It is not all water main installations that can be completed without a trench but there is a specific criteria that will allow for a trenchless install. The first rule of thumb for NYC residents is to determine if the DEP will allow tunnels to be made for the water main installation. If you are having a water main that is 3” or larger, the DEP will not allow for tunnels and will require the job to be trenched out.
If you are having a copper water main installed and your home is located a short distance from the city water main, it is possible that the entire water main service can be installed with one hole. This would require one 3’x4’ hole in the street and a water main tunnel to be made with compressed air. Once the tunnels are completed the new copper pipe is pulled or pushed from the roadway excavation, to inside the building where the new ball valve and connection are completed.
If the city water line is on the opposite side or if the house is set back from the street it is still possible to make a “trenchless” installation however, it will most likely require additional excavations from where the tunnels are completed.
At the end of the day, the water main is installed the same way and will bring domestic water in the house, we always suggest that people do not get hung up on the “trenchless” process as long as the end results remains the same.