Originally Posted by my83300cd

It depends on how the records were kept. Did the city put the sewer in, or was the area built up by a developer back in the day? Got to town hall and look up the deed- its public record. Buildings in NY are over train tracks and subways, so a sewer should be pretty simple.

I designed an addition to a house that is over a storm drain runnoff from a state highway. The state has no record of the storm drain grate, and the grate connects to old field drains for the farm that used to be across the street. As far as the state was concerned, their responsibility ended at the limit of the right of way for the highway...

The design however has foundation walls at each end and nothing in the center- like a bridge- so that if/when repairs have to be made, you can trench away to fix the drain.