I was around when the first 911 Washington state tax was established back around 1992. It funded the first state 911 Office staffing and started building a fund to support technology improvements in the 911 system.
In the story above, they note that the tax supports 24% of local 911 offices' funding. I can't be positive, but likely some of those funds are supporting staffing at the 911 centers. Maybe not ... in my perfect world it should be funding technology improvements only. Once you start with funding staffing, that then sucks money away from keeping up with technology.