As stated in the Mitigation chapter of the Final Environmental Impact Statement (EIS):
There would be significant adverse noise impacts at the Dean Playground from construction activities. The project sponsors have committed to working with the New York City Department of Parks and Recreation (DPR) to work with DPR’s planned improvements to the Dean Playground. This commitment would partially mitigate a temporary noise impact on the playground due to construction activities.
That mitigation also would help make up for a lack of open space.
And what might that mitigation be? According to the EIS:
The New York City Department of Parks and Recreation (DPR) currently has plans for the renovation of Dean Playground to include a little league baseball field with artificial turf and some other improvements. The project sponsors have committed to working with DPR to build a comfort station for park patrons.
It was not stated whether the toilets would have soundproof walls.