OMB Rockfort Hearing for Tues. January 26th, 2010.

Continuing Evidence of Andy Hims (Hydro-Geology) and Trevor Carter (Grout Curtain) for the Town and Region led by Mr. Garrod (Region lawyer)

To Mr. Hims, looking at his work and comments in 2003:

• Letter Aug 2003 from Hims to CRA peer review of the AMP: He noted that for the most part the issues had not been resolved and had been no direct response from JDCL on the outstanding issues. If the investigations to the South of the site had been done on the Hydro-G more answers would be at hand. The situation still remains today; the work has not been done. 
  
• Hims has no problem with the approach of the AMP if it is done reasonably and properly. He uses it himself (Duntroon) but he does not believe the local area has been properly characterized so the foundation of understanding and factual information is not there. Just because you keep a recharge well at a certain level, it does not necessarily mean that the groundwater and surface water in the area will be protected. Hims still questions, in the lake filling period, that considering the grout barrier, the buttresses and the lakes, whether or not enough water will get through to supply local wells and water resources. These questions remain unanswered.

To Dr. Carter--his work and comments in Oct 2003:

• Nothing more substantive had been submitted, so the comments from 2001 basically remained unchanged. The entire curtain system is a substantial engineering project in scale and scope and more information and testing needed to be done. Some work had been done but not on vertical fractures at that time (it is proposed for Milestone #1). Two critical tests demonstrating that the recharge system works and that the cut-off system works needed to be done.
  
• A presentation was given to the Region, agencies and JDCL in Aug 2003. 
  
• He agrees with Mr. Naudts regarding Naudts' concerns of how effective the grouting will be under flow conditions in high gradient situations (wherever there is more than a 10 meter difference between the water head on either side of the curtain). This is all dependent on being sure about the Hydro G model for the design of the curtain as well. Carter has significant concerns about this and the inherent costs involved in such a large project with many unknowns.

To Mr. Hims: from work and comments from 2003-2008:

• JDCL completed the CBSES, which Hims was not retained to examine, as it did not include site-specific information. In 2008 JDCL submitted updated plans.
  Summary of concerns:
  
• Design and mitigation measures and technical info are very similar to was submitted in 2000.
  
• Even with the CBSES info done, there is no comparison of the site-specific modeling and the regional scale Hydro-G modeling done.
  
• There is concern that the model does not reflect what is on the ground. Since there is a lack of information from JDCL since 2001, they did not do a detailed review of the 2000 model or run it and test it, and it still has not been tested.
  
• Hims was asked to prepare a document for the Region of options that the Region could take--1) turn down the approval 2) attempting a proof of concept, allowing a staged approval. Do you have an opinion about those two options as to which is more appropriate?
  Answer--From a strictly technical view, it might be acceptable to do a staged process, but from a public policy basis that is beyond his expertise. From a personal point of view, there is connection of the ground and surface water and he thinks the proponent would want to know that his system would work to protect the environment and would have done the work.
• Looking at the detailed Lugeon testing during the grout demonstration: these holes along the A line were drilled prior to grouting.  In the graph, each stage refers to another 3 meter in depth. The table shows each stage of each borehole, the Lugeon value. The average is shown on the graph. This testing does give a pattern of the differing Lugeon values at different depths. There are four major zones: The upper weathered zone (7-10 meters below grade) has a high Lugeon value of 175 Lugeons. The next zone is a less transmissive zone (10-25 meters) of 30-50 Lugeon and then by the 3rd zone, stages 9 to 11 (at 25-38 meters)-it is the most transmissive zone (100-375 Lugeon). Then the fourth and deepest zone has low values at 15-20 Lugeon. These numbers don't support a single hyro-graphic unit, which is used in the model. There is not strong evidence to support a single value. The grouting test data supports a more complex approach. The data don't fit the model.
  
  
  He is concerned about the Hydro-G model representing only a seasonal model (averaged conditions) rather than a transient model (which is the actual seasonal variation is used).  He has run transient models at Duntroon.

To Dr Carter: His comments and work from 2003-2008:

• They were pleased to see the Bruce/McCreath reports and the improved intent on the engineering. They were shocked not to see any further work on characterization of the site and info on all the joints and fracturing. He liked Dr Bruce's details of design--still there is a major concern that reports have not updated the sensitivity testing and verification of Hydro-G modeling and mitigation design.
  
