october 28, 2008 garrod pickfield llp davis & company · 2018. 8. 21. · 10/31/2008 2:02:58 pm...

10/31/2008 2:02:58 PM C:\DOCUME~1\nhoran\LOCALS~1\Temp\XPgrpwise\AGH-L Preliminary Comments Oct 28 2008.doc

October 28, 2008 Garrod Pickfield LLP Davis & Company 221 Woolwich Street AND 1 First Canadian Place, Suite 5300 Guelph, Ontario 100 King Street West N1H 3V4 Toronto, Ontario M5X 1E2 Attention: Mr. Stephen Garrod & Mr. Chris Barnett Dear Sirs: Re: Proposed Rockfort Quarry Licence Application Peer Review Preliminary Comments on Consultant Addendum Submissions August 2008

Water Resources Aspects File 04-0984.04 Further to your request, we are providing our preliminary peer review comments, related to water resources aspects, of the addendum technical submissions provided in August 2008 by consultants on behalf of James Dick Construction Limited (JDCL) with respect to their application for a Class A Category 2 Licence for their Rockfort Quarry property. The subject property is located in the Town Of Caledon, Region of Peel. Our current peer review is a continuation of the peer review process that was started in 1998 for the licence application, and was suspended in 2003/2004 while the Comprehensive Broader Scale Environmental Study (CBSES) of Resource Area 9A was developed and subsequently completed by JDCL. The final report for the CBSES was submitted to the Town Of Caledon at the end of March 2008. Staff from Credit Valley Conservation provided technical input to the development of the Terms Of Reference for the CBSES, and also provided comments on drafts of the report. The CBSES deals with broader-scale issues related to the physical setting and natural environment within Resource Area 9A. The CBSES also addresses potential impacts

Garrod Pickfield LLP & Davis & Company October 28, 2008


associated with extraction of the entire rock resource within Resource Area 9A, and discusses possible mitigation measures to manage those impacts. The CBSES does not address site-specific issues related to the proposed extraction at the Rockfort Quarry, and, as such, we have not undertaken a technical review of the CBSES final report. The addendum documentation related to the Rockfort application that was submitted by the proponent in August 2008, which we have reviewed, is as follows:

A. Water Resources Evaluation And Design Addendum Rockfort Quarry, Town Of Caledon, Ontario. Prepared by Conestoga Rovers Associates, July 2008; Reference No. 009595 (11).

B. Updated Adaptive Management Plan Water Resources Protection Rockfort Quarry, Town Of Caledon, Ontario. Prepared by Conestoga Rovers Associates, Ecoplans Limited and Goodban Ecological Consulting, July 2008; Reference No. 009595 (8).

The Water Resources And Design Addendum report provides the results of additional data collection and site characterization information that has been obtained since the submission of the technical support reports in 2000. As well, this addendum report describes modifications to the proposed mitigation measures and monitoring for the quarry operation, as well as providing additional technical support for the proposed mining and mitigation operations. The Updated Adaptive Management Plan Water Resources Protection report provides details of the proposed operational water management, and mitigation monitoring programs that are intended to protect the existing water resources and natural environment around the periphery of the quarry and within any potential zone of influence of the quarry operations. It is stated that this report updates and supersedes the August 2000 Adaptive Management Plan document. Although not stated as such, we have assumed that this Updated Report also supersedes the April 2003 Modifications To The adaptive Management Plan document that was submitted by the applicant. REVIEW CONTEXT To place our review into an overall context with respect to the short-term and long-term protection of ground water and surface water resources, and the associated natural environment features and functions, the following summary is provided. The summary applies to both the active extraction operation and the post-rehabilitation final lake conditions.



UNMITIGATED EXTRACTION OPERATION = SIGNIFICANT ENVIRONMENTAL IMPACTS The predicted scope and extent of the impacts associated with an unmitigated extraction operation is not discussed in any of the reports; we do not know if this base-case has been modeled by the proponent. It is our contention that it is important for the review agencies to know the magnitude of the predicted impacts for the unmitigated operation, as a base-case, so that the importance of the mitigation measures functioning as designed can be fully appreciated. Impacts would be expected to occur to the following:

Local residential and/or farm water supplies (wells, springs etc.). Some supplies may be lost while other supplies may not be as productive.

Local surface water courses and local springs may be affected by reduced flows and/or reduced groundwater inputs.

Local fish habitat may be affected, possibly resulting in a Harmful Alteration Disruption Destruction (HADD) of fish habitat which would then involve the Department of Fisheries and Oceans under the Federal Fisheries Act.

Local wetlands, ponds, vernal pooling amphibian habitat and other natural environmental features and functions may be affected as a result of reduced groundwater levels, surface water flows and shorter hydro-periods.

FULLY MITIGATED EXTRACTION OPERATION = MINIMAL/ACCEPTABLE LEVEL OF ENVIRONMENTAL IMPACTS The initial design of the mitigation measures is based on computer modeling of the groundwater system and is premised on the maintenance of quasi pre-quarry groundwater levels in the bedrock aquifer around the extraction area. Full mitigation will require:

An effective grout barrier wall around the entire extraction area to reduce/manage groundwater discharge into the quarry extraction area.

An effective groundwater recharge system around most of the extraction area to maintain groundwater levels in the adjacent bedrock.

A water storage system that is sufficient to supply the groundwater recharge system on a year-round basis.

An effective groundwater/surface water/natural environment monitoring program and Adaptive Management Plan that is sensitive enough to detect changes upgradient of, and/or at, the receptors to provide sufficient early warning of potential impact to allow timely implementation of mitigation measures.



Final lake levels following rehabilitation that will maintain the groundwater levels and surface water flows that protect the features and functions of the downgradient natural environment receptors.

INTERMEDIATE LEVEL OF MITIGATION = SOME DEGREE OF ENVIRONMENTAL IMPACT, BUT MAGNITUDE NOT KNOWN An intermediate level of mitigation would result in some degree of environmental impact to the features noted above, as a result of:

Not fully-effective grout wall. Not fully effective groundwater recharge system. Insufficient water storage system. Insensitive monitoring program that does not detect change soon enough and/or does

not monitor at the right locations to prevent environmental impact occurring. Final lake levels which are not high enough to protect the downgradient natural

environment receptors. Therefore, in order to prevent unacceptable environmental impact from occurring, we need to understand the sensitivity of the groundwater/surface water/natural environment systems with respect to change, and the sensitivity of the mitigation measures with respect to their level of effectiveness and resulting potential change in the downstream receptors. As well, there needs to be confidence that the rehabilitation lakes will fill to a level that will be sufficient to maintain local groundwater levels and surface water flows that will protect the downgradient natural environment receptors. REVIEW COMMENTS Based on our review of the documentation to-date, we provide the following comments. 1. The design of the proposed quarry operation and the associated mitigation measures, and

the technical documentation supporting that design/mitigation remains, in large part, as described in the suite of reports submitted by the proponent in August 2000. The proponent intends to rely on that original documentation in addition to the 2008 reports, as listed in Section 1.0 Introduction, page 1 Updated Adaptive Management Plan Water Resources Protection.

2. The work completed by the proponent for the CBSES was carried out at a broad scale of study (similar to a sub-watershed level of detail), and does not address site-specific issues that have been raised with respect to the proposed design/operation/mitigation of the



Rockfort Quarry. In particular, there has not been a comparison between the results of computer modeling that was undertaken for the CBSES and the modeling that was completed in 2000 for the Rockfort application. The recent documentation for the Rockfort application does not provide any commentary with respect to how closely the results of the two models correlate. It is our understanding that no new modeling has been undertaken for the Rockfort application, and that the proponent intends to rely on the work that was reported in 2000. We understand that the CBSES modeling included similar mitigation measures to that of the Rockfort modeling (i.e. a grout curtain wall and groundwater recharge wells). The site-specific Rockfort grout curtain was assigned a hydraulic conductivity value of 2 x 10-4 cm/s around the entire perimeter of the extraction area. The CBSES model included sections of the grout curtain that required a lower hydraulic conductivity value in the order of 1 x 10-5 cm/s. The proponent should explain this difference between the two models, and whether the lower value is feasible to achieve for a quarry operation.

