R. F. Favreau Ph. D. Professor Emeritus, Royal Military College, Kingston On

Transcription

1 EVALUATION OF THE CONSEQUENCES OF THE BLASTING METHODS INTENDED FOR THE PROPOSED SCOTIAN MATERIALS QUARRY AT GOFFS, HALIFAX REGIONAL MUNICIPALITY, NOVA SCOTIA R. F. Favreau Ph. D. Professor Emeritus, Royal Military College, Kingston On April 27, 2016 I) Mandate: I have been requested by Mr. Miller to carry out an objective evaluation of the expected consequences of the blasting from a rock quarry on the traveling public on Highway 102 and on the inhabitants of the region of Goffs and Fall River, in Halifax Regional Municipality, and on the natural gas pipeline located adjacent to the proposed quarry, the study to be based on the blasting methods intended for the proposed quarry according to information obtained by Mr. Miller via a FOIPOP (Freedom of information and protection of privacy) application. II) Information available about the proposed quarry: This report is a second report on the same subject. The first report (reference 1) used the meager technical information then available regarding the blast methods intended for the proposed quarry, and included a request to the sponsor of the quarry Scotian Materials for the technical information required for a study, and which people affected by the presence of the quarry have a right to obtain. But in a letter dated January 5, 2016, the quarry s attorney refused to supply the legitimate data required by the writer of the present report, further stating that You have asked for a great deal of technical 1

2 information about the blasting. It is not possible to provide answers for all your questions that would encompass the entire progression of blasting during the lifespan of the quarry. On the contrary, the writer maintains that this is exactly the purpose of the present study; the inhabitants who will have to live with the consequences of the blasting for the whole lifespan of the quarry have the right to know now what provisions the quarry is making to insure their protection during this whole lifespan. The writer gets the impression that the quarry plans its blasting as if it was to be located far away from a significant population, the traveling public on Highway 102, and an important gas pipeline supplying the whole of Halifax, without any special plans for the blasting to account for the fact that on the contrary there is such a population and pipeline, and it is not the people who have chosen to build their homes near the proposed quarry but rather the latter who is a late comer. Highway 102 is a five lane major arterial route to and from the Halifax area, and is the most traveled highway in Nova Scotia. This same reply from the quarry s attorney continues: The public consultation component of the industrial approval process, as we understand it, is intended to provide an opportunity for consultation and input on environmental issues. It is certain that flyrock, vibrations, and air blasts from blasting with explosives are indeed environmental issues. These aspects of a quarry much affect the normal quality of life to which people have a right, especially people who established their homes and life in the area before the quarry was proposed. Other information about the proposed quarry, such as the number of tons of rock to be excavated per blast, how plans are for a small quarry that would gradually increase its operations, etc., are presented in the first report reference 1. Recently information about the blasting methods intended for the proposed quarry have been obtained by Mr. Miller via a FOIPOP (Freedom of information and protection of privacy) application, (see reference 9) and the present study is based on the blasting methods intended for the proposed quarry according to this information obtained by Mr.Miller. 2

3 III) Risk of danger due to blasting: The present study evaluates the several consequences to be expected from the blasting by a rock quarry, on the inhabitants and traveling public on Highway 102 of the region where the quarry is proposed, and on the natural gas pipeline located adjacent to the proposed quarry. The following consequences are evaluated: Risks from fly rock. Risks from ground vibrations. Risks from air blasts. Accordance with the Canada Oil and Gas Regulation Each one of these aspects is evaluated separately below. IV) Risks from Flyrock: Amongst the blasting methods intended for the proposed quarry, according to information obtained by Mr. Miller, there are proposed in Appendix D, Sample blast design, 3 blasts methods, two with 4.5 (11.4 cm) diameter and one with 5.5 (14 cm) diameter, as shown on the Appendix D diagram entitled 2015 blast planning. There is some ambiguity in the Golder document regarding which detailed data sheets pertain to the blast method with a 5.5 (inch) diameter (14 cm diameter), but careful scrutiny allows the identification of which detailed data sheets pertain to the 5.5 (14 cm) diameter method, and so the present report begins by evaluating the expected consequences of the blasting from blast methods of this 5.5 (14 cm) type on the inhabitants of the region of Goffs and Fall River, the traveling public on Highway 102, and on the natural gas pipeline and other facilities located near to the proposed quarry. For this 5.5 (14 cm) type of blast method, each of the types of risks listed above in Section III above will next be evaluated. 3

4 IV-A) Risks from fly rock: Example of intended blast method #3 in the Golder document Appendix D, Sample Blast Design : This type of risk is that which is most pertinent for the inhabitants in the vicinity of the quarry, and for the traveling public on Highway 102, since not only it can cause death, damage to motor vehicles using Highway 102, and possibly cause multi-vehicle accidents, but moreover it can cause anguish every time the people hear the noise from a blast. For blast holes that have the nominal blast parameters proposed by Golder as shown below, the expected quality of the blast results and the flyrock range and altitude are predicted below using the blast simulator Blaspa whose accuracy has been proven by over 40 years of trials in the field (see Appendix 1 in the present report): 4

5 Simulation A: Expected quality of the blast results predicted with the accurate simulator Blaspa for the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder: The blast parameters used for Simulation A above are the nominal values for the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder, namely: Bench height H= 45 (ft)(14.8m) subdrilling G=3 (.98m) hole depth=48 (15.7m) Hole diameter D=5.5 (14 cm) burden B=13 (4.3 m) spacing S=13 (4.3 m) Collar C=10 (3.3 m) Explosive=bulk 70/30 Emulsion/anfo at density 1.2 gm/cc Regarding the rock, Golder gives no information. However, according to the information obtained from Dyno Nobel, the rock is Granite, for which Golder does not give the rock properties Young s modulus Y, Poisson s ratio s, density d and resistance in compression Sc. Hence Simulation A above 5

6 uses properties measured from a drilling in Granite for a project on autoroute 50 in Quebec Province, namely Y=526 Kbars, s=0.3, d=2.65 gm/cc, and Sc=111 Mpa. From the results of Simulation A it can be concluded that the expected quality of the blast results for the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder is very adequate, at least for those holes that have the nominal values of the blast parameters. For this blast method, the expected flyrock range and altitude are shown in Simulation B below: Simulation B: flyrock range and altitude predicted with the accurate simulator Blaspa for the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder: The blast parameters used for Simulation B above are the same as those for Simulation A. From the results of Simulation B above, it can be concluded 6

7 that the flyrock range and altitude for the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder are safe, at least for those holes that have the nominal values of the blast parameters. In practice, however, for all blasts there are some holes for which the values of the blast parameters vary from the nominal values. The size of the variations can differ significantly from blast to blast; for some blasts they may not be too significant, especially if the operation is far from any inhabitants, or if the inhabitants have been evacuated from the vicinity of the blast. However, from his 40 years of experience in the field of blasting, the writer knows by how much the values of the blast parameters can for some holes vary from the nominal values. Large variations of burden usually occur near the edges of the blast, and for some holes only. If the large variations are recognized, corrections are sometime made before the blast; but often this is very difficult to achieve. The worst neglected large variations from the nominal values of the blast parameters are often for a situation where the blast must be detonated not later than at a certain hour, and when that hour arrives there is no time to check or correct the large variations, and the blast is nevertheless detonated hoping that all will be safe. The writer can evaluate accurately the maximum size of the variations in the values of the blast parameters from the nominal values that can occur for some holes of the blast. For the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder, such variations can be as shown below, and several of these variations can occur for the same hole: Bench height H= 45 (14.8 m) +/-5 (1.6 m) due to variations in the rock thickness. Subdrilling G=3 (.98 m)+/-1 (.33 m) due to inattention by the driller. Hole diameter D=5.5 (14 cm)+/-1 (.4 cm) due to an old drill bit or wobbling of the drill bit. 7

