dufferin aggregates, a division of holcim (canada) inc. part ii -...

Dufferin Aggregates,

a Division of Holcim (Canada) Inc. Part II - Section I Water Budget

Part II — Section I Water Budget

Table of Contents

Page

Section 1.0 Introduction 1

Section 2.0 Monitoring 2

2.1 Monitoring Locations 2

2.2 Monitoring Frequency 2

2.3 Other Monitoring Information 2

Section 3.0 Data Evaluation 2

CONESTOGA-ROVERS & ASSOCIATES

030193 (22) AMP Part ILI

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Part II - Section I

Water Budget

Section 1.0 Introduction

The established water budget for the entire Acton Quarry will be evaluated on a regular basis to

ensure that sufficient water is available for ongoing and future mitigation, operational, and

rehabilitation requirements. The objectives of the water budget evaluation include:

• Verify that the amount of water available/in storage is consistent with anticipated water

budget conditions and to confirm the representativeness of the overall water budget

calculations

• Establish the annual distribution of the water from the reservoir in accordance with the

allocation priorities identified in Part I Section 2.0

• Confirm the representativeness of key water budget parameter values that have the

potential to significantly affect the reliability of the long-term water budget calculations in a

negative manner (i.e., potentially less water available than forecast)

• Identify and adapt to any long-term trends in water budget availability that are evidenced

by the monitoring data and/or recognized by the scientific community

The principal basis for assessment will be through measurement of the reservoir water level

(i.e., amount of water in storage) and the progression of rehabilitation lake filling in the

extracted phases. On an annual basis, these data will be compared to anticipated water budget

conditions to ensure the water budget is acceptable.

At key milestones (refer to Part II Section J, subsections 3.2 and 3.4), the water budget will be

reviewed and the underlying surface water and/or groundwater models will be

updated/re-calibrated as warranted to reflect the information collected to date.

More specific information on the water budget program for the AMP is described below. This

program described herein will be reported and reviewed annually to evaluate whether the

objectives of the water budget verification are being achieved and whether it is appropriate to

modify the monitoring and/or analysis program.


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Section 2.0 Monitoring

2.1 Monitoring Locations

• Water levels will be measured in the reservoir and any other quarry area holding significant volumes of water (e.g., partially flooded phases holding more than an estimated

250,000 cubic metres [m 3 ] of water)

• Water flow will be monitored from individual dewatering/transfer points and individual

discharge locations and mitigation recharge wells

2.2 Monitoring Frequency

• Reservoir water levels will be measured on a "continuous" basis using an automated water level recorder.

• Water levels will be measured in other areas holding an estimated volume of more than 250,000 m 3 of water at a minimum frequency of monthly during non-frozen conditions.

• Water flows from individual dewatering, transfer, and discharge/recharge points (local

recharge well clusters may have combined total flow readings) will be measured continuously (i.e., totalizing flow meters). Readings will be recorded at a minimum

frequency of once per month.

2.3 Other Monitoring Information

In order to determine anticipated water storage levels, an accurate topographic survey will be conducted following completion of extraction and rehabilitation earthworks in each water storage area, including the Phase 1 and Phase 2 reservoirs and the Phase 4 and Phase 3/5/6

lakes (refer to Part I Figure 3). The survey will be completed prior to the initiation of substantial lake filling, although some survey limitations may occur for the existing Phase 1 area which presently retains a large depth of water. The survey will be used to calculate a stage-storage

curve for each area. Using the available information and the water budget information

currently estimated filling times can be refined based on the measured storage volumes.

In order to facilitate water budget assessments, additional data will be collected as necessary.

Section 3.0 Data Evaluation

The measured water levels (volumes) and flows will be compared to the anticipated water budget conditions (refer to CRA memorandum of October 27, 2014, or as may be updated from

time-to-time, for supporting technical information) over time to assess the water budget and


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lake filling progression in accordance with the objectives identified above. The analysis of the

water budget will be completed in accordance with the following procedure:

1. Complete water budget analysis as described herein. This analysis occurs at different

levels of detail at different frequencies:

• Ongoing - assessment of flow and storage data relative to previous measurements,

forecasted water budget conditions, and ongoing operations and climatic conditions

• Annual - review of data relevant to individual monitoring parameters and overall

water budget

• 5-Year Review - analysis of overall water budget considerations and

representativeness of water budget calculations

2. Identification of whether actual water budget conditions are consistent with anticipated

conditions, or whether more/less water is available.