• Looking at the AMP protocol chart for construction of the grout curtain. You need to start with a good ground model--then set up the design--then construction with a monitoring feedback loop, then review and if it's not working go back to the beginning. The proper ground model is VERY important to get right and Carter doesn't believe they have enough information. JDCL continued to insist that no further field exploration was needed. This work is really fundamental to the design. When this work should be done is a matter of public policy decisions and outside his expertise, but it should be done before approvals.
  
• With the new AMP, Carter is less concerned about implementation but still concerned about the design verification of the curtain. His opinion is that a 10 Lugeon curtain may be achievable but he questions if it is practical given the costs of the grout and the field data.
• When ACT did the demonstration test they used state-of-the-art technology, but Carter talked to them and they said all the problems were due to the "on the ground" conditions. The daily detailed reports from ACT on Dec 22nd/1999 show detailed activities. ACT was doing frequent coring in this process but the information from those cores has not been provided to Carter.
  
• Looking at the test logs, there are areas where heavy grouting was required. Even after grouting, the V (verification) holes drilled were showing permeability at 120 Lugeons or 10 to the minus 3 permeability, when the target was 10-15 Lugeons (ten times the target)!  Looking at hole A3; it has the highest grout take (4.5 tons of grout into that one hole). In the table it shows that hole took about 8,400 liters of grout. Most of that grout went into stages 9,10,and 11. Beside that is the V5 hole which shows there is still a high 120 Lugeon factor after grouting, with still very high grout takes. During the next two holes further to the east, V6 and V7, the test was stopped. Carter thinks the high grout takes are because of the sub-vertical jointing nature of that area one joint on a NW/SE axis and another on a NE/SW axis. Potentially more than two rows of holes of grouting will be needed, plus further grouting in the AMP after extraction. Construction will be difficult under flow conditions.
• The details of the ACT report show the ground conditions being difficult with quite a number of holes that needed downstage grouting. This means it could be a very expensive project.
• In the test Box, hole # TB 4 showed that there was a 4 foot void and they hit a zone of high permeability at depth of about 30 meters. The grouting did not meet the goal of closure of the box. A number of holes showed no refusal of grout.
• Looking at Dr Wolofsky's Report: Regarding the B Line one hole is taking the highest amount of grout of 734 liters per meter of depth going into the ground.
• Looking at C7 (jointing); C5 and C9 (vuggy) from the day before where we noted high permeability. The conditions in the grout test holes relate to the C7, C5 an C9.
• During the pumping test, a maximum drawdown was achieved to a maximum of 4 meters without grout and across gradient. Mr. Naudts notes this in his report. It appears there is cross-contamination between the injection well and the grout. Carter recommends at least a 10-meter distance between these two to prevent cross contamination.
• Dr Carter goes to the down hole video logs drilled by Harden in 1999. He was given 9 videos and some were not complete because the hole collapsed. Carter watched all the videos and annotated each one. Looking at BH C8 it's at the north of the quarry area. The video shows the instrument swinging free with water moving through a large vuggy area of space and rubble. A blockage happens at 16 meters so drilling was discontinued there. This is typical of vuggy zones. Core hole C3 shows major horizontal fractures and there is interconnected porosity. The videos clearly show the layer-cake formations all over the site.
• Looking at Dr Low's rock mechanics report; he was trying to develop how far back to set the grout curtain. He looked at rock mechanics 1) In-situ stresses, 2) Sheer Strength (rock sliding) and 3) Modulus (squashy-ness strength). He analyzed the grout test holes and he noted high fractures per meter at the near surface zones and the 30-meter zones. His notes show that a layered model is representative of the site. He had concerns about "pop-ups" and the need for a 5-meter cover over the lower limits of excavation, which JDCL has incorporated. He also recommended a monitoring system of the rock movement. Again it illustrates how you have to get the ground information right.
• Carter believes that the site has not been properly characterized.

To Mr. Hims:

• There were meetings that happened between late 2008 and early 2009. During which CRA provided some figures about the hydraulic stratigraphy, which Hims did not agree with. The 2009 Peer Review by Hims indicated that he still did not agree with the single value hydraulic conductivity used in the model. The issue of the characterization is central to the issue of the mitigation system being practical. Well-calibrated models can be very helpful to show relative sense of future changes to the flow conditions.
• Because there were no bored core holes within the grout curtain test area to compare to the test results, we can't extrapolate to other core holes on the site. Instead field data is not fitting with the model. Why is that a reasonable thing to do? So he has a low level of confidence that the proposed mitigation will work. With more information provided, but that info may constrain the application due to impracticality or cost. (Read his summary statement of the 2009).

Evidence to continue tomorrow.