February 18, 2011 File No: 538-1 Nova Scotia Transportation & Infrastructure Renewal Municipal & Design Section J. W. Johnston Building 1672 Granville Street PO Box 186 Halifax, Nova Scotia B3J 2N2 ATTN: Kim Cooke, MNSAA, LEED AP RE: Kings County Academy/Superior Propane Kentville, NS In accordance with your email request dated February 4, 2011 the RMS (Risk Management Services) risk assessment document dated December 16, 2010 has been reviewed. Calculations to determine the zone of influence and effects of a potential propane storage tank explosion have been completed. As you noted, the RMS assessment indicates that there are no unusual hazards associated with the location of the propane tank with respect to the Kings County Academy property. The effects of a potential storage tank explosion was beyond the scope of the RMS assessment and was not addressed. In addition you indicated that you had been provided with information that the bulk plant was in compliance with CSA B149.2 Propone Tank Storage and Handling Code. This report is intended to be considered as supplemental to the above information. The site was visited on February 10, 2011 and information regarding the propane storage tank capacity and site dimensional data was obtained. This information was used as input for a BLEVE (Boiling Liquid Expanding Vapour Explosion) calculation. The intent was to provide information regarding the effects of a potential storage tank explosion. The propane storage tank has a liquid storage capacity of 30,000 US gallons and is located 84 metres from the nearest wall of the school building and 48 metres from the property line. The calculations were performed in accordance with Roberts, Michael W. “Analysis of Boiling Liquid Expanding Vapour Explosion Vapour Events at DOE Sites”, EQE International Inc. and were performed by Grant Roach, P.Eng. Professional Loss Control.

Kim Cooke February 18, 2011 Page 2

The calculations resulted in the following:

• BLEVE Combustion Duration = 14 seconds • Maximum Fireball Diameter = 227m • Height to the Centre of the Fireball will range between 113m to 340m during the 14 sec

duration • Maximum Thermal Flux emitted from the Fireball = 400kW/m2 • Maximum Thermal Flux at the Building location = 180kW/ m2 • Missile Effects: The majority of vessel fragments are expected to travel up to 590m in

the transverse direction from the tank. However, severe rocketing fragments in the longitudinal direction have the potential to reach distances approximately 4 – 8 times greater than this distance.

The impact of human exposure within this 84m vicinity (distance from the tank to the school building) is that full thickness skin burns (3rd degree burns) would be expected to occur on any exposed skin surfaces. There is also the potential for being hit by flying projectiles. The impact on nearby buildings is that ignition of combustible materials is possible if struck by a flaming projectile.

I trust the foregoing information is suitable for your present requirements. Yours truly,

John T. Davis, P.Eng /bm