Colleague had handed in her notice at work and I fully expect that her job will be divided up amongst others rather than replaced.
I suspect that it might be attempted to give some of that work to me but it is way beyond my job description.
Bearing in mind I'm not the only person with my job description but i am the only one with the technical capabilities to do this part of the work is it unreasonable to put my foot down and refuse to take on anything extra for no reward.
(in the past year I've already taken on additional responsibility due to someone else leaving)