3. In the event that significantly less water is available or there is other indication that

there are other potentially significant discrepancies between the actual and forecast

water budget, further assessment of the water budget and water use, including

groundwater recharge operations, will be undertaken and appropriate response actions

implemented, if necessary. These measures may include:

• Further evaluation of monitoring data, parameter estimates, water budget

calculations, water management system operation

• Completion of micro-water budgets for sub-components of the overall water budget

• Specific field investigation/monitoring programs to collect additional information

(e.g., installation of additional monitoring wells, flow meters, lysimeters, etc.)

• Further review of the scientific literature for related water budget consideration

The timeframes for the foregoing measures will be based on the objective that the

quarry progression will be limited during this period if necessary, to ensure that the

Water Management System is sustainable based on the current water budget

parameterization.

In the unexpected event that appropriate response actions do not appear to be

available based on longer term evaluation (i.e., annual and 5-year reviews) the

appropriateness of continuing extraction over the long term will be evaluated to

determine whether a cessation of extraction activities that result in further water

budget stresses is necessary in some or all areas. Based on work completed to date,

there is ample water to protect off-Site features, and any significant reduction would be

based on future climatic conditions (in which case the features would not have the same

amount of water regardless).


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4. In the event that there is more water available than forecast, the amount of additional

water will be established and dealt with in accordance with the water allocation

priorities described in Part I Section 2.0.

As the final lake filling stage is approached, the water budget will be further reviewed and

refined to ensure that sufficient water will be available and to confirm how much excess water

will be available under the final "lakes filled" condition. This assessment will include an analysis

of any changed circumstances, including an updated analysis of the potential effects of global

climate change which may be much better defined at that time than they are at present. Such

assessments will include review and, if necessary, additional assessment of anticipated water

budget parameters associated with revegetation/rehabilitation conditions, as required to

confirm the sustainability of the rehabilitation conditions. These analyses may be used as a

basis for further refinement of the rehabilitation plan and ultimate land use plans in the event

that conditions indicate a revised plan would be of greater overall benefit to the water

resources and associated features.

CONESTOGA-ROVERS 8. ASSOCIATES

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a Division of Holcim (Canada) Inc. Part II - Section 1 Reporting

Part II — Section J Reporting

Table of Contents Page


Section 2.0 Regular Reporting 1

2.1 Annual AMP Monitoring Report 1

2.2 5-Year Review Report 3

2.3 On-Line Reporting 4

Section 3.0 Circumstance-Specific Reporting 5

3.1 Pre-Extraction Reports 5

3.2 Mitigation Implementation Verification 6

3.3 Agency Notifications and Mitigation Plans 7

3.4 Confirmatory Reporting Prior To Lake-Filling 8

3.5 Other Circumstances 8


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a Division of Holcim (Canada) Inc. Part II - Section J Reporting

Part ll - Section .1

Reporting


The AMP includes both regular reporting and circumstance-specific reporting.

Regular reporting includes the annual monitoring report, the 5-year review reports, and the

ongoing provision of on-line data access as described in Section 2.0. The annual and 5-year

review reports will be made available to the public by Dufferin. The on-line data access will be

provided to designated agency technical representatives responsible for assessing Dufferin's

implementation of the AMP. The following sections detail the reporting associated with the

AMP.

Circumstance-specific reporting includes pre-extraction reports, mitigation verification reports,

agency notifications, and other circumstances as described in Section 3.0.

For report submission timing, refer to Part I Sections 3.0 (AMP Requirements) and 4.0 (Ongoing

Requirements).

Further information on these reporting requirements is provided below. Note: some of

information such as private water supply monitoring or complaints may be limited in respect of

privacy limitations.

Section 2.0 Regular Reporting

2.1 Annual AMP Monitoring Report

A comprehensive AMR will be prepared documenting the implementation and operation of the

mitigation measures and recommendations for future mitigation system requirements in

accordance with the AMP. The report will be submitted to the agencies by April 30 of each year

covering the previous calendar year. The first report will be due April 30 in the year following

issuance of the licence, for the previous year in which the licence was issued.


030193 (22) AMP Part 11.1

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The AMR will include the following:

• Status and summary of quarry operations (e.g., development, extraction, and

rehabilitation).

• Status and summary of mitigation system development and implementation, including any

anticipated upcoming changes in requirements.

