N.Y.C. Admin. Code § 27-2024: § 27-2024 Water supply to buildings.

The owner of a dwelling shall provide and maintain a supply of pure and wholesome water sufficient in quantity and at sufficient pressure to keep all plumbing fixtures adequately supplied for their sanitary maintenance. Where water mains are available in the street, every dwelling shall be supplied with water from such mains. The owner shall keep the water supply free from connection to any unsafe water supply or from cross-connections to any drainage system.