5479 0

2017 Median Concentrations 48-I 48-II 48-V LFZ UMFZ VFZ Flux (L/day) 7.395 7.62 7.64 8600 5350 5000 1.8 3.15 3.35 280 345 350 2950 1850 1950 0.0235 0 0 865 600 650 195 88.5 88 780 520 460 28 13 10.5 1950 1005 820 0.745 0.7 0.62 1500 1400 1400 2.85 0.995 0.78 3 1.25 1.1 0 0 0 0 0 0 0 0 0 0.0185 0.031 0.034 0 0 0 1.9 0.465 0.355 21.5 0 0 0 0 0.00016 0 0 0 0 0 0 0 0 0 0 0 0 0 0.12 0.43 0.11 0.13 0.105 0 0 0.00025 0 0.00055 0.00135 12 3.9 3.45 0 0 0 0 0 0 0 0 0

Forecasted Concentrations 48-I 48-II 48-V LFZ UMFZ VFZ 74,000 25,000 2,800 6.5 - 8.5 6.5 - 8.5 6.5 - 8.5 8162 5826 5807 2.5 5.2 20.9 280 360 440 2950 1840 1900 0.03 0.01 0.11 860 600 630 190 90 90 780 530 510 29.6 17.7 51.2 1950 1010 880 0.7 0.7 0.7 1500 1400 1360 3.1 1.7 6.9 0 0 10 0 0 0 0 0 0 0 0 0.004 0.019 0.032 0.039 0 0 0 1.902 0.477 0.458 21.558 0.254 2.201 0 0 0.0002 0 0.0001 0.0004 0 0 0 0 0.0001 0.0013 0 0 0.0002 0.001 0.123 0.444 0.1101 0.1301 0.107 0.0006 0.0018 0.0158 0.0002 0.0012 0.0074 11.99 3.91 3.51 0.0001 0.0003 0.0028 0.0001 0.0004 0.0037 0 0 0

Table B.3

pg 1 of 1

Groundwater Compliance Forecast - Trigger Assessment Alternative 5 Detailed Impact Assessment Environmental Assessment for the SCRF Landfill Expansion Terrapure Environmental

Parameter Vinemount Flow Zone Well ID P10‐IV 2017 Median

B

Ba

Cd

Cl

Cr

Cu

F

Fe

Mn

Na

NO2-N

NO3-N

Pb

SO4

Zn

1.8

0.00615

0.0

335

0.00

0.0

1.65

0.0

0.0425

405

0.0

0.0

0.0

1200

0.0

1.9

0.012

0.0

580

0.00

0.0

1.15

0.0

0.05

460

0.0

0.0

0.0

1700

0.0

Downgradient Median (2017)

0.92

0.02

0.0000

403

0.00

0.0

0.66

0.11

0.09

270

0.00

0.00

0.00

1113

0.00

47-III

Trigger Forecast 2017 Median

3 1.7 1.6

0.36 0.02 0.02

0.0013 0.0000 0.0000

193 320 225

0.01 0.00 0.00

0.5 0.0 0.0

0.98 0.80 0.65

0.71 0.03 0.00

0.07 0.05 0.05

147 220 145

0.4 0.0 0.0

2.7 0.0 0.0

0.05 0.00 0.00

1330 800 825

2.65 0.00 0.00

48-V


4 0.5 0.4

0.26 0.04 0.03

0.0013 0.0002 0.0002

304 890 820

0.01 0.00 0.00

0.5 0.0 0.0

1.28 0.70 0.62

0.24 0.45 0.43

0.106 0.107 0.105

201 530 460

0.25 0.00 0.00

2.5 0.0 0.0

0.01 0.00 0.00

1770 1350 1400

2.51 0.00 0.00

60-III


1.96 0.98 0.88

0.38 0.03 0.03

0.006 0.000 0.000

342 420 325

0.02 0.00 0.00

0.5 0.0 0.0

1.05 0.80 0.67

0.25 0.08 0.05

0.15 0.09 0.08

188 320 240

0.48 0.00 0.00

4.1 0.0 0.0

0.01 0.00 0.00

780 630 650

2.59 0.02 0.02

61-III


4.69 1.07 0.97

0.34 0.02 0.02

0.005 0.000 0.000

232 570 480

0.02 0.00 0.00

0.51 0.00 0.00

1.43 1.00 0.89

0.39 0.19 0.16

0.09 0.13 0.13

201 370 300

0.4 0.00 0.00

2.7 0.0 0.0

0.05 0.00 0.00

1790 1540 1600

2.71 0.00 0.00

72‐III (Upgradient)