8 Burden B=13 (4.3m) can be as low as 2 (.66m) for a hole near the face of the bench. Spacing S=13 (4.3 m)+/-2 (.66 m) due to difficulty in placing the drill. Collar C=10 (3.3 m) can be as low as 1 (.33 m) or even 0 due to expansion of the Emulsion explosive column. Explosive density= 1.2 gm/cc can be as high as 1.35 if the emulsifier fails to work properly. The writer has seen many cases of all these large variations. The Simulations D, F and H below demonstrate the consequences of such variations on the range and altitude of the flyrock from a hole that has some of these variations from the nominal values of the blast parameters, while Table A below summarizes more examples: 8

9 Simulation D: flyrock horizontal range and altitude predicted with the accurate simulator Blaspa for the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder, if the value of the bench height H=50 (16.4 m), subdrilling G=4 (1.3 m), collar C=5 (1.6 m), burden B=5 (1.6 m), diameter D=6.5 (16.5 cm): 9

10 Simulation F: horizontal flyrock range and altitude predicted with the accurate simulator Blaspa for the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder, if the value of the bench height H=50 (16.4 m), subdrilling G=4 (1.3 m), collar C=1 (.33 m), burden B=5 (1.6 m), diameter D=5.5 (14 cm), the explosive is Emulsion at density 1.34 gm/cc: 10

11 Simulation H: horizontal flyrock range and altitude predicted with the accurate simulator Blaspa for the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder, if the value of the bench height H=50 (16.4 m), subdrilling G=4 (1.3 m), collar C=1 (.33 m), burden B=5 (1.6 m), diameter D=5.5 (14 cm), the explosive is emulsion at density 1.34 gm/cc, there is a blasting mat on top of the hole: 11

12 Table A Examples of the consequences on the horizontal flyrock range and altitude of variations in the values of the blast parameters from tne nominal values for a hole: Simu- H G D C BxS Flyrock Lation range altitude B x m.98m 14cm 3.3m 50m 21m 4.3x4.3m C x m 1.3m 16.5cm 1.6m 85.6m 62m 4.3x4.3m D x m 1.3m 16.5cm 1.6m 257m 107m 1.6x4.3m E x m 1.3m 14cm.33m 286m 212m 1.5x4.3m F* x13 1, m 1.3m 14cm.33m 347m 261m 1.5x4.3m G x13 1, m 1.3m 16.5cm.33m 406m 308m 1.5x4.3m H*# x13 1, m 1.3m 14cm.33m 347m 67.5m 1.5x4.3m 12

13 *This simulation uses a pure emulsion at density 1.34 gm/cc due to bad emulsifier action. *#This simulation uses a pure emulsion at density 1.34 gm/cc due to bad emulsifier action, plus a blasting mat on top of the hole. As can be seen from Simulations B, D, E and H above and the simulated results in Table A, variations in the values of the blast parameters from the nominal values for one hole can increase very significantly the range and altitude of the flyrock, with corresponding important effect on the nearby inhabitants, both regarding danger to their life and anguish each time they hear a blast. One may argue that the proposed quarry could use blasting mats on top of some holes. But as can be seen from the results of simulation H, compared with those of simulation F, this only reduces the altitude of the projection while the horizontal range remains as dangerous. Comment: Usually the majority of holes in a blast have values of blast parameters that correspond mostly with the nominal values, although it does occur that many holes do have dangerous values of their blast parameters, in which case the blast sends a shower of flyrock. For example this occurred recently for two operations in the Province of Quebec, which sent large showers of flyrock on nearby cities. Comment: The key point is that dangerous flyrock from even one or two holes of the blast still sends very many pieces of flyrock, which suffices to make that blast totally unacceptable for the nearby inhabitants and the traveling public on Highway 102. A single piece of flyrock can kill a person, and cause an operator of a motor vehicle to lose control while traveling at 110 kms per hour, the posted speed limit. Comment: The writer does not propose that all the blasts from the proposed quarry would necessarily send dangerous flyrock every time. But the results of the simulations above do show that for the variations of the values of the blast parameters that the writer has encountered in quarries, the type of blasts intended for the proposed Scotian Materials quarry will without any doubt send dangerous fly rock regularly, and this is an 13

14 unacceptable situation for the nearby inhabitants and the traveling public on Highway 102 Comment: The reason why the simulated results above show not only the horizontal range of the flyrock but also its altitude is that, even if a flyrock hits a person only if its range takes it outside the quarry, even so the altitude is seen and a high altitude causes as much anguish as the horizontal range because the viewer has the impression that a flyrock of high altitude will hit him. Thus high altitudes make flyrock as unacceptable for the inhabitants near a quarry as do large horizontal ranges. IV-B) Other risks from fly rock: Another risk of dangerous flyrock from blasts is one that occurs regularly but of which very few blasters are aware of, as explained in reference 2. It is as follows: when a blaster is worried that his blast method might cause dangerous fly rock, he tends to weaken his blast method assuming that this will remove the danger of long horizontal range flyrock, but which on the contrary can often increase it. The reason that it increases it is that a weaker blast method can, for a multirow blast, lead to a raising quarry floor and some very long range flyrock, as explained in reference 2. The blast methods intended for the proposed quarry are multirow blasts. Since the proposed quarry is to be located in a region near a gas pipeline, a highway, residences, etc, hence the blaster will be worried about dangerous flyrock; therefore it is essentially certain that this cause for long range flyrock will occur for the intended blasts at the proposed Goffs quarry. In fact, the lack of accurate knowledge of the rock properties Y, s and Sc for the site confirms that this cause for long range flyrock could even occur for the very first intended blasts at the proposed Goffs quarry, as demonstrated below. The Dyno Nobel section, figure 2, of the information obtained by Mr. Miller states that General parameters of granite were used for the evaluation of flyrock range. This strongly indicates that not a single exploratory borehole has been drilled to obtain samples that would have 14

15 allowed to obtain accurate rock properties, and so predict accurately the horizontal flyrock range; it seems that the Scotian Materials people do not consider that the security of the inhabitants near the projected quarry deserve drilling even one exploratory borehole, nor sending rock samples for measurements by a rock mechanics laboratory.. Hence they used so called general parameters of granite, namely Young s modulus Y=40.00 Gpa and a resistance in compression Sc=180 Mpa. But in fact available values Y of Young s modulus from the literature inform that the latter can be as low 11 Gpa and as high as 73.8 Gpa, while available values of the resistance in compression can be as low as 38 Mpa and as high as 276 Mpa, so that the simulated fly rock results with the values of 40 Gpa and 180 Mpa (not obtained from a borehole on the site) are rather meaningless. Thus it can be that some of the granite of the proposed quarry has values of Y= 73.8 Gpa (or 738 Kilobars) and Sc=276 Mpa. It is pertinent to examine the resulting quality of the blast results and flyrock if the 4.5 (11.4cm) blast method intended for the proposed quarry according to Golder was used in granite of these properties for the first blast shown on the Golder figure 2015 blast planning. 15

16 Simulation I: Expected quality of the blast results for the first row, predicted with the accurate simulator Blaspa for the 4.5 (11.4cm) diameter blast method intended for the first blast at the proposed quarry according to Golder, if the rock has properties Y=738 Kb, s= 0.22, d= 2.65, Sc=276 Mpa: The blast parameters used for Simulation I above are the nominal values for the 4.5 (11.4cm) diameter blast method intended for the proposed quarry according to Golder, namely: Bench height H= 25 (ft)(8.2m) subdrilling G=3 (.98m) hole depth=28 (9.2m) Hole diameter D=4.5 (11.4cm) burden B=11 (3.6m) spacing S=11 (3.6m) Collar C=8 (2.6m) Explosive=bulk 70/30 Emulsion/anfo at density 1.2 gm/cc Regarding the rock, Simulation I above uses the properties Y=738 Kb, s= 0.22, d= 2.65, Sc=276 Mpa. 16

