Sanitary Drainage
The drainage systems within private and public buildings are designed and constructed to convey sewage, various types of liquid waste, and rainwater away from the building to a place where it can be safely disposed of.
A drainage system doesn’t include the mains of public sewer systems owned by various departments of buildings, or any sort (public or private) of disposal plants or sewage treatment works.
There are specific types of drainage systems:
- Gravity drainage systems that drain into the building sewer by gravity.
- Storm drainage systems that carry potable clear water waste, stormwater, or groundwater.
- Sanitary drainage systems that only carry sewage or similar matter.
For obvious health and safety reasons, there is strict legislation that governs sanitary drainage including various local codes.
The Plumbing Code of New York State, which is based on the International Plumbing Code (PIC), and the New York City Plumbing Code are similar but not worded exactly the same way.
The NYC Plumbing Code specifies that all buildings with drainage piping must be connected to a sanitary or combined public sewer where this is feasible. If multiple buildings are located on one property, it is acceptable for them to be connected to a common building sewer that is connected to the public sewer. Feasibility is determined in accordance with the standards set by the DEP.
If neither of these options is available, a private sewer or disposal system must be provided in accordance with the specifications for construction documents in the Code that provide:
- Certification from the DEP that public sanitary or combined sewer connections are either not available or not feasible.
- A proposal for the design and construction of a private system that will dispose of sewage on site in accordance with the Code, and subject to the approval of the DEP.
Sometimes the latter option is a temporary solution and public sewers are later made available by the City. When this happens, the property owner has six months to connect to the public sewer and must then literally abandon the private disposal system. It is important to remember that all abandoned building sewers need plug permits from the DEP and that they must be sealed securely as close to the curb as possible.