3. The Updated/Addendum reports that were submitted in August 2008 do not include any substantive departures from the original interpretation of the physical setting of the subject area or the water resources and natural environment resources present in the area. Some relatively minor modifications have been incorporated into the design, operation and mitigation measures for the quarry, and additional technical support is provided with respect to the mining/grouting plan. It is stated in the Updated Adaptive Management Plan (Section 1.0, page 1), that the original Plan was modified to incorporate advice provided in 2003 by the Department of Fisheries and Oceans and their hydrogeological consultant Blackport Hydrogeology Inc. That advice pertains to the protection and monitoring of water resources and associated fish habitat that are present in the vicinity of the Rockfort property.

4. Jagger Hims Limited undertook technical review of the water resources reports that were submitted by the proponent in August and October 2000. We submitted preliminary review comments in June 2001, in our June 18 letter to Turkstra Mazza Associates (copy attached). We submitted detailed review comments and questions for clarification in our letter addressed to Turkstra Mazza Associates, dated October 16, 2001 (copy attached). We understand that our review comments were submitted to the proponent for response by their consultants. Jagger Hims Limited has not received a response to those review comments/questions. Therefore, as the proponent intends to continue to rely on the 2000 suite of reports, our 2001 comments/questions remain outstanding and require a response from the proponent.



5. The groundwater modeling component is an integral part of the Water Resources Evaluation and Quarry Design reports that were submitted by the proponent in August/October 2000. A detailed review of that modeling component was not undertaken by Jagger Hims Limited at that time pending a response from the proponent to our October 16, 2001 review comments. Since a response to our review comments has not been received to date, we have not undertaken a detailed review of the modeling component. Given the tight schedule for review of the recent technical reports provided by the proponent and submission of our review comments to the Region, we are not in a position to complete a detailed evaluation of the modeling component prior to submission of our review comments. We are not aware that a detailed review of the modeling component has been completed by CVC staff or their hydrogeology consultant Blackport Hydrogeology Inc. The modeling component should be reviewed prior to the start of the OMB Hearing.

6. Jagger Hims Limited submitted detailed review comments on the proposed Adaptive Management Plan (AMP) to Garrod Pickfield and Davis & Company, in our letter dated August 28, 2003. At that time, we provided review comments on the original AMP document dated August 2000 and on the April 2003 Modifications To Adaptive Management Plan document. A copy is attached here. Given that the proponent proposes to rely upon the Updated 2008 AMP report, some of those original comments may have been addressed in the Updated AMP document, and others may remain outstanding.

7. Jagger Hims Limited submitted a Summary Statement letter to Garrod Pickfield and Davis & Company, dated September 16, 2003, prior to the review process being suspended while the CBSES work was undertaken. The content of that letter continues to apply, pending receipt of a response from the proponent with respect to our 2001 and 2003 review comments noted above. A copy of our September 16 2003 Summary Statement letter is attached.

8. The following general comments are provided with respect to the document entitled: “Updated Adaptive Management Plan Water Resources Protection Rockfort Quarry, Town Of Caledon, Ontario”, prepared by Conestoga-Rovers & Associates, Ecoplans Limited and Goodban Ecological Consulting, dated July 2008 Reference No. 009595 (8). a. As stated in Section 1.0 Introduction, page 1 of the AMP document, in principal we

agree with the following general statement: “The AMP is a well-established method of managing natural systems where there is inherent variability in the conditions that will be encountered (e.g. bedrock permeability). The AMP method is based on a system of design, implementation, performance monitoring, evaluation, and optimization to ensure that the mitigation objectives are achieved.” Jagger Hims



Limited has been associated with the development of AMPs or variations thereof for other pit/quarry applications, and we support their use.

b. When structured and implemented appropriately, AMPs are an effective science-based instrument to monitor the real-time progression of impacts on-site related to a specific type or types of land use, while providing sufficient lead time to implement pre-determined mitigation measures that are designed to ensure protection of off-site groundwater, surface water and other natural environment features and functions. Measured impacts are compared to predicted impacts, so that initial predictive models can be refined and adjustments made to existing and/or proposed mitigation measures if necessary to protect the off-site environment.

c. In our August 2003 review of the Adaptive Management Plan documents (August 2000, and April 2003 Modifications), we stated the following:

“As a general comment, we consider that the basic philosophy of the AMP approach is sound provided that: (a) You understand the physical system that you are monitoring, including the

groundwater/surface water/ecology interactions at off-site locations. (b) The initial impact predictions are reasonable. (c) The design mitigation measures are implemented at the outset. (d) The monitoring program monitors the correct parameters in the right locations at

the right times of the year to identify and quantify any changes that occur. Such changes have to be evaluated in terms of being acceptable or unacceptable.

(e) In the event that unacceptable changes do occur, the additional mitigation measures are successful in returning the physical conditions to acceptable levels.

When implemented correctly, this type of approach is reasonable and supportable. If, however, this approach is done incorrectly, then unacceptable change can occur and remain un-noticed to the point where permanent and significant (unacceptable) impact may occur. We have stated previously that, in our opinion, given the scope of the proposed quarry operation and the sensitivity of the area, the proponent should provide a practical demonstration that recharge wells located along the property boundary can develop a positive hydraulic connection that will protect and maintain the groundwater regime at: (i) groundwater discharge zones at specific off-site fishery habitat areas, and (ii) local residential wells. A program to investigate and characterize the groundwater flow conditions at key off-site fishery habitat areas south of the property is proposed



by the applicant following approval of the quarry, before any extraction takes place. It is our opinion that such work, together with a practical demonstration of the effectiveness of recharge wells along the property boundary, should be undertaken before the application is heard by the OMB. The type of factual information noted above would provide strong support that the mitigation system recharge well concept can provide the type of protection to the off-site groundwater and surface water resources that will be required at this site.” We continue to hold this position.

d. The general scope of the proposed Updated AMP performance monitoring program

appears reasonable as a starting point for discussion with the regulatory/review agencies to achieve the stated objectives. However, since further “proof of concept” for the grout wall and groundwater recharge system (beyond that provided in the 2000 suite of reports and the 2008 Addendum reports), which are to be the main mitigation measures to limit off-site impacts of the quarry, has not been provided, the options are to refuse approval until such proof is provided, or to stage or phase approval in tandem with proof of concept. This type of phased Stop-Go approval would ensure that the mitigation measures are shown to be operational and effective for each subsequent phase of the extraction prior to the need for the mitigation being realized. A phased financial assurance package commensurate with the degree of risk/cost of failure tied to the Stop-Go milestones would also need to be developed to ensure that all necessary mitigation measures would be implemented as required.

e. Section 2 of the AMP describes the configuration and progression of mining and

mitigation measures that are being proposed. As we understand the proposal, Phase 1 is to be extracted sub-aqueously in a single lift that is 25 m deep down to elevation 357 m above sea level (masl). The extraction area is to be allowed to fill with water as extraction is occurring, to create the North Reservoir, and, as such, off-site impacts are predicted to be minimal, and mitigation should not be required. During extraction of Phase 1, which is expected to last approximately 3 years, the detailed design for the section of the groundwater recharge system required for Phase 2 will be completed and construction of that system initiated.

By the end of Phase 1, the groundwater recharge system will be “complete and demonstrated to be effective as required for Phase 2 initiation” (page 12). Details should be provided by the proponent with respect to the extent of the recharge system that will be required for “initiation of Phase 2”. Section 2.2 Phase 2-Plant Area, page 13, indicates that prior to extraction in Phase 2, the groundwater recharge system for



Phase 2, including construction and testing will be completed as well as confirmation that the minimum water storage is available in the North Reservoir.

This could be a suitable Stop-Go milestone event if there is a phased approval. Agency sign-off with respect to operation/effectiveness of the groundwater recharge system would be required prior to approval being given to proceed with any extraction in Phase 2.

The proposed testing methodology to demonstrate that individual groundwater recharge wells will be effective along a particular section of the recharge system is discussed in the footnote on page 12:

“The recharge demonstration testing will include injecting water into each recharge well and observing the water level/pressure response in the adjacent recharge wells. If there is a measurable response in the recharge wells immediately adjacent to either side of the well being tested, then the demonstration is complete for that recharge well (i.e. the system has successfully provided water to the flow pathways that intersect the recharge well alignment between the wells, and thus the downgradient features will be maintained.” “Monitoring and evaluation of the demonstration testing will also include the nested monitoring wells, the off-Site feature wells (i.e. locations ii, iii and iv as shown on Figure 4.1 and described in Section 4.1.1.2), and other monitoring wells that exist in the potential zone of influence of the recharge well(s) being tested.”