• All monitoring data for the reporting period (Note: transducer data may be sub-sampled for

presentation in the AMR to limit size of data files), including available climate data from

regional or local stations.

• Analysis and presentation of monitoring results, including summary of any notifications

provided under the response action framework (Part ll Section F).

• Summary of response actions taken to maintain PBT levels (and effectiveness of actions).

• Explanation and assessment of potential for impacts resulting from any period or area in

which water level PBTs or water quality effluent criteria were not continuously maintained.

• Any PBT adjustments based on climate conditions (background monitoring) and

supplemental monitoring and operating experience, as appropriate

• Assessment of supplemental monitoring program findings, including ecological aspects,

following triggers identified in Part ll Section G, Table G.1. The trigger-based assessment

framework for assessing the supplemental monitoring results and to stream-line the

reporting such that reporting can be focused to potentially important aspects of the

monitoring results as identified by the triggers.

• Evaluation of overall water budget and determination of excess water and appropriate

water allocation for the subsequent year.

• Documentation of any minor variations or exceptions in the AMP implementation that were

encountered throughout the year.

• Summary of any water-related complaints received and actions taken in response (subject

to privacy considerations).

• Review appropriateness of response/notification timelines identified in Part II Section H.

• Identification of a suitable interim extraction area (if needed due to required cessation of

extraction elsewhere) and any continued/future interim extraction.

• Summary of any amendments or modifications to the monitoring, mitigation, PBTs, or AMP

implementation that were agreed to throughout the year.

• Conclusions.

• Recommendations, including any proposed amendments or modifications to th,?

monitoring, mitigation, PBTs, or AMP implementation reflecting knowledge gained from

actual operating conditions and monitoring results (e.g., re-survey locations, calibration of


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a Division of Holcim (Canada) Inc. Part II - Section .1 Reporting

monitoring equipment, adjustment of monitoring frequency, addition or amendment of

monitoring locations, etc.).

In addition to the above aspects, the annual reporting will include an overall evaluation of the

performance of the mitigation measures to confirm that the mitigation performance objectives

are being achieved and that continued extraction and mitigation operation is sustainable over

the long term. This evaluation will consider all aspects of the operation and monitoring

activities described in the AMP. Some specific considerations that will be addressed include the

following questions:

1. Are the operating practices consistent with the mitigation performance objectives?

Specifically, are the PBTs being maintained in a manner that is protective of the water

resources? The appropriate pattern of water level variations relative to the target levels

will become more evident as operating data becomes available; however, it is the

intended performance objective that the PBTs will be maintained for the majority of the

time, without large fluctuations in water level above or below the target levels, and that

the duration of such fluctuations will be kept to a minimum. It is recognized that

climatic conditions may result in wider variations (e.g., extreme wet events) and

additional discharge of water may be necessary for provision of downstream systems

(particularly 1.6 Mile Creek) consistent with historic quarry operating practices.

2. Are the mitigation measures protective of the water-dependent ecological features?

The ecological monitoring information will be evaluated in conjunction with the other

monitoring data to identify whether ecological features are being protected. In the

event that a negative effect to ecological features appears to be evident (unless the

change is clearly not attributable to Dufferin's activities - e.g., climate, upstream

issues, etc.), further investigation and assessment will be undertaken to determine what

response actions may need to be implemented to ensure the protection of the

water-dependent ecological features.

2.2 5-Year Review Report

Once every 5 years, a reassessment of the AMP will be conducted and reported in conjunction

with the annual monitoring reports. The timing for initial and subsequent review reports is

described in Part I Section 4.0.

This assessment will consider all aspects of the AMP from a broader context than the annual

review, including:

• Monitoring programs, including monitoring locations and frequency.

CONESTOGA-ROVERS ASSOCIATES

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• Supplemental monitoring triggers (expected conditions based on monitoring). The

trigger-based assessment includes the framework for assessing the supplemental

monitoring results and to stream-line the reporting such that reporting can be focused to

potentially important aspects of the monitoring results as identified by the triggers.

• PBT refinements, if warranted, and identification and development of

additional/replacement PBTs, if needed.

• Ongoing monitoring and site investigation results and any updates to hydrogeology,

hydrology, or ecology characterization.

• Mitigation measures.

• Mitigation objectives in relation to effects of long-term climate variation.

• Water budget.

• AMP procedures.

• Overall evaluation of performance of the mitigation measures in achieving the primary

objectives of the system.

• Analysis and evaluation of relevant trends in monitoring data.