17 From the results of Simulation I above, it can be seen that the blast method produces toe of height 9 (3m). As a consequence, the floor of the blast for the second row will be higher by 9 (3m), with an effective bench height of unbroken rock of 25-9=16 (5.2m) and a subgrade of 3+9=12 (3.9m) for the second row. For these values of the bench geometry for the second row, Simulation J below shows that the blast will produce a further toe of 7.5 (2.5m): Simulation J: Expected quality of the blast results for the second row, predicted with the accurate simulator Blaspa for the 4.5 (11.4cm) diameter blast method intended for the first blast at the proposed quarry according to Golder, if the rock has properties Y=738 Kb, s= 0.22, d= 2.65, Sc=276 Mpa, and the blast of the first row has raised the floor for the blast of the second row by 9 (3m) : Thus Simulation J above shows that the blast of the second row produces a further toe of 7.5 (2.5m), so that the floor of the blast for the third row will be higher by a further 7.5 (2.5m), with an effective bench height of 17

18 unbroken rock of =8.5 (2.8m) and a subgrade of =19.5 (6.4m) for the third row. For these values of the bench geometry for the third row, the blast will produce still more toe, so that the floor of the blast for the third row, the fourth row, etc will keep rising, and the height of unbroken rock at the top of the bench keeps getting shorter for back rows. As a consequence, for such back rows the action of the full column of explosive is concentrated on a smaller and smaller mass of rock, so that the horizontal range and altitude of the flyrock from the back rows become larger. The blast for back rows is less like a bench blast, but rather it becomes like a sinking cut blast; the flyrock from such a situation can be predicted with the Blaspa simulator Flyrock Maximum Sinking Cut, as shown in Simulation K below: Simulation K: horizontal flyrock range and altitude predicted with the accurate simulator Blaspa for the first 4.5 (11.4cm) diameter blast method intended for the proposed quarry according to Golder, if the rock has properties Y=738 Kb, s= 0.22, d= 2.65, Sc=276 Mpa, and the blasts of the front rows has raised the floor for the blast of the back rows: 18

19 Thus the simulations above show that for the very first 4.5 (11.4cm) blast intended for the proposed quarry according to Golder, should it be in granite of very strong rock properties, then the flyrock will have a range of 466 (153m) i. e. four times greater than the expected range of 110 (36m). The planners of the proposed quarry give the impression that they have not enough concern for the security of the inhabitants and the traveling public on Highway 102 near the proposed quarry to even get the required accurate properties of the rock from an exploratory drill hole. IV-C) Further risks from fly rock: Still another risk of dangerous flyrock from blasts is one that very few blasters are aware of, again as explained in reference 2. It is once more that when a blaster is worried that his blast method might cause dangerous fly rock, he then tends to weaken his blast method assuming that this will remove the danger of long horizontal range flyrock, but which on the contrary can increase it. This situation will next be demonstrated by an example of what can occur, say in a blast of the 4.5 (11.4 cm) method intended for the proposed quarry according to Golder. From his experience in blasting, the writer is very well aware that a blaster can alter the explosive type for some holes that are part of the whole blast. This occurs for a variety of reasons, e. g. i) because that region of the blast is close to properties outside the quarry, or close to say quarry equipment like a crusher, and the blaster is therefore worried about flyrock or ii) even simply because the blast is due in a half hour and there is a shortage of explosives to fill the last 10 holes. Hence the blaster can replace the usual bulk Emulsions by bagged Emulsions, because he feels that this will be safer against the risk of dangerous flyrock, or maybe simply because such explosives are available on the spot while there is a shortage of bulk explosive available. It is to be noted that there is provision for the use of packaged explosives according to Golder: Explosives products will be packaged and bulk. 19

20 Simulation L below demonstrates the consequences of replacing the bulk emulsion by packaged explosive: Simulation L: Expected quality of the blast results predicted with the accurate simulator Blaspa for the 4.5 (11.4cm) diameter blast method intended for the proposed quarry according to Golder, if the bulk Emulsion is replaced by packaged Emulsion: As can be seen from the results of Simulation L above, the rock of the bench does not fully break all the way from the vertical face to the borehole (see the explanation for this in reference 3). However, at the top of the hole, there is a region of thickness 2.7 (.88m) which does break, so that the entire 20 (6.6m) column of explosive will concentrate its action on that small rock mass. To predict the range and altitude of the flyrock imposed on that limited mass of rock by the action of the whole explosive column, the Blaspa simulator Flyrock Maximum Sinking Cut is used below: 20

21 Simulation M: horizontal flyrock range and altitude predicted with the accurate simulator Blaspa for the 4.5 (11.4cm) diameter blast method intended for the proposed quarry according to Golder, if the bulk Emulsion is replaced by packaged Emulsion: 21

22 As can be seen from the results of Simulation M above, the consequences of replacing the bulk Emulsion by packaged Emulsion on the range and the altitude of the flyrock are very severe, because the whole action of the full column of explosive is concentrated on a small mass of rock. The horizontal flyrock range increases from the expected 110 (36m) to 2,723 (893m), while the altitude is increased from 55 (18m) to 2,989 (981m). The flyrock from this blast is very dangerous for the safety and anguish of the inhabitants in the vicinity of the quarry. The writer has regularly been aware of dangerous flyrock due to this cause. IV-D) Risks from fly rock for the Dyno blast method: The flyrock predictions in sections IV-A, IV-B and IV-C above are for blast methods intended for the proposed quarry according to Golder. However, in the information obtained by Mr. Miller there is another blast method intended for the proposed quarry, but this one according to Dyno. The expected horizontal flyrock range and altitude for this intended blast method according to Dyno are presented below in Simulations Z3 and Z4: 22

23 Simulation Z3: horizontal flyrock range and altitude predicted with the accurate simulator Blaspa for the blast method intended for the proposed quarry according to Dyno: 23

24 Simulation Z4: horizontal flyrock range and altitude predicted with the accurate simulator Blaspa for the blast method intended for the proposed quarry according to Dyno, if H=62 (20m), G=4 (1.3m), B=5 (1.6m), C=1 (.33m), D=6.5 (16.5cm): The blast parameters used for Simulation Z3 above are the nominal values for the blast method intended for the proposed quarry according to Dyno, namely: Bench height H= 57 (ft)(18.7m) subdrilling G=3 (.98m) hole depth=60 (19.7m) Hole diameter D=5.5 (14cm) burden B=13 (4.3m) spacing S=13 (4.3m) Collar C=10 (3.3m) Explosive=bulk 70/30 Emulsion/anfo at density 1.2 gm/cc Rock properties assumed by Dyno (not from an exploratory drill hole on the site nor measurement by a rock mechanic laboratory): Y=400 Kbars, s=0.22, d=2.65 gm/cc, and Sc=180 Mpa. 24