The specifics of such well testing and verification monitoring should be provided by the proponent that will ensure that an appropriate measurable and sustainable hydraulic response is achieved throughout the saturated thickness of the Amabel aquifer adjacent to the recharge well being tested (i.e. not just a small water table response). As well, the testing should confirm that an appropriate hydraulic connection/response can be obtained and sustained in the aquifer at selected key locations downgradient from the recharge wells in order to ensure adequate protection of surface flow conditions and associated fish habitat.

f. The proponent anticipates that extraction of Phase 2 (the Plant Area) down to

elevation 370 masl can be completed without the need for any additional mitigation measures over and above the groundwater recharge wells that will be in place prior to the start of extraction in Phase 2. Should additional recharge wells be required (presumably, based on the monitoring results), they would be installed and operated as needed. The design does not call for a grout curtain wall in order to extract Phase 2. The timing of the design/construction of the grout wall that is required for Phase 3 is unclear, as noted below.



Page 13: Phase 2: During Extraction Period—“Complete design of grout curtain as required for Phase 3. Initiate grout curtain installation along recharge perimeter if required based on design.” It is not clear as to whether installation of the grout curtain wall will be initiated during Phase 2, or whether some form of evaluation will be undertaken to determine if the grout wall will be necessary, and if it is deemed to be necessary, then construction will be initiated. This should be clarified and support rationale provided by the proponent.

Page 14: Phase 2: Anticipated Status at End of Extraction Period—“Grout curtain wall design complete as required for Phase 3 initiation.” There is no mention here of any actual construction of the grout curtain wall prior to any extraction in Phase 3.

Page 15: Phase 3: Pre-Extraction: There is no mention of any construction of the grout curtain wall in this section. There is mention of a verification study prior to extraction to ensure that thermal effects of the groundwater recharge system will not result in an unacceptable change in temperature in the groundwater adjacent to cold water fish habitat located to the south of the site.

Page 15: Phase 3: During Extraction Period—“Initiate construction of grout curtain in accordance with grout curtain design. The current anticipated grout curtain alignment for completion of Phase 3 extraction is shown on Figure 2.5. At a minimum, the portion of the alignment adjacent to Phase 3 will have a grout curtain installed to limit recirculation. Further grout curtain development (i.e. tightening of horizontal extension of the curtain alignment) will be completed as required to limit recirculation of recharge water and minimize drawdown to the east (as feasible). The proponent should indicate what action would be taken in the event that it is not feasible to “minimize drawdown to the east”.

Page 16: Phase 3: Anticipated Status at End of Extraction Period—“Grout curtain system complete as required for Phase 4 initiation.”

Based on the foregoing, the remaining Stop-Go milestone events could be:

at the end of Phase 2 and prior to any extraction in Phase 3, provided that the grout curtain wall for Phase 3 is in place and is shown to be effective;

at the end of Phase 3 and prior to any extraction in Phase 4, provided that the grout curtain wall for Phase 3 has been confirmed to be effective under all extraction conditions and the grout curtain wall for Phase 4 is in place, and

at the end Phase 4A, and prior to any extraction of Phase 4B, provided that the grout curtain wall around the entire perimeter is shown to be effective and the South Reservoir is in place and full of water.



Each new phase will require additional and/or expansion of mitigation measures and, as such, would pose a progressively larger potential risk with respect to the overall protection of the natural environment. Therefore, in tandem with the Stop-Go milestone events, the regulatory agencies may wish to consider a commensurate increase in the financial assurances that should be provided to ensure that the mitigation measures could continue to be operated for the necessary period of time in the event that JDCL could no longer operate the quarry.

g. There may be additional points that will be raised with respect to the Updated AMP

document, pending a response from the proponent to previous peer review comments dating back to 2001.

9. The following relate to the document entitled “Rockfort Quarry Project Report on

Mitigation Demonstration” prepared by Douglas M Heenan, P.Eng., Advanced Construction Techniques Ltd., dated July 18, 2000. a) The water testing data and the grout-take demonstration data for the various lines of

grout holes indicate that there are reasonably well-defined horizons or stratifications within the vertical profile of the Amabel/Renales rock mass that have differing hydraulic characteristics. Based on a preliminary assessment of the data, the following horizons appear to be present:

An upper zone from ground surface down to 7 to 10 m below grade that exhibits

lugeon values in the order of 100 to 300. A middle zone that extends down to about 25 to 28 m below grade that exhibits

lugeon values less than 100, and typically in the 10 to 30 lugeon range. A lower zone that is present between approximately 25 to 38 m below grade that

exhibits lugeon values in the range of 160 to 375. A deeper zone that extends to the bottom of the Reynales Formation that exhibits

low lugeon values in the order of 15. There is a correlation between the lugeon value and the hydraulic conductivity of the rock. This apparent stratification within the Amabel does not seem to support the proponent’s interpretation of the aquifer as a single hydrostratigraphic unit, the vertical profile of which can be characterized by a single hydraulic conductivity value, as was used in the modeling. The proponent should indicate the significance of such stratification and the associated variation in the hydraulic conductivity. How would the incorporation of such stratification into the groundwater model affect the results of the model?



10. In the normal process for this type of study, the CBSES work would be undertaken first, and the hydrogeological conceptual model would be developed and broad-scale modeling would be done. Since site-specific detail normally would not be available, we understand that the Rockfort detail was not incorporated into the CBSES work or groundwater model.

The CBSES model characterizes the Amabel as a two layer aquifer, with an upper, more fractured/weathered higher k zone that is underlain by lower k material, which was considered to be a "conventional" interpretation for the Amabel, because fracturing generally is thought to decrease/become tighter with depth. Generally, at the site-specific level of detail, the hydrogeology at a particular property is seen to be more-complicated, rather than less-complicated than is used at the broad scale of assessment, and the site-specific model would reflect this.

So, for Rockfort, the model would be at least a two layer system for the Amabel, and possibly more layers, with differing k values. Based on the grout demonstration testing, a three layer characterization of the Amabel could be supported, with a higher k zone at depth.

Since the proponent still contends that the Amabel aquifer at this location is best-characterized as a single unconfined aquifer unit that can be characterized by a single k value in vertical profile, with some lateral variation, then strong supporting evidence for this more-simplistic interpretation should be provided. The grouting demonstration work seems to support a more-complex system, yet there is no discussion of this provided by the proponent in the recent submissions. It seems that wherever detailed field testing, such as pumping tests and grouting testing have been undertaken, the data do not fit the simple relatively homogeneous unconfined aquifer conceptual model that is being proposed.

Since there are groundwater springs that feed surface water courses located to the south of the proposed extraction areas, it is not unreasonable to require that the model be adapted to run in transient mode to show that it can simulate the seasonal variation that is observed in the groundwater/surface water system. Currently, only long-term steady state average groundwater conditions are modeled. It is recognized that developing a transient model will require significant effort; however, well-calibrated transient and steady-state models would provide confidence that the models can simulate observed field conditions.

11. If the two or three layer system is shown to be more-reflective of actual conditions, then

the AMP testing and monitoring of the recharge system has to be rigorous enough to be able to confirm that water can be recharged into the various zones in the right quantities and right locations to protect all of the downgradient features/functions. More specifics



are required with respect to how the proponent intends to define a “successful demonstration” of each recharge well. The AMP simply talks about a "measurable response" in adjacent recharge wells and in downgradient sentry wells (which are to be multi-level monitor nests).

CLOSURE We trust that this information is of assistance to the Region of Peel and the Town of Caledon in their assessment of the Rockfort Quarry application by JDCL. Please contact our office if you have any questions. Yours truly, JAGGER HIMS LIMITED Andrew G. Hims, P.Eng Consulting Engineer AGH:nah Attachments: (i) Jagger Hims Limited June 18, 2001 Letter to Turkstra Mazza Associates: Rockfort

Quarry Licence Application Peer Review Hydrogeological Aspects. File 980984.02. (ii) Jagger Hims Limited October 16, 2001 Letter to Turkstra Mazza Associates: Rockfort

Quarry Application Peer Review Hydrogeological Aspects. File 980984.02. (iii) Jagger Hims Limited August 28, 2003 Letter jointly to Garrod Pickfield and Davis &

Company: Rockfort Quarry Licence Application Peer review Hydrogeological Aspects Adaptive Management Plan Water Resources Protection. File 980984.03.

