I couldn't find the link to the audio directly from the ScanBC site, but I listened and didn't hear anything as well. Therefore I couldn't find any description of what the feed is suppose to consist of.
Nelson has its own local police force. As such, they do their own thing. Recently they have implemented their own system for the NCP (Nelson City Police) and their municipal fire department. They now operate Mototrbo. Funny that as these entities upgrade to digital, it seems like interoperability is not considered and many people just think digital is digital (all one flavour). From what I can tell, there is also no encryption being used.
It almost seems like this feed may be feeding nothing at all. NCP has retained their old analog frequency for their new Mototrbo system and I believe the Fire Department now shares the same system to some extent. If the feed was still working, we should at least hear data bursts every so often. If the feed was forwarding RCMP though, they may have relinquished the previous local analog frequency. Ambulance has not changed as far as I know. Therefore I suspect the feed is just feeding dead air.