Congratulations on the impending new little one.
I pumped at school with both my boys. I was as successful as I could have hoped to be, considering my schedule. I was an elementary music specialist at the time, and taught 10 classes per day. The only time I had to pump was at lunch, and once a day just did not keep my supply up sufficiently to BF exclusively - we wound up supplementing with formula. On the other hand, I had a nice private store/workroom that I could lock, with convenient sink and outlet, so that was easy.
So, if you have a well timed planning time and/or long breaks that allow you to pump twice a day, I think you will be fine.
I'm pumping now...ds is 2.5 months old and I've been back at work for 2 weeks.