25 The blast parameters used for Simulation Z4 above are variations of the nominal values expected for some holes, as explained in section IV-A above. As can be seen from the results of Simulation Z3 above, the flyrock range and altitude can be expected to be mostly safe values of 163 (53m) and 60 (19.7m) for many holes, but as can be seen from the results of Simulation Z4 above, the flyrock range and altitude can be expected to be for some holes the very dangerous values of 1169 (384m) and 866 (284m), i. e. for holes whose blast parameters diverge from the nominal values. Such divergences from the nominal values invariably occur regularly. IV-E) The advisers for the proposed quarry use inadequate calculations to predict flyrock: In the Dyno Nobel, 3. Projections section of the data relating to the application to the NSE which has been obtained by Mr. Miller, figure 3 supplies flyrock results that are unreliable, namely: a value of maximum range of meters, which is dubious because the diagram from which this range is predicted simply does not correspond with the way that a blast creates flyrock; and a value of altitude of 17.4 m which is also dubious because it does not predict any flyrock emitted from the top of the bench in the region of the collar, i. e. the region from which any observation of a blast shows that this is the source of the most far reaching fly rock (see for example Simulation F above). In fact, comparing these values of range of m and altitude of 17.4 m with the values of range of 384 m and altitude of 284 m predicted in Simulation Z4 above with the accurate simulator Blaspa, it is seen that the Dyno predictions are largely undervalued, not only because Dyno uses an unreliable calculation method, but also because Dyno does not take into account the variations from the nominal values which invariably occur for the actual values of the blast parameters. 25

26 The calculation method used by Dyno is called I-Blast. Its inaccurate calculations have been demonstrated by its prediction of a maximum range of 46 m for a blast at a mine in Northen Quebec, whereas in fact the actual flyrock range from that blast was as large as 1000 (328 m) and the blast sent a large shower of rock on the city of Malartic. It is pertinent that the Province of Quebec s environment agency did not trust the prediction of 46 m made with I-Blast before the actual blast. Hence, again before the blast, it then mandated the writer of the present report to use the same data but to make flyrock predictions with the reliable simulator Blaspa, which predictions were that much flyrock would reach about 200 m while some far flyrock could reach as far 328 m. Based on these predictions, the mine was instructed to create a region of 200 m in the town from which the people of Malartic were evacuated during the blast. When the blast occurred, it sent a large shower of large flyrock fragments on the evacuated region, as well as many small flyrock fragments as far as 328 m into the rest of the town. The writer of the present report was there when the blast occurred and, together with technicians from the Province of Quebec s environment agency, he took measurements of the range reached by the flyrock. It is pertinent that a large section of the evacuated region was a park where, without the evacuation, school children would have been present during their recess, as well as citizens who normally run there for their health. The evacuation that resulted from the reliable flyrock predictions made with the simulator Blaspa undoubtedly saved lives. Subsequently, the person who sells I-Blast presented a paper on the blast at Malartic, pretending that it had been a success because it had excavated much rock, but omitting to mention that it had sent a shower of flyrock on the town. In view of the inaccurate predictions that I-Blast makes for the flyrock, e. g. as demonstrated at Malartic, the use by the projected Scotian Material quarry advisers of these unreliable I-Blast calculations in their study for the projected Goffs quarry is dangerous for the safety of the inhabitants and 26

27 the traveling public on Highway 102 near the projected Goffs quarry at Halifax. It is pertinent that neither the writer of the Golder study nor that of the Dyno study signed his report, hinting that they did not have full confidence in the calculation methods which they used.. V) Risks from vibrations: The writer recognizes that vibrations do not pose for the inhabitants near the proposed quarry as much a threat of danger to life as does flyrock. Nevertheless they may in some cases cause damage to structures, and even cause a part of a structure to fall on someone. But certainly they affect the quality of life, and the authorities define for a given region a specific limit on the maximum vibration level allowed as a result of the blasts. In the region of the proposed Goffs quarry, the value of this allowed limit is a particle velocity of 12.5 mm/second. V-A) Risks from vibrations due to variations in the values of the blast parameters: For blast holes that have the nominal blast parameters proposed by Golder for 5.5 (14cm) holes, and which are shown below, the expected level of the vibrations at the natural gas pipeline is predicted below using the blast simulator Blaspa whose accuracy has been proven by over 40 years of trials in the field (see Appendix 1 and reference 4 in the present report): 27

28 Simulation N: Expected vibration level at the natural gas pipeline at 656 (200m) from the blast, predicted with the accurate simulator Blaspa, for the 5.5 (14cm) diameter blast method intended for the proposed quarry according to Golder: The blast parameters used for Simulation N above are the nominal values for the 5.5 (14cm) diameter blast method intended for the proposed quarry according to Golder, namely: Bench height H= 45 (ft)(14.8m) subdrilling G=3 (.98m) hole depth=48 (15.7m) Hole diameter D=5.5 (14cm) burden B=13 (4.3 m) spacing S=13 (4.3m) Collar C=10 (3.3m) Explosive=bulk 70/30 Emulsion/anfo at density 1.2 gm/cc Regarding the rock, Golder gives no information. However, according to the information obtained from Dyno Nobel, the rock is Granite, for which 28

29 Golder does not give the rock properties Young s modulus Y, Poisson s ratio s, density d and resistance in compression Sc. Hence Simulation N above uses properties measured from a drilling in Granite for a project on autoroute 50 in Quebec Province, namely Y=526 Kbars, s=0.3, d=2.65 gm/cc, and Sc=111 Mpa. Regarding the quality of the rock, Golder does not supply any values of RQD (rock quality determination). Hence for Simulation N above, the rock has been assumed of good quality, namely a rock quality factor of 1.01, based on the fact that the Scotian Materials people have picked the site for a projected quarry which usually indicates that the rock is of good quality. From the results of Simulation N above it can be concluded that the expected vibration level at the natural gas pipeline for the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder is very excessive, namely 58.2 mm/s versus 13.3 mm/s as estimated by Golder. This level of 58.2 mm/s not only fails to respect the allowed limit of 12.5 mm/s, but in fact it is of such magnitude that it exceeds the usual limit of 50 mm/s imposed by Hydro-Ontario for its hydroelectric structures, and might very possibly damage the natural gas pipeline that supplies all of Halifax. The vibration level in Simulation N above is for those holes that have the nominal values of the blast parameters. In practice, however, for all blasts there are some holes for which the values of the blast parameters vary from the nominal values. The size of the variations can differ significantly from blast to blast; for some blasts they may not have too much significance. However, from experience in blasting, the writer knows by how much the values of the blast parameters may for some blasts vary from the nominal values. Large variations of burden usually occur near the edges of the blast, and maybe for a few holes only. If the large variations are recognized, corrections are sometime made before the blast; but often this is very difficult to achieve. The worst neglected large variations from the nominal values of the blast parameters are often for a situation where the blast must be detonated not later than a certain hour, and when that hour arrives there is no time to check or correct the large variations, and the blast is nevertheless detonated hoping that all will be safe. 29

30 The writer can evaluate accurately the maximum size of the variations in the values of the blast parameters from the nominal values that can occur for a few holes of the blast. For the 5.5 diameter blast method intended for the proposed quarry according to Golder, such variations can be as shown below, and several of these variations can occur for the same hole: Bench height H= 45 (14.8m) +/-5 (1.6m) due to variations in the rock thickness. Subdrilling G=3 (.98m)+/-1 (.33m) due to inattention by the driller. Hole diameter D=5.5 (14cm)+/-1 (2,54cm) due to an old drill bit or wobbling of the drill. Burden B=13 (4.3m) can be as low as 2 (.66m) for a hole near the face of the bench. Spacing S=13 (4.3m)+/-2 (.66m) due to difficulty in placing the drill. Collar C=10 (3.3m) can be as low as 1 (.33m) or even 0 due to expansion of the Emulsion column. Explosive density= 1.2 gm/cc can be as high as 1.35 if the emulsifier fails to work properly. The writer has seen cases of all these large variations. Simulations P and S below demonstrate the consequences of such variations on the level of vibrations at the natural gas pipeline at 656 (215m) from the blast, due to a hole that has some of these variations from the nominal values of the blast parameters, while Table B summarizes more examples: 30

31 Simulation P: vibration level predicted with the accurate simulator Blaspa for the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder, if the value of the bench height H=50 (16.4m), subdrilling G=4 (1.3m), collar C=5 (1.6m) : 31

