Air dispersion (computer) models will be used to assess the impacts that the extension of the existing gypsum storage area may have on local air quality.  As part of a continuing effort to assess air quality impacts, we continue to monitor air quality parameters around the Redwater Site.

What about the dust?

Concern about potential health impacts of dust particles has been increasing over the last several years.  In June of this year the federal, provincial and territorial governments of Canada agreed to ratify the CWS (Canada-wide Standard) for PM2.5*. All jurisdictions have committed to meet this new Standard by year 2010 or sooner.

In response to this new standard and in conjunction with the gypsum stack extension plan, we have begun an ambient air monitoring program to characterize the dust in the vicinity of our site.  The sampling program began in May of 2002, and will continue into August of 2002.

How is the study being done?

We are monitoring at four locations using two hi-volume particulate samplers and 4 low-volume particulate samplers.  The study will look at total suspended particulate matter, PM10 (particulate matter less than or equal to 10 microns) and PM2.5 (particulate matter less than or equal to 2.5 microns).  The study will also attempt to determine how much the gypsum stack contributes to the amount of dust in the air. 

Two of the sampling locations are on our site near the gypsum stack.  The other two sampling locations are situated offsite at two of our neighbors’ residences.  The sampling protocol requires collecting enough sample for the analysis of the collected dust portions to determine the constituents.  The time of sampling at any one location will need to be adjusted to ensure we are collecting enough dust for a proper analysis.  This is likely to involve continuous sampling for 3-4 weeks at each location because ambient dust levels are relatively low.  
 
What determines how much dust comes from the gyp stack?

There are a few factors that affect how much dust comes from the gyp stack..  One factor is how dry the gypsum is on the stack surface, particularly on the gypsum stack roadways.  Another factor is the amount of heavy equipment operating on the gypsum stack.  This is a particular concern during the period of May to October.  To keep dust levels low, the gypsum stack roadways are sprayed with water as required.  The sampling program has been designed to evaluate the highest potential gypsum dust loading as a result of the continuous operation of the gypsum stack. 

What do we hope to learn?

This sampling will give us a picture of the state of the environment prior to extending the gypsum stack to the north.  We will sample for dust again during the construction of the new extension and after the new extension has been active.  This sampling will help ensure the air in the vicinity of our operations is not significantly impacted by construction and will let us know if we need to take further action to minimize dust.