• Reporting.

• Conclusions.

• Recommendations, including any proposed amendments or modifications to the

monitoring, mitigation, PBTs, rehabilitation, or AMP implementation.

It is noted that wetland U3 has been assigned a PBT and a diffuse discharge; however it may be

adequately maintained without the use of diffuse discharge to this feature. Wetland U3 may be

supported adequately by its natural condition, support of underlying groundwater levels (via

recharge well operation), and seasonal overflow from wetland U4. The need and merits for a

PBT and dedicated mitigation for U3 will be assessed as part of the 5-year reviews.

The effectiveness of the planned Green Line well and supplemental monitoring for the

protection of wetland U2 will be evaluated as part of the 5-year reviews. If warranted, the

planned new supplemental monitoring well at the northwest corner of Phase 4 (between the

extraction limit and wetland U4) could be considered for use as an additional Green Line PBT

well.

2.3 On-Line Reporting

During the operation of bedrock extraction and/or mitigation measures, suitable monitoring

data will be promptly entered into an electronic database, which can be accessed on-line by the


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a Division of Holcim (Canada) Inc. Part II - Section.) Reporting

appropriate regulating agencies. The information that will be available on-line will include, at a

minimum:

• All physical monitoring data such as groundwater levels, surface water levels, flows, and

water quality. High frequency transducer data will generally be reduced (sub-sampled) to

manage data set size. Some data for off-Site locations may be subject to privacy limitations.

• Map of all associated monitoring locations.

• Applicable PBTs and historic water levels ranges.

• Summary of the current operating condition relative to those levels (e.g., green, yellow, or

red zone) and any current occurrences or incidents as described in Part II Section F.

• Electronic copies of all public and agency reports and agency notifications.

• Identification of key personnel and responsibilities as well as associated contact and site

access information.

Prior to commencing extraction below the bedrock groundwater level within Phase 4, the

on-line (i.e., internet accessible) database will be developed and made operational and

accessible to designated agency technical representatives. As identified above, data will

promptly be made available. For example, data for applicable PBT monitoring locations

(groundwater and surface water) will be entered into the on-Site operations database on a daily

basis (operating days) and uploaded to be available on-line within 24 hours (or the next

business day). The specific implementation and access details for the database will be

confirmed with the agencies prior to Phase 4 bedrock extraction.

Section 3.0 Circumstance-Specific Reporting

To ensure that the implementation is conducted in a progressive, proactive, and protective

manner with clear accountability, a series of two pre-extraction reports and two mitigation

implementation verification milestones, as well as other circumstance-specific reporting

requirements have been identified in Part I of the AMP. These requirements are described

herein.

3.1 Pre-Extraction Reports

Reports will be submitted to document the pre-extraction requirements described in Part I

Section 3. Two pre-extraction reports are required; one prior to extraction below the bedrock

groundwater level in Phase 4 and one prior to extraction below the bedrock groundwater level

in Phase 5 West/6. Phase 5 East does not require a pre-extraction report.


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The pre-extraction report will include:

• Location of selected "final" PBT and Green Line monitoring locations for the applicable area

north or south of 22nd Sideroad (refer to Part I Section 3.1.1 and Part I Section 3.2.1)

• Selection of "final" PBTs for associated monitoring locations including associated analysis

and confirmation that the PBTs are appropriate (e.g., achieve the intended outflow

conditions from wetland U7 towards wetland U8 but not unintended outflow conditions

such as discharge from wetland U5).

• Location of background monitoring locations and existing supplemental monitoring

locations

• Summary of baseline water level data, including historic ranges (e.g., monthly)

• Summary of baseline ecological monitoring data

• Current information from private well baseline survey and water supply augmentation

assessments (subject to privacy limitations)

• Summary of key information from mitigation design and implementation verification

• Water budget table update and amount of water in storage in reservoir(s)

• Appropriate recommendations, if any, to amend the AMP relative to available information

The mitigation implementation verification requirements are described separately in

Section 3.2 below.

3.2 Mitigation Implementation Verification

Further to Part I of the AMP, the identified mitigation implementation milestones and

associated requirements are described below:

Milestone 1 Phase 4 Mitigation Implementation Verification

For the groundwater recharge well system component, the verification will include

confirmation that there is connectivity between installed recharge wells (i.e., by individual

recharge well operation and monitoring) and that all associated Green Line wells (i.e., to the

north) can be influenced. For the diffuse wetland discharge components, the verification will

include confirmation that the water levels can be raised in the associated features and that

there are no unexpected interfering conditions such as downed trees or beaver dams

obstructing surface flow.

