Patrick88
Plumber
1-1/2 is standard for a tub, but 2" is code minimum for any buried pipe.
Rip it out, cap everything. Ask the city how extensive that needs to be. It could be kind of major - one of the plumbers mentionned something like this on another thread, something about having to pour cement down the drains to make sure it wouldn't be put back. Easier than digging them up, I guess.
Frenchie is right 2" is the min size for under ground. Sorry for my mistake.
I agree with others that said you should fight this.