On May 5th, 2005 Custom Environmental Services, a hazardous waste handling facility in Edmonton mixed incompatible chemicals triggering an explosive fire. Alberta Environment deployed its mobile air monitoring unit to measure air quality surrounding the fire.

The results of the non-continuous monitoring parameters (those pollutants which required laboratory analysis) were released today.

The monitoring data shows that for many pollutants levels in the air rose. Alberta Environment compares these levels to ambient air quality objectives or effects screenling levels where these guidelines exist in order to draw conclusions of significance.

We are concerned about such comparisons since data measurements are subject to "measurement arguments" about timing, placement of monitors, prevailing winds, and the arithmetic 'dilution' of averaging measurements over time. People downwind of the fire noticed effects of the fire.

This is not to say that Alberta Environment should not have responded. Their data clearly indicate that toxic chemical pollution goes up when a hazardous waste facility burns. But to us this does not mean that we need to address 'measurement arguments' to monitor fires better, (although real time information would be useful in making evacuation decisions).

The Custom Environmental Services fire emphasizes to us that there is a continuing need for an environmental regulator with a policing and inspection function. At Toxics Watch's request, the Environmental Law Centre is conducting a compliance history search of Custom Environmental Services to in order to assess hearsay of operational issues at the facility. Mixing incompatible chemicals is a basic operational error which suggests poor operational practises.

Good environmental policing of hazardous substance managements will prevent emergencies like the Custom fire.