All information and data will be included in a verification report to be submitted to the agencies

for review in advance of extraction below the bedrock groundwater level in Phase 4. To the


030193 (22) AMP Part II

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extent that any components of the water management system are in a temporary condition (e.g., manual operation or overland piping) a timetable for permanent operating condition and

assessment of suitability of operating with the temporary condition will be included in the verification report.

Milestone 2 Phase 5 West/6 Mitigation Implementation Verification

For the groundwater recharge well system components, the verification will include confirmation that there is connectivity between installed recharge wells (i.e., by individual recharge well operation and monitoring) and that all associated Green Line and Groundwater

PBT monitoring wells can be influenced. For the diffuse wetland discharge components, the verification will include confirmation that the wetland water levels can be raised in the

associated features and that there are no unexpected interfering conditions such as downed trees or beaver dams obstructing surface flow.

The Phase 5 West/6 mitigation implementation verification will also include an assessment of

the performance effectiveness of the Phase 4 mitigation system relative to the ability to maintain PBTs, comparison to anticipated conditions, and overall effectiveness in protection of water resources and related ecological features. This assessment will include a review of the

groundwater and surface water analyses, including an update of the underlying models if warranted based on the review.

In the event the Phase 5 West/6 mitigation implementation is not verified to operate as intended or the Phase 4 mitigation performance is not reliably achieving PBTs, extraction will not proceed below the bedrock groundwater level in Phases 5 West/6.

All information and data will be included in a verification report to be submitted to the agencies for review in advance of extraction below the bedrock groundwater level in Phase 5 West/6. To

the extent that any components of the water management system are in a temporary condition (e.g., manual operation or overland piping) a timetable for permanent operating condition and assessment of suitability of operating with the temporary condition will be included in the

verification report.

3.3 Agency Notifications and Mitigation Plans

Agency notifications required pursuant to the response action plan described in Part II Section F will be provided by email, or other means acceptable to MNRF, to the MNRF ARA Inspector and other agency representatives as typically involved at the time of notification.

Notifications will also be recorded and maintained in the on-line data access tool described in Section 2.3 above.


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In the event that a response action mitigation plan as described in Part II, Section F.2.2.3 and

Part I Figure 1 is necessary, the mitigation plan will include the following components:

• Summary of the situation resulting in the yellow/red zone condition

• Summary of the response actions implemented and results to date

• Analysis of potentially applicable alternative solutions, including a "no further action"

alternative

• Recommended alternative solution and rationale for selection, including assessment of any

risk of impacts from implementation and measures that can be implemented to prevent

re-occurrence

3.4 Confirmatory Reporting Prior To Lake-Filling

Due to the variability associated with in-field conditions and climate conditions over the

long-term, confirmatory studies will be conducted prior to the completion of rehabilitation in

accordance with Part II Section K and if necessary suitable refinements, contingency measures,

and/or monitoring can be implemented. This assessment will be submitted for agency review

and will include a review of the groundwater and surface water analyses, including an update of

the underlying models if warranted based on the review, and may coincide with analyses

described in Section 3.2 (above).

3.5 Other Circumstances

As necessary, other circumstances will be documented and reports submitted to MNRF and

other agencies.


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a Division of Holcim (Canada) Inc. Part II —Section K Rehabilitation Implementation

Part II — Section K Rehabilitation Implementation

Table of Contents

Page


Section 2.0 Confirmatory Reporting Prior To Lake-Filling 1

Section 3.0 Post Lake-Filling Confirmation and Monitoring 3

List of Figures

(Following Text)

Figure K.1

Figure K.2

Figure K.3

Figure K.4

Figure K.5

Rehabilitation Plan - Key Plan

Rehabilitation Water Management and Mitigation - Phase 4

Rehabilitation Water Management and Mitigation - Phase 5/6 Western Portion

Rehabilitation Water Management and Mitigation - Phase 5/6 Eastern Portion

Rehabilitation Water Management and Mitigation - Phase 5 East


030193 (22) AMP Part 11.1( November 2014


a Division of Holcim (Canada) Inc. Part ll — Section K Rehabilitation Implementation

Part ll - Section K

Rehabilitation Implementation


This section of the AMP describes the overall water management system considerations and

requirements for establishment of long-term (post lake-filling) rehabilitation conditions. The

rehabilitation plans are illustrated on Figure 3 of Part I and described in Part ll Section A.4.0 and

on the ARA Site Plans. Figures K.1 to K.5 herein present additional detail regarding the

rehabilitation water management and mitigation plans for the Site (refer also to CRA

memorandum of October 27, 2014, or as may be updated from time-to-time, for supporting

technical information).