(iv) Jagger Hims Limited September 16 2003 Letter jointly to Garrod Pickfield and Davis &

Company: Rockfort Quarry Licence Application Peer review Hydrogeological Aspects Summary Statement. File 980984.03.

10/31/08 1:55 PM 98/0984/02/wp/AGH-L Peer Review

June 18, 2001 Turkstra Mazza Associates 221 Woolwich Street Guelph, Ontario N1H 3V4 Attention: Mr. Stephen Garrod Dear Sirs: Re: Rockfort Quarry Licence Application Peer Review Hydrogeological Aspects File 980984.02 We have completed a preliminary review of the identified reports that have been prepared by Conestoga-Rovers & Associates in support of the application for a licence for the proposed Rockfort Quarry. The enclosed information is provided to assist Region of Peel staff in their assessment of the application and technical issues arising that should be resolved with the proponent, as part of the review and approvals process under the Aggregate Resources Act. As part of our continued assessment of the hydrogeological aspects of the application, we have reviewed the following documents:

(1) Water Resources Evaluation Volumes 1, 2 and 3. Rockfort Quarry Town of Caledon, Ontario. August 2000. Prepared by Conestoga-Rovers & Associates. Ref. No. 9595 (1).

(2) Adaptive Management Plan Water Resources Protection Rockfort Quarry Town Of

Caledon. August 2000. Prepared by Conestoga-Rovers & Associates and Ecoplans Limited. Ref. No. 9595 (5).

Turkstra Mazza Associates June 18, 2001


(3) Preliminary Design Report Water Resources Mitigation Measures Rockfort Quarry Town Of Caledon, Ontario. October 2000. Prepared by Conestoga-Rovers & Associates. Ref. No. 9595 (6).

(4) Environmental Impact Assessment Proposed Rockfort Quarry Town OF Caledon

Regional Municipality of Peel. August 2000. Prepared by Ecoplans Limited. File No. EC096-1854.

In addition, we have reviewed information provided by Harden Environmental Services Limited (Harden) in their document entitled “Rockfort Quarry Application Response To Jagger Hims Limited Peer Review”, dated April 6, 1999. We visited the site on August 27th, 1999 to view rock cores from boreholes that had been drilled on and off site under the supervision of Harden. Photographs of the rock core were provided by Harden in their document entitled “Rockfort Quarry Project Report On Site Investigations Volume 3-Core Photographs”, dated Spring 1999. It is noted that Volumes 1 and 2 of that document were not provided for review. Our review focuses primarily on the revised design and operations plan for the proposed quarry, and the associated documentation prepared by Conestoga-Rovers & Associates (CRA), although the earlier work completed by Harden was referenced. A considerable amount of additional field investigations, monitoring, analysis and design were undertaken by the proponent’s study team through 1999 and 2000. The knowledge base with respect to the physical setting of the site and the associated natural environment has been enhanced by the recent level of investigation and assessment. As a result of the new work, the proposed mining plan and mitigation measures have been modified from the original application, although the basic concept remains similar. Extraction of the bedrock resource will occur in phases in a dewatered quarry, with the exception of Phase 1 that will be extracted under water so that a reservoir of water can be maintained to supply the mitigation system and quarry operations. In order to minimize impacts on the ground water, surface water and aquatic habitat resources in the vicinity of the subject property, engineered mitigation measures are incorporated into the design and operation of the quarry. Those measures include grout curtain walls and a system of ground water recharge wells around the perimeter of the quarry, and soil buttresses against the inside of the final excavation to moderate the outflow of water from the lakes that will develop during the post-closure period.



The majority of the impact assessment with respect to ground water and surface water resources, and the mitigation of potential impacts, is based on the computer model that was developed for the site and the surrounding area. The potential magnitude of the impacts that might occur without the benefit of engineered mitigation measures is not provided in the documentation, except to state that predicted impacts would be unacceptable. An integral component of the quarry operations as proposed will be an Adaptive Management Plan for the water resources mitigation measures. The report by CRA states on page 1 that “The AMP method is based on a system of design, implementation, performance monitoring, evaluation, and optimization to ensure that the mitigation objectives are achieved.” In simpler terms, the basic premise of the AMP appears to be that whatever actual physical conditions are encountered during the quarrying process, an appropriate level of monitoring and mitigation measures will be implemented to “ensure that predetermined mitigation objectives and superior overall mitigation results are achieved” (page 55 AMP report). Based on our review of the documents provided, the key to whether or not the quarry can be operated safely as proposed, and the natural environment protected as predicted, is going to be controlled by three main factors, as follows.

(1) The actual quantity of water that will be required to operate the ground water recharge mitigation system of injection wells around the perimeter of the quarry as proposed, so that ground water resources and surface water resources adjacent to the site are maintained at existing levels.

(2) The actual availability of water within the quarry property to sustain the recharge

system throughout the operating life of the quarry and the post-closure period until the final lake levels are achieved.

(3) The actual final lake levels that can be maintained through passive means at the

end of the post-closure period, and how those lake levels will affect ground water and surface water resources adjacent to the quarry.

The assessment that is presented contains several simplifying assumptions with respect to ground water movement through the rock mass, and the interaction between the ground water and surface water resources. The reality is that ground water movement through the fractured, layered bedrock aquifer is complex at the local scale. Ground water movement will be somewhat erratic, and will occur along preferred and discrete flow paths within the rock mass such as fractures and bedding planes, rather than the more consistent and



predictable flow that occurs in sand and gravel aquifers. The interaction between the ground water and the surface water resources is similarly complex. Adjacent to the site, the surface water resources include spring-fed ponds and other spring areas, ephemeral, intermittent and perennial water courses, some of which receive ground water discharge through part or all of the year, and the associated aquatic habitat that includes a cold water fishery south of the site. Given this physical setting, there is a case to be made that the system is complex and may be sensitive to relatively small amounts of change. The simplifying assumptions that are adopted into the assessment, each of which tend to move the computer modeling assessment away from the actual physical conditions that prevail at the site, include the following.

ASSUMPTION USED IN MODEL ACTUAL CONDITION 1. The Amabel and the underlying Reynales

bedrock act as a single hydrostratigraphic unit. The horizontal hydraulic conductivity of the full thickness of the unit at a specific location is characterized by a single value. Lateral variation is incorporated into the model.

1. The Amabel is a layered bedrock formation that includes discrete beds that are separated by bedding plane discontinuities. The hydraulic conductivity characteristics will vary through the rock mass, both vertically and laterally. The Reynales Formation is recognized as a separate stratigraphic horizon from the Amabel that has different lithology and hydraulic conductivity characteristics.

2. The Amabel/Reynales unit is considered to

behave as an equivalent porous medium (similar to a granular soil) that can be characterized by a single value for hydraulic conductivity. Ground water movement is considered to occur in a predictable manner through the “pore space” in the medium.

2. The Amabel Formation is a fractured, layered bedrock aquifer. Ground water movement occurs along discrete and preferred flow paths that include the fracture and bedding plane discontinuities, and any solution channels that may be present in the rock mass. As such, ground water movement is more erratic and less predictable, particularly at the local scale, when compared to the porous medium characterization.

3. The computer model is based on a simple

two-dimensional hydrostratigraphic conceptual characterization of the aquifer that does not allow for vertical heterogeneities in the rock mass.

3. The Amabel is a complex three-dimensional aquifer that exhibits vertical heterogeneities within the rock mass.



ASSUMPTION USED IN MODEL ACTUAL CONDITION 4. The recharge well mitigation measures are

modeled such that ground water levels in the bedrock are maintained at pre-extraction levels around the perimeter of the quarry. It is assumed that this will ensure that minimal change occurs with respect to the pattern of ground water discharge (location and quantity) to local watercourses, ponds and spring areas adjacent to the site.

