It is unclear what is being monitored, or by whom. Efforts are continuing to ascertain the purpose of this monitoring well and if its proximity to Con Edison's Headquarters is incidental.

No Fill Monitor Well

This is a monitoring well "curb box" made by the Morris Pipe Company of South Pompton Plains, New Jersey. These are typically installed for the purposes of tracking groundwater contamination problems and/or measuring water levels to estimate plume direction. This is most frequently done in the vicinity of a current or former gas station or other facility that has an underground storage tank that may be leaking.

In this case, the curb box is identified as and is used for protecting the top of a monitoring well. The triangle on the cap is a symbol specifically used to note that it is used for that purpose, and not as a pipe for filling an undeground tank (a mistake of identity that would severely contaminate a well).
The water table depth from surface grade can vary greatly. Generally, along coastal areas, it approximately corresponds to the adjacent sea level. This is an approximation, of course, and does not apply in all cases. Only by placing monitoring wells, surveying them to an established benchmark for datum elevation, and taking measurements of the well water level against that datum can you determine the true depth in each well, relative to each other and the datum.

In New York State, responsibility for groundwater monitoring rests with the NYS Department of Environmental Conservation (NYSDEC).

Thanks to James Laughlin, Editor, WaterWorld -
Randall W. Austin, New York State
Department of Environmental Conservation -
David Warne of the New York City
Department of Environmental Protection