2017 Median

6.75

0.018

0.0

5300

0.00

0.00

0.9

0.00

0.30

2700

0.00

0.0

0.00

1900

0.0

47-II


2.4 0.2 0.1

0.39 0.08 0.07

0.0013 0.0003 0.0003

340 240 175

0.02 0.00 0.00

0.5 0.0 0.0

1.2 0.6 0.5

3.17 0.02 0.00

0.22 0.10 0.10

207 210 155

0.48 0.00 0.00

2.7 0.0 0.0

0.01 0.00 0.00

1280 260 260

2.6 0.5 0.6

56-II*


1.7 0.7 0.6

0.37 0.0 0.0

0.005 0.0 0.0

900 440.0 385.0

0.01 0.0 0.0

0.5 0.0 0.0

0.83 1.0 0.9

0.65 0.4 0.4

0.11 0.1 0.1

365 320.0 275.0

0.4 0.0 0.0

2.7 0.0 0.0

0.01 0.0 0.0

1140 870.0 890.0

2.59 0.0 0.0

61-II


41.9 1.7 1.6

0.35 0.02 0.02

0.007 0.000 0.000

508 290 225

0.01 0.00 0.00

0.5 0.0 0.0

1.43 0.70 0.65

0.53 0.02 0.00

0.16 0.05 0.05

630 200 145

0.29 0.00 0.00

2.7 0.0 0.0

0.01 0.00 0.00

2540 810 825

2.6 0.0 0.0

Upper-Mid Flow Zone Well ID 72‐II 2017 Median

6.2

0.0235

0.00

24500

0.00

0.00

0.45

0.00

0.65

8900

0.00

0.0

0.00

1350

0.0

(Upgradient) 51‐IV (Upgradient)

2017 Median

Upper Flow Zone Well ID

(Upgradient) 46-IIR


1.43 0.18 0.17

0.36 0.05 0.05

0.005 0.00 0.00

307 190 180

0.01 0.00 0.00

0.53 0.00 0.00

2.9 0.3 0.3

0.73 0.18 0.18

0.17 0.11 0.11

144 100 88

0.48 0.00 0.00

3.6 0.0 0.0

0.01 0.00 0.00

531 360 360

2.54 0.00 0.00

48-II


1.86 0.48 0.47

0.34 0.03 0.03

0.006 0.00 0.00

983 1010 1005

0.01 0.00 0.00

0.5 0.00 0.00

1.13 0.70 0.70

0.7 0.12 0.12

0.1 0.13 0.13

380 530 520

0.4 0.0 0.0

2.8 0.0 0.0

0.01 0.00 0.00

1520 1390 1400

2.58 0.00 0.00

56-I


1.55 0.34 0.33

0.45 0.05 0.05

0.01 0.00 0.00

1150 490 480

0.01 0.00 0.00

0.51 0.00 0.00

0.83 0.40 0.35

0.31 0.48 0.48

0.09 0.15 0.15

241 210 205

0.48 0.00 0.00

2.7 0.0 0.0

0.01 0.00 0.00

1110 940 945

2.67 0.00 0.00

72‐I (Upgradient)