4. The movement of ground water through the rock will be controlled by the degree of horizontal and vertical interconnectivity of the fractures and bedding planes. The ground water / surface water interactions with respect to vertical hydraulic gradient conditions at areas of ground water discharge have not been characterized/ quantified. The relationship between ground water levels and gradient conditions at the quarry and discharge conditions at the surface water locations has not been established in detail.

5. The quantity of water that will be available to

maintain the ground water recharge mitigation system, supply the aggregate processing requirements and fill the lakes following extraction is based on several assumptions as well as the computer simulations.

5. The availability of water will be a critical factor in the successful operation of the quarry. The water budget as presented demonstrates that there will be a fine balance between water availability and requirements, with little room for error. The sensitivity of the values used in the water budget has not been evaluated.

6. The closure plan assumes that the water level

in the two lakes will achieve the elevations as modeled, and that ground water movement out of the quarry will result in similar flow patterns and ground water discharge areas as currently exists.

6. It is our understanding that the soil buttresses in the final quarry and the perimeter grout curtain wall will both be in place at the end of extraction. The ability to achieve the required hydraulic conductivity of the buttress/grout wall combination, so that ground water movement out of the quarry and the resulting discharge patterns maintain a similar flux and distribution as exists today, will be a difficult, but critical task. Further detail is required on how the permeability values will be achieved and evaluated, and what the sensitivity of the system will be with respect to ground water discharge patterns adjacent to the quarry.



In summary, the proponent has undertaken additional field investigations, analysis and ground water modeling since the original application, and has prepared a revised design and operations plan for the quarry. In order for the quarry to operate as intended and not cause unacceptable impacts on local ground water and surface water resources, all of the engineering mitigation measures have to function as predicted. The availability of, and need for, water within the quarry will be a key factor through both the operating life and the post-closure period, and the water budget assessment indicates that there is little margin for error available. For example, at the end of Phase 5 the quarry dewatering system and other sources are predicted to provide 10.92 million cubic metres of water per year, while the ground water recharge system will require about 10.69 million cubic metres per year. A 10% contingency water use is incorporated into the assessment, leaving a surplus of 130,044 cubic metres per year to fill the quarry. Since this represents only about 1.2% of the water required for the recharge system, there is not a large “comfort factor” that surplus water will be available to fill the lakes given the inherent variability in the physical setting, and the assumptions that are used in the water budget assessment. Based on the above, it would be prudent that a comprehensive sensitivity assessment be completed that addresses the likely range of values for the various input parameters and assumptions that are used in the analysis and the computer simulations. This will provide the review agencies with an upper bound and lower bound assessment of potential impacts. Given the large amount of technical data that have been presented, we are in the process of preparing a series of detailed questions/comments that require clarification by the proponent. We will forward those detailed comments and questions as soon as they have been finalized. Please contact our office if you have any questions. Yours truly, JAGGER HIMS LIMITED Andrew G. Hims, P.Eng. Consulting Engineer AGH:jmm c. Simone Banz, Region of Peel

10/31/2008 1:53 PM 98/0984/02/wp/AGH-R Detailed Questions Oct 16

October 16, 2001 Turkstra Mazza Associates 221 Woolwich Street Guelph, Ontario N1H 3V4 Attention: Mr. Stephen Garrod Dear Sirs: Re: Rockfort Quarry Licence Application Peer Review Hydrogeological Aspects File 98 0984.02 Further to our summary letter dated June 18, 2001, we have compiled a series of detailed questions/comments that require clarification by the proponent. The questions/comments are provided in the attached Appendix, and are numbered for ease of response by the proponent. A copy of our June 18, 2001 letter is also provided in the Appendix for completeness. The enclosed information is provided to assist Region of Peel staff in their assessment of the application and technical issues arising that should be resolved with the proponent, as part of the review and approvals process under the Aggregate Resources Act. As part of our continued assessment of the hydrogeological aspects of the application, we have reviewed the following documents:

(1) Water Resources Evaluation Volumes 1, 2 and 3. Rockfort Quarry Town of Caledon, Ontario. August 2000. Prepared by Conestoga-Rovers & Associates. Ref. No. 9595 (1).

(2) Adaptive Management Plan Water Resources Protection Rockfort Quarry Town Of Caledon. August 2000. Prepared by Conestoga-Rovers & Associates and Ecoplans Limited. Ref. No. 9595 (5).

Turkstra Mazza Associates October 16, 2001


(3) Preliminary Design Report Water Resources Mitigation Measures Rockfort Quarry Town Of Caledon, Ontario. October 2000. Prepared by Conestoga-Rovers & Associates. Ref. No. 9595 (6).

(4) Environmental Impact Assessment Proposed Rockfort Quarry Town OF Caledon Regional Municipality of Peel. August 2000. Prepared by Ecoplans Limited. File No. EC096-1854.

In addition, we have reviewed information provided by Harden Environmental Services Limited (Harden) in their document entitled “Rockfort Quarry Application Response To Jagger Hims Limited Peer Review”, dated April 6, 1999. We visited the site on August 27th, 1999 to view rock cores from boreholes that had been drilled on and off site under the supervision of Harden. Photographs of the rock core were provided by Harden in their document entitled “Rockfort Quarry Project Report On Site Investigations Volume 3-Core Photographs”, dated Spring 1999. It is noted that Volumes 1 and 2 of that document were not provided for review. As with the initial review that was completed in December 1998, for the purpose of summarizing the results of our peer review, we have been asked to respond to the six questions listed below. Our response is provided foe each question.

1. Does the work that has been undertaken comply with the regulatory standards; that is, does it meet the minimum requirements of the Aggregate Resources Act?

The hydrogeological study report does address all of the items listed in the Application Standards of the Aggregate Resources Act for a Category 2: Class “A” licence for a quarry operation which intends to extract aggregate material from below the established ground water table, Section 2.2 Technical Reports, Section 2.2.1 and 2.2.2 Hydrogeological Level 1 and Hydrogeological Level 2. The Application Standards indicate that for a Hydrogeological Level 2 Assessment, the technical report must address 14 items. The reports prepared by Conestoga-Rovers & Associates (CRA) address those 14 items. However, for the reasons outlined, we are not satisfied that these items have been addressed sufficiently to adequately characterize the hydrogeologic setting and the potential for adverse impacts. With respect to the local municipality, the Official Plan of the Town of Caledon and OPA 124 define the planning policies and guidelines that deal with Ecosystem Planning and Management to guide the land-use decision-making process. Section 3.1.5.12 of the Official Plan deals with Performance Measures for ground water, and includes nine items that should



be addressed when planning new development within the Town. In order for the Rockfort quarry operation to comply with the Town’s Performance Measures with respect to ground water, the monitoring and mitigation measures that are incorporated into the quarry design must function as described in the various reports prepared by CRA. It is our opinion that, whereas the knowledge base with respect to the physical setting of the site and the associated natural environment has been enhanced by the field investigations and assessment work that was completed during 1999 and 2000, the generalized nature of the computer modeling does not permit ground water / surface water interactions to be simulated at specific locations in any detailed manner. Since the whole impact assessment and design of the mitigation systems is based on the computer modeling, this lack of specific predictability is considered a significant weakness. Total reliance is placed on the Adaptive Management Plan to detect and prevent and/or mitigate any and all unacceptable impacts around the site.

2. Is the methodology that has been used appropriate for the type of study that is required?

The overall study methodologies that have been used for the hydrogeologic assessment are considered to be generally appropriate in order to achieve the stated objectives. Additional field investigations and office analysis components were undertaken in order to characterize the hydrogeologic setting and the general ground water / surface water interactions. As a result of the work during 1999 and 2000, the proposed mining plan and mitigation measures have been modified from the original application, although the basic concept remains similar. In order to minimize and manage impacts on the ground water, surface water and aquatic habitat resources in the vicinity of the site, engineered mitigation measures are incorporated into the design and operation of the quarry. The Adaptive Management Plan, which forms the cornerstone of the monitoring / mitigation plans for the site, is essentially a “try it and see” approach that is to be relied upon to protect the natural environment. Since the computer modeling does not incorporate any assessment of the fracture-flow nature of ground water movement in the layered bedrock aquifer, it is unable to predict specific impacts at specific locations, and the specific level of mitigation that will be required to manage those impacts in an appropriate manner. This is considered a significant weakness in the technical assessment, particularly since the nature of the ground water / surface water interaction and fishery habitat (that is, the vertical hydraulic gradient conditions) at the watercourses adjacent to the site are not documented in any detailed manner.



