Yes you can work there BUT AS TO what position you will hold, it depends, it will mainly be about managing their computing systems. The fire service is not a modern institution and there they lack a lot of computing power. They need disaster monitoring equipments, text messaging systems for easy communications and well documented and centralized databases that can put online for easy management of the whole fire service systems. This is what you will be doing mainly and a computer scientist. What can you do with your computing skills to help improve their productivity and efficiency?
if you can answer these question, instead of working for the fire service, start a company to help the service instead. By the way we speaking to them to find out what position you will hold so check back later.