2017 Median

6.1

0.11

0.00

59500

0.00

0.00

0.185

0.00

2.00

18500

0.00

0.00

0.00

1150

0.00

48-I


12.8 1.9 1.9

0.35 0.02 0.02

0.056 0.000 0.000

20500 1950 1950

2.24 0.00 0.00

0.5 0.0 0.0

1.13 0.70 0.75

8.48 0.00 0.00

1.18 0.11 0.11

5700 780 780

0.3 0.00 0.00

2.5 0.00 0.00

0.01 0.00 0.00

1580 1500 1500

2.6 0.00 0.00

60-IV


2.5 1.5 1.5

0.25 0.02 0.01

0.0013 0.0000 0.0000

2950 1600 1600

0.1 0.0 0.0

0.57 0.00 0.00

1.2 0.9 0.9

0.23 0.00 0.00

0.16 0.11 0.11

1330 830 825

2 0.00 0.00

2.5 0.0 0.0

0.7 0.0 0.0

2020 1800 1800

2.55 0.00 0.00

Lower Flow Zone Well ID

NOTES: All units are in mg/L Parameters below detection limits are reported as 0.00 mg/L * - Monitoring well 56-II has been dry during recent years. Median concentrations from nearby UFZ monitor 60-II have been used Trigger levels for the Lower-Mid flow zone have not been developed as the lateral extent of the unit is limited across the Operating Site Trigger concetrations were established in 1997 and are based on Reasonable Use Policy (MOE Guideline B-7) and historic background concentrations (1996) Concentration (forecasted or 2016 median) are above their respective trigger limit

GHD 11102771 (12)

Table B.4

pg 1 of 1

Groundwater Compliance Forecast - Mass Balance Approved Scenario (Post-Closure) Detailed Impact Assessment Environmental Assessment for the SCRF Landfill Expansion Terrapure Environmental

Parameter Vinemount Flow Zone Well ID P10‐IV 2017 Median

B

Ba

Cd

Cl

Cr

Cu

F

Fe

Mn

Na

NO2-N

NO3-N

Pb

SO4

Zn

1.8

0.00615

0.0

335

0.00

0.0

1.65

0.0

0.0425

405

0.0

0.0

0.0

1200

0.0

1.9

0.012

0.0

580

0.00

0.0

1.15

0.0

0.05

460

0.0

0.0

0.0

1700

0.0

Downgradient Median (2017)

0.92

0.02

0.0000

403

0.00

0.0

0.66

0.11

0.09

270

0.00

0.00

0.00

1113

0.00

47-III


3 1.7 1.6

0.36 0.02 0.02

0.0013 0.0000 0.0000

193 300 225

0.01 0.00 0.00

0.5 0.0 0.0

0.98 0.70 0.65

0.71 0.03 0.00

0.07 0.05 0.05

147 210 145

0.4 0.0 0.0

2.7 0.0 0.0

0.05 0.00 0.00

1330 800 825

2.65 0.00 0.00

48-V


4 0.5 0.4

0.26 0.04 0.03

0.0013 0.0002 0.0002

304 880 820

0.01 0.00 0.00

0.5 0.0 0.0

1.28 0.70 0.62

0.24 0.44 0.43

0.106 0.107 0.105

201 510 460

0.25 0.00 0.00

2.5 0.0 0.0

0.01 0.00 0.00

1770 1360 1400

2.51 0.00 0.00

60-III


1.96 0.96 0.88

0.38 0.03 0.03

0.006 0.000 0.000

342 400 325

0.02 0.00 0.00

0.5 0.0 0.0

1.05 0.80 0.67

0.25 0.08 0.05

0.15 0.09 0.08

188 300 240

0.48 0.00 0.00

4.1 0.0 0.0

0.01 0.00 0.00

780 630 650

2.59 0.02 0.02

61-III


4.69 1.05 0.97

0.34 0.02 0.02

0.005 0.000 0.000

232 550 480

0.02 0.00 0.00

0.51 0.00 0.00

1.43 1.00 0.89

0.39 0.18 0.16

0.09 0.13 0.13

201 360 300

0.4 0.00 0.00

2.7 0.0 0.0

0.05 0.00 0.00

1790 1550 1600

2.71 0.00 0.00

72‐III (Upgradient)