3. Are the data sufficient for the purpose for which they are being used? The proponent’s study team through 1999 and 2000 undertook a considerable amount of additional field investigations, monitoring, analysis and design. As a result of that work, the mining plan and mitigation measures have been modified from the original proposal. However, the computer modeling assessment that is presented by CRA is based on a more simplified conceptual model of the physical setting compared to the original assessment that was presented by Harden Environmental Services Limited. The original work by Harden incorporated the layered nature of the bedrock aquifer and attempted to build that into an equivalent porous medium three-dimensional computer model to simulate the ground water flow system. The work by CRA uses the much-simplified approach of representing the bedrock aquifer as a single layer that has the same hydraulic conductivity throughout it’s full thickness, but which does vary laterally. In reality, the bedrock aquifer is a complex discretely fractured and layered aquifer that, at the local scale, will not behave as an equivalent porous medium. Since the operational water budget for the quarry, the proposed mitigation measures, impact assessment and the initial Adaptive Management Plan are all based, to a large degree, on the computer modeling, a strong technical rationale for using the current simplified approach to a complicated problem has to be provided, and it is not. The data that are available should be used to demonstrate why the simplified approach is supportable, and what the limitations are.

4. Are the data accurate and reasonable? Except as noted below, the data collected through the field investigations appear to be appropriate, within the general context of this type of study and objectives. The study was not intended to provide an academic level of research, but rather to provide a sufficient level of understanding of the physical setting to be able to evaluate the potential effects of the proposed quarry. The field data are, however, incomplete with respect to the ground water/surface water interactions at the local watercourses. The ground water hydraulic gradient conditions beneath the watercourses were not established during the study, and the actual nature of the ground water discharge pattern at the creeks is not known. Since these conditions at the creeks are not known, it is difficult to see how these conditions will be monitored and protected as the quarry progresses. In addition to the gaps in the data set, we have also identified a concern with respect to the apparent limited use that has been made of much of the detailed field test data that were collected. As noted in response to question 3 above, the simplified hydrogeologic characterization of the Amabel aquifer that is presented does not appear to have incorporated much of the in-situ test data that are available from the boreholes. The rationale for this



approach is not justified in the report. As a result, the level of reliance that can be placed on the computer model simulations to accurately reflect actual field conditions throughout the rock mass is questioned, and the model’s ability to predict local effects from the proposed quarry at adjacent surface water resources is severely limited.

5. Are the conclusions accurate and reasonable? At the larger scale, the assessment appears to reasonably represent the general configuration of the ground water table across the site. At the local scale, the simplified approach of the computer model is not able to simulate/predict actual vertical hydraulic gradient conditions either in the bedrock aquifer or at the local surface water resources. This is considered a significant weakness in the assessment.

6. In these circumstances, that is, given that Caledon is in a unique geographic location, has sufficient detailed study and technical assessment been undertaken?

It is our opinion that a more rigorous evaluation of the field data is required, and additional site-specific ground water / surface water information is required, to better understand and simulate the physical setting and the operation of a quarry at this site. As noted in our comments on Section 9.0 in Appendix A, we have not provided any discussion or analysis of the proposed Impact Assessment, the Adaptive Management Plan or the Computer Modelling Appendix, since response to our other comments and questions are required to complete that work. We trust that this information is satisfactory at this time. Please contact the undersigned if you have any questions. Yours truly JAGGER HIMS LIMITED Andrew G. Hims, P.Eng. Consulting Engineer AGH:jmm

APPENDICES

APPENDIX A

PEER REVIEW COMMENTS

WATER RESOURCES EVALUATION ROCKFORT QUARRY

TOWN OF CALEDON, ONTARIO CONESTOGA-ROVERS & ASSOCIATES

August 2000 Ref. No. 9595 Volumes 1, 2 and 3

Peer Review Comments 980984.02 Rockford Quarry Application – Water Resources Evaluation Report October 16, 2001

Jagger Hims Limited 10/31/2008 1:53 PM 98/0984/02/wp/AGH-R Detailed Questions Oct 16 Page A-1

PEER REVIEW COMMENTS ROCKFORT QUARRY APPLICATION

WATER RESOURCES EVALUATION REPORT Bold italic numbers are provided for questions/comments for ease of response by the proponent. 1.0 INTRODUCTION 1.1: PROJECT STATUS AND ROLE OF CONESTOGA-ROVERS & ASSOCIATES 1: It is stated on page 1 that, initially, CRA was retained to provide a hydrogeologic opinion on the proposed Rockfort Quarry, and that CRA performed an independent evaluation of the data presented in the Harden report and reached similar conclusions to those in the Harden report. It further states that the current water resource evaluation by CRA supercedes that previously submitted by Harden and CRA does not rely on the Harden report with the exception of the base data. In the computer modeling completed by Harden, the bedrock aquifer is characterized as a three layered hydrostratigraphic unit that exhibits variable hydraulic conductivity values with depth as well as laterally, and was modeled accordingly. Did CRA concur with that assessment and that approach? What is the basis for CRA now using a simplified single layer approach to the characterization of the aquifer? Please specify how the original data collected by Harden and that subsequently collected in 1999 and 2000 are now used to support the single layer characterization as opposed to the multiple layered approach. This question, or a variant thereof, arises on several occasions in this peer review. 1.2: PROJECT OVERVIEW 2: On page 3 it is stated that “The potential changes in ground water levels around the quarry that could arise from dewatering activities and the creation of lakes under rehabilitation conditions result in the need for ground water mitigation measures to prevent unacceptable impacts to the water resources in the vicinity of the site.” Since the impacts from an “unmitigated”quarry operation are not documented in the report, what level of impact is considered by the proponent to be unacceptable?; what level of impact is considered acceptable?



It would be beneficial to illustrate the level of impact that could be expected from an “unmitigated” quarry operation, so that the mitigation measures as proposed can be assessed within an overall context. 1.3: REPORT ORGANIZATION 3: On page 5, it is stated that “It should be noted that north referred to in this report is project north which is the top of the figures presented in the report. Project north is approximately 45o northwest of true north.” As a point of clarification, is the use of directions in the text and/or appendices of the documents, such as north, south etc., always consistent with respect to a reference point of “page north”, rather than true north? Are there any exceptions to this? 2.0: REGIONAL SETTING 2.1: PHYSIOGRAPHY AND TOPOGRAPHY No comments. 2.2: HYDROLOGY 4: On page 7, para.3, the extraction area is stated to be 59 ha. Does this refer to the rock extraction area? Table 1.1 indicates that the rock extraction area for the amended concept is 46 ha, while the original concept had a rock extraction area of 59 ha. Which value is correct within the context of para.3? If the value of 46 ha is to be used, the percentage of the catchment would also change. 2.3: REGIONAL GEOLOGY 2.3.1: OVERBURDEN No comments. 2.3.2: BEDROCK 5: On page 10, para.3, the Village of Rockwood is stated to be approximately 35 kilometres east of the site. Does this refer to Rockwood located to the southwest of the site? (See Figure 1.1). 6: With reference to Outcrop 1 and the area immediately to the west, please define the term “massive”. What was the thickness of individual beds that are referenced in the statement



“sub-horizontal bedding was prominent which dipped very gently to the southwest at less than 9 m per 100m”? Should the dip be less than 9 m per 1000 m (not 100 m), to be consistent with page 8? 7: With reference to the fractures observed in the outcrops, do the fractures pass through the bedding planes, or do they terminate at the bedding planes? Was consideration given to carrying out a fracture pattern analysis at these outcrops to see if there is a preferential orientation of the fractures? 8: On page 11, para.2, it is stated that “On-site data indicates that the Amabel is underlain by the Reynales in the vicinity of the Rockfort Site.” How was the presence of the Reynales (and not the Fossil Hill) confirmed/differentiated at the site? 2.4: REGIONAL HYDROGEOLOGY 2.4.1: GROUND WATER FLOW SYSTEM 9: Reference to Figure 2.6 shows that cross-sections A-A’ and B-B’ are oriented map north-south and east-west respectively. Figures 2.7 and 2.8 indicate the orientations of the two sections to be northwest-southeast and southwest-northeast respectively. Which orientations are correct? 10: With reference to Figure 2.7, cross-section A-A’, are the “inferred ground water flow path lines” shown on the section based on a flow-net interpretation of ground water levels, or are they merely schematic representations of what the general flow directions are thought to be? 11: At the top of page 13, it is stated that: “The variable water depth conditions are typical of flow in fractured bedrock systems with a shallow water table. The hydraulic head (i.e. elevation of the water in a well with respect to a datum) may vary significantly from location to location due to variations in topography and hydraulic conductivity between blocks of competent rock and highly fractured rock.” How was this type of spatial and vertical anisotropy incorporated into the single layer equivalent porous medium model? How representative is the model of actual ground water flow conditions at the site and vicinity? The following paragraph quotes previous work by Nadon and Gale and others to support the use of an equivalent porous medium approach in representing the bedrock aquifer. How was the interconnectivity of the horizontal and vertical fractures demonstrated at this site?