32 Simulation S: Vibration level predicted with the accurate simulator Blaspa for the 5.5 (14cm) diameter blast method intended for the proposed quarry according to Golder, if the value of the bench height H=50 (16.4m), subdrilling G=4 (1.3m), collar C=5 (1.6m), hole diameter D=6.5 (16.5cm), the emulsion explosive has density 1.34 gm/cc: 32

33 Table B Examples of the consequences on the vibration level at the gas pipeline (200 m from the blast site) of variations on the values of the blast parameters from tne nominal values for a hole: Simu- H G D C BxS rock vibration lation quality mm/s N x13 good m.98m) 14cm 3.3m 4.3x4.3m O x13 fair m.98m) 14cm 3.3m 4.3x4.3m P x13 good m 1.3m) 14cm 1.6m 4.3x4.3m Q x13 good m 1.3m) 16.5cm 1.6m 1.6x4.3m R* x13 good m 1.3m) 14cm 1.6m 4.3x4.3m S* x13 good m 1.3m) 16.5cm 1.6m 4.3x4.3m *This simulation uses a pure emulsion at density 1.34 gm/cc due to bad emulsifier action. 33

34 As can be seen from the simulations N, P and S above, and the simulated results in Table B above, variations in the values of the blast parameters from the nominal values for one hole can increase very significantly the vibration level at the natural gas pipeline (200 m from the blast site). From the results simulated in Table B above, it can be concluded that for some blasts the expected vibration level at the natural gas pipeline due to one hole for the 5.5 (14cm) diameter blast method intended for the proposed quarry according to Golder will undoubtedly be very excessive, namely as high as 86.4 mm/s versus 13.3 mm/s as estimated by Golder. All the vibration levels in Table B not only fail to respect the allowed limit of 12.5 mm/s, but in fact those of vibration level above 50 mm/s are of such magnitude that they exceed the limit usually imposed by Hydro-Ontario for its hydroelectric structures; the vibration level of 86.4 mm/s is very likely to damage the natural gas pipeline that supplies all of Halifax, especially after repetitive impact of high vibration levels. Comment: The writer does not propose that all the blast holes from the proposed quarry would necessarily create a vibration level as high as 86.4 mm/s. But the results of the simulations above show that for the variations in the values of the blast parameters that the writer has encountered in quarries, the type of blasts intended for the proposed quarry will without any doubt create vibration levels as excessive as those shown in Table B, and this is an unacceptable situation for the safety of the natural gas pipeline which supplies the whole of Halifax, especially because it only takes one blast that creates a vibration level of 86.4 mm/s to cut the pipeline. This is further unacceptable because the pipeline was there first; the proposed quarry is the latecomer. V-B) Risks from vibrations due to variations in the number of holes detonated at the same time: The level of vibration caused at a given distance from the blast depends on the number of holes blasted on the same delay. In the document 34

35 Appendix D, Sample Blast Design, by Golder, presenting the blasting methods intended for the proposed quarry, Golder reports regarding the delay schemes for two intended blast methods, namely a 4.5 (11.4 cm) blast method and a 5.5 (14 cm) blast method. However, it does happen in practice that at a given distance from the blast, vibrations from more than one hole may occur at the same time, in which case the total vibration level is higher. Such situations can occur for the following reasons, e. g. i) a blaster helper inadvertently forgets to include the 25 msec delay between some holes of the same row, or ii) there is a shortage of 25 msec delay and the blast has to be detonated in the next 30 minutes, so the blaster is told to take a chance and blast without 25 msec delays for part of a row, or iii) some 25 msec delays are old and defective, and so fail to create a delay; etc. The writer has regularly been aware of such situations. Simulations T and U below show examples of the resulting total vibration level expected when vibrations from more than one hole occur simultaneously: 35

36 Simulation T: Expected vibration level at the natural gas pipeline at 656 (200m) from the blast, predicted with the accurate simulator Blaspa for the 5.5 (14cm) diameter blast method intended for the proposed quarry according to Golder, two adjacent holes detonate simultaneously: 36

37 Simulation U: Expected vibration level at the natural gas pipeline at 656 (200m) from the blast, predicted with the accurate simulator Blaspa for the 5.5 (14cm) diameter blast method intended for the proposed quarry according to Golder, five adjacent holes detonate simultaneously: As can be seen from the results of simulation N in section V-A and simulations T and U above, when two or five adjacent holes detonate simultaneously, the level of vibrations at the natural gas pipeline increases very excessively, namely from 58.2 mm/s to mm/s and mm/s. The level of vibration of mm/s creates an unacceptable situation for the safety of the natural gas pipeline which supplies the whole of Halifax, because it only takes one blast that creates a vibration level of mm/s to cut the pipeline. The writer has regularly been aware of situations where inadvertently several holes detonated simultaneously. 37

38 V-C) Risks from vibrations for the Dyno blast method: The vibration level predictions in sections V-A, and IV-B above are for blast methods intended for the proposed quarry according to Golder. However, in the information obtained by Mr. Miller, there is another blast method intended for the proposed quarry, but this one according to Dyno. The expected vibration level at the natural gas pipeline for this intended blast method according to Dyno are presented below in Simulations Z5 and Z6: Simulation Z5: vibration predicted with the accurate simulator Blaspa for the blast method intended for the proposed quarry according to Dyno: 38

39 Simulation Z6: vibration predicted with the accurate simulator Blaspa for the blast method intended for the proposed quarry according to Dyno, if H=62 (20.3m), G=4 (1.3m), C=5 (1.6m), D=6.5 (16.5cm); this simulation uses a pure emulsion at density 1.34 gm/cc due to bad emulsifier action. The blast parameters used for Simulation Z3 above are the nominal values for the blast method intended for the proposed quarry according to Dyno, namely: Bench height H= 57 (ft)(18.7m) subdrilling G=3 (.98m) hole depth=60 (19.7m) Hole diameter D=5.5 (14 cm) burden B=13 (4.3m) spacing S=13 (4.3m) Collar C=10 (3.3m) Explosive=bulk 70/30 Emulsion/anfo at density 1.2 gm/cc Rock properties assumed by Dyno (not from an exploratory drill hole on the site nor measurement by a rock mechanic laboratory): Y=400 Kbars, s=0.22, d=2.65 gm/cc, and Sc=180 Mpa. 39

40 The blast parameters used for Simulation Z4 above are variations of the nominal values expected for a few holes, as explained in section IV-A above. As can be seen from the results of Simulation Z5 above, the vibration level can be expected to be 59.7 mm/s at the natural gas pipeline, which exceeds the allowed vibration level of 12.5 mm/s. Moreover, as can be seen from the results of Simulation Z6 above, the vibration level at the pipeline can be expected for some holes to be of the dangerous value of 84.9 mm/s, e. g. for those holes whose blast parameters diverge from the nominal values. The writer from his experience in blasting knows that such divergences from the nominal values invariably occur from time to time. Thus the expected vibration level at the natural gas pipeline for this intended blast method according to Dyno, as presented above in Simulations Z5 and Z6, not only exceeds the allowed level of 12.5 mm/s, but can be of a level that may break the pipeline. Also, as explained in section V-B above, should more than one hole detonate on the same delay then the vibration level can reach values above 200 mm/s, i. e. so high as to very likely break the pipeline. The writer has regularly been aware of situations where inadvertently more than one hole detonated simultaneously. V-D) Risks from vibrations due to predictions made with inadeqately accurate calculations: In the document Appendix D, Sample Blast Design by Golder, presenting the blasting methods intended for the proposed quarry according to information obtained by Mr. Miller, Golder predicts the vibration levels using the Holmberg Equation. This equation has been proposed empirically and not on the basis of the fundamental principles of chemistry and rock mechanics which govern what happens in a rock mass during a blast with explosives. It proposes a level of vibration based on the total length of the explosive column detonated for one delay. It does not take into account the mechanical properties of the rock Y, s, d and Sc, nor the geometrical 40

