Are the main drainage pipes considered common areas of a condo?

Are the main drainage pipes and drum traps, in the walls, and under bathroom floors, considered common areas of a condo association building? 

 

Our declaration says it is if it serves more than one unit; this can be confusing and easily misinterpreted; it has to because it is a system of pipes, one tub is directed underneath and above each other, which means they share the same pipes, from my understanding. If it leaks it affects other units?