Multi-dwelling plumbing systems work similarly to single-family home systems, except that the plumbing branches further to provide water to each unit. As water reaches a multi-dwelling apartment from the municipal supply, a system of pipes, faucets and valves ensures that the water reaches where it is needed. The pipe in an apartment building consists of two sets of pipes: one set brings fresh water to the building and the other set removes wastewater. Each apartment inside the building has a subset of pipes that perform these same functions.
Freshwater system uses pressure to supply water to different parts of the building. Wastewater systems, on the other hand, do not need pressure, since wastewater moves under the influence of gravity downwards and leaves the building. Drain pipes are always directed downwards. To prevent minor plumbing problems from escalating (and to increase your chances of recovering that security deposit), make sure all parts are working properly.
Understanding how your plumbing system is configured and how it works inside your apartment building is important in the event of a plumbing problem. Similarly, make sure your tenants report any potential plumbing issues so that they can be addressed immediately. That's why it's important to be aware of common plumbing problems in apartment buildings, such as clogged toilets, clogged drains, overflowing tubs, and frozen plumbing. If he goes back again and a plumber comes out clear, ask him where the blockage is and that will determine liability.
At this point, you now have a broader idea of how your apartment's plumbing system is set up and how it works inside your buildings. The population resides in apartment buildings, and most of them do not know how commercial plumbing works in such structures. The apartment building I live in boasts of its cast iron pipe systems, but I know the building is quite old. We only serve South Florida, so it would be best to contact a licensed plumber in New Jersey if you have questions about local legality. The association has their preferred plumber who said the problem is outside (street) my house on the first floor, but the association has said it was too expensive and would not pay for the repair.