41 parameters of the blast H, G, D, BxS, C, nor the thermochemical behaviour of the explosive compositions involved during the blast. It is unfortunate that the Scotian Material people do not use the reliable methods available (see references 4 and 3) for predicting accurately the vibration levels due to the intended blast methods for the proposed quarry. The documents Appendix D, Sample Blast Design by Golder, using Holmberg, propose vibration levels of 9.2 mm/s and 13.3 mm/s at the natural gas pipeline for the blast methods intended for the proposed quarry. As can be seen from the vibration levels calculated above in Table B of section V of the present report, these levels will in fact be much exceeded. It is pertinent that the proposed quarry s consultant recognizes that their own 13.3 prediction exceeds the allowed limit of 12.5 mm/sec. It is also pertinent that the proposed quarry s consultant seems not to be aware of the One Third Practice. This practice is followed by several contractors, e. g. contractors doing blasts at Hydro-Quebec hydroelectric constructions. It is a practice that recognizes that empirical methods for predicting the level of vibration to be expected from a given blast are so unreliable that contractors using them use blasts designed to predict one third the value of the allowed vibration limit. For example, if the allowed vibration limit is 12.5 mm/s, they use blasts designed to predict 12.5 divided by 3 equals 4.2 mm/s. As the region of the proposed quarry is very sensitive, e. g. with a natural gas pipeline (200 m from the blast site) that supplies all of Halifax, and as Golder uses the empirical Holmberg approach, it would be wise for the proposed quarry to plan blasts that would predict vibration levels of only 4.2 mm/s at the pipeline. 41

42 VI) Risks of excessive Air Blast levels: In addition to causing flyrock and vibrations, the intended blasts for the proposed quarry would also cause air blasts, which then travel away from the blast and diminish the quality of life of the inhabitants in the vicinity of the quarry. Society now recognizes that air blasts of excessive intensity are not acceptable, and most regions and major highways have limits on the maximum air blast intensity acceptable. In the region for the proposed quarry, this allowed limit is 128 decibels (db). Researchers such as the US Bureau of Mines physicists (e. g. see reference 5) propose that the main air blast due to a blast is caused by the horizontal movement of the bench face under the action of the explosion gases in the borehole; this movement results in a piston like push by the rock of the bench on the air in front of the bench, and the simulator Blaspa can predict the resulting intensity of the air blast. The air blast is a wave in the air, and as this wave rubs against the surface of the ground below, it attenuates. The degree of attenuation depends on the shape of the surface of the ground, and the simulation with Blaspa of the intensity of the air blast at a given distance S of the blast takes this attenuation into account (see reference 6). VI-A) Risks of excessve air blast intensity due to variations in the values of the blast parameters: For blast holes that have the nominal blast parameters proposed by Golder for 4.5 (11.4cm) and 5.5 (14cm) holes (the blast parameters for 4.5 (11.4cm) holes are listed in section IV-B above; the blast parameters for 5.5 (14cm) holes are listed in section IV-A above), some values of expected level of the air blast intensity at 50 (16.4m) from the blast hole are predicted below, using the blast simulator Air Blast, of the Blaspa set of simulators whose accuracy has been proven by over 40 years of trials in the field (see Appendix 1 and reference 6 in the present report): 42

43 Simulation V: Expected air blast intensity at the limit of the quarry, predicted with the accurate simulator Blaspa for the 4.5 (11.4cm) diameter blast method intended for the proposed quarry according to Golder: 43

44 Simulation Z1: Expected air blast intensity at the limit of the quarry, predicted with the accurate simulator Blaspa for the 5.5 (14cm) diameter blast method intended for the proposed quarry according to Golder: Regarding the rock, Golder gives no information. However, according to the Dyno Nobel information obtained by Mr. Miller, the rock is Granite, for which Golder does not give the rock properties Young s modulus Y, Poisson s ratio s, density d and resistance in compression Sc. Hence the simulations V and Z1 above, and simulation Y below and those in Table C below, use properties measured from a drilling in Granite for a project on autoroute 50 in Quebec Province, namely Y=526 Kbars, s=0.3, d=2.65 gm/cc, and Sc=111 Mpa. Regarding the distance S at which the air blast intensities are calculated in Simulations V and Z1 above, Figure 2015 Blast Planning by Golder in Appendix D, Sample Blast Design of the blast methods intended for the proposed quarry indicate that the holes in two of the first three blasts 44

45 closest to the limit of the quarry would be at a distance S of about 50 (16.4m) from the limit of the quarry. As the pertinent aspect of the Air Blasts predicted for the intended blast methods for the proposed quarry is their intensity when they leave the limit of the quarry, the Air Blast levels in Simulations V and Z1 above, in Simulation Y below, and those in Table C below have been predicted mostly at distance S=50 (16.4m). The limit allowed for Air Blasts is 128 db. The blast parameters used for the Simulations V and Z1 above use the nominal values of the blast parameters proposed for the blast methods intended for the proposed quarry according to Golder. In practice, however, for all blasts there are holes for which the actual values of the blast parameters vary from the nominal values. The size of the variations can differ significantly from blast to blast; for some blasts they may not be too significant, especially if the operation is far from any inhabitants, or if the inhabitants have been evacuated from the vicinity of the blast. However, from his experience in blasting, the writer knows by how much the values of the blast parameters can for some holes vary from the nominal values. Large variations of burden usually occur near the edges of the blast, and often for a few holes only. If the large variations are recognized, corrections are sometime made before the blast; but often this is very difficult to achieve. The worst neglected large variations from the nominal values of the blast parameters are often for a situation where the blast must be detonated not later than at a certain hour, and when that hour arrives there is no time to check or correct the large variations, and the blast is nevertheless detonated hoping that all will be safe. The writer can evaluate accurately the maximum size of the variations in the values of the blast parameters from the nominal values that can occur for a few holes of the blast. For the 5.5 (14 cm) diameter blast method intended for the proposed quarry according to Golder, such variations can be as shown above in section IV-A above, while for the 4.5 (11.4cm) diameter blast method intended for the proposed quarry according to Golder, such variations can be as shown below, and several of these variations can occur for the same hole: 45

46 Bench height H= 25 (8.2m) +/-5 (1.6m) due to variations in the rock thickness. subdrilling G=3 (.98m)+/-1 (.33m) due to inattention by the driller. Hole diameter D=4.5 (11.4cm)+/-1 (2.54cm) due to an old drill bit or wobbling of the drill. burden B=11 (3.6m) can be as low as 2 (.66m) for a hole near the face of the bench. spacing S=11 (3.6m)+/-2 (.66m) due to difficulty in placing the drill. Collar C=8 (2.6m) can be as low as 1 (.33m) or even 0 due to expansion of the emulsion column. Explosive density= 1.2 gm/cc can be as high as 1.35 if the emulsifier fails to work. The writer has regularly seen cases of all these large variations. Simulation Y below demonstrates the consequences of such variations on the air blast intensity from a hole that has some of these variations from the nominal values of the blast parameters, while Table C below summarizes more examples: 46

47 Simulation Y: Expected air blast intensity at the limit of the quarry, predicted with the accurate simulator Blaspa for the 4.5 (11.4cm) diameter blast method intended for the proposed quarry according to Golder, if the value of the hole diameter D=5.5 (14 cm): Table C below summarizes more examples of the expected air blast intensity, mostly at the limit of the quarry, predicted with the accurate simulator Blaspa for blast methods intended for the proposed quarry according to Golder: 47