Under long-term rehabilitation conditions lake levels will be maintained by inter-lake leakage

through the remaining rock and constructed buttresses (where present), gravity overflow

pathways (i.e., swales and culverts), limited lake-to-lake water transfers (i.e., pumping and

gravity flows) as necessary, and some continued seasonal interim mitigation system operation

(as required). Some seasonal top-up of lake levels is anticipated to optimize the beneficial use

of the available water. The lakes will tend to stabilize the natural groundwater level

fluctuations near the quarry; however the lake level variations in conjunction with the natural

seasonal fluctuations of bedrock groundwater will increase away from the lake, allowing natural

or passive ephemeral/intermittent flooding of the wetlands once the lakes are full.

Section 2.0 Confirmatory Reporting Prior To Lake-Filling

Due to the variability associated with in-field conditions and climate conditions over the

long-term, confirmatory studies will be conducted and submitted for agency review prior to the

completion of rehabilitation and, if necessary, suitable refinements or contingency measures

can be implemented. The confirmatory rehabilitation studies include confirmation of the

optimum final lake levels and seasonal variations, water budget analysis, detailed design for the

hydraulic buttresses and geotechnical engineering analysis for the quarry walls, as well as

long-term seepage assessments. The required modifications to transition the interim WMS to

the final rehabilitation WMS will also be determined. The preference for discharges will be by

gravity, however, may be pumped based on in field conditions (e.g., W2-N) and overall

optimization of ecological conditions and water benefits and minimization of long-term

engineering requirements such as active pumping and hydraulic buttress elevation (i.e., lake

CONESTOGA-ROVERS ASSOCIATES

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a Division of Holcim (Canada) Inc. Part II — Section K Rehabilitation Implementation

level). These requirements are described in Part I (Section 3.0), Part II Sections A and I, and on

the Site Plans in addition to the following information.

Hydraulic Buttresses

The construction of buttresses for rehabilitation along certain quarry faces is proposed. The

buttresses will create variable edge habitat characteristics and the 'hydraulic buttresses' will

also support the Phase 3/5 West/6 lake level to buffer the lake level and natural groundwater

level fluctuations, as well as limit seepage of water through the buttresses. The hydraulic

buttress will limit flow/seepage across it, but not prevent flow, therefore, rapid changes in lake

levels or groundwater levels in these areas will be buffered/slowed by the hydraulic buttress.

In areas where buttresses are proposed for hydraulic control purposes (as opposed to simply

"landscaping"), a detailed engineering design will be completed prior to construction to ensure

appropriate consideration of the available buttress materials, exposed bedrock conditions, and

hydraulic requirements. The potential areas identified are south of 22nd Sideroad. The

preliminary engineering design has been completed (CRA letter report dated May 27, 2013) and

further requirements for the hydraulic buttress engineering design are addressed under the

ARA Site Plans. Part of the final design may consider alternate designs taking into consideration

site-specific circumstances encountered and available material. Any major deviations to the

design will require an amendment to the ARA Site Plans.

Quarry Wall Seepage and Karst Analysis

Prior to commencement of lake filling in Phase 4 or Phase 3/5 West/6, the areas between

adjoining quarry cells that are not covered by a hydraulic buttress will be evaluated to ensure

that they are suitably stable (e.g., no loose rock) and that long-term seepage will not increase

to any unacceptable level over the long-term due to the process of dissolution of the bedrock.

While all carbonate rocks in contact with water are generally subject to some dissolution over

time, dolostone bedrock, including the Amabel found at this Site, has a dramatically slower rate

of dissolution than limestone. Limestone (and other more soluble minerals) is recognized to be

susceptible to appreciable dissolution over periods of centuries (or less) in some situations.

Although the rate of dolostone dissolution is known to be very slow relative to limestone, the

following program will be implemented for the areas of Phase 4 and Phase 3/5 West/6 West

noted above (i.e., exposed final rock faces). This information will also be considered in the

geotechnical analysis described above.