2017 Median

6.75

0.018

0.0

5300

0.00

0.00

0.9

0.00

0.30

2700

0.00

0.0

0.00

1900

0.0

47-II


2.4 0.2 0.1

0.39 0.08 0.07

0.0013 0.0003 0.0003

340 230 175

0.02 0.00 0.00

0.5 0.0 0.0

1.2 0.6 0.5

3.17 0.02 0.00

0.22 0.10 0.10

207 200 155

0.48 0.00 0.00

2.7 0.0 0.0

0.01 0.00 0.00

1280 260 260

2.6 0.5 0.6

56-II*


1.7 0.7 0.6

0.37 0.0 0.0

0.005 0.0 0.0

900 430.0 385.0

0.01 0.0 0.0

0.5 0.0 0.0

0.83 1.0 0.9

0.65 0.4 0.4

0.11 0.1 0.1

365 310.0 275.0

0.4 0.0 0.0

2.7 0.0 0.0

0.01 0.0 0.0

1140 870.0 890.0

2.59 0.0 0.0

61-II


41.9 1.6 1.6

0.35 0.02 0.02

0.007 0.000 0.000

508 280 225

0.01 0.00 0.00

0.5 0.0 0.0

1.43 0.70 0.65

0.53 0.02 0.00

0.16 0.05 0.05

630 190 145

0.29 0.00 0.00

2.7 0.0 0.0

0.01 0.00 0.00

2540 810 825

2.6 0.0 0.0

Upper-Mid Flow Zone Well ID 72‐II 2017 Median

6.2

0.0235

0.00

24500

0.00

0.00

0.45

0.00

0.65

8900

0.00

0.0

0.00

1350

0.0

(Upgradient) 51‐IV (Upgradient)

2017 Median

Upper Flow Zone Well ID

(Upgradient) 46-IIR


1.43 0.18 0.17

0.36 0.05 0.05

0.005 0.00 0.00

307 190 180

0.01 0.00 0.00

0.53 0.00 0.00

2.9 0.3 0.3

0.73 0.18 0.18

0.17 0.11 0.11

144 100 88

0.48 0.00 0.00

3.6 0.0 0.0

0.01 0.00 0.00

531 360 360

2.54 0.00 0.00

48-II


1.86 0.48 0.47

0.34 0.03 0.03

0.006 0.00 0.00

983 1010 1005

0.01 0.00 0.00

0.5 0.00 0.00

1.13 0.70 0.70

0.7 0.12 0.12

0.1 0.13 0.13

380 530 520

0.4 0.0 0.0

2.8 0.0 0.0

0.01 0.00 0.00

1520 1400 1400

2.58 0.00 0.00

56-I


1.55 0.34 0.33

0.45 0.05 0.05

0.01 0.00 0.00

1150 490 480

0.01 0.00 0.00

0.51 0.00 0.00

0.83 0.40 0.35

0.31 0.48 0.48

0.09 0.15 0.15

241 210 205

0.48 0.00 0.00

2.7 0.0 0.0

0.01 0.00 0.00

1110 940 945

2.67 0.00 0.00

72‐I (Upgradient)

2017 Median

6.1

0.11

0.00

59500

0.00

0.00

0.185

0.00

2.00

18500

0.00

0.00

0.00

1150

0.00

48-I


12.8 1.9 1.9

0.35 0.02 0.02

0.056 0.000 0.000

20500 1950 1950

2.24 0.00 0.00

0.5 0.0 0.0

1.13 0.70 0.75

8.48 0.00 0.00

1.18 0.11 0.11

5700 780 780

0.3 0.00 0.00

2.5 0.00 0.00

0.01 0.00 0.00

1580 1500 1500

2.6 0.00 0.00

60-IV


2.5 1.5 1.5

0.25 0.02 0.01

0.0013 0.0000 0.0000

2950 1600 1600

0.1 0.0 0.0

0.57 0.00 0.00

1.2 0.9 0.9

0.23 0.00 0.00

0.16 0.11 0.11

1330 830 825

2 0.00 0.00

2.5 0.0 0.0

0.7 0.0 0.0

2020 1800 1800

2.55 0.00 0.00

Lower Flow Zone Well ID

NOTES: All units are in mg/L Parameters below detection limits are reported as 0.00 mg/L * - Monitoring well 56-II has been dry during recent years. Median concentrations from nearby UFZ monitor 60-II have been used Trigger levels for the Lower-Mid flow zone have not been developed as the lateral extent of the unit is limited across the Operating Site Trigger concetrations were established in 1997 and are based on Reasonable Use Policy (MOE Guideline B-7) and historic background concentrations (1996) Concentration (forecasted or 2016 median) are above their respective trigger limit

GHD 11102771 (12)