N.Y. Comp. Codes R. & Regs. tit. 16, § 255.455
(a) Except as provided in subdivisions (b), (c), (f), and (g) of this section, each buried or submerged pipeline installed after July 31, 1971, must be protected against external corrosion.
(b) An operator need not comply with subdivision (a) of this section, if the operator can demonstrate by tests, investigation, or experience in the area of application, including, as a minimum, soil resistivity measurements and tests for corrosion accelerating bacteria, that a corrosive environment does not exist.
(c) An operator need not comply with subdivision (a) of this section, if the operator can demonstrate by tests, investigation or experience that:
(f) This section does not apply to electrically isolated, metal alloy fittings in plastic pipelines, if;