Brooklyn Union plans to use the property as a satellite station.
The agreement with Brooklyn Union is one of its largest.
Brooklyn Union projected that the average monthly bill for an apartment building would drop next year to $5,917 from $6,827.
Officials from Brooklyn Union said they had been betrayed by their new partner.
Brooklyn Union has almost 1,000 vehicles, and the city has 700 in several departments.
Brooklyn Union, on the other hand, has been aggressive in seeking to prepare for the new competitive world.
Brooklyn Union will still handle all emergency repairs, such as gas leaks, for free, he said.
"In order to stay competitive, Brooklyn Union is going to have to get out of the social service business."
"There's an opportunity to take Brooklyn Union to a new level."
Brooklyn Union plans to demolish the tanks, but no schedule has been set.