12: Given the values for the hydraulic conductivity of the Reynales unit (Table 2.2) relative to those of the overlying Amabel unit and the underlying units, why is the Reynales not considered to represent a lower confining layer for the Amabel? 2.4.2: GROUND WATER QUALITY No comments. 3.0: FIELD INVESTIGATIONS No comments. 3.1: SUBSURFACE INVESTIGATIONS 13: With respect to the cored boreholes, and particularly the inclined boreholes, how were the fracture orientation data incorporated into the assessment of ground water flow at the site? 3.2: AQUIFER TESTING 3.2.1: PACKER TESTING 14: Were the results of the various types of packer testing (including the Lugeon testing) used to support the interpretation that the Amabel behaves as a single hydrostratigraphic unit? If yes, please provide that assessment. If not, why not? 3.2.2: SHORT-TERM PUMPING No comments. 3.2.3: LONG-TERM CONTINUOUS PUMPING TESTS No comments. 3.3: GROUND WATER MONITORING 15: Were the ground water conditions (i.e. vertical gradients) monitored at any of the creeks and/or ponds adjacent to the site, for comparison against the surface water monitoring data? If yes, are those data available. If not, why not? 3.4: RESIDENTIAL WELL SURVEY



No comments. 3.5: SURFACE WATER MONITORING 16: What is the general accuracy of the stream flow gauging methods? Is it considered sufficient to measure ground water discharge impacts at the site scale? 3.6: SURVEY No comments. 3.7: OFF-SITE ASSESSMENTS No comments. 3.8: FIELD GROUTING DEMONSTRATION PROGRAM Golder Associates Ltd. has provided extensive review comments with respect to the grouting aspects of the application, and our review has been more general in nature. It is unfortunate that the peer review consultants were not permitted to provide input to the demonstration project, nor view the field program while it was underway; that would have saved the need for much of the written discussion on this matter. 17: On page 22, it is stated that: “The coreholes were logged for geologic and hydrogeologic characteristics. Coreholes A1 and A4 were also water tested using an interval packer testing procedure. The results are shown in Table 3.2. This information is included in the Site characterization documented in this report.” Specifically, what analysis was completed on that information, and how does it support the characterization of the Amabel aquifer as a single hydrostratigraphic unit? 18: The September 1, 2000 report on the grouting demonstration project by L. Wolofsky (in Appendix B of the Preliminary Design Report Rockfort Quarry, by CRA, October 2000) indicates that considerably more water pressure (Lugeon) testing was carried out in the grout line boreholes during the field program. Was that information included in the characterization of the site? How does that information support the single hydrostratigraphic unit approach that has been adopted in the water resources assessment? 4.0: SITE GEOLOGY



19: Figures 4.2 to 4.8 are cross-sections through the area that illustrate the general geology and which form the basis for the conceptual three-dimensional geologic model of the site. Apart from the large-scale geology, these sections do not show any detailed information with respect to geologic fabric in the Amabel or ground water / surface water features. Except for the two regional hydrogeologic sections provided in Figures 2.7 and 2.8, were any sections produced that illustrate the hydrogeologic detail at the site? Given the level of field data that were collected, detailed hydrostratigraphic sections and/or fence diagrams through the site should be constructed to illustrate the pertinent features and provide technical support for the characterization that is presented. 4.1: OVERBURDEN 20: On page 24 para. 3, it is stated that the drumlin is oriented in a northwesterly direction. Does this refer to true north or map north? 4.2: BEDROCK No comments. 4.2.1: ERAMOSA 21: Page 25 indicates that fracture frequency distribution in the bedrock boreholes is provided on Table 4.2. That table lists the fracture frequency values as breaks/run. Since the core runs were not always the same length, how do these values correlate with the more normal method of expressing fracture frequency in terms of the number of fractures per unit length, such as per foot or per metre? 4.2.2: AMABEL 22: Paragraphs 3 and 4 provide a general discussion of the fabric (fractures and other discontinuities) of the Amabel bedrock. Was there any statistical (or other) assessment of those data carried out to assist in the characterization of the site? 4.2.3 REYNALES & 4.2.4 UNDERLYING BEDROCK UNITS No comments. 5.0: SITE HYDROLOGY



5.1: OVERVIEW 23: On page 30, it is stated: “The following presents a discussion of the ground water / surface water interaction for the key surface water features (F1 through F15).” Specifically, what ground water investigations and monitoring have been undertaken at the key surface water features that permit the actual ground water / surface water interactions in those features to be characterized and quantified? 5.2: ON SITE No comments. 5.3: AREA SURROUNDING SITE No comments. 5.3.1: NORTH SIDE No comments. 5.3.2: WEST SIDE 24: With respect to the West Branch, on page 33, it is stated that: “The pattern of a perennial upstream reach and intermittent flow at RW1 suggests that surface water is recharging the ground water downstream of the perennial reach.” Has the West Branch been walked to map where and why the surface flow begins to recharge the ground water? Have the vertical hydraulic ground water / surface water gradients been established along any of the West Branch? 25: Have the vertical hydraulic ground water / surface water gradients been established at any locations along the Main Branch and/or at the on-line and off-line ponds west of the site? The report documents anecdotal information that suggests that some of the ponds at least receive ground water discharge. Has any site-specific information been collected to quantify and characterize the ground water discharge conditions in those areas? 5.3.3: EAST SIDE 26: Have the vertical hydraulic ground water / surface water gradients been established at any locations along the East Branch and/or at the on-line or off-line ponds east of the site?



27: What is the estimated level of accuracy of the stream flow measurements that are reported. 5.3.4: SOUTH SIDE 28: Have the vertical hydraulic ground water / surface water gradients been established at any locations along the Main Branch and Second Creek and/or at the on-line or off-line ponds south of the site, particularly in the Feature F13 reach from Pond D down to Ballinafad Road, and Feature F15 both of which support cold water fisheries? 5.4: WATER CYCLE 29: Have climatic water budgets (Thornthwaite or other methods) been completed for the climate data presented on Tables 5.2 and 5.3? Reference to Table 5.3 shows that climatic conditions have been quite variable since 1997. How does the estimated amount of ground water recharge vary during the period 1997 to 2000, and how would ground water levels and discharge conditions be affected? Was the reported variability in climatic conditions incorporated into the water budget analyses that were prepared for the quarry operations? 6.0: SITE HYDROGEOLOGY 6.1: OVERVIEW 30: On page 48 para.1, it is stated that: “The Amabel is considered as one hydrostratigraphic unit consistent with the available information and traditional characterization. While localized heterogeneities may be present in the Amabel, persistent hydrostratigraphic sub-units (i.e., aquifers and aquitards) within the Amabel can not be identified.” Where, specifically, in the report is the “available information” shown to support the characterization of the Amabel as a single hydrostratigraphic unit? How does the grout curtain demonstration project work by Wolofsky, which suggests that in the area of the demonstration the Amabel contains identifiable zones of differing hydraulic conductivity, fit with the single hydrostratigraphic approach? How would the presence of two or more different hydrostratigraphic units within the Amabel aquifer affect the validity of the computer modeling that has been completed?



