The UTM sub-set that MOH uses defines a 1km block. A "full" UTM, as you might see on a GPS, would have more digits, and also have a map designation. In Eastern Ontario, that's usually 18T. So often the CACC-issued UTM requires a bit more local knowledge to decode.
For the actual crews, their computers are set at start of shift to their general area of interest, so the map number is preset.
As an example, Parliament Hill is at (approximately) 45.4237 by -75.7004. That translates to UTM "18T 445206E 5030266N", which may be expressed as "18T4452065030266". That gets you to a 1m resolution.
The software used by MOH only takes the digits required for a 1km resolution, so in this example "18T 445E 5030N", or "4455030".
A while back, I took a sample javascript web page from
Javascript Calculators and modified to a smaller and somewhat simpler version that lets me plug in the CACC-supplied UTM and pop up Google Maps in the defined area. Because of the 1km resolution, the actual location is somewhere in that vicinity.
If anybody's interested, you can grab what I have at
UTM interface to Google maps
I'd recommend doing a SaveAs to your local machine, then bookmark your local copy. If you want to set a different default map (mine's set as 18T), you can edit your local copy.
Brad.