The City's Construction Equipment Cometh...After Midnight

Something tells us the city may not be following its own rules when it comes to repair work on a sewer line in Park Slope. A GL reader emailed at a very late hour to say:

For the last three weeks, the city has been working on a sewer repair project in Park Slope, almost right outside my window. The noisy, earth shaking work goes on during normal hours for construction. Equipment for the project, however, is picked up and dropped off several times a week, like it's being taken to other sites when it's not needed outside. The contractors always do their pick ups and drop offs between 11PM and Midnight. Tonight, they were outside dropping off a backhoe at 12:30 AM. It's gotten so that I can tell when they've arrived by the sound of the huge truck beneath my window. Then, for the next 15 minutes or so, I get to listen to clanking and banging as the equipment is unloaded from the trailer it came on. Is this legal?

Interesting question and we're fairly certain there's an appropriate bureaucratic response.