N.J. Stat. Ann. § 48:2-27

The board may, after hearing, upon notice, by order in writing, require any public utility to establish, construct, maintain and operate any reasonable extension of its existing facilities where, in the judgment of the board, the extension is reasonable and practicable and will furnish sufficient business to justify the construction and maintenance of the same and when the financial condition of the public utility reasonably warrants the original expenditure required in making and operating the extension.