1. Final extraction faces will be mapped in detail (such as high resolution photography) to

identify fracture occurrence and character with particular attention to the size, extent,

and character of any open fractures. Mapping will include seepage surveys under


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a Division of Holcim (Canada) Inc. Part II — Section K Rehabilitation Implementation

winter freezing conditions and spring freshet conditions. Any significant water bearing

feature will be located by survey for future reference if necessary.

2. Hydraulic conductivity of the entire thickness of the rock mass will be tested (pressure

packer testing) at representative locations suspected of having higher permeability,

including areas of potentially significant seepage that may be noted (as above).

3. The potential for ongoing dissolution under the long-term rehabilitation conditions will

be analyzed using the then current scientific understanding and predictive techniques

available. If necessary, this may include the commissioning of particular research

focused on the dissolution kinetics of Amabel dolostone.

4. If the foregoing work concludes that significant increases in seepage may occur as a

result of long-term dissolution processes, appropriate measures will be implemented to

manage the situation. Such measures may include: consideration of potential top-up

flow requirements, extension of hydraulic buttresses to address localized or broader

areas, localized grouting of more permeable zones, long-term monitoring and

accommodations for future contingencies, or a combination of these (or other)

measures.

5. During the lake filling period, seepage surveys of downstream quarry faces and water

budget evaluations will be utilized to help identify any unanticipated levels of leakage

and, if necessary, implement measures as described above.

Section 3.0 Post Lake-Filling Confirmation and Monitoring

Upon achievement of the final rehabilitation lake levels, monitoring will be conducted to ensure

that suitable long-term conditions are achieved. Monitoring will include assessment of water

levels and flows (e.g., lake top-up flows) as well as ecological conditions. If necessary, the

proposed lake levels will be modified to better protect the surrounding ecological features. If

adjustment of lake levels is not adequate, additional measures will be considered such as

grouting, additional fill material, additional gravity drainage structures, etc., depending on

Site-specific conditions identified at that time.

The need for, and requirements of, any ongoing long-term monitoring will be identified prior to

cessation of monitoring. At present, it is anticipated that some monitoring will continue to be

necessary. At a minimum, it is anticipated that monitoring will include water levels in the

reservoirs and possibly lakes, as well as flows for pumped discharges and perhaps gravity

overflows.

The confirmatory analysis will be submitted for agency review as described in Part I,

Section 3.1.3 and 3.2.3.


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GLEN • 125 250 37501

BLACK C

1; 7:64,'Ij s•:\

• • PLANT \ YARD Low.

UPPER SETTLING POND \

•

• • • •

• \ • • • ‘‘

• \ PHASE 1

RESERVOIR MAX 341 m AMSL

---------------

------------

-------- - - - - -

--

W2-S

----------

PHASE 5 WEST/ 6 WEST

------ —

PHASE u6 5 EAST

5 --- 2•1'

"9-N)

HYDRAULIC —"*" BUTTRESS TO 2357 m AMSL

-U27

NOTES: 1. ACTUAL ALIGNMENT OF WATERMAINS/DISCHARGES MAY VARY. 2. REFER TO ARA SITE PLANS FOR EXTENTS OF REHABILITATION

LAKES AND RESERVOIRS WITHIN EXTRACTION LIMITS. 3. REFER TO PART II SECTION K.1.0.

LOCAL DISCHARGERNTERCONNECTION OF WATER (GRAVITY FLOW) SITE DISCHARGE OF WATER (GRAVITY FLOW) GRAVITY WATERMAIN/CHANNEL FLOW PUMPED FLOW PROPOSED QUARRY DISCHARGE/MITIGATION (PUMPED)

SOURCE BASE MAPPING OBTAINED FROM NORTHWAY PHOTOMAP cos INC , DERIVED FROM NOVEMBER 22.2011 AERIAL PHOTOGRAPHY 0 QUEENS PRINTER FOR ONTARIO PRINTED IN ONTARIO, CANADA OCTOBER 2011 figure K.1

REHABILITATION PLAN KEY PLAN

ACTON QUARRY EXTENSION Town of Halton Hills, OnZwio

30193-10(022)GN-WA005 NOV 2112014

MOVEMENT OF WATER

LOCAL DISCHARGE/INTERCONNECTION OF WATER (GRAVITY FLOW) SITE DISCHARGE OF WATER (GRAVITY FLOW) GRAVITY WATERMAIN/CHANNEL FLOW PUMPED FLOW

NOTE ACTUAL ALIGNMENT OF WATERMAINS/DISCHARGES MAY VARY.

711°. WMS CONTROL HUT 111111111119/11111)J11-111111)1)A1,,IIIIII VV1111111I figure K.2 REHABILITATION WATER MANAGEMENT AND MITIGATION

PHASE 4 ACTON QUARRY EXTENSION

Town of Halton Hills, Ontario

SOURCE. BASE MAPPING OBTAINED FROM NORTHWAY PHOTOMAP INC.. DERIVED FROM NOVEMBER 22. 2001 AERAL PHOTOGRAPHY CONTOUR INTERVAL RI METRE

SWOOP 2010 0 2011 OF THE QUEENS PRETTER FOR ONTARIO. ALL ROOTS RESERVED.

30193-10(022)GN-WA017 OCT 3112014

?ILIA: . -,77Arvilr. i .i., fd-ffler

1

77,e e

LAKE AVG -355 m Alan

RAN

ol•

11. •

-g■ figure K.3

MOVEMENT OF WATER

LOCAL DISCHARGE/INTERCONNECTION OF WATER (GRAVITY FLOW) SITE DISCHARGE OF WATER (GRAVITY FLOW) GRAVITY WATERMAIN/CHANNEL FLOW

NOTE: ACTUAL ALIGNMENT OF WATERMAINS/DISCHARGES MAY VARY. PUMPED FLOW PROPOSED QUARRY DISCHARGE/MITIGATION (PUMPED) WMS CONTROL HUT

SOURCE. BASE MAPPING OBTAINED FROM NORTHWAY PHOTOMAP INC. DERIVED FROM NOVEMBER 22, 2001 AERIAL PHOTOGRAPHY

NNIIILI.122 PIEEITEE

REHABILITATION WATER MANAGEMENT AND MITIGATION PHASE 5/6 WEST - WESTERN PORTION

ACTON QUARRY EXTENSION SWOOP 2010 0 2011 OF THE QUEEN'S POKIER FOR ONTARIO ALL RIGHTS RESERVED Town of Halton Hills, Ontario

LAKE AVG -355 m AMSL

••"*-.

2357 rn AMSL

I HYDRAULIC Whilit4

BUTTRESS TO

MOVEMENT OF WATER

LOCAL DISCHARGE/INTERCONNECTION OF WATER (GRAVITY FLOW) SITE DISCHARGE OF WATER (GRAVITY FLOW) GRAVITY WATERMAIN/CHANNEL FLOW NOTE: ACTUAL ALIGNMENT OF WATERMAINS/DISCHARGES MAY VARY PUMPED FLOW WMS CONTROL HUT

SWOOP 2010 0 2011 OF THE QUEEN'S PRINTER FOR ONTARIO ALL

RIGHTS RESERVED

figure K.4

REHABILITATION WATER MANAGEMENT AND MITIGATION PHASE 5/6 WEST - EASTERN PORTION

ACTON QUARRY EXTENSION Town of Halton Hills, Ontanb

SOURCE BASE MAPPING OBTAINED FROM NORTHWAY PHOTOMAP

INC DERIVED FROM NOVEMBER 22, 2001 AERIAL PHOTOGRAPHY

CONTOUR INTERVAL DI METRE

30193-10(022)GN-WA017 OCT 3112014

RESERVOIR MAX 338 rn AMSI

-01■

MOVEMENT OF WATER

LOCAL DISCHARGEANTERCONNECTION OF WATER (GRAVITY FLOW) SITE DISCHARGE OF WATER (GRAVITY FLOW) GRAVITY WATERMAIN/CHANNEL FLOW PUMPED FLOW

NOTE: ACTUAL ALIGNMENT OF WATERMAINS/DISCHARGES MAY VARY.

SOURCE BASE MAPPING OBTAINED FROM NORTHWAY PHOTOMAP INC DERIVED FROM NOVEMBER 22, 2001 AERIAL PHOTOGRAPHY CONTOUR INTERVAL IS 1 METRE

SWOOP 2010 0 2011 OF THE QUEEN'S PRNIER FOR ONTARIO. ALL RIGHTS RESERVED

figure K.5

REHABILITATION WATER MANAGEMENT AND MITIGATION PHASE 5 EAST

ACTON QUARRY EXTENSION Town of Halton Hills, Ontario

30193-10(022)GN-WA017 OCT 31/2014

dufferin aggregates, a division of holcim (canada) inc. part ii -...

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