31: The Reynales is obviously a different lithological unit from the Amabel, and it has different hydraulic properties (hydraulic conductivity values etc.). What is the effect on the ground water flow assessment and computer modeling of retaining the Reynales as part of the Amabel, compared to treating it as a separate hydrostratigraphic unit? 6.2: HYDROGEOLOGIC ZONES AND GROUND WATER FLOW 6.2.1: UPPER WATERBEARING ZONE No comments. 6.2.2: AMABEL AQUIFER Previous comments and questions with respect to the inclusion of the Reynales unit into the Amabel aquifer, and the characterization of the Amabel as a single hydrostratigraphic unit apply in this section also. 32: Given the demonstrated variability in the hydraulic conductivity of the Amabel, both vertically and laterally (see page 52), and the resulting local changes in the flow direction, gradient and discharge, have the ground water discharge patterns been established and quantified at the adjacent water courses at the local scale? How will changes in those patterns be monitored at the local scale in order to determine if and when mitigation is required? 33: On page 52, it is stated that: “For the purpose of this and other water resource evaluations, the Amabel is sufficiently permeable and “well-connected” to be represented as an equivalent porous medium characterization. For micro-scale behaviour, the variability in the bedrock conditions must be considered further.” Please define micro-scale and macro-scale. Given the inherent variability in the hydraulic properties of the bedrock aquifer, would the ground water discharge patterns at specific locations along the adjacent surface water bodies be considered macro- or micro-scale effects? 34: Figures 6.1 to 6.6 illustrate the Amabel ground water contours for various dates between April 1997 and January 2000. There appears to be a noticeable difference between the contour pattern (i.e. water levels) for April 25, 1997 and January 17, 2000, particularly along the eastern side of the site. What is the explanation for the difference along the eastern side? Was this type of variability incorporated into the impact assessment?



6.3: HYDRAULIC TESTING 35: On page 35 para.2 of this section, it is stated that: “In general, results from these tests indicated that higher hydraulic conductivity zones are present in the bedrock in the vicinity of these test pumping wells.” Since the three test well sites are spread across the property, is it not reasonable to infer that most, if not all, of the site is underlain by such “higher hydraulic conductivity zones”? Is this site considered different from the adjacent lands(with respect to hydraulic properties), and if so, what is the basis for that position? 6.3.1: PW1 AND PW2: 3-DAY CONTINUOUS PUMPING TESTS 36: Reference to the results of these tests that are provided in Appendix C, shows that some monitors exhibited reasonable Theis and/or Cooper-Jacob plots, while others did not. Is there an explanation for this? Could the degree of interconnectivity of the fractures be one factor? Were all of the data used equally to calculate the ranges and means of the hydraulic conductivity values? 37: What is the explanation for the drawdown pattern that was observed around test well PW2 at the end of the 3-day test? 38: Would the type of pumping well and monitor construction used at the site be conducive to differentiating any effects associated with the presence/absence of different hydrostratigraphic layers or units within the Amabel? 39: In addition to the pumping tests at the three wells, a considerable number of other types of hydraulic tests were completed at this site, including various types of packer testing / Lugeon testing. How were these data used in the analysis of the hydraulic properties of the bedrock? How do these data support the characterization of the Amabel as a single hydrostratigraphic unit? 6.3.2: PW2: 36-DAY CONTINUOUS PUMPING TEST 40: The results from the first three days of this pumping test yield similar values of hydraulic conductivity as was obtained from the April 1997 three-day test at PW2 (geometric mean values in the order of 2 x 10-2 cm/s). Looking at the results obtained from the entire 36-day test, the geometric mean values obtained are in the order of 4 x 10-3 cm/s. Also, the degree of “fit” of the drawdown plots to the Theis and/or the Cooper-Jacob methods of analysis is generally much poorer for the 36-day results. The late-time data generally show a significant departure from the classic straight-line Cooper-Jacob analysis, with the rate of drawdown increasing per log cycle of time compared to the early-time data.



The explanations given for the lower permeability values are lower surficial recharge during the August test and less contribution from the shallow bedrock, and/or the intersection of an area of lower hydraulic conductivity at some distance from the pumping well. Do these explanations suggest the presence of at least two hydrostratigraphic units in the Amabel, an upper higher permeability zone and an underlying lower permeability zone? How does this characterization fit with the work of Wolofsky for the grout wall demonstration project, in that he identified zones of differing hydraulic conductivity with depth in the Amabel? 41: Given that the 36-day test results presumably better reflect the response of the aquifer to longer-term stress under summertime conditions, and thus better reflects the long-term operation of a deep quarry, why would the computer model use a hydraulic conductivity value of 1.2 x 10–2 cm/s in this area, rather than the lower value that was given by the longer-term test? 6.3.3: PW3: 7-DAY CONTINUOUS TEST 42: Values of hydraulic conductivity for the Amabel in this area were 1.9 x 10 –2 cm/s for the unconfined portion of the aquifer, and 1.8 x 10 -3 cm/s for the confined portion. What is the basis for using a value of 5.8 x 10-3 cm/s in the computer model for this area? 43: On page C-6 in Volume 3 Appendix, it is stated that: “It was noted during drilling of this well that very little water yield was encountered until the lower portion of the Amabel was reached and high yield was achieved. It is believed that this well derives the majority of its water through this lower Amabel zone.” Has “lower Amabel zone”.been defined anywhere? How does this fit with the single hydrostratigraphic unit approach that was modeled? 6.4: GROUNDWATER / SURFACE WATER INTERACTIONS 44: This section describes the interpreted ground water / surface water interactions around the site. Have any subsurface field investigations and/or ground water monitoring been completed at these off-site locations to verify and quantify the actual ground water / surface water interactions and the seasonal variations? Given the apparent spatial variability in the ground water discharge patterns around the site, how will any changes to those patterns be monitored to determine if mitigation is necessary? 6.4.1: NORTH SIDE



No comments. 6.4.2: WEST SIDE 45: On page 60 par. 1, it is stated that: “The West Branch is hydrogeologically separated from the site by the Main Branch, which is at a similar or lower elevation. An east-west ground water flow divide is likely present between the West and Main Branches.” What is the basis for the “east-west” flow divide, and is that map east-west or relative to true north? Given that the Main Branch of Rogers Creek “generally exhibits intermittent flow with two identified areas of perennial flow north of Olde Baseline Road” (page 60 para.2), and that “Between the No. 5 Sideroad and the confluence with the Main Branch, the West Branch is intermittent” (page 59, last para.), what factual data is there to support the statement that the West Branch is hydrogeologically separated from the Site? 6.4.3: EAST SIDE No comments 6.4.4: SOUTH SIDE 46: On page 63, para.4, it is stated that: “Ground water levels along the southern portion of the Site decline considerably from spring to fall.” Given that this area of the site is in a relatively downgradient position in the local flow system, what is the explanation for such declines in the ground water levels in that area? 6.5: WATER SUPPLY WELLS 47: Prior to any start-up of quarry operations, would well tests be completed at individual wells around the quarry property to establish baseline conditions, for comparison against future conditions that may arise as the quarry proceeds? 7.0: WATER QUALITY 7.1: OVERVIEW No comments. 7.2: GROUNDWATER



7.2.1: ON SITE No comments. 7.2.2 OFF SITE 7.2.2.1: RESIDENTIAL WELLS No comments. 7.2.2.2: MONITORING WELLS No comments. 7.2.3 DISCUSSION 48: Was there any sampling of the actual ground water discharges at the local watercourses around the Site to see which group (i.e. A or B) that water would fit into? 7.3 SURFACE WATER 49: The water sampling work completed by Novakowski, as documented in his report dated February 2001, indicates that isotope data can be used to identify waters of ground water origin in the watercourses around the site. Was this type of analysis considered by the study team, and what comments can be provided with respect to the Novakowski results? 50: Given that the surface water chemistry data suggests that ground water discharge is derived from the shallow bedrock for the most part, what impacts will there be to water quality when the deeper ground water, which will be intercepted by the quarry, is used to supply the mitigation recharge wells? 51: How does the water chemistry data (ground water and surface water) support the characterization of the Amabel as a single hydrostratigraphic unit? 8.0: MINING PLAN 8.1: OVERVIEW 52: On page 73, para.2, it is stated that: “These changes in water levels are likely to result in adverse impacts on the water resources in the vicinity of the Site if mitigative measures are not implemented.” Why is the unmitigated quarry scenario not presented? It should be

october 28, 2008 garrod pickfield llp davis & company · 2018. 8. 21. · 10/31/2008 2:02:58 pm...

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