48 Table C Examples of the consequences on the air blast intensity at the limit of the quarry of variations on the values of the blast parameters from the nominal values for a hole: Simu- H G D C BxS attenu- S db lation ation V x11 weak m.98m 11.4cm 2.6m 16.4m 3.6x3.6m W x11 stronger m.98m 11.4cm 2.6m 16.4m 3.6x3.6m X* x11 weak m.98m 11.4cm 2.6m 16.4m 3.6x3.6m Y x11 weak m.98m 14cm 2.6m 16.4m 3.6x3.6m Z* x11 weak m.98m 11.4cm.33m 16.4m 3.6x3.6m Z x13 weak m.98m 14cm 3.3m 16.4m 4.3x4.3m Z x13 weak m.98m 14cm 3.3m 32.8m 4.3x4.3m Z11* x13 weak

49 11.4m.98m 14cm 3.3m 16.4m 4.3x4.3m Z12* x13 weak m.98m 14cm 3.3m 201m 4.3x4.3m Z13* x13 weak m.98m 14cm 3.3m 317m 4.3x4.3m *This simulation uses a pure emulsion at density 1.34 gm/cc due to bad emulsifier action. As can be seen from the results of Simulations V, Y and Z1 above, and the simulated results in Table C above, the air blasts leaving the proposed quarry for all the intended blast methods for the proposed quarry would be of a level far exceeding the allowed limit of 128 db. VI-B) Risks from air blasts due to predictions made with inadeqately accurate calculations: In the document Dyno Nobel presenting a blasting method intended for the proposed quarry according to information obtained by Mr. Miller, Dyno estimates the air blast intensity at distances of 100 (32.8m) to 9,840 (3,228m) using an approach proposed in the US Bureau of Mines report RI This USBM approach has been proposed empirically and not on the basis of the fundamental principles of chemistry, rock mechanics and air mechanics which govern what happens in a rock mass and in the air in front of the rock mass during a blast with explosives. It proposes to estimate the levels of air blast intensity as a function of distance S based solely on the quantity of explosive detonated for one delay. It does not take into account the mechanical properties of the rock Y, s, d and Sc, nor the geometrical parameters of the blast H, G, D, BxS, C, nor the thermochemical behaviour of the explosive compositions involved during the blast, nor the attenuation of the air wave as it travels over the ground. 49

50 According to these Dyno predictions, the air blast level from the blasting method intended for the proposed quarry would exceed the allowed limit of 128 db up to a distance S=4,000 (1,312m). These predictions therefore dictate to the NSE that the proposed quarry cannot be allowed to operate, since there is no way that such blasts can respect the 128 db rule of the NSE (see Table 2 in reference 1). It is unfortunate that the Scotian Material people do not use the reliable methods available (see references 6 and 3) for predicting accurately the air blast intensities for the intended blast methods for the proposed quarry. According to Table C of the present report, the air blasts leaving the proposed quarry for all the intended blast methods for the proposed quarry would be of a level far exceeding the allowed limit of 128 db. With the simulator Air Blast, blasts that respect the 128 db limit can be calculated; this would help the Scotian Material people to realize that their proposed quarry in the locality of Goffs simply cannot be operated within the allowed air blast limits. Dyno Nobel also presents air blast predictions using the French calculation method called I-Blast 7.0 TBT by Thierry Bernard. As explained above in section IV-D of the present report, this is the calculation method with which the horizontal range of flyrock was predicted as 46 m for a mine in Northen Quebec, whereas in fact the actual flyrock horizontal range was as large as 1000 (328m) and the blast sent a large shower of rock on a city. The air blast results shown in figures 4 and 6 of the Dyno report are very dubious. The use by the projected Scotian Material quarry advisers of such unreliable calculations is risky for the safety of the inhabitants near the projected quarry, and should not be considered by the NSE in its decision regarding the safety of a quarry in the Goffs region. 50

51 VII) Accordance with the Canada Oil and Gas Regulation: The Canadian Government has done studies that evaluate the risk of damage to a gas pipeline from blasting. Appendix 2 presents a table of the minimum distance between an explosive charge and an oil or gas pipeline, as published in Canada Oil and Gas Geophysical Operations Regulations. From maps of the location of the proposed quarry and its vicinity, it can be measured that for the blast methods intended for the proposed quarry, as obtained by Mr. Miller, the shortest distance between the natural gas pipeline feeding Halifax and the proposed quarry is about 200 m. From the table in Appendix 2, it is seen that for blasts involving more than 100 Kgm, the distance between the blast and the pipeline must be at least 500 m. It is pertinent that, according to section 17(2) of the Canada Oil and Gas document, the amount of explosive referred to in the table of Appendix 2 is not the amount of explosives per delay, but rather the amount of explosives to be detonated in any shot hole or array of shot holes. Amongst the blasting methods intended for the proposed quarry, there are proposed in Appendix D, Sample blast design, 2 blasts methods, one with a 4.5 (11.4 cm) diameter and one with a 5.5 (14 cm) diameter, as shown on the Appendix D diagram entitled 2015 blast planning, which information is according to Golder. The values of the other blast parameters for the 4.5 (11.4 cm) method are presented above in section IV-B of the present report, while the values of the other blast parameters for the 5.5 (14 cm) method are presented above in section IV-A of the present report. Using these data, the explosive weight per hole for each of these methods is calculated to be as follows: 4.5 (11.4 cm) blast method: weight = 80.8 kgm per hole 5.5 (14 cm) blast method: weight = kgm per hole As each of these two blast methods intended for the proposed quarry involve 110 holes, the total explosive weight per blast for each of these method is calculated to be as follows: 4.5 (11.4 cm) blast method: weight=80.8 kgm x 110=8,888 kgm 5.5 (14 cm) blast method: weight=226.3 kgm x 110=24,893 kgm 51

52 Thus for both of these blast methods intended for the proposed quarry, the total weight of explosive exceeds 100 kgm by a very wide margin. Hence according to entry 9 in the table in Appendix 2, the minimum distance between the blast and the natural gas pipeline that feeds Halifax must be at least 500 m. Since this minimum distance of 500 m substantially exceeds the actual distance of 200 m between the proposed quarry and the pipeline, therefore the intended blasting methods are not in accordance with the Canada Oil and Gas regulation. This is further reason why the NSE cannot allow the operation of the Goffs quarry proposed by Scotian Materials. It is pertinent that a quarry, located at 200 m from the natural gas pipeline and which respects the Canada Oil and Gas regulation, such a quarry would have to restrict the total amount of explosive per blast to about 34 kgm. This amount of explosive does not allow a blast of even a single borehole to be in accordance with the Canada Oil and Gas regulation. VIII) Conclusions: I have been requested by Mr. Miller to carry out an objective evaluation of the expected consequences of the blasting from a rock quarry on the inhabitants and the traveling public on Highway 102 of the region of Goffs and Fall River, in Halifax Regional Municipality, and on the natural gas pipeline and other facilities located near to the proposed quarry. The first study by the writer (reference 1) used the very meager technical data available at the time about the blast methods intended for the proposed quarry, and it asked for more precise data from Scotian Materials; such data was refused. The writer is not against quarries, because society needs stones, and so he has carried out an objective study. However, the continuous refusal by the Scotian Materials people to supply the requested required technical data to carry out a study on the expected consequences of the blasting from a rock quarry on the nearby inhabitants, the traveling public on Highway 102, the natural gas pipeline and other 52

53 facilities, gives to the writer the impression that Scotian Materials does not make any serious plans to insure that the quarry s blasting will be safe. Since the refusal to supply data, however, more information on the blast methods intended for the proposed quarry has been obtained from Scotian Materials by Mr. Miller via a FOIPOP application. Hence the present study is based on this new information. The present study evaluates the risks to the inhabitants and the traveling public on Highway 102 in the vicinity of the proposed quarry, to the natural gas pipeline and other facilities, due to the blasting including the risks due to flyrock, due to ground vibrations, and due to air blasts. Regarding each of these risks, the study evaluates the following results. Risks due to flyrock: Although the majority of blast holes are expected to create flyrock of acceptable values of horizontal range and altitude, e. g. about 152 (50 m) and 64 (21 m), nevertheless it is certain that regularly some blast holes will create flyrock of very excessive horizontal range and altitude, e. g. 1,238 (406 m) and 939 (308 m) because of the variations from the nominal values which invariably occur for the actual values of the blast parameters, or even horizontal range and altitude of values as high as 2,724 ( 893 m) and 2,989 (981 m) because of a type of inadequate blast design regularly used in a city environment. The flyrock of horizontal range 893 m will reach some pertinent targets near the quarry, such as the pipeline at about 200 m, the highway #102 at 317 m, and the weight scale at 777 m. Even if every blast does not send dangerous flyrock on every inhabitant and on every vehicle traveling on Highway 102, nevertheless the fact that some of the blasts will regularly send dangerous flyrock means that whenever a person, including the traveling public who travel in vehicles daily over Hifgway 102, hears the sound of a blast they will live the next few minutes in anguish of being struck by a flyrock, a situation that is unacceptable. 53

54 The 981 m altitude of the flyrock will be a risk for the flights of airplanes at a level of about 300 (98 m) above the quarry, as they come in and leave the airport. Risks due to ground vibrations: The majority of blast holes are expected to create ground vibration of level much greater than the allowed limit of 12.5 mm/s; the table below resumes the highest levels of vibrations that will impact several pertinent targets near the quarry: Target Distance Vibration (mm/sec) (m) one hole five holes Pipeline Highway # Weight scale Residences 1, Industries L3 1, Pratt&Withney 2, Legal Limit The vibration levels in the table above take into account the variations from the nominal values which invariably occur for the actual values of the blast parameters, as well as the occurrence of several holes inadvertently detonated on the same delay, an occurrence which the writer has regularly encountered in his many years in the field of blasting. 54

55 Thus the vibrations impacting the pipeline not only exceed the 12.5 mm/s legal limit, but they even exceed the usual limit of 50 mm/s that Hydro- Ontario imposes for its hydroelectric structures. At the level of 354 mm/s the pipeline can be expected to break; it would require only one such impact to break it. Hence the writer is of the opinion that the risks of flyrock and ground vibrations together will eventually break the natural gas pipeline supplying Halifax. Repetitious impacts of 23.6 mm/s, plus some impacts of 96.9 mm/s, will gradually damage the weight scale and its foundation. Vibrations of 10.3 mm/s or 6.57 mm/s from one hole blasts on Industries L3 and Pratt & Withney do not violate the legal limit of 12.5 mm/s, but when they occur repetitiously they will perturb the accuracy of the sensitive apparatus which these industries use. Vibrations of 42.0 mm/s and 26.9 mm/s do violate the legal limit of 12.5 mm/s, and they will perturb the accuracy of the sensitive apparatus which these industries use. Risks due to air blasts: All the blast holes are expected to create air blasts that will exit the limits of the proposed quarry at levels that much exceed the allowed limit of 128 db, e. g. 141 db to 144 db at the quarry limit, and 133 db at 100 ft from the blast hole. But because of the variations from the nominal values which invariably occur for the actual values of the blast parameters, many blast holes will create air blasts that will exit the limits of the proposed quarry at levels that exceed even more the allowed limit of 128 db, e. g. as high as 147 db at the quarry limit. There are recreational areas near the proposed quarry. Accordance with the Canada Oil and Gas Regulation: The Canadian Government has established a table of the minimum distance between a given explosive weight and an oil or gas pipeline. According to it, blasts of more than 100 kgm cannot be carried out at a distance of less than 500 m from a pipeline. 55

56 As the proposed quarry is located at about 200 m from the natural gas pipeline that feeds Halifax, and as the blasts intended for the proposed quarry involve 8,888 kgm or even 24,893 kgm, therefore the intended blasting methods according to Golder, as obtained from Scotian Materials by Mr. Miller, such blast methods are not in accordance with the Canada Oil and Gas regulation. This is further reason why the NSE cannot allow the operation of the Goffs quarry proposed by Scotian Materials. Evaluation methods used in the report: The evaluations of the above risks have been achieved using the reliable blast simulator Blaspa, which is described in Appendix 1, and the accuracy of whose calculations has been demonstrated by field tests as reported in more than 40 publications in the technical literature. It is pertinent that vibration levels and horizontal flyrock ranges and altitudes predicted by Scotian Materials are largely undervalued, because the calculation methods used by their advisors are not accurate, as well as because their calculations neglect to take into account the variations from the nominal values which invariably occur for the actual values of the blast parameters. As a final conclusion, the writer is of the opinion that the authorities must not under any circumstances give approval to the proposed quarry, because blasting in the location of the proposed quarry is unacceptably dangerous. New quarries should be located far from inhabited regions and pipelines. Quarry operators should accept this, even if it raises their costs of transportation of the excavated stones R. F. Favreau Ph. D. Professor Emeritus, Royal Military College, Kingston On 56

57 APPENDIX 1 Description of the Simulators Blaspa: The simulator BLASPA applies the fundamental principles of Physics and Chemistry to express mathematically the mechanisms involved when explosives are used to break and move brittle rock. The main mechanisms are outlined in Fig. I below. In Fig. I(a), the detonation of the explosives has converted the latter into very high pressure gases (Cook 1958), the transition occurring as the detonation head sweeps the explosive column at a rate called the Detonation Velocity. The sudden increase in the pressure applied to the rock near the wall of the borehole causes the latter to expand, thereby generating strong shock waves in the rock mass (Favreau 1969); these travel away from their explosive source toward the free faces of the solid rock bench. During this phase, the shock waves act on the rock in compression; they cause little fragmentation because rock is very resistant to compressive failure (Duvall 1987). Fig. I(b) shows how the compressive shock waves, after reflection at the boundaries of the bench, travel back through the rock mass; on the return passage, however they act on the rock in tension because reflection at the rock/air boundary has converted them from compressive to tensile. The passage of the tensile waves initiates primary cracks in the rock mass, because rock is not resistant to tensile failure. As the compressive and tensile waves travel across the rock, their intensity attenuates; nevertheless, if the distance from the borehole to the free faces of the bench is not excessive, the reflected tension wave will still have adequate intensity to initiate primary cracks all the way back to the line of the boreholes. The weakening of the rock induced by the primary cracks near the borehole will allow the high pressure gases, which had been under containment by the solid rock around the borehole, to resume their blasting action as shown in Fig. I(c). As can be seen in Fig. I(c), this new blasting action takes place as follows: the gases create a quasi-static stress field whose intensity diminishes from the vicinity of the borehole to that of the air/rock boundary, the most rapid drop in stress occurring near the dashed line representing the front that separates fully broken rock from that which has only been weakened by the primary cracks. The large stress gradient just to the right of this front further fragments the weakened rock, converting it to fully broken rock, so that the front progresses from left to right converting primary cracks into full fragmentation. When the front reaches the free faces of the rock mass, Fig. I(d), the whole rock bench is fully broken and it bursts out, throwing the various fragments ahead into the muck-pile of broken rock. 57

58 FIG. I: Mechanisms of the blasting process: The study for the proposed quarry near Halifax uses mainly the Blaspa simulators that deal with the flyrock resulting from a blast, the ground vibrations that result from a blast, and the air blasts that result from a blast. Each of these simulators uses equations that are based on the fundamental principles of Chemistry, Physics and rock